Radiation therapy patient platform

Abstract

To provide a radiation therapy patient platform.SOLUTION: A system, a device, and a method are described for imaging and a radiation therapy procedure. Generally, a radiation therapy system may include a radiation permeable patient platform, a radiation source joined to a multi-leaf collimator, and a detector facing a collimator surface. The radiation source may be configured so as to discharge a first beam through the collimator, and provide a therapy to a patient on the patient platform. A controller may be configured so as to control the radiation therapy system.SELECTED DRAWING: Figure 4C

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 62 / 422,494, filed November 15, 2016, and entitled “RADIATION THERAPY PATIENT PLATFORM,” the contents of which are incorporated herein by reference in their entirety.

[0002] SYSTEMS, DEVICES AND METHODS FOR CONTROL OF RADIATION THERAPY FIELD OF THE DISCLOSURE The present invention relates to systems, devices and methods that may be used for stimulated emission high energy photon delivery. [Background technology]

[0003] Radiation therapy (or radiotherapy) uses high-energy photons to treat a variety of diseases. For example, radiation therapy is commonly applied to cancerous tumors. Some radiation therapy systems use a radiation source or a linear accelerator (linac) system to deliver a beam of photons to the tumor. The linac may be mounted on a gantry that rotates around the patient. The gantry may be a C-arm gantry or a circular gantry. The linac may be rotated around the patient to focus the dose of photons on the tumor and reduce radiation exposure of healthy tissue surrounding the tumor. The patient may be placed on a patient couch that moves in and out of the bore of the circular gantry to receive the treatment.

[0004] For a rotational radiotherapy system to deliver effective treatment, the patient couch, referred to herein as the patient platform, must be substantially radiolucent in the treatment beam plane and provide rigid support to the patient as the patient platform is cantilevered in and out of the gantry bore. However, due to the patient's weight and the length of the platform, the platform will typically sag, introducing errors into the beam treatment plan. Also, typical carbon fiber patient platforms provide a generally uncomfortable flat or slightly curved surface for the patient to lie on. This is less important for imaging procedures, which can be completed very quickly (e.g., in less than an hour). In contrast, some radiotherapy procedures may require the patient to remain stationary for much longer periods of time (e.g., more than an hour). Therefore, additional systems, devices, and methods for patient platform control and radiotherapy procedures may be desirable. Summary of the Invention [Means for solving the problem]

[0005] Described herein are systems, devices, and methods for controlling a patient's position in a radiation therapy system. Also described herein are systems, devices, and methods for measuring patient platform subsidence during a treatment session, which may be used to aid in the delivery of a radiation therapy treatment. In some variations, the system may include a patient platform having a patient area and a longitudinal axis, and a radiopaque extension element coupled to the patient platform. The extension element may have a longitudinal axis parallel to the longitudinal axis of the platform. A method for quantifying a change in location of a radiation therapy patient platform due to a patient's weight may include emitting a first beam from a radiation source through a multi-leaf collimator to irradiate the radiopaque element. The multi-leaf collimator leaf pattern may be configured such that the first beam irradiates the radiopaque extension element with a fractional irradiation (if applicable) of the patient area of ​​the patient platform. The first beam may be received by a detector facing the radiation source. A first location of the extension element (e.g., when the platform is unweighted in the absence of a patient) may be determined using the detector. After the patient lies on the patient platform, a second beam may be emitted from the radiation source through a multi-leaf collimator, the multi-leaf collimator having the same leaf pattern as when the first beam was emitted. A second location of the extension element (e.g., when the platform is weighted in the presence of the patient) may be determined using the detector. A change in location of the extension element may be calculated between the first and second locations of the extension element, the second location may correspond to the weighted platform. A change in location of the platform may be determined using the change in location of the extension element.

[0006] The radiolucent patient platform may include a first material that is substantially transparent to high energy photons, and the radiopaque element may include a second material that is substantially opaque to high energy photons. In some variations, the first location of the elongated element may be determined from multiple images of the elongated element using a radiation beam detector. In other variations, the first beam may be emitted from the radiation source relative to a horizontal plane between a first positive rotation angle and a second negative rotation angle. In some of these variations, the first beam may be emitted from the radiation source with the radiation source parallel to the horizontal plane.

[0007] In some variations, the radiolucent patient platform system may include a radiolucent patient platform having a radiopaque elongate element located along a longitudinal axis parallel to the longitudinal axis of the platform. The radiolucent patient platform may include a first material that is substantially transparent to high energy photons, and the radiopaque elongate element may include a second material that is substantially opaque to high energy photons. The patient platform may include a first side having a patient support and a second side opposite the first side. The elongate element may be coupled to the second side of the patient platform. A radiolucent support element may couple the elongate element to the patient platform. In some variations, the elongate element may comprise a metal rod. A radiation source may be coupled to the multi-leaf collimator. The radiation source may be configured to emit a first beam through the collimator to illuminate the elongate element. A detector may face the collimator and be configured to receive the first beam. The controller may be configured to determine a first location of the elongation element using the detector (e.g., when the platform is unweighted), calculate a change in location of the elongation element between the first location and a second location of the elongation element, the second location corresponding to the weighted platform, and use the change in location of the elongation element to determine a change in location of the platform.

[0008] Also described herein is a method for quantifying a change in location of a radiation therapy patient platform due to a patient. The patient platform may optionally comprise one or more optical markers, and the method of quantifying a change in location of the platform may include imaging the one or more optical markers using an optical sensor. The one or more optical markers may comprise a longitudinal axis parallel to a longitudinal axis of the platform. The optical sensor may be coupled to a rotatable gantry. A first location of the optical marker may be determined using the optical sensor. A change in location of the optical marker may be calculated between the first location and a second location of the optical marker. The second location may correspond to the weighted platform. The change in location of the platform may be determined using the change in location of the one or more optical markers. In one variation, the second location of the optical marker may be determined using multiple images of the one or more optical markers (e.g., acquired by the optical sensor as the gantry rotates around the patient platform). The controller may be configured to determine the first location of the one or more optical markers using the one or more optical sensors (when the platform is unweighted). The second location may correspond to a weighted platform.

[0009] In some variations, the optical sensor may comprise an infrared sensor and / or an infrared illumination source. In another variation, the optical marker may comprise a retroreflector or reflector. In yet another variation, the optical sensor may comprise a laser. In one variation, the patient platform may comprise a first side including the patient support and a second side opposite the first side. The optical marker may be coupled to the second side of the patient platform.

[0010] Also described herein are systems, devices, and methods for quality assurance of radiation therapy systems. For example, to determine whether a desired dose of radiation is delivered by a radiation therapy system, radiation may be applied to a phantom that includes radiation sensors (e.g., dosimeters) at various locations within the phantom. The phantoms described herein may aid in the calibration of various components of a radiation system (e.g., radiation sources, radiation detectors, etc.). In general, the system may include a patient platform having a patient support surface and an underside opposite the patient support surface. A phantom may be mounted on the underside. The phantom may include a plurality of stages and a plurality of radiation detectors having corresponding pre-determined depths. Each of the radiation detectors may be disposed at a pre-determined depth of its corresponding stage. Alternatively or in addition, the phantom may include a plurality of radiation detectors, a first region having a first density, and a second region having a second density different from the first density. The radiation detectors and regions may each be arranged along a longitudinal axis.

[0011] In some variations, the radiation detector may include an ionization chamber and a dosimeter slot. The ionization chamber may be arranged along a longitudinal axis of the phantom and along a vertical axis perpendicular to the longitudinal axis. The dosimeter slot may be parallel to the longitudinal axis and disposed at a predetermined depth of its corresponding step. In some variations, at least one of the dosimeter slots may be approximately parallel to a vertical axis perpendicular to the longitudinal axis of the phantom. In some other variations, the phantom may include a housing defining an internal fluid-tight volume. A mount may couple the phantom to a patient platform. In some of these variations, the mount may be configured to slidably position the phantom relative to the patient platform.

[0012] In some variations, the radiation detector may include an ionization chamber and a dosimeter slot. In some of these variations, each dosimeter slot may intersect its corresponding ionization chamber. The ionization chamber and the dosimeter slot may be spaced apart from one another along the longitudinal axis. In some variations, a mount may couple the phantom to a patient platform. The mount may be configured to slidably position the phantom relative to the patient platform.

[0013] Also described is a phantom that may be useful for determining the contrast resolution of the detector. In some variations, the system may include a patient platform having a patient support surface, a lower surface opposite the patient support surface, and a longitudinal axis. A phantom may be mounted on the lower surface. The phantom may include a first repeating pattern having a spatial frequency range and a second repeating pattern having a contrast range. The first pattern may include a series of high contrast edges or stripes with the space between the edges or stripes varying according to the spatial frequency range. The second pattern may include a series of repeating shapes with different levels of contrast relative to the background intensity. The first and second repeating patterns may be spaced apart along the longitudinal axis of the phantom. The spatial frequency range may be within the spatial frequency limits of the radiation detector, and the contrast range may be within the contrast limits of the radiation detector.

[0014] In some variations, the first and second repeating patterns may comprise sets of contrasting shapes spaced at different intervals. The set of shapes may comprise a first shape having a first thickness and a second shape having a second thickness different from the first thickness. The set of shapes may comprise a first shape having a first density and a second shape having a second density different from the first density. In some variations, the width of the phantom may be aligned parallel to the length of the patient platform. In some variations, the phantom may be positioned within an imaging region of the patient platform. A mount may couple the phantom to the patient platform.

[0015] Also described herein are methods for adjusting a radiolucent patient platform to a patient's body contour that may improve patient comfort and radiation therapy procedure compliance. One variation of a radiation therapy patient platform system may include a radiolucent patient platform having a conformable substrate with a plurality of enclosures and a pressure sensor coupled to the conformable substrate. The controller may be configured to independently control the height of each of the plurality of enclosures using the pressure sensor. The method for adjusting the contour of the conformable substrate may include measuring a pressure on the patient platform using the pressure sensor. The pressure may include a plurality of enclosure pressures. The height of each of the plurality of enclosures may be independently controlled using the pressure such that the conformable substrate contours to the shape of the patient. For example, the plurality of enclosures may be coupled to a pressure source.

[0016] In some variations, the method may further include determining a patient configuration corresponding to a height of each of the plurality of enclosures. The patient configuration may comprise at least one of a pressure and a height of each of the plurality of enclosures. In some of these variations, the method may further include storing the patient configuration in a memory and readjusting the height of each of the plurality of enclosures using the stored patient configuration. In yet another variation, a thermoelectric layer of the patient platform may be heated to form a flexible configuration, and cooling the thermoelectric layer may form a rigid configuration.

[0017] In some variations, a pressure channel may couple a pressure source to each of the multiple enclosures. In some of these variations, the pressure channel may include a radiolucent material that is substantially transparent to high energy photons. In other variations, the multiple enclosures may include a fluid. In some of these other variations, the fluid may include a gas. In one variation, the thermoelectric layer and the heating element may each be coupled to the patient platform. In some of these variations, the thermoelectric layer may transition between a flexible configuration and a rigid configuration based on temperature. In another variation, a thermal insulation layer may be coupled to the thermoelectric layer. In yet another variation, the multiple enclosures may include a flexible membrane. In yet a further variation, the multiple enclosures may each include a honeycomb configuration.

[0018] Also described herein is a method for calculating subsidence of a radiolucent patient platform. A weighted patient platform with a reduced amount of subsidence may enable more accurate treatment planning and improved delivery of radiation therapy treatments. The patient platform may comprise an upper portion and a lower portion coupled to the upper portion. The upper and lower portions may move relative to each other or may move relative to the base. A variation of the method may include emitting an imaging beam using an imaging radiation source in an imaging plane perpendicular to a longitudinal axis of the patient platform. The lower portion may not intersect the imaging plane, and the upper portion may intersect the imaging plane.

[0019] In some variations, a treatment beam may be emitted from a therapeutic radiation source coupled to a multi-leaf collimator in a treatment plane perpendicular to a longitudinal axis of the patient platform, and the upper and lower portions may be moved such that the lower portion does not intersect the treatment plane and the upper portion does intersect the treatment plane.

[0020] In other variations, moving the upper portion into the imaging plane may include positioning the lower portion such that a leading edge of the lower portion is located a first distance away from the imaging plane. In some of these other variations, moving the upper portion into the treatment plane may include positioning the lower portion such that a leading edge of the lower portion is located a second distance away from the treatment plane. The upper portion may include a first material that is substantially transparent to high-energy photons, and the lower portion may include a second material that is substantially opaque to high-energy photons.

[0021] A variation of a patient platform system may be configured to coordinate movement of the patient platform with timing of imaging and / or therapy beam emission. In general, these systems may include a radiolucent patient platform having an upper portion coupled to a lower portion. A base may be coupled to the lower portion of the patient platform. A radiation source may be coupled to the multi-leaf collimator. The controller may be configured to move the upper portion relative to the lower portion such that the upper portion is in a beam plane of the imaging and / or therapy beam while the lower portion is not in the beam plane (e.g., the lower portion may not intersect the beam plane and the upper portion may intersect the beam plane). The radiation source may be configured to emit a first beam in a beam plane perpendicular to a longitudinal axis of the patient platform.

[0022] Also described herein is a method for controlling a radiolucent patient platform. The patient platform may comprise an upper portion and a lower portion secured to the upper portion. The upper and lower portions may comprise different radiolucencies. The patient platform may move relative to the base. An imaging beam may be emitted by an imaging radiation source in an imaging plane perpendicular to a longitudinal axis of the patient platform. The lower portion may not intersect the imaging plane, and the upper portion may intersect the imaging plane.

[0023] In some variations, the method may further include emitting a treatment beam from a therapeutic radiation source coupled to the multi-leaf collimator in a treatment plane perpendicular to a longitudinal axis of the patient platform. The patient platform may be moved such that a lower portion does not intersect the treatment plane and an upper portion intersects the treatment plane.

[0024] In other variations, moving the upper portion into the imaging plane may include positioning the lower portion such that a leading edge of the lower portion is located a first distance away from the imaging plane.

[0025] In some of these variations, the upper portion may be moved into the treatment plane and may include positioning the lower portion such that a leading edge of the lower portion is located at a second distance away from the treatment plane. In another variation, the upper portion may include a first material that is substantially transparent to high-energy photons and the lower portion may include a second material that is substantially opaque to high-energy photons.

[0026] Also described herein is a radiation therapy patient platform system. In general, the system described herein may include a radiolucent patient platform having an upper portion secured to a lower portion. A base may be coupled to the lower portion of the patient platform. A radiation source may be coupled to the multi-leaf collimator. The radiation source may be configured to emit a first beam in a beam plane perpendicular to a longitudinal axis of the patient platform. A controller may be configured to move the patient platform relative to the base. The lower portion may not intersect the beam plane, and the upper portion may intersect the beam plane.

[0027] Also described herein is a method of irradiating a first region of interest of a patient. For example, a radiation therapy patient platform may be moved relative to one or more regions of interest to aid in the delivery of a radiation therapy treatment. In general, the method may include moving a radiation therapy patient platform into a patient region of a gantry. The gantry may define an isocenter point about which the gantry rotates. An isocenter axis intersects the isocenter point and is parallel to a first longitudinal axis of the patient region. The patient platform may be moved to position the first region of interest on the isocenter axis. A radiation beam may be emitted from a radiation source to the first region of interest on the isocenter axis.

[0028] In some variations, moving the patient platform to position the first region of interest on the isocenter axis may include moving the patient platform laterally. In other variations, at least one of the pitch and yaw of the patient platform may rotate. In some of these variations, a second longitudinal axis of the first region of interest may be aligned on the isocenter axis. In another variation, the patient may include a second region of interest. The patient platform may move to alternately position the first and second regions of interest on the isocenter axis. In some of these variations, a third longitudinal axis of the second region of interest may be aligned on the isocenter axis.

[0029] Also described herein is a radiation therapy patient platform system. For example, the radiation therapy patient platform may include one or more drive systems that may be configured to adjust the platform position or location in multiple degrees of freedom. In general, the system may include a radiolucent patient platform coupled to a base. The patient platform may include an upper portion coupled to a lower portion. An axial drive system may be coupled to the patient platform. The axial drive system may be configured to move the patient platform axially relative to the base. A lateral drive system may be coupled to the patient platform. The lateral drive system may be configured to move the patient platform laterally relative to the base. A vertical drive system may be coupled to the patient platform. The vertical drive system may be configured to move the patient platform vertically relative to the base. The vertical drive system may include first and second scissor elements coupled to the patient platform. A pitch drive system may be coupled to the platform. The pitch drive system may be configured to tilt the upper portion relative to the lower portion about a pitch pivot. A yaw pivot may couple the upper portion to the lower portion at first respective ends of the upper and lower portions. A yaw drive may be coupled to the first end of the upper portion. The yaw drive may be configured to orient the upper portion relative to the lower portion about the yaw pivot.

[0030] In some variations, the pitch drive system may include a first wedge coupled to the yaw drive system and a second wedge coupled to the upper portion. In some variations, the axial drive system may be coupled between the lower portion and the lateral drive system. The lateral drive system may be coupled between the axial drive system and the yaw drive system. The yaw drive system may be coupled between the lateral drive system and the pitch drive system. The pitch drive system may be coupled between the yaw drive system and the upper portion.

[0031] In some variations, the axial drive system may include an axial drive element coupled to the first end of the lower portion and an axial rail coupled to the axial drive element. In other variations, the lateral drive system may include a lateral drive element coupled to the patient platform and a lateral rail coupled to the lateral drive element.

[0032] In another variation, a first scissor element may be coupled to a first end of the lower portion and a second scissor element may be coupled to a second end of the lower portion. In some variations, the vertical drive system may include a vertical drive element comprising a first linear screw coupled to the first scissor element. In some cases, the vertical drive element may include a second linear screw coupled to the second scissor element.

[0033] In some variations, the radiation therapy patient platform system described herein may further include a handheld controller. The handheld controller may include a first switch and a docking port. The first switch may be configured to generate a movement signal. In some variations, the first switch may include at least one of a button, an analog stick, a trackball, a touch screen, a directional pad, a jog dial, a motion detector, an image sensor, and a microphone. In other variations, the system may include a proximity sensor configured to detect the proximity of the controller to the patient platform. The patient platform may be configured to move using the movement signal and the detected proximity. In another variation, the controller may include a wireless transmitter that outputs the movement signal. In yet another variation, a tether may be coupled to the patient platform and the controller. In a further variation, the movement signal may control at least four degrees of freedom of movement.

[0034] In some variations, the system may include a second switch. In some of these variations, the second switch may be a step switch. The controller may be configured to output a movement signal in response to activation of the first and second switches. The controller may include the second switch and a housing. The first switch may be provided on a first side of the housing and the second switch may be provided on a second side of the housing opposite the first side.

[0035] Some of the radiation therapy patient platform systems described herein may further include a head fixation device configured to hold the patient head at a predetermined position relative to the patient platform. Generally, the head fixation device may include a hinge coupled to the base, a head rest coupled to the hinge, and a drive system coupled to the head rest. The drive system may be configured to extend generally perpendicular to the base. The head rest and drive system may each include a radiolucent material that is substantially transparent to high energy photons.

[0036] In some variations, the drive system may include a pneumatic element. In other variations, the drive system may include an electromechanical element. In another variation, an actuator may be coupled to the drive system. The actuator may be coupled to a first end of the patient platform. In a further variation, the hinge may include a lock having a plurality of detents and a pin.

[0037] Also described herein is a method of positioning a patient's head relative to a radiation therapy patient platform. For example, a head immobilization device may be used to position the patient's head relative to the patient platform to assist in the delivery of a radiation therapy treatment. In general, the method includes coupling the patient's head to the head immobilization device, which includes a base coupled to a head rest by a hinge and a head rest drive system coupled to the head rest. The drive system may extend generally perpendicular to the base.

[0038] In some variations, the headrest may be locked to the base. In other variations, at least one of the patient torso and the patient shoulders may be coupled to the base. In some other variations, the headrest may be tilted and pivoted relative to the base. In still other variations, the headrest may be pivoted about a hinge in response to neck flexion. The present invention provides, for example, the following: (Item 1) 1. A radiation therapy patient platform system comprising: a radiolucent patient platform coupled to a base, said patient platform comprising an upper portion coupled to a lower portion; an axial drive system coupled to the patient platform, the axial drive system configured to move the patient platform axially relative to the base; a lateral drive system coupled to the patient platform, the lateral drive system configured to move the patient platform laterally relative to the base; a vertical drive system coupled to the patient platform, the vertical drive system configured to move the patient platform in a vertical direction relative to the base, the vertical drive system comprising first and second scissor elements coupled to the patient platform; a yaw pivot connecting the upper portion to the lower portion at first ends of the upper and lower portions; a yaw drive system coupled to a first end of the upper portion, the yaw drive system configured to orient the upper portion relative to the lower portion about the yaw pivot; a pitch drive system coupled to the platform, the pitch drive system configured to tilt the upper portion relative to the lower portion about a pitch pivot; A system comprising: (Item 2) 2. The system of claim 1, wherein the pitch drive system comprises a first wedge coupled to the yaw drive system and a second wedge coupled to the upper portion. (Item 3) Item 1, wherein the axial drive system is coupled between the lower portion and the lateral drive system, the lateral drive system is coupled between the axial drive system and the yaw drive system, the yaw drive system is coupled between the lateral drive system and the pitch drive system, and the pitch drive system is coupled between the yaw drive system and the upper portion. (Item 4) Item 1, wherein the axial drive system comprises an axial drive element coupled to a first end of the lower portion and an axial rail coupled to the axial drive element. (Item 5) Item 1, the lateral drive system comprising a lateral drive element coupled to the patient platform and a lateral rail coupled to the lateral drive element. (Item 6) 2. The system of claim 1, wherein the vertical drive system comprises a vertical drive element comprising a first linear screw coupled to the first scissor element. (Item 7) 7. The system of claim 6, wherein the vertical drive element comprises a second linear screw coupled to the second scissor element. (Item 8) 1. A method of irradiating a first region of interest on a patient, comprising: moving a radiation therapy patient platform into a patient region of a gantry defining an isocenter point about which the gantry rotates and an isocenter axis that includes the isocenter point and extends parallel to a first longitudinal axis of the patient region; moving the patient platform to position the first region of interest on the isocenter axis; emitting a radiation beam from a radiation source onto the first region of interest on the isocenter axis; A method comprising: (Item 9) 9. The method of claim 8, wherein moving the patient platform and positioning the first region of interest on the isocenter axis moves the patient platform laterally. (Item 10) 9. The method of claim 8, further comprising rotating at least one of a pitch and a yaw of the patient platform. (Item 11) Item 11. The method of item 10, further comprising aligning a second longitudinal axis of the first region of interest on the isocenter axis. (Item 12) 9. The method of claim 8, wherein the patient comprises a second region of interest, further comprising moving the patient platform to alternately position the first and second regions of interest on the isocenter axis. (Item 13) 12. The method of claim 11, further comprising aligning a third longitudinal axis of the second region of interest on the isocenter axis. (Item 14) 1. A radiation therapy patient platform system comprising: a radiolucent patient platform including a radiopaque elongate element positioned along a longitudinal axis parallel to a longitudinal axis of the platform; a radiation source coupled to a multi-leaf collimator, the radiation source configured to emit a first beam through the collimator to irradiate the elongated element; a detector facing the collimator and configured to receive the first beam; a controller configured to: determine a first location of the extension element using the detector; calculate a change in location of the extension element between the first location and a second location of the extension element, the second location corresponding to a weighted platform; and use the change in location of the extension element to determine a change in location of the platform; A system comprising: (Item 15) Item 15. The system of item 14, wherein the patient platform comprises a first side comprising a patient support and a second side opposite the first side, the extension element being coupled to the second side of the patient platform. (Item 16) 15. The system of claim 14, further comprising a radiolucent support element coupling the extension element to the patient platform. (Item 17) Item 15. The system of item 14, wherein the elongation element comprises a metal rod. (Item 18) 15. The system of claim 14, wherein the radiolucent patient platform comprises a first material that is substantially transparent to high energy photons and the radiopaque elongate element comprises a second material that is substantially opaque to the high energy photons. (Item 19) 1. A method for quantifying patient induced change in location of a radiation therapy patient platform, comprising: emitting a first beam from a radiation source through a multi-leaf collimator to irradiate a radiopaque elongate element, the elongate element being coupled to a patient platform weighted by the patient, the elongate element having a longitudinal axis parallel to a longitudinal axis of the platform; receiving the first beam by a detector facing the collimator; determining a first location of the elongation element using the detector; and calculating a change in location of the extension element between a first location and a second location of the extension element, the second location corresponding to a non-weighted platform; determining a change in location of the platform using the change in location of the extension element; and A method comprising: (Item 20) 20. The method of claim 19, wherein the second location of the elongation element is determined using multiple images of the elongation element. (Item 21) 20. The method of claim 19, wherein the first beam is emitted from the radiation source between a first positive rotation angle and a second negative rotation angle relative to a horizontal plane. (Item 22) 22. The method of claim 21, wherein the first beam is emitted from the radiation source with the radiation source parallel to the horizontal plane. (Item 23) 20. The method of claim 19, wherein the radiolucent patient platform comprises a first material that is substantially transparent to high energy photons and the radiopaque element comprises a second material that is substantially opaque to the high energy photons. (Item 24) 1. A radiation therapy patient platform system comprising: a radiolucent patient platform; one or more optical markers coupled to the patient platform; an optical sensor coupled to a rotatable gantry, the optical sensor configured to image the one or more optical markers as the rotatable gantry rotates; a controller configured to: determine a first location of the one or more optical markers using the optical sensor; calculate a change in location of the one or more optical markers between the first location and a second location of the one or more optical markers, the second location corresponding to a weighted platform; and use the change in location of the one or more optical markers to determine a change in location of the platform; A system comprising: (Item 25) 25. The system of claim 24, wherein the optical sensor comprises an infrared sensor and / or an infrared illumination source. (Item 26) 25. The system of claim 24, wherein the optical marker comprises a retroreflector or reflector. (Item 27) 25. The system of claim 24, wherein the optical sensor comprises a laser. (Item 28) 25. The system of claim 24, wherein the patient platform comprises a first side comprising a patient support and a second side opposite the first side, and the optical marker is coupled to the second side of the patient platform. (Item 29) 1. A method for quantifying patient induced change in location of a radiation therapy patient platform, comprising: imaging an optical marker using an optical sensor, the optical marker coupled to the patient platform weighted by the patient, the optical marker having a longitudinal axis parallel to a longitudinal axis of the platform, the optical sensor coupled to a rotatable gantry; determining a first location of the optical marker using the optical sensor; calculating a change in location of the optical marker between a first location and a second location of the optical marker, the second location corresponding to a weighted platform; determining a change in location of the platform using the change in location of the optical marker; and A method comprising: (Item 30) 30. The method of claim 29, wherein the second location of the optical marker is determined using multiple images of the optical marker. (Item 31) 1. A system comprising: a patient platform having a patient support surface and an underside opposite the patient support surface; a phantom mounted on said underside, said phantom comprising a plurality of stages having corresponding predetermined depths, and a plurality of radiation detectors, each of said radiation detectors being disposed at a predetermined depth of its corresponding stage; A system comprising: (Item 32) Item 32. The system of item 31, wherein the radiation detector comprises an ionization chamber and a dosimeter slot. (Item 33) Item 32. The system of item 31, wherein the ionization chambers are aligned along a longitudinal axis of the phantom and along a vertical axis perpendicular to the longitudinal axis. (Item 34) Item 33. The system of item 32, wherein the dosimeter slot is parallel to the longitudinal axis and positioned at a predetermined depth of its corresponding step. (Item 35) Item 32. The system of item 31, wherein at least one of the dosimeter slots is approximately parallel to a vertical axis perpendicular to a longitudinal axis of the phantom. (Item 36) Item 32. The system of item 31, wherein the phantom comprises a housing defining an internal fluid-tight volume. (Item 37) 32. The system of claim 31, further comprising a mount for coupling the phantom to the patient platform. (Item 38) Item 38. The system of item 37, wherein the mount is configured to slidably position the phantom relative to the patient platform. (Item 39) 1. A system comprising: a patient platform having a patient support surface, a lower surface opposite the patient support surface, and a longitudinal axis; a phantom mounted on said underside, said phantom comprising a plurality of radiation detectors, a first region having a first density, and a second region having a second density different from the first density, said radiation detectors and regions each arranged along said longitudinal axis; A system comprising: (Item 40) 40. The system of claim 39, wherein the radiation detector comprises an ionization chamber and a dosimeter slot. (Item 41) Item 41. The system of item 40, wherein each of the dosimeter slots intersects its corresponding ionization chamber. (Item 42) Item 41. The system of item 40, wherein the ionization chamber and dosimeter slot are spaced apart from one another along the longitudinal axis. (Item 43) 40. The system of claim 39, further comprising a mount for coupling the phantom to the patient platform. (Item 44) Item 44. The system of item 43, wherein the mount is configured to slidably position the phantom relative to the patient platform. (Item 45) 1. A system comprising: a patient platform having a patient support surface, a lower surface opposite the patient support surface, and a longitudinal axis; a phantom mounted on said underside, said phantom comprising a first repeating pattern having a spatial frequency range and a second repeating pattern having a contrast range; Equipped with The first and second repeating patterns are spaced along a longitudinal axis of the phantom, the spatial frequency range is within a spatial frequency limit of a radiation detector, and the contrast range is within a contrast limit of the radiation detector. (Item 46) Item 46. The system of item 45, wherein the first and second repeating patterns comprise sets of contrasting shapes spaced at different intervals. (Item 47) Item 47. The system of item 46, wherein the set of shapes comprises a first shape having a first thickness and a second shape having a second thickness different from the first thickness. (Item 48) Item 47. The system of item 46, wherein the set of shapes comprises a first shape having a first density and a second shape having a second density different from the first density. (Item 49) Item 46. The system of item 45, wherein the width of the phantom is aligned parallel to the length of the patient platform. (Item 50) Item 46. The system of item 45, wherein the phantom is positioned within an imaging region of the patient platform. (Item 51) Item 46. The system of item 45, further comprising a mount for coupling the phantom to the patient platform. (Item 52) 1. A radiation therapy patient platform system comprising: a radiolucent patient platform comprising a conformable substrate having a plurality of enclosures and a pressure sensor coupled to the conformable substrate; a controller configured to independently control a height of each of the plurality of enclosures using the pressure sensors; and A system comprising: (Item 53) Item 53. The system of item 52, further comprising a pressure channel coupling a pressure source to each of the plurality of enclosures. (Item 54) Item 54. The system of item 53, wherein the pressure channel comprises a radiolucent material that is substantially transparent to high-energy photons. (Item 55) Item 53. The system of item 52, wherein the plurality of enclosures contain a fluid. (Item 56) Item 56. The system of item 55, wherein the fluid comprises a gas. (Item 57) 53. The system of claim 52, further comprising a thermoelectric layer and a heating element, each of the thermoelectric layer and heating element coupled to the patient platform. (Item 58) Item 58. The system of item 57, wherein the thermoelectric layer transitions between a flexible configuration and a rigid configuration based on temperature. (Item 59) Item 53. The system of item 52, further comprising a thermal insulation layer coupled to the thermoelectric layer. (Item 60) Item 53. The system of item 52, wherein the multiple enclosures comprise flexible membranes. (Item 61) Item 53. The system of item 52, wherein the plurality of enclosures comprises a honeycomb configuration. (Item 62) 1. A method for adjusting a radiolucent patient platform, comprising: measuring a pressure on a patient platform, the platform comprising a conformable substrate having a plurality of enclosures and a pressure sensor coupled to the conformable substrate, the pressure including a plurality of enclosure pressures; using said pressure to independently control a height of each of said plurality of enclosures such that said conformable substrate contours to a shape of a patient; A method comprising: (Item 63) 63. The method of claim 62, further comprising determining a patient configuration corresponding to a height of each of the plurality of enclosures, the patient configuration comprising at least one of a pressure and a height of each of the plurality of enclosures. (Item 64) 64. The method of claim 63, further comprising storing the patient configuration in a memory and readjusting a height of each of the plurality of enclosures using the stored patient configuration. (Item 65) 63. The method of claim 62, further comprising heating a thermoelectric layer of the patient platform to form a flexible configuration and cooling the thermoelectric layer to form a rigid configuration. (Item 66) 1. A method for reducing subsidence of a radiolucent patient platform, comprising: providing a patient platform coupled to a base, the patient platform comprising an upper portion and a lower portion coupled to the upper portion; moving the upper portion and the lower portion; emitting an imaging beam by an imaging radiation source in an imaging plane perpendicular to a longitudinal axis of the patient platform, the lower portion not intersecting the imaging plane and the upper portion intersecting the imaging plane; A method comprising: (Item 67) Item 67. The method of item 66, further comprising emitting a treatment beam from a therapeutic radiation source coupled to a multi-leaf collimator in a treatment plane perpendicular to a longitudinal axis of the patient platform, and moving the upper and lower portions such that the lower portion does not intersect the treatment plane and the upper portion intersects the treatment plane. (Item 68) Item 67. The method of item 66, wherein moving the upper portion into the imaging plane includes positioning the lower portion such that a leading edge of the lower portion is located at a first distance away from the imaging plane. (Item 69) Item 68. The method of item 67, wherein moving the upper portion into the treatment plane includes positioning the lower portion such that a leading edge of the lower portion is located at a second distance away from the treatment plane. (Item 70) Item 67. The method of item 66, wherein the upper portion comprises a first material that is substantially transparent to high-energy photons and the lower portion comprises a second material that is substantially opaque to the high-energy photons. (Item 71) 1. A radiation therapy patient platform system comprising: a radiolucent patient platform comprising an upper portion coupled to a lower portion; a base coupled to the lower portion of the patient platform; a radiation source coupled to a multi-leaf collimator, the radiation source configured to emit a first beam in a beam plane perpendicular to a longitudinal axis of the patient platform; a controller configured to move the upper portion relative to the lower portion, the lower portion not intersecting the beam plane and the upper portion intersecting the beam plane; A system comprising: (Item 72) 1. A method for controlling a radiolucent patient platform, comprising: providing a patient platform coupled to a base, the patient platform comprising an upper portion and a lower portion secured to the upper portion, the upper portion and the lower portion comprising different radiolucencies; moving the patient platform relative to the base; emitting an imaging beam by an imaging radiation source in an imaging plane perpendicular to a longitudinal axis of the patient platform, the lower portion not intersecting the imaging plane and the upper portion intersecting the imaging plane; A method comprising: (Item 73) 73. The method of claim 72, further comprising emitting a treatment beam from a therapeutic radiation source coupled to a multi-leaf collimator in a treatment plane perpendicular to a longitudinal axis of the patient platform, and moving the patient platform such that the lower portion does not intersect the treatment plane and the upper portion intersects the treatment plane. (Item 74) 73. The method of claim 72, wherein moving the upper portion into the imaging plane includes positioning the lower portion such that a leading edge of the lower portion is located at a first distance away from the imaging plane. (Item 75) Item 75. The method of item 74, wherein moving the upper portion into the treatment plane includes positioning the lower portion such that a leading edge of the lower portion is located at a second distance away from the treatment plane. (Item 76) Item 73. The method of item 72, wherein the upper portion comprises a first material that is substantially transparent to high-energy photons and the lower portion comprises a second material that is substantially opaque to the high-energy photons. (Item 77) 1. A radiation therapy patient platform system comprising: a radiolucent patient platform having an upper portion secured to a lower portion; a base coupled to the lower portion of the patient platform; a radiation source coupled to a multi-leaf collimator, the radiation source configured to emit a first beam in a beam plane perpendicular to a longitudinal axis of the patient platform; a controller configured to move the patient platform relative to the base, the lower portion not intersecting the beam plane and the upper portion intersecting the beam plane; A system comprising: (Item 78) 2. The patient platform of claim 1, further comprising a handheld controller comprising a first switch and a docking port, the first switch configured to generate a movement signal. (Item 79) 80. The patient platform of claim 78, wherein the first switch comprises at least one of a button, an analog stick, a trackball, a touch screen, a directional pad, a jog dial, a motion detector, an image sensor, and a microphone. (Item 80) 80. The patient platform of claim 78, further comprising a proximity sensor configured to detect proximity of the controller to the patient platform, the patient platform being configured to move using the movement signal and the detected proximity. (Item 81) 80. The patient platform of claim 78, wherein the controller comprises a wireless transmitter that outputs the movement signal. (Item 82) 80. The patient platform of claim 78, further comprising a tether coupled to the patient platform and the controller. (Item 83) 80. The patient platform of claim 78, wherein said movement signals control movement in at least four degrees of freedom. (Item 84) 80. The patient platform of item 78, further comprising a second switch. (Item 85) 85. The patient platform of claim 84, wherein the second switch is a step switch. (Item 86) 80. The patient platform of claim 78, wherein the controller is configured to output the movement signal in response to activation of the first and second switches. (Item 87) 80. The patient platform of claim 78, wherein the controller comprises the second switch and a housing, the first switch being provided on a first side of the housing and the second switch being provided on a second side of the housing opposite the first side. (Item 88) Item 1. The system of item 1, further comprising a head fixation comprising a hinge coupled to a base, a headrest coupled to the hinge, and a drive system coupled to the headrest, the drive system configured to extend generally perpendicular to the base, and the headrest and the drive system each comprising a radiolucent material that is substantially transparent to high-energy photons. (Item 89) Item 91. The system of item 88, wherein the drive system comprises a pneumatic element. (Item 90) Item 91. The system of item 88, wherein the drive system comprises an electromechanical element. (Item 91) Item 89. The system of item 88, further comprising an actuator coupled to the drive system, the actuator coupled to a first end of the patient platform. (Item 92) Item 91. The system of item 88, wherein the hinge comprises a lock, the lock comprising a plurality of detents and a pin. (Item 93) 1. A method of positioning a patient's head relative to a radiation therapy patient platform, comprising: coupling the patient's head to a head immobilization device, the head immobilization device comprising a base coupled to a head rest by a hinge and a head rest drive system coupled to the head rest; extending the drive system generally perpendicular to the base; A method comprising: (Item 94) Item 94. The method of item 93, further comprising locking the head rest to the base. (Item 95) 94. The method of claim 93, further comprising coupling at least one of a patient torso and a patient shoulder to the base. (Item 96) Item 94. The method of item 93, further comprising tilting and orienting the head rest relative to the base. (Item 97) Item 94. The method of item 93, further comprising pivoting the head restraint about the hinge in response to neck flexion. [Brief description of the drawings]

[0039] [Figure 1A]1A-1F are illustrative depictions of variations of a radiation therapy patient platform system: FIG 1A is a cross-sectional side view of a variation of the patient platform and gantry; FIG 1B-1F are cross-sectional front views of a variation of the patient platform and gantry of FIG 1A; [Figure 1B] 1A-1F are illustrative depictions of variations of a radiation therapy patient platform system: FIG 1A is a cross-sectional side view of a variation of the patient platform and gantry; FIG 1B-1F are cross-sectional front views of a variation of the patient platform and gantry of FIG 1A; [Figure 1C] 1A-1F are illustrative depictions of variations of a radiation therapy patient platform system: FIG 1A is a cross-sectional side view of a variation of the patient platform and gantry; FIG 1B-1F are cross-sectional front views of a variation of the patient platform and gantry of FIG 1A; [Figure 1D] 1A-1F are illustrative depictions of variations of a radiation therapy patient platform system: FIG 1A is a cross-sectional side view of a variation of the patient platform and gantry; FIG 1B-1F are cross-sectional front views of a variation of the patient platform and gantry of FIG 1A; [Figure 1E] 1A-1F are illustrative depictions of variations of a radiation therapy patient platform system: FIG 1A is a cross-sectional side view of a variation of the patient platform and gantry; FIG 1B-1F are cross-sectional front views of a variation of the patient platform and gantry of FIG 1A; [Figure 1F] 1A-1F are illustrative depictions of variations of a radiation therapy patient platform system: FIG 1A is a cross-sectional side view of a variation of the patient platform and gantry; FIG 1B-1F are cross-sectional front views of a variation of the patient platform and gantry of FIG 1A; [Figure 2A]2A-2C are illustrative depictions of variations of a radiation therapy patient platform. Fig. 2A is a perspective view of a variation of a patient supported by a conformable patient platform. Fig. 2B is a perspective view of the conformable patient platform of Fig. 2A. Fig. 2C is a cross-sectional side view of another variation of a patient supported by a conformable patient platform. [Figure 2B] 2A-2C are illustrative depictions of variations of a radiation therapy patient platform. Fig. 2A is a perspective view of a variation of a patient supported by a conformable patient platform. Fig. 2B is a perspective view of the conformable patient platform of Fig. 2A. Fig. 2C is a cross-sectional side view of another variation of a patient supported by a conformable patient platform. [Figure 2C] 2A-2C are illustrative depictions of variations of a radiation therapy patient platform. Fig. 2A is a perspective view of a variation of a patient supported by a conformable patient platform. Fig. 2B is a perspective view of the conformable patient platform of Fig. 2A. Fig. 2C is a cross-sectional side view of another variation of a patient supported by a conformable patient platform. [Figure 3A] 3A-3D are illustrative depictions of a variation of a radiation therapy patient platform system. FIGURES 3A-3B are cross-sectional side views of a variation of a telescoping patient platform and gantry. FIGURES 3C-3D are cross-sectional side views of another variation of a telescoping patient platform and gantry. [Figure 3B] 3A-3D are illustrative depictions of a variation of a radiation therapy patient platform system. FIGURES 3A-3B are cross-sectional side views of a variation of a telescoping patient platform and gantry. FIGURES 3C-3D are cross-sectional side views of another variation of a telescoping patient platform and gantry. [Figure 3C] 3A-3D are illustrative depictions of a variation of a radiation therapy patient platform system. FIGURES 3A-3B are cross-sectional side views of a variation of a telescoping patient platform and gantry. FIGURES 3C-3D are cross-sectional side views of another variation of a telescoping patient platform and gantry. [Figure 3D] 3A-3D are illustrative depictions of a variation of a radiation therapy patient platform system. FIGURES 3A-3B are cross-sectional side views of a variation of a telescoping patient platform and gantry. FIGURES 3C-3D are cross-sectional side views of another variation of a telescoping patient platform and gantry. [Figure 4A]

[0023] Figures 4A-4F are illustrative depictions of a variation of a radiation therapy patient platform system. Figures 4A-4B are side views of a variation of the patient platform system. Figure 4C is a perspective view of the patient platform system of Figure 4B. Figure 4D is a side view of another variation of the patient platform system. Figure 4E is a perspective view of the patient platform system of Figure 4D. Figure 4F is a perspective view of the patient platform system of Figure 4C. [Figure 4B]

[0023] Figures 4A-4F are illustrative depictions of a variation of a radiation therapy patient platform system. Figures 4A-4B are side views of a variation of the patient platform system. Figure 4C is a perspective view of the patient platform system of Figure 4B. Figure 4D is a side view of another variation of the patient platform system. Figure 4E is a perspective view of the patient platform system of Figure 4D. Figure 4F is a perspective view of the patient platform system of Figure 4C. [Figure 4C]

[0023] Figures 4A-4F are illustrative depictions of a variation of a radiation therapy patient platform system. Figures 4A-4B are side views of a variation of the patient platform system. Figure 4C is a perspective view of the patient platform system of Figure 4B. Figure 4D is a side view of another variation of the patient platform system. Figure 4E is a perspective view of the patient platform system of Figure 4D. Figure 4F is a perspective view of the patient platform system of Figure 4C. [Figure 4D]

[0023] Figures 4A-4F are illustrative depictions of a variation of a radiation therapy patient platform system. Figures 4A-4B are side views of a variation of the patient platform system. Figure 4C is a perspective view of the patient platform system of Figure 4B. Figure 4D is a side view of another variation of the patient platform system. Figure 4E is a perspective view of the patient platform system of Figure 4D. Figure 4F is a perspective view of the patient platform system of Figure 4C. [Figure 4E]

[0023] Figures 4A-4F are illustrative depictions of a variation of a radiation therapy patient platform system. Figures 4A-4B are side views of a variation of the patient platform system. Figure 4C is a perspective view of the patient platform system of Figure 4B. Figure 4D is a side view of another variation of the patient platform system. Figure 4E is a perspective view of the patient platform system of Figure 4D. Figure 4F is a perspective view of the patient platform system of Figure 4C. [Figure 4F]

[0023] Figures 4A-4F are illustrative depictions of a variation of a radiation therapy patient platform system. Figures 4A-4B are side views of a variation of the patient platform system. Figure 4C is a perspective view of the patient platform system of Figure 4B. Figure 4D is a side view of another variation of the patient platform system. Figure 4E is a perspective view of the patient platform system of Figure 4D. Figure 4F is a perspective view of the patient platform system of Figure 4C. [Diagram 5] FIG. 5 is an illustrative cross-sectional side view of a variation of a handheld controller for a radiation therapy system. [Figure 6A] 6A-6B are illustrative side views of a variation of a head fixation device. [Figure 6B] 6A-6B are illustrative side views of a variation of a head fixation device. [Figure 7] FIG. 7 is a flow chart representation of one variation of a radiation therapy process. [Figure 8] FIG. 8 is a flow chart representation of one variation of a patient platform subsidence determination process. [Figure 9]FIG. 9 is a flow chart representation of one variation of the decompression element location determination process. [Figure 10] FIG. 10 is a flow chart representation of one variation of the patient platform loading process. [Figure 11A] 11A-11B are a flowchart representation of a variation of the patient platform loading process. [Figure 11B] 11A-11B are a flowchart representation of a variation of the patient platform loading process. [Figure 12] FIG. 12 is a flow chart representation of another variation of the patient platform movement process. [Figure 13A] 13A-13E are illustrative top views of a variation of a radiation therapy patient platform. [Figure 13B] 13A-13E are illustrative top views of a variation of a radiation therapy patient platform. [Figure 13C] 13A-13E are illustrative top views of a variation of a radiation therapy patient platform. [Figure 13D] 13A-13E are illustrative top views of a variation of a radiation therapy patient platform. [Figure 13E] 13A-13E are illustrative top views of a variation of a radiation therapy patient platform. [Figure 14] FIG. 14 is a flow chart representation of one variation of a patient head immobilization process. [Figure 15] FIG. 15 is an illustrative depiction of subsidence of the patient platform. [Figure 16A] 16A and 16B are illustrative cross-sectional side views of a variation of a phantom for a radiation therapy system. [Figure 16B] 16A and 16B are illustrative cross-sectional side views of a variation of a phantom for a radiation therapy system. [Figure 17] FIG. 17 is an illustrative cross-sectional side view of a variation of a phantom for a radiation therapy system. [Figure 18]FIG. 18 is an illustrative plan view of a variation of a phantom for a radiation therapy system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Described herein are systems, devices, and methods useful for radiation therapy procedures. As used herein, radiolucency refers to the property of being substantially transparent to high-energy photons, in that there is little or no attenuation of the high-energy photons. Conversely, radiopacity refers to the property of being substantially opaque to high-energy photons. For example, a radiopaque material may attenuate or block the transmission of high-energy photons.

[0041] Generally, to perform imaging and / or radiation therapy procedures, a patient is loaded onto a patient platform. The patient platform may comprise carbon fiber due to its radiolucency and ability to provide rigid support to the patient. Once loaded, the platform is moved into the patient area (e.g., bore, central opening, cavity) of the ring gantry. Typically, the large size and geometry of the gantry sets physical constraints on the configuration of the patient platform and other system components. In some radiation therapy systems, the gantry may comprise a C-shape that defines a patient area through which the patient platform may extend into and out of. The gantry may comprise one or more beam delivery systems that may rotate about the patient platform and provide one or more imaging and / or treatment beams from multiple angles. To precisely and / or accurately deliver the treatment beam to the patient's area of ​​interest (e.g., lesion, tumor), the location of the patient relative to the gantry must be precisely determined and account for any subsidence, deviation, or deflection of the patient platform in the treatment beam plane. It should be appreciated that an effective radiotherapy treatment is not just the ability to deliver high energy photons to an area of ​​interest to treat a disease, but to do so while reducing the delivery of high energy photons to healthy tissue. Alternatively, for example, a cancerous tumor may be treated at the expense of damage to healthy organs and tissues.

[0042] Further described herein are systems, devices, and methods for controlling the movement of a patient platform. For ease of explanation, a set of reference axes are defined in FIG. 15 and used throughout (e.g., FIG. 1A-1F, 3A-3D, 4A-4F, 6A-6B, 13A-13E, 16A-16B, 17, 18, etc.) to define a set of translational and rotational axes relative to the patient platform (1500). In particular, FIG. 15 is an illustrative depiction of the subsidence (1520) of the patient platform (1500) in the XY plane. The patient platform (1500) may be coupled to and extend from a base (1502). The subsidence (1520) of the patient platform (1500) corresponds to the vertical distance (along the Z axis) between a horizontal plane (1510) (e.g., the XY plane) and the submerged patient platform (1500). The horizontal plane (1510) corresponds to the plane of an ideal patient platform mounted on the base (1502) that extends from the base (1502) without any deflection. As shown in FIG. 15, the subsidence (1520) of the patient platform (1500) may increase along the length of the patient platform (1500) that extends from the base (1502). As used herein, axial movement corresponds to movement along the X-axis, vertical movement corresponds to movement along the Z-axis, and lateral movement corresponds to movement along the Y-axis (extending into and out of the XZ plane). As illustrated in FIG. 15, yaw rotation corresponds to rotation about the Z-axis, and pitch rotation corresponds to rotation about the Y-axis.

[0043] In some variations of the present systems, the subsidence of the ideal patient platform may be measured and used to aid in the delivery of the radiation therapy treatment. For example, measuring the degree to which the patient platform subsides may be used to adjust the treatment plan to more accurately and / or more precisely apply radiation to the patient's region of interest. In some of these variations, the patient platform may include a radiopaque extension element. One or more leaves of a multi-leaf collimator of the gantry may be opened as the gantry rotates about the patient platform to selectively direct an imaging beam to intersect the extension element and a detector located opposite the radiation source. Various methods, for example, Winston-Lutz based methods, may be used to determine the amount of subsidence of the extension element using the detector data. According to the systems, devices, and methods herein, the patient platform subsidence and the location of the region of interest may be determined. Furthermore, by selecting an image beam angle where the radiation beam intersects the extension element rather than the patient, the location of the region of interest may be determined without exposing the patient to additional radiation. Thus, the therapeutic dose may be delivered to the patient more accurately and / or precisely, thus sparing healthy tissue and improving occupancy delivery.

[0044] In some variations of the system, a conformable patient platform may be provided to improve patient platform ergonomics, reduce patient alignment and setup time, and increase patient compliance. In some cases, the patient may be sedated to limit their movement on the patient platform. However, sedation may pose risks and may be undesirable for some patient groups, such as the elderly, patients with advanced illnesses, and / or patients taking medications. The conformable patient platform may promote patient comfort and encourage patients to remain motionless for longer periods to receive radiation therapy treatments, which may help reduce the use of sedatives. In some of these variations, the configuration of the patient platform, which may be unique or customized for a particular patient, may be stored in the memory of the controller and reapplied for future procedures. The patient platform, described in more detail below, may uniformly conform to each patient and act as an ergonomic restraint to limit patient movement on the patient platform. Importantly, it should be understood that the conformable patient platform may be radiolucent and the patient platforms described herein may be used for diagnostic imaging and / or radiation therapy procedures. In some variations, the patient platform may comprise a conformable substrate having multiple independently height adjustable enclosures that may deform and rigidify to contour to the shape of the patient. In other variations, the patient platform may comprise a thermoelectric layer that forms a flexible configuration when heated and a rigid configuration when cooled.

[0045] Some variations of the patient platform may telescope (e.g., portions of the platform may move relative to one another, or a portion of the platform may extend from another portion to make the entire platform longer) to reduce subsidence of the patient platform, as described in more detail below. For example, some patient platforms may be formed from a piece of carbon fiber that is cantilevered to extend from a base. These platforms are radiolucent, but may gradually subside as they extend out from the mounting base and into the patient area of ​​the gantry. For example, as shown in FIG. 1A, a first end (105) of the patient platform (102) will exhibit less subsidence than a second end (107). According to some of the variations of the invention, the patient platform may comprise multiple portions that may move or telescope relative to one another and / or the base of the patient platform. A first portion of the patient platform may be formed from a radiolucent material, while a second portion may be formed from a more rigid material (any radiolucent) that exhibits less subsidence than the first portion. The patient platform may be controlled such that a more rigid second portion is cantilevered from the base and moves up and to the right, but does not cross the plane of the imaging and / or therapy beams that would otherwise interfere with the imaging and / or therapy procedure. Thus, the patient platform as a whole may exhibit additional stiffness, reducing subsidence of the patient platform.

[0046] In some variations of the present system, the patient platform may move in multiple degrees of freedom to position the patient and aid in the delivery of the radiation therapy treatment, as described in more detail below. Some conventional patient platforms provide motors at each axial end of the patient platform to provide yaw control. These conventional motors may utilize radiopaque wires that extend along the length of the patient platform through the treatment beam plane and unnecessarily interfere with imaging and / or treatment. In contrast, in some variations of the present invention, the patient platform may include a yaw drive and an axial drive system coupled to a first end of the patient platform and configured to pivot about a pivot point without reducing the radiolucency of the patient platform. In other variations, the patient platform may include a vertical drive system configured to control the height and / or pitch of the patient platform, which may be useful, for example, for the treatment of head lesions. In some variations of the method for delivering a radiation therapy treatment, the patient platform may position a region of interest on an isocenter of the gantry, such as an isocenter of the beam source, to focus the radiation dose to the region of interest and reduce the radiation dose to healthy tissue.

[0047] Further described herein are systems, devices, and methods for characterization, qualification, verification, and / or calibration of a radiation therapy system. To assess or confirm that components of a radiation therapy system are configured to precisely and accurately deliver a desired radiation dose to a target region within a patient, the system may undergo quality assurance testing, alignment, calibration, and / or verification procedures prior to a treatment session and / or at pre-determined intervals (e.g., daily, monthly, quarterly, etc.). Such procedures may include measuring emissions or radiation using one or more radiation detectors positioned at pre-determined locations. For example, a phantom having multiple radiation detectors may be placed on or below the patient platform. The phantom may include multiple dosimetry sensors and types configured to receive doses of radiation dose data. Dose data generated from the phantom may be compared to a set of reference dose data to determine the calibration of one or more components (e.g., detectors) of the radiation therapy system.

[0048] Some variations of the patient platform system may include a handheld controller for controlling the patient platform. A radiation therapy system operator may use the handheld controller to adjust the position of the patient relative to the gantry by controlling the movement of the patient platform. For example, one or more switches may be integrated into the housing of the controller for a user to operate. The controller may be docked to the gantry or patient platform to enable a first set of control functionality and undocked from the system to enable a second set of control functionality. The handheld controller may generate movement signals, as described in more detail below. Additionally, control of the patient platform may be limited to a pre-determined proximity of the system. Thus, the operator may gain increased mobility while ensuring patient safety and regulatory compliance.

[0049] In general, it is desirable for a radiation therapy procedure to deliver treatment beams from multiple angles, which can help reduce radiation dose to healthy tissue. This can be particularly desirable for the head and neck, as salivary glands, eyes, ears, and nerve cells can be particularly sensitive to radiation dose. In some variations, a head fixation device can be useful for precisely positioning the patient's head on the patient platform. However, some patients experience difficulty and / or discomfort with devices that are attached to the head and / or control head movement. The head fixation device can allow the patient to manually move their head through the neck flexion to a desired position and lock or fix the head in place for treatment, as described in more detail below. Additionally or alternatively, the patient and / or operator may control a drive system, such as a pneumatic drive system, to lock or fix the head in a desired position. Any of the systems, devices, and methods described below may be used in combination. The variations described herein below may improve patient comfort associated with a radiation therapy procedure. (I. System) (Radiation Therapy Patient Platform)

[0050] In general, the systems described herein may be useful in determining the subsidence of a patient platform and the location of a patient's region of interest on the patient platform. FIG. 1A is a cross-sectional side view of a radiation therapy patient platform system (100). The system (100) may include a patient platform (102), a gantry (120), and a base (112). The patient platform (102) may include a radiolucent first material, such as carbon fiber. The patient platform (102) may further include a first side (104) (top) that includes a patient support on which a patient (114) may lie. A second side (106) (lower side) of the patient platform (102) may be provided opposite the first side (104). In some variations, the patient platform (102) may have a length of about 1.5 to 3.0 meters, a width of about 0.05 to 2.0 meters, and a thickness of about 0.05 to 0.50 meters, preferably a length of 2 meters, a width of 0.50 meters, and a thickness of 0.10 meters. As shown in FIG. 1A, at least a portion of the patient platform (102) may extend (e.g., be cantilevered) from an edge of the base (112) such that the second end (107) of the patient platform (102) may gradually sink due to the weight of the patient (114). In some variations, a radiopaque extension element (108) may be coupled to the second side (106) of the patient platform (102). The extension element (108) may be secured to the patient platform (102) such that the amount of space between the extension element (108) and the patient platform (102) is a fixed or known quantity (e.g., the patient platform (102) and the extension element (108) may be separated by the thickness of the support element (110). In some cases, a radiolucent support element (110) may couple the radiopaque extension element (108) to the patient platform (102). In some variations, the extension element (108) may have a thickness of about 0.001 to 0.01 meters and the support element (110) may have a thickness of about 0.001 to 0.50 meters.

[0051] In some variations, the elongated element (108) may be formed from a second material that is radiopaque. By imaging the elongated element (108) from one or more gantry angles using the first radiation beam (126), the location of the elongated element (108) may be precisely determined. In some cases, the elongated element (108) may include a metal such as aluminum, although other radiopaque materials and combinations of radiopaque materials may also be used. As shown in FIGS. 1A-1D and 1F, the elongated element (108) may have a wire or rod shape. In some variations, the length of the elongated element (108) may correspond to the length of the region of interest (116) of the patient (114). In other variations, the elongated element (108) may correspond to the length of the patient platform (102) through which the first beamlet (127a) may cross and pass. It should be noted that any length of the extension element (108) may be selected so long as the extension element (108) is located at a location where subsidence determination is desired. Additionally or alternatively, the radiolucent support element (110) may be coupled to one or more radiopaque spheres (e.g., beads, balls, pellets, orbs, etc.) in some of the variations described herein.

[0052] The first end (105) of the patient platform (102) may be coupled to a base (112). The base (112) may be provided outside the patient region (140) of the gantry (120) and may not be radiolucent. In the variation depicted in FIGS. 1B-1E, the gantry (120) may include a radiation source (122) for generating and directing a first beam (126) at a radiopaque extension element (108) facing the multi-leaf collimator (124) and a detector (128). The controller (130) may include a processor and memory for determining subsidence of the patient platform (102) using detector data, as described in more detail below. It should be understood that the first beam (126) directed at the extension element (108) may be generated by the radiation source (122) without the use of a multi-leaf collimator (124).

[0053] 1B is a cross-sectional front view of the patient platform (102) and gantry (120) illustrating the intersection of the first beamlet (127a) with the radiopaque elongated element (108) and detector (128). As shown in FIG. 1B, the elongated element (108) may be provided on a second side (106) of the patient platform (102) and coupled to the patient platform (102) by a radiotransparent support element (110). The radiation source (122) may be rotated around the patient area by the gantry (120) such that the first beamlet (127a) and the second beamlet (127b) may be emitted from above, below, and to the side of the patient (114). Although the radiation source (122) may rotate circularly around the patient gantry (120), Figures 1B-1C and 1E illustrate the radiation source (122) within the gantry (120) when aligned in a horizontal plane (118) (e.g., the XY plane).

[0054] A pre-determined estimate of the patient platform subsidence may be used to determine which leaves of the multi-leaf collimator (124) to open and direct the first beamlet (127a) to the radiopaque elongate element (108) and the detector (128). For example, an estimate of the patient platform subsidence for a given patient weight may be stored in a database in memory and used to determine the set of leaves of the multi-leaf collimator (124) to open for a given gantry angle. A controller (130) controlling the radiation source (118) and the multi-leaf collimator (124) may ensure that the first beamlet (127a) does not cross the patient (114). Optionally, the multi-leaf collimator (124) may open one or more leaves to allow the second beamlet (127b) to irradiate the region of interest (116). Emission of the radiation beam (126) from the radiation source (122) at the gantry angles depicted in Figures 1B-1C and 1E may enable the radiation therapy system to provide therapeutic radiation to the region of interest (116) using the second beamlet (127b) while collecting image data (e.g., subsidence data) for patient platform (104) position information in parallel (e.g., simultaneously or sequentially) using the first beamlet (127a). In Figures 1B-1C, the beam (126) emitted from the radiation source (122) through the multi-leaf collimator (124) may select the first beamlet (127a) that intersects the elongated element (108) without intersecting the patient (114). More generally, the first beamlet (127a) may be emitted at the elongated element (108) from any gantry angle, so long as the first beamlet (127a) does not intersect the patient (114). As a result, determining to lower the patient platform may not increase the radiation dose to the patient 114. In some variations, the first beamlet 127a may be emitted toward the radiation source 122 relative to the horizontal plane 118 between a first positive rotation angle α1 and a second negative rotation angle α1 of about ±45°.The duration and power of the first beamlet (127a) are not particularly limited since the first beamlet (127a) does not intersect the patient (114). Irradiation of the elongated element (108) by the beamlet (127a) may be detected by the detector (128), and this detector data may be used to identify the elongated element (108) of the patient platform (102) weighted by the patient (114) relative to a known location of the elongated element (108) of the unweighted patient platform (102). The difference in these locations corresponds to the amount of subsidence of the patient platform (102). Detector data generated from multiple gantry angles may therefore improve real-time subsidence determination.

[0055] It should be appreciated that one or more radiopaque elongate elements (108) may be coupled to the patient platform (102) as long as the first beamlet (127a) that intersects the elongate element (108) does not intersect the patient (114). In some variations, two or more elongate elements (108) may be coupled to the patient platform (102) by separate radiolucent support elements (110) at a predetermined distance (D) from each other. In some examples, the elongate element (108) may comprise a pair of cylindrical rods of the same or different dimensions (e.g., length, diameter) provided along different portions of the patient platform (102). In FIG. 1C, one of the elongate elements (108) is positioned on a first side (e.g., left side) of the patient platform (102), while another elongate element (108) is positioned on a second side (e.g., right side) of the patient platform (102). The elongated elements (108) may be disposed parallel to the longitudinal axis of the patient platform (102). The elongated elements (108) depicted in FIGS. 1C-1D may have the same or different shapes and / or dimensions. In other variations, three or more radiopaque elements (e.g., elongated elements (108) and / or radiopaque spheres) may be non-collinearly coupled to the patient platform (102). That is, the radiopaque elements may intersect the same line except for at least one of the radiopaque elements. For example, the first and second radiopaque elements may be disposed along a line parallel to the Y-axis (e.g., the width of the patient platform (102)), while the third radiopaque element may be disposed between the first and second radiopaque elements along the Y-axis and spaced apart from the first and second radiopaque elements along the X-axis (e.g., the length of the patient platform (102)). In one variation, the three radiopaque elements may comprise any combination of shapes and dimensions as discussed above. For example, the radiopaque elements may comprise three spheres (e.g., beads) or three elongate elements (e.g., rods), two spheres and one rod, and one sphere.The shape, size, dimensions, and location of one or more radiopaque elements may be stored in a memory of the controller.

[0056] In another variation, as illustrated in FIG. 1D, each extension element (108) may be imaged using a corresponding beamlet (132, 134). Similar to FIG. 1C, the extension elements (108) may be positioned on opposite sides of the patient platform (102). The beamlets (132, 134) may be emitted from a beam assembly (123) that includes a multi-leaf collimator and a radiation source. Imaging the extension element (108) using different beamlets (132, 134) may increase the number of gantry angles at which the extension element (108) may be imaged, since each beamlet does not need to intersect both extension elements (108). In the variation depicted in FIG. 1D, patient platform subsidence measurements may be obtained without irradiating the patient. This may help reduce radiation exposure to the patient.

[0057] Both the elongated element (108) may be imaged using one or more beamlets at a pre-determined gantry angle. Detector data generated by the one or more beamlets may be used to determine the amount of patient platform (102) subsidence. As best shown in FIG. 1D, for one or more beamlets (132, 134) emitted at a given gantry angle, the detector (128) will generate detector data having projections of the elongated element (108) separated by a projection distance (D'). The subsidence of the patient platform (102) corresponds to the projection distance (D') such that a change in the projection distance (D') indicates a change in the subsidence of the patient platform (102). For example, an increase in the distance (D') may correspond to an increase in the subsidence of the patient platform (102). Thus, the patient subsidence may be determined using one or more beamlets emitted from a single gantry angle. Of course, the elongated element (108) may be imaged from multiple gantry angles to generate detector data.

[0058] Additionally or alternatively, the extension element (108) may be imaged by beamlets from multiple gantry angles to determine the absolute location of the extension element (108). For example, a first extension element disposed on a first side (e.g., left side) of the patient platform (102) may intersect a first beamlet emanating from a first side (e.g., left side in FIG. 1C) of the gantry (120) from a set of angles relative to the horizontal plane (118). Similarly, a second extension element disposed on a second side (e.g., right side) of the patient platform (102) may intersect a second beamlet emanating from a second side (e.g., right side in FIG. 1C) of the gantry (120) from a set of angles relative to the horizontal plane (118). Thus, a pair of extension elements may be imaged from the left and right sides of the patient platform (102) to increase the number of angles at which the extension elements may be imaged, thereby improving patient platform subsidence determination.

[0059] In addition to determining subsidence, the difference in absolute location of the extension elements (108) relative to one another may be used to calculate the roll of the patient platform (102), i.e., the rotation of the patient platform (102) about the longitudinal axis (e.g., the X-axis in FIG. 1C) of the patient platform (102). For example, each of the extension elements (108) in FIG. 1C may be coupled to the patient platform (102) at equal heights from the second side (106) of the patient platform (102). If the height of one of the extension elements (108) changes relative to the other extension element (108), the patient platform (102) is rolling (e.g., twisting) a corresponding amount. Thus, the change in location of the patient platform (102) due to a patient (114) being positioned on the patient platform (102) may be determined along multiple axes.

[0060] In another variation, the patient platform (102) may include three non-collinear extension elements (108) that are used to calculate roll and yaw using the absolute locations of the three extension elements (108) relative to one another. For example, the three extension elements (108) may be spaced apart along the X-axis and Y-axis of the patient platform (102) and coupled to the patient platform (102). If the detector data projections of the extension elements (108) along the X-axis change distance, the patient platform (102) is turning (e.g., pivoting) a corresponding amount. Thus, the sag, roll, and yaw of the patient platform (102) due to the patient (114) may be determined using a set of extension elements (108) and at least two beamlets.

[0061] FIG. 1E is another cross-sectional front view of the patient platform (102) and gantry (120) illustrating the intersection of the first beamlet (127a) with the laterally extending radiopaque elongated element (109). This configuration may allow imaging from opposite sides of the gantry (120) (e.g., the left and right sides of the patient (114)). As shown in FIG. 1E, the radiopaque elongated element (109) may comprise a thin metal foil (e.g., a metal plate). A thin, wide foil with a width greater than its thickness may provide significant attenuation only in a direction along the width of the foil (e.g., along the plane of the metal plate) such that the foil does not significantly attenuate the imaging beam at other angles. In one instance, the elongated element (109) may comprise aluminum and have a thickness of about 0.0001 to 0.001 meters and a width of about 0.10 to 0.5 meters.

[0062] In some variations, the elongate elements (108, 109) may include multiple materials and configurations. For example, the elongate elements (108, 109) may form a radiolucent portion and one or more radiopaque portions, and the radiopaque portions may form a discernible shape after imaging. In some instances, the imaged radiopaque elongate elements (108, 109) may display one or more symbols (e.g., numbers, letters), geometric shapes, and other fiducials corresponding to pre-determined locations along the length of the patient platform (102) that may aid in patient platform subsidence determination.

[0063] In some variations, the patient platform (102) may include one or more radiopaque portions without being attached to the extension elements (108, 109) and / or the radiolucent support elements (110). For example, the radiopaque portions may be attached to the edges of the patient platform (102) by fasteners, adhesives, and the like.

[0064] Additionally or alternatively, the elongated element may not be radiopaque as long as image contrast can be formed with the patient platform. It should be understood that any material capable of generating image contrast for the radiolucent patient platform (102) may be used. In some variations, the patient platform (102) may include multiple bores (e.g., elongated holes) for detecting subsidence of the patient platform (102). For example, the radiolucent support element (110) may include one or more bores coupled to the second side (106) of the patient platform (102) and allowing portions of the radiation beam (126) to pass unobstructed and be received by the detector (128). The bores may extend longitudinally (e.g., along the X-axis) as elongated bores, for example, or may have a spherical shape. In another example, the support element (110) may include aluminum to enhance image contrast between the empty space in the bore and the support element (110). It should be understood that the shape of the bore is not limited, so long as the detector data of the bore can be used to determine the location of the patient platform (102). For example, the bore may comprise a rod shape or a sphere as discussed above. In some variations, the length of the bore may correspond to the length of the region of interest (116) of the patient (114). In other variations, the bore may correspond to the length of the patient platform (102) through which the first beamlet (127a) may intersect and pass.

[0065] The bores may comprise a number of shapes and sizes as discussed above. In some instances, the bores may have a diameter of approximately 0.001 to 0.01 meters. The support element (110) and patient platform (102) may be radiolucent, but a faint outline of the support element (110) and patient platform (102) may still be visible when imaging the platform (102), such that image contrast between solid portions of the support element (110) and one or more bores in the patient platform (102) may serve as a reference for location tracking. The detector data may be used to identify one or more bores in the support element (110) and / or patient platform (102) relative to known locations. The difference in these locations corresponds to the amount of subsidence of the patient platform (102). In this manner, the subsidence of the patient platform (102) may be determined without artifacts associated with high density radiopaque materials.

[0066] 1F is a cross-sectional front view of the patient platform (102) and gantry (120) with an optical sensor (150) configured to image one or more optical markers (160) coupled to the patient platform (102). The optical sensor (150) may be coupled to the gantry (120) such that the optical sensor (150) rotates with the gantry (120) about the patient (114) in the patient region (140). As the gantry (120) rotates, the optical sensor (150) may image the one or more optical markers (160) from one or more gantry angles (e.g., from the side and from below the patient (114)). The imaging data generated by the optical sensor (150) may be used to identify the optical markers (160) of the patient platform (102) weighted by the patient (114) relative to the reference locations of the optical markers (160) of the unweighted patient platform (102). The difference in these locations corresponds to the amount of subsidence of the patient platform (102). Imaging of two or more optical markers (160) may enable the controller to determine one or more of the subsidence, roll, and yaw of the patient platform (102) in a similar manner as discussed above with respect to the extension element (108).

[0067] The optical markers (160) may be imaged by the optical sensor (150) to generate optical marker (160) data that has high contrast relative to other imaged elements within the bore (140) of the gantry (120), including the patient platform (102), the patient (114), the patient support element (110), and the gantry housing. The image contrast allows the optical markers (160) to be spatially separated from other imaged elements, such as the patient platform (102) and the patient (114). The optical markers (160) may provide high contrast sensor data within one or more wavelength ranges of the light spectrum (e.g., visible, infrared, ultraviolet wavelengths). In some variations, the optical markers (160) may comprise a reflector configured to generate a high contrast image using the optical sensor (150). For example, one or more optical markers (160) may comprise a material and / or structure (e.g., a retroreflector) for reflecting light back to the optical sensor (160) with minimal scattering. The optical markers (160) may comprise, for example, a mirror (e.g., for reflecting light from an illumination source such as a laser) or a high-contrast colored surface. The optical markers (160) may have the same size, shape, number, and location of radiopaque elements (e.g., elongated elements, spheres) discussed above. For example, one or more optical markers (160) may be coupled to the patient platform (102), and each optical marker (160) may comprise a rod or sphere. The optical markers (160) may be located along a longitudinal axis parallel to the longitudinal axis of the patient platform (160).

[0068] Imaging of the optical marker (160) using the optical sensor (150) may provide subsidence determination without emission of additional beamlets (127a) from the radiation source (122) as illustrated in Figures 1B-1E. Subsidence determination using the optical sensor (150) and the optical marker (160) may be performed in parallel with a radiation therapy treatment using the radiation source (122) and the multi-leaf collimator (124). In some variations, the optical sensor (150) may include an infrared sensor and may further include an illumination source to enhance the amount of reflected light received from the optical marker (160). In some of these variations, the optical sensor (150) may include a filter to reduce infrared data from the patient (114) and / or other non-retroreflective sources (160). In other variations, the optical sensor (150) may comprise a visible light sensor (e.g., a charge-coupled device (CCD), an active pixel sensor (APS)) and may further comprise a visible light illumination source. In still other variations, the optical sensor (150) may comprise an ultraviolet sensor and may further comprise an ultraviolet illumination source. In some other variations, the optical sensor (150) may comprise a time-of-flight range finder including a laser for identifying one or more optical markers (160). In other variations, the optical sensor (150) may image the patient (114) as the gantry (120) rotates to monitor a condition of the patient (114).

[0069] In some non-limiting exemplary variations, the patient platform (102) may have a weight capacity of approximately 210 kilograms and an extension length from the end of the base (112) of approximately 2 meters. The subsidence of the patient platform (102) may be a few centimeters in some cases and will vary based on patient characteristics such as patient weight and positioning, and the patient platform material and design. (Conformable Patient Platform)

[0070] In general, the patient platform devices described herein may provide a conformable support for a patient in imaging and / or radiation therapy procedures. In particular, the shape of the patient platform may be personalized for each patient to reduce patient movement and motion artifacts during treatment and to improve patient comfort. For example, the patient may be loaded and positioned outside the gantry on the patient platform in a patient alignment process, thereby reducing the set-up time of the patient platform in the gantry. This may allow for more efficient scheduling of the radiation therapy system and allow more patients to receive treatment from the radiation therapy system.

[0071] FIG. 2A is a perspective view of a variation of a conformable radiolucent patient platform (200) comprising a conformable substrate (202) having a rigid base (216) coupled to a plurality of enclosures (204). A patient (220) is depicted on the patient platform (200). It should be understood that the patient (220) may typically have his / her arms at his / her sides during imaging and / or treatment procedures. The height of each of the plurality of enclosures (204) may be independently pressure controlled by a controller coupled to a pressure source (e.g., gas, liquid) (not shown in FIGS. 2A-2B). The base (216) and the enclosures (204) may be radiolucent so as not to interfere with the imaging and / or radiotherapy procedures. As shown in FIG. 2A, the enclosures (204) may be airtight and expandable such that the pressure and rigidity of the enclosures (204) may be adjustable to comfortably and securely restrain the patient (220). FIG. 2B is a perspective view of the conformable patient platform (200) with the patient removed to illustrate the patient contour (222).

[0072] In some variations, the enclosure (204) may comprise a polyurethane and / or other low-Z material bag or balloon that may be filled with a fluid, including gas and / or liquid. In other variations, the enclosure (204) may comprise a flexible membrane. In some variations, the enclosure (204) may have a diameter of about 0.001 to 0.050 meters and a fully pressurized height of about 0.01 to 0.30 meters. For example, the enclosure (204) may have a diameter of about 0.05 meters and a fully pressurized height of about 0.15 meters. As shown in FIGS. 2A-2B, the multiple enclosures (204) may be cylindrical and provided in an alternating array configuration. In some variations, the multiple enclosures (204) may comprise a honeycomb configuration.

[0073] For a non-weighted conformable substrate (202) (e.g., a conformable substrate (202) without a load applied to the patient (220) or the enclosure (204)), the enclosure (204) may be set to a predetermined pressure such that the enclosure (204) may have the same or different heights. For example, the height of the enclosure (204) along the edges of the platform (200) may be higher than other portions to form a curvature on the surface of the patient platform (200). This may encourage the patient (220) to position itself in the center of the patient platform (200) or place its head in a predetermined area. In other variations, the height of the enclosure (204) of the patient platform (200) may be gradually changed to compensate for expected subsidence of the weighted patient platform (200). For example, the average height of the enclosure extending from the base of the platform may increase along the longitudinal axis of the patient platform.

[0074] The number of enclosures (204) is not particularly limited, so long as the patient (220) loaded on the platform (200) can remain stable and restrained. In some variations, the size and density of the enclosures (204) may vary across different portions of the conformable substrate (202). For example, a lower density of larger diameter enclosures (204) may be provided along the outer edge of the substrate (202), while a higher density of smaller diameter enclosures (204) may be provided for the patient head and torso area. In some of these cases, a third size of enclosures (204) may be provided for the patient extremity area. In this manner, the number of enclosures may be selected to optimize patient ergonomics. In some variations, other radiolucent support elements (e.g., cushions, pads, pillows) may be coupled to the substrate (202) to aid in patient comfort and to further secure the patient (220) in place on the patient platform (200).

[0075] Additionally or alternatively, FIG. 2C illustrates a cross-sectional side view of a conformable patient platform (200) comprising a conformable substrate (202) and a thermoelectric layer (210) having a heating element. In some variations, the heating element may comprise a set of very thin wires, such as the thickness of a human hair. The conformable substrate (202) may further comprise a pressure sensor (206) coupled to the conformable substrate (202) and configured to measure a pressure of the conformable substrate (202). For example, the pressure sensor (206) may be configured to measure a pressure of the multiple enclosures (204). A pressure source (208) may be coupled to each of the multiple enclosures (204) of the conformable substrate (202) via a pressure channel (214). The pressure channel (214) may comprise a radiolucent material and may comprise, for example, a multiple tube coupled to a corresponding enclosure (204) through a base (216). In some variations, pressure source (208) may comprise one or more of a pneumatic pressure source (e.g., compressed gas). As discussed in further detail below, controller (218) may use pressure sensor (206) and pressure source (208) to independently control the height of each of the multiple enclosures (204).

[0076] The thermoelectric layer (210) may be provided between the patient (220) and the plurality of enclosures (204). In some variations, the thermoelectric layer (210) may be about 1.0-5.0 mm thick, for example, about 2.0-3.0 mm thick. One or more thermal insulation layers (212) may be provided above and / or below the thermoelectric layer (210) to insulate either the patient (220) and / or the conformable substrate (202) from heat generated by the thermoelectric layer (210). In some variations, the thermal insulation layer (212) may be about 1.0-15.0 mm thick. In some cases, the thermal insulation layer (212) may be about 5.0-10.0 mm thick. Heating the thermoelectric layer (210) may transition the thermoelectric layer (210) to a flexible configuration based on temperature. In some variations, the thermoelectric layer (210) may transition to a flexible configuration at about 80°C. In some variations, the thermoelectric layer (210) may be heated through an electric current provided by an electrical conductor (e.g., metal wire) coupled to the thermoelectric layer (210). In some cases, the thermoelectric layer (210) may reach the flexible configuration in about one minute. The flexible configuration may be flexible to conform to the patient's body shape, and the rigid configuration may fix the shape and contour of the thermoelectric layer (210). In some variations, one or more of the thermoelectric layer (210) and the thermal insulation layer (212) may comprise a cooling element to cool and rigidify the thermoelectric layer (210) after the patient (220) adjusts the patient platform (200) to a desired level of comfort. For example, the cooling element may comprise a lumen (e.g., channel) through which a fluid (e.g., air, water) may travel to cool the thermoelectric layer (210). In some variations, the thermoelectric layer (210) may not span across the entire surface area of ​​the patient platform (202) and may comprise the patient body contour.

[0077] One variation of the patient platform adjustment process using the patient platform (200) of FIG. 2C may include filling the multiple enclosures (204) to a pre-determined set of pressures based on a pre-determined patient configuration. In some variations, the set of pressures may be about 1-2 atm. The thermoelectric layer (210) may be heated to form a flexible configuration that may conform to the patient's body (e.g., a load applied to the enclosures). The patient (220) may then be laid on the patient platform (200) where the height of the enclosures (204) may equalize and the conformable substrate (202) may conform to the patient (220).

[0078] The height of each of the multiple enclosures (204) may then be adjusted for patient comfort by increasing or decreasing the pressure from the pressure source (208) using the controller (218). The heating elements may be deactivated such that the thermoelectric layer (210) cools to a rigid configuration that may comfortably and securely restrain the patient (220) in generally less than 60 seconds. In some of these variations, the cooling elements of one or more of the thermoelectric layer (210) and the insulating layer (212) may be activated to more quickly transition the thermoelectric layer from the flexible configuration to the rigid configuration.

[0079] Once the desired shape of the patient platform (200) is achieved, the controller (218) may store the patient configuration in memory as the patient configuration comprises at least one of the pressures and / or heights of each of the multiple enclosures (204). Thus, a personalized patient configuration may be provided for each patient (220) to reduce set-up time for patient alignment and increase imaging and / or treatment consistency. Furthermore, the patient configuration may be transferable between patient platforms of different radiation therapy systems to increase consistency of patient positioning in imaging and / or treatment procedures across various systems. The patient platform (200) discussed herein may be particularly useful for improving ergonomics and compliance for radiation therapy procedures that require more time and / or higher dose accuracy.

[0080] In some non-limiting exemplary variations, the enclosures (204) may comprise one or more shapes, including a cylinder, a cube, a triangular prism, a hexagonal prism, a polygonal prism, and the like. In some variations, different fluids (e.g., gases, liquids) and combinations of fluids may be used to fill different sets of the enclosures (204).

[0081] Although FIG. 2C illustrates a thermoelectric layer (210) and an enclosure (204), the conformable substrate (202) may include a thermoelectric layer (210) without an enclosure (204), or an enclosure (204) without a thermoelectric layer (210). (Extendable patient platform)

[0082] In general, the patient platform devices described herein may be configured to coordinate patient platform movement with imaging and / or therapy beam emission. For example, the movement and positioning of the rigid lower portion of the patient platform may be controlled to avoid intersection with the imaging and / or therapy beam. Meanwhile, the radiolucent upper portion of the patient platform may be controlled to intersect the imaging and / or therapy beam. This spatial and temporal control of the patient platform and beam may allow for movement of the rigid portion into the patient region of the gantry without adversely affecting or otherwise interfering with the imaging and / or therapy beam. Thus, the length of the radiolucent portion may be shortened such that patient platform subsidence may be reduced. As discussed in more detail below, the rigid lower portion and the radiolucent upper portion of the patient platform may move relative to each other (FIGS. 3A-3B) or maintain their position relative to each other (FIGS. 3C-3D).

[0083] In one variation, Figures 3A-3B illustrate a patient platform (301) having a rigid portion and a radiolucent portion that may move relative to one another. Figures 3A-3B are cross-sectional side views of a telescoping patient platform system (300). The system (300) may include a patient platform (301) having an upper portion (302) coupled to a lower portion (304). The upper portion (302) may be configured to move axially along an X-axis relative to the lower portion (304). In some variations, the upper portion (302) may be radiolucent and the lower portion (304) may be radiopaque. A base (306) may be coupled to the lower portion (304) of the patient platform (301). The lower portion (304) may be configured to move relative to the base (306). Thus, the patient platform (301) may telescope axially as it is extended in and out of the patient area of ​​the gantry (310). In some variations, the upper portion (302) may include a set of rails coupled to a drive mechanism (e.g., a single motor) configured to move the upper portion (302) relative to the lower portion (304). Similarly, the lower portion (304) may include a set of rails coupled to a drive mechanism configured to move the lower portion (304) relative to the base (306).

[0084] In some variations, the upper portion (302) and the lower portion (304) may have different radiolucencies. For example, the upper portion (302) may be radiolucent and less stiff, relative to the lower portion (304), which may be radiopaque and have more stiffness.

[0085] The system (300) may further include a gantry (310) having an imaging radiation source (320) and a therapeutic radiation source (330). For example, the imaging radiation source (320) may be a kV radiation source and the therapeutic radiation source (330) may be an MV radiation source. The therapeutic radiation source (330) may be coupled to a multi-leaf collimator (332) and may be located opposite the detector (336). The therapeutic radiation source (330) may be configured to emit a treatment beam (334) in a treatment beam plane perpendicular to a longitudinal axis of the patient platform (301). The imaging radiation source (320) may be configured to emit an imaging beam (322) in a treatment beam plane perpendicular to a longitudinal axis of the patient platform (301), and transmission of the imaging beam (322) through the patient may be detected by the imaging detector (337). 3A depicts both the imaging beam (322) and the treatment beam (334) being emitted simultaneously, thereby treating one area of ​​the patient while imaging another area of ​​the patient, it should be understood that each of these beams may be activated sequentially or separately, i.e., imaging of the patient using the imaging beam (322) need not occur while the patient is being treated with the treatment beam (334) (e.g., the imaging beam (332) and the treatment beam (334) are not activated simultaneously).

[0086] For an imaging procedure, the system (300) may be in an imaging configuration, an example of which is depicted in FIG. 3A. As shown there, the controller (340) may be configured to move the rigid lower portion (304) (which may be radiopaque) as close to the imaging beam (322) as possible without intersecting the imaging beam (322). The leading edge of the lower portion (304) may be separated from the plane of the imaging beam (322) by a first distance. In some variations, the first distance may be about 2 centimeters. In this way, the more rigid portion of the patient platform (301) may be moved as close to the imaging beam (322) as possible without interfering with the imaging beam (322). The upper portion (302) may be free to move (telescopic) axially relative to the lower portion (304) to intersect the imaging beam (322) and image a desired area of ​​the patient (not shown).

[0087] 3A, the controller (340) of the system (300) may be configured to move the upper portion (302) and the lower portion (304) such that the lower portion (304) does not intersect the imaging plane of the imaging beam (322) and the upper portion (302) intersects the imaging plane of the imaging beam (322). In this manner, only the radiolucent upper portion (302) intersects the imaging beam (322).

[0088] For a radiation therapy procedure, the system (300) may be placed in a treatment configuration, an example of which is depicted in FIG. 3B. As shown there, the controller (340) may be configured to move the rigid lower portion (304) (which may be radiopaque) as close to the treatment beam (334) as possible without intersecting the treatment beam (334). In this way, the more rigid portion of the patient platform (301) may be moved as close to the treatment beam (334) as possible without interfering with the treatment beam (334). In some variations, the lower portion (304) may be positioned (e.g., by a drive mechanism) such that a leading edge of the lower portion (304) may be located at a predetermined second distance away from the treatment plane (FIG. 3B). For example, the second distance may be about 2 centimeters. The upper portion (302) may be free to move (telescopic) axially relative to the lower portion (304) to intersect the treatment beam (334) and treat the patient (not shown). In the treatment configuration depicted in FIG. 3B, the imaging radiation source (320) does not need to be activated because the rigid lower portion (304) (which may be radiopaque) is located in the beam path of the imaging radiation source (320).

[0089] 3B, the controller (340) of the system (300) may be configured to move (e.g., by a drive mechanism) the upper portion (302) and the lower portion (304) such that the lower portion (304) does not intersect the treatment plane of the treatment beam (334) and the upper portion (302) intersects the treatment plane of the treatment beam (334). In this manner, only the radiolucent upper portion (302) intersects the treatment beam (334).

[0090] 3C-3D illustrate cross-sectional side views of another variation of a patient platform system (350) comprising a patient platform (351) having a rigid portion and a radiolucent portion that maintain their position relative to one another. The system (350) may comprise a patient platform (351) having an upper portion (352) that is fixed relative to a lower portion (354). For example, the length of the cantilevered portion of the upper portion (352) is constant in FIGS. 3C-3D. In some variations, the upper portion (352) may be radiolucent and the lower portion (354) may be radiopaque. A base (356) of the patient platform (351) may be coupled to the lower portion (354) and configured to control the height and / or pitch of the patient platform (351). The lower portion (354) may be movable relative to the base (356) such that the patient platform (351) may move relative to the base (356). Thus, the patient platform (351) may telescope axially relative to the base (356) as it is extended into and out of the gantry (310). The lower portion (354) may be cantilevered from the base (356) (e.g., FIG. 3D) and may be made from any material that is sufficiently rigid such that the lower portion (354) does not sink relative to the base (356), regardless of the length of the lower portion (354). Additionally or alternatively, the lower portion (354) may be made from any material that is stiffer than the material of the upper portion (352).

[0091] It should be appreciated that because the upper portion (352) may be fixed relative to the lower portion (354), a patient (not shown) lying on the patient platform (351) may cause a certain subsidence of the patient platform (351) (assuming the patient does not move). As a result, the subsidence of the patient platform (351) may comprise a set of known values ​​across the length of the patient platform (351). The subsidence of the patient platform in a particular area of ​​interest of the patient may be determined prior to and / or at the start of a treatment session and remain the same throughout the session, regardless of how the platform (352) moves relative to the base (356). Additionally, by fixing the upper portion (352) to the lower portion (354), the patient platform (351) illustrated in FIGS. 3C-3D may be simpler to manufacture than the patient platform (301) illustrated in FIGS. 3A-3B.

[0092] For an imaging procedure, the system (350) may be in an imaging configuration, an example of which is depicted in FIG. 3C. As shown there, the controller (340) may be configured to move the lower portion (354) (which may be radiopaque) as close to the imaging beam (322) as possible without intersecting the imaging beam (322). In this manner, the radiopaque portion of the patient platform (351) may be moved as close to the path of the imaging beam (322) as possible without interfering with the imaging beam (322). In some variations, the lower portion (354) may be positioned such that a leading edge of the lower portion (354) may be located at a predetermined first distance away from the imaging plane (FIG. 3C). For example, the first distance may be about 2 centimeters. The upper portion (352) may intersect the imaging beam (322) and image a desired area of ​​the patient (not shown).

[0093] 3C, the controller (340) of the system (350) may be configured to move the upper portion (352) and the lower portion (354) such that the lower portion (354) does not intersect the imaging plane of the imaging beam (322) and the upper portion (352) intersects the imaging plane of the imaging beam (322). In this manner, only the radiolucent upper portion (352) intersects the imaging beam (322).

[0094] For a radiation therapy procedure, the system (350) may be arranged in a treatment configuration, an example of which is depicted in FIG. 3D. As shown there, the controller (340) may be configured to move the rigid lower portion (304) (which may be radiopaque) as close to the treatment beam (334) as possible without interfering with the treatment beam (334). In this manner, the lower portion (354) of the patient platform (351) may be moved as close to the treatment beam (334) as possible without receiving a radiation dose. In some variations, the lower portion (354) may be positioned such that a leading edge of the lower portion (354) may be located at a predetermined second distance away from the treatment plane (FIG. 3D). For example, the second distance may be about 2 centimeters. The upper portion (352) may intersect the treatment beam (334) and treat the patient (not shown). In the treatment configuration depicted in FIG. 3D, the imaging radiation source (320) does not need to be activated because the rigid lower portion (354) (which may be radiopaque) is located in the beam path of the imaging radiation source (320).

[0095] As shown in Figure 3D, the controller (340) of the system (350) may be configured to move the patient platform (351) such that the lower portion (354) does not intersect the treatment plane of the treatment beam (334) and the upper portion (352) intersects the treatment plane of the treatment beam (334). In this manner, only the radiolucent upper portion (352) intersects the treatment beam (334).

[0096] In some non-limiting exemplary variations, the upper portion (302, 352) may comprise radiolucent carbon fiber and the lower portion (304, 354) may comprise radiopaque aluminum or other rigid low-Z material. In these variations, the aluminum portion of the patient platform (301, 351) may be configured to sink less than the carbon fiber portion (302, 352). In some variations, the lower portion (304, 354) may be thicker than the upper portion (302, 352). In some variations, the lower portion (304, 354) may have a height of about 0.02 to 0.50 meters and the upper portion (302, 352) may have a height less than the lower portion (302, 354). In some variations, the described patient platform (300, 350) may include a vertical drive system (e.g., scissor element), as described in detail with respect to Figures 4A-4E. (Adjustable Patient Platform)

[0097] Generally, the patient platform devices described herein may provide multiple degrees of freedom to move a patient on the patient platform to a desired position and orientation relative to the radiation therapy treatment beam. As shown in Figures 4A-4C and 4F, the patient platform (401) may provide at least one of axial, lateral, and vertical translation, and pitch and / or yaw rotation.

[0098] 4A-4B and 4D are side views and FIGS. 4C, 4E, and 4F are perspective views of a system (400) including a radiolucent patient platform (401) coupled to a base (420). The base (420) may be provided outside of the patient area of ​​the gantry (not shown for clarity) and may not be radiolucent. The patient platform (401) may include an upper portion (402) and a lower portion (404). The upper portion (402) is not drawn to scale for illustrative purposes (e.g., the upper portion (402) is relatively short in FIG. 4A). A pivot (412) may couple the upper portion (402) of the patient platform (401) to the lower portion (404) of the patient platform (401). In some variations, the pivot (412) may include a set (e.g., two) of curved rails. It should be appreciated that the pivot portion (412) may enable the upper portion (402) of the patient platform (401) to rotate about the Z-axis (414) without interfering with either the imaging or treatment beams.

[0099] In some variations, one or more of the axial drive system (440), the lateral drive system (450), the vertical drive system (460), the pitch drive system (470), and the yaw drive system (410) may be coupled to the patient platform (401). For example, the axial drive system (440) may be coupled between the lower section (404) and the lateral drive system (450), the lateral drive system (450) may be coupled between the axial drive system (440) and the yaw drive system (410), the yaw drive system (410) may be coupled between the lateral drive system (450) and the pitch drive system (470), and the pitch drive system (470) may be coupled between the yaw drive system (410) and the upper section (402). This configuration allows the axial drive system (440), lateral drive system (450), pitch drive system (470), and yaw drive system (410) to move axially relative to the vertical drive system (460) such that the movement of the vertical drive system (460) may be independent of the other drive systems.

[0100] In some variations, the system (400) may include a controller (not shown) comprising a processor and memory configured to control one or more of the lateral drive system (450), the vertical drive system (460), the pitch drive system (470), and the yaw drive (410). In some variations, the axial drive system (440), the lateral drive system (450), and the pitch drive system (470) may each include a pair of linear rails driven by a single motor (e.g., a lead screw drive, a linear motor). The axial drive system (440) may include an axial drive element (442) coupled to the lower portion (404) of the patient platform (401). A pair of axial rails (444) may be coupled to the axial drive element (442). The axial drive system (440) may be configured to move the upper portion (402) axially (along the X-axis) relative to the lower portion (404) by moving the upper portion (402) along the axial rail (444). In some variations, the axial drive element (442) may comprise a rotary motor coupled to a lead screw and / or drive belt, which in turn is coupled to the axial rail (444). For example, the axial drive element (442) may generate a motor continuous peak torque of up to about 0.5 Nm. In other variations, the axial drive element (442) may comprise a linear motor coupled to the axial rail (444). In some variations, the axial rails (444) may be spaced apart from one another between about 35 cm and 55 cm. The cross-sectional width of each rail (444) may be between about 15 mm and about 30 mm. In some variations, the axial drive system (440) may be configured to translate the upper portion (402) axially relative to the lower portion (404) within a range of up to about 200 cm.

[0101] The lateral drive system (450) may include a lateral drive element (452) coupled to the patient platform (401). A pair of lateral rails (454) may be coupled to the lateral drive element (452). The lateral drive system (450) may be configured to move the upper portion (402) laterally (along the Y-axis) relative to the lower portion (404) by moving the patient platform (401) along the lateral rails (454). For example, FIGS. 13A-13C illustrate a patient platform (1310) moving laterally (along the Y-axis) within a gantry (1330). The lateral rails (454) may be disposed perpendicular to the axial rails (444). The lateral drive element (452) may generate a motor continuous peak torque of up to about 0.5 Nm. In some variations, the lateral rails (454) may be spaced apart from one another between about 45 cm and about 75 cm. The cross-sectional width of each rail (454) may be from about 15 mm to about 30 mm. In some variations, the lateral drive system (450) may have a lateral range of motion of up to about 200 cm.

[0102] A pitch drive system (470) coupled to the patient platform (401) may be configured to raise and / or lower an end of the upper portion (402) to tilt the upper portion (402) about a pitch pivot (478). The pitch drive element (472) may be coupled to one or more wedges (474) to vertically translate an end of the upper portion (402). In some variations, the pitch drive system (470) may comprise a pitch drive element (472) coupled to the patient platform (401). In some variations, the pitch drive system (470) may comprise a pair of wedges (474) coupled to the pitch drive element (472) via a pitch linear screw (476). The pitch drive system (470) may be configured to tilt the patient platform (401) about the pitch pivot (478) (about the Y-axis). For example, the pitch drive element (472) and screw (476) may drive one of the two wedges (474) laterally (along the Y-axis) such that the second of the two wedges (474) is pushed upward (along the Z-axis). Pushing the second wedge upward may tilt the upper portion (402) of the patient platform (401) such that a first end of the upper portion (402) of the patient platform (401) (to which the wedge (474) is coupled) is higher than a second end of the upper portion (402) of the patient platform (474). Rotation about the pitch pivot (478) allows for the tilting or tilting of the upper portion (402) of the patient platform (474) relative to a horizontal plane (e.g., the XY plane and the lower portion (404) plane).

[0103] FIG. 4F is a perspective view of a variation of the pitch drive system (470) as depicted in FIG. 4C. In particular, the pitch drive element (472) may comprise a motor (471) with a toothed belt coupled to a pitch linear screw (476). For example, the motor (472) may be coupled to a first linear screw (476a) and a second linear screw (476b). The first and second linear screws (476a, 476b) may be coupled to separate portions of the first wedge (474a) (e.g., the lower wedge). Each portion of the first wedge (474a) may be coupled to a pair of laterally oriented linear rails. The first wedge (474a) may move symmetrically laterally via the screw (476) such that the two portions of the first wedge (474a) move toward or away from each other simultaneously.

[0104] The wedge (474) may further comprise a second wedge (474b) (e.g., an upper wedge) slidably coupled to the first wedge (474a) via a set of linear rails. For example, the first wedge (474a) may comprise a first angled surface (477) disposed facing a second angled surface (479) of a corresponding second wedge (474b). The second angled surface (479) may comprise a set of linear rails on which the first wedge (474a) slides. Lateral movement of the first wedge (474a) may thus be translated into vertical movement of the second wedge (474b) and the upper portion (402) such that the upper portion (402) may tilt. In some variations, the pitch drive system (470) may tilt the proximal end of the upper portion (402) up by up to about 5 degrees and tilt the upper portion (402) down by up to about 3 degrees. In some variations, the change in pitch of the upper portion (402) may be used to counteract subsidence of the cantilevered end of the upper portion (402).

[0105] In some variations, each portion of the first wedge (474a) may have a width of about 200 mm to about 250 mm, a length of about 60 mm to about 120 mm, and a height of about 25 mm to about 75 mm. For example, each portion of the first wedge (474a) may have a width of about 220 mm, a length of about 90 mm, and a height of about 50 mm. In some variations, the first angled surface (477) may have an angle of about 30 degrees to about 50 degrees with respect to the horizontal plane (i.e., the XY plane). For example, the first angled surface (477) may have an angle of about 38 degrees.

[0106] In some variations, each portion of the second wedge (474b) may have a width of about 40 cm to about 60 cm, a length of about 50 mm to about 150 mm, and a height of about 10 cm to about 30 cm. For example, each portion of the second wedge (474b) may have a width of about 50 cm, a length of about 10 cm, and a height of about 20 cm. In some variations, the second angled surface (479) may have an angle of about 130 degrees to about 150 degrees with respect to the horizontal plane (i.e., the XY plane). For example, the second angled surface (479) may have an angle of about 142 degrees.

[0107] As shown in FIGS. 4A-4C, the vertical drive system (460) may, in some variations, comprise a pair of scissor elements (462) and corresponding cylinders (468) (e.g., hydraulic, pneumatic) coupled to the patient platform (401). The vertical drive system (460) may be configured to move the patient platform (401) vertically (along the Z-axis) relative to the base (420). The vertical movement of the patient platform (401) may be independent of other translational and / or rotational movements provided by the axial drive system (440), lateral drive system (450), pitch drive system (470), and yaw drive system (410). The vertical drive element (464) may be coupled to the scissor elements (462) through one or more linear screws (466) and configured to raise and / or lower the patient platform (401). The one or more cylinders (468) may be configured to generate an upward force to assist the vertical drive element (464) in moving the patient platform (401). In some of these variations, one or more of the cylinders (468) may be pivotally coupled to the base (420) and lower portion (404) of the patient platform (401). The scissor element (462) may include a first arm (463) and a second arm (465) coupled to each other about a pivot point (467). The pivot point (467) may couple an intermediate portion of the first arm (463) to an end portion of the second arm (465). The other end of the second arm (465) may be pivotally coupled to the base (420). The end of the first arm (463) may be pivotally coupled to the lower portion (404). The other end of the first arm (463) may be pivotally coupled to a track on the base (420) such that the first arm (463) may slide axially (along the X-axis) along the track. A track (469) may be provided for each first arm (463). As shown in Figures 4C and 4E, some variations of the vertical drive system (460) may include four pairs of first and second arms (463, 465), with two pairs disposed at each end of the base (420) and lower portion (404).The scissor element (462) shown in Figures 4A-4C may comprise a mirror configuration. In some variations, the vertical drive system (460) may be located in a fixed position outside the gantry, while the other drive system may translate axially relative to the gantry.

[0108] 4A and 4C illustrate a vertical drive element (464) comprising two linear screws (466) configured to drive a pair of scissor elements (462) disposed at each end of the patient platform (400). When the vertical drive element (464) drives one or more of the linear screws (466) axially (along the X-axis) away from the vertical drive element (464), the lower portions of the first arms (463) may be brought closer to their respective second arms (465) such that the height of the scissor elements (462) and lower portion (404) is increased. Conversely, the vertical drive element (464) may decrease the height of the lower portion (404). The patient platform (400) may be tilted (e.g., tilted) when the linear screws (466) are driven unevenly. In some variations, the first arm (463) may have a length of about 60 cm to about 100 cm and the second arm (465) may have a length of about 30 cm to about 60 cm. In some variations, the track (469) may have a length of about 50 cm to about 90 cm. In some variations, the vertical drive system (460) may have a vertical range of motion of up to about 60 cm.

[0109] In some variations, as shown in Figures 4D and 4E, the vertical drive system (460) may comprise a pair of scissor elements (462) in a parallel configuration. That is, in the parallel configuration, each of the first arms (463) faces in the same direction and is parallel to one another. Similarly, each of the second arms (465) faces in the same direction and is parallel to one another. This configuration of scissor elements may reduce the size and / or simplify the vertical drive element (464). The vertical drive element (464) may be directly coupled to the pair of scissor elements (460) via a linear screw (466) at one end of the patient platform. The pairs of scissor elements (462) at each end of the patient platform (400) may be coupled via a linkage (461). For example, the linkage (461) may interconnect the first arms (463) at each end of the patient platform (400). This allows the vertical drive element (464) to drive each of the scissor elements (462) simultaneously (e.g., together) using one linear screw (466) rather than providing a linear screw for the scissor elements at each end of the patient platform (400). Driving (e.g., rotating) the linear screw (466) axially (along the X-axis) away from the vertical drive element (464) may move the lower portions of the first arm (463) farther away from their respective second arm (465) such that the height of the scissor elements (462) and lower portion (404) is reduced. In some variations, the vertical drive element (464) may comprise a pneumatic, electromechanical, or hydraulic element. In some variations, the cylinder (468) may further comprise one or more cylinders as described with respect to FIGS. 4A-4C.

[0110] The yaw drive system (410) may be coupled to the upper portion (402) of the patient platform (401). The yaw drive system (410) may include a yaw drive element and be configured to orient (rotate) the upper portion (402) of the patient platform (401) relative to the lower portion (404) of the patient platform (401) about the pivot axis (414) of the pivot (412) by moving the patient platform (401) along the curved rail (412). In some variations, the curved rail provides a rigid base and may include a length of about 1.0 cm to about 10.0 cm. In some variations, the curved rail (412) may include a radius of about 25 cm to about 35 cm and may be spaced between about 50 cm to about 70 cm. In some variations, the yaw drive system (410) may provide a range of motion of up to about 25 degrees.

[0111] The lower portion (404) of the patient platform (401) depicted in FIG. 4A does not rotate. In some variations, the patient platform (401) may include a handle (480) for an operator to manually adjust the position of the patient platform (e.g., adjust the axial and / or lateral position). Note that the system (400) described above may be used in conjunction with any of the methods corresponding to FIGS. 12 and 13A-13E described and illustrated below. In some variations, the system (400) as described herein may be used to move the patient platform as described in detail herein, such as with respect to the methods described in FIGS. 13A-13E.

[0112] In some variations, one or more portions of the patient platform (401) may include carbon fiber due to its radiolucency and ability to provide rigid support to the patient. In some variations, the patient platform (401) may have a length of about 1.5 m to about 3.0 m, a width of about 0.50 m to about 2.0 m, and a thickness of about 0.05 m to about 0.50 m, preferably a length of about 2 m, a width of about 0.50 m, and a thickness of about 0.10 m. In some variations, the patient platform (401) may have a weight capacity of about 210 kilograms and an extension length from the end of the base (112) of about 2 meters. In some variations, the patient platform (401) may include one or more of the extension elements and / or bores as described in detail herein with respect to Figures 1A-1F. In some variations, the patient platform (401) may include a conformable substrate as described in detail herein with respect to Figures 2A-2C. (phantom)

[0113] Generally, disclosed herein is a patient platform comprising a phantom for use in calibrating one or more components of a radiation therapy system. For example, the radiation therapy system may comprise a rotatable gantry, one or more radiation detectors mounted on the gantry, a radiation source (e.g., a linac) mounted on the gantry, and a beam-shaping assembly disposed in a radiation beam path of the radiation source. The beam-shaping assembly may comprise one or more sets of jaws and / or collimators. Additionally or alternatively, some radiation therapy systems may comprise an imaging system, such as a CT system, which may be used to acquire CT images. The radiation detector may receive a beam emitted from the radiation source through the phantom. The phantom may comprise multiple types of radiation detectors and may be used to characterize, verify, and / or calibrate expected or desired functionality of the radiation source, multi-leaf collimator, radiation detector, and to verify the performance of dose delivery and dose calculation algorithms. Data generated by one or more of these dosimeters may be used for quality assurance procedures. For example, a daily quality assurance procedure may rapidly generate dose data using two beams delivered through two water-filled stages at different depths for calibration of the radiation detectors. Another quality assurance procedure (e.g., weekly, monthly, quarterly) may use multiple beams delivered through multiple radiation detectors (e.g., water-filled stages, ionization chambers, radiographic film). Generating a larger set of dose data from multiple radiation detector types may increase the accuracy of the dose data and subsequent validation and / or calibration by allowing cross-calibration of dose data generated by different types of radiation detectors (e.g., ionization chambers, radiographic sheets, etc.). In some variations, the phantom may be mounted to the underside of the patient platform at a pre-determined location that allows for convenient storage outside of the patient treatment area of ​​the patient platform. In particular, the location of the phantom below and away from the patient treatment area allows the patient to be placed on the patient support surface of the patient platform and receive a radiation therapy treatment without interference from the phantom.In other words, a portion of the space beneath the patient platform can be efficiently used to mount the phantom without modifying the radiation therapy procedure that uses the patient platform.

[0114] 16A-16B depict cross-sectional side views of several variations of a phantom (1602). For example, FIG. 16A depicts a radiation therapy system (1600) comprising a patient platform (1620) and a phantom (1602) coupled (e.g., mounted) to an underside of the patient platform. The patient platform (1620) may have a patient support surface (e.g., the side facing the radiation source (1630) in FIG. 16A) configured to hold a patient thereon, with an underside (e.g., the side facing the radiation detector (1640) in FIG. 16A) disposed opposite the patient support surface. The patient platform (1620) is not drawn to scale for illustrative purposes (e.g., the patient area (1650) is relatively short in FIG. 16A). The radiation source (1630) and radiation detector (1640) may be disposed on a gantry (not shown for clarity) and positioned relative to the patient platform (1620) to generate a beam path that intersects the patient platform (1620) and the phantom (1602). The phantom (1602) may be disposed within a phantom region (1660) of the patient platform (1620) outside of the patient region (1650). That is, the patient region (1650) and not the phantom region (1660) may be positioned such that the beam plane of the radiation source (1630) intersects the phantom region (1660) during a treatment session. The patient platform (1620) may be advanced such that the beam plane intersects the phantom region (1660) only during quality assurance procedures. The phantom (1602) may include a housing having an interior volume configured for a liquid, such as water. For example, the housing may define an interior fluid-tight volume. The housing may comprise a material, such as an acrylic (eg, polymethylmethacrylate (PMMA)), that may be formulation-compatible with water.

[0115] As shown in FIG. 16A, the housing of the phantom (1602) may include multiple stages (1604) arranged along a longitudinal axis (e.g., X-axis) of the phantom (1602). Each stage may have a corresponding pre-determined depth. The system (1600) may be configured to deliver a pre-determined radiation dose to one or more of the stages such that the delivered dose measurements may be compared to reference dose data (e.g., expected dose measurements) for each stage. The difference between the measured dose and the expected dose may be used to calibrate one or more components of the system (1600). The phantom (1602) may include two or more stages such that the detector (1630) may generate dose data corresponding to at least two stage depths of the phantom as the individual beams (1632) pass through each stage. The dose data at different stage depths may be used for absolute and / or relative dosimetry calculations. In some variations, dose data generated by the detector (1640) using the stage (1604) may be calibrated against one or more of dose data generated using the ionization chamber (1606), dose data generated using radiographic film, and / or dose data generated by other dosimeters.

[0116] In some variations, the dose data may be used to calculate a tissue-phantom ratio (TPR) where a first point dose of radiation is measured at a first depth (e.g., a reference depth of about 5 cm) and at least a second point dose is measured at a second depth (e.g., about 10 cm). The TPR may be used to characterize the beam quality of the radiation source, and point dose measurements at multiple depths may be used to improve the accuracy of the TPR value.

[0117] In some variations, the phantom (1602) may include 2, 3, 4, 5, 6, 7 or more stages. For example, the phantom (1602) may include 5 or 6 stages of the same material (e.g., water). In some variations, the stages may have different materials. For example, each stage may have different density and / or attenuation characteristics. Each stage may have a depth (i.e., along the Z axis) of about 1 cm to about 4 cm or more when filled with water. The phantom (1602) may have a width (i.e., along the Y axis) of at least about 2 cm. Each stage (1604) may have a length of about 2 cm to about 5 cm. For example, a phantom (1602) with six stages may have a depth of about 25 cm to about 40 cm. Each stage (1604) of the phantom (1602) may include a plateau parallel to the longitudinal axis (i.e., the X axis) of the phantom (1602). In other variations, the steps (1604) of the phantom (1602) may be spaced along the horizontal axis (i.e., y-axis) of the patient platform (1620). The steps (1604) depicted in Figure 16A correspond to a monotonic function and resemble a set of stairs, although the steps (and their corresponding depths) may be ordered and spaced along the vertical axis of the phantom in any desired configuration.

[0118] The phantom (1602) may further comprise a number of radiation detectors (e.g., ionization chambers and dosimeter slots). In some variations, the radiation detectors (1606, 1608) may each be positioned at a predetermined depth of its corresponding stage (1604). In some variations, the phantom (1602) may comprise one or more radiation detectors, including a gas-filled radiation detector, such as the ionization chamber (1606). The ionization chamber (1606) may comprise an air chamber having an anode-cathode electrode pair. The electrode pair may be coupled to an electrometer and a power supply (not shown in FIG. 16A). A voltage potential applied between the electrode pair may generate an electric field within the chamber (1606). When the gas within the chamber is ionized by the radiation beam (1632) emitted by the radiation source (1630), the resulting ionization current generated within the ionization chamber (1606) may be measured by the electrometer. The ionization current is proportional to the amount of radiation received by the ionization chamber and may be used for absolute and / or relative dosimetry. Thus, the absolute dose of the beam (1632) may be calculated and used to calibrate the system (1600) (e.g., the radiation source (1630)).

[0119] As shown in FIG. 16A, each of the ionization chambers (1606) and dosimeter slots (1608) may be substantially in the plane of its corresponding step (1604). That is, each of the ionization chambers (1606) may be disposed at a predetermined depth of its corresponding step (1604) along the longitudinal axis of the phantom (1602). This allows dose data generated using the ionization chambers (1606) to be calibrated against one or more of dose data generated using the steps and radiation detectors (1640), dose data generated using radiographic film, and / or dose data generated using other dosimeters. For example, dose data generated from an electrometer coupled to the ionization chambers (1606) may be used to calculate absolute dose at a predetermined depth of the phantom (1602). In some variations, the ionization chamber (1606) may comprise a parallel plate chamber, a cylindrical chamber, a well-type chamber, a free-air chamber, a vented chamber, a sealed chamber, combinations thereof, and / or the like.

[0120] As shown in FIG. 16B, the ionization chambers (1606) may be arranged along the longitudinal axis (i.e., X-axis) and along the vertical axis (i.e., Z-axis) of the phantom (1602) in some variations. In this way, a beam (1632) emitted parallel to the Z-axis may intersect a single ionization chamber without interference from another ionization chamber, thus reducing crosstalk and / or cavity effects due to attenuation variations from gases in another ionization chamber. In some variations, multiple ionization chambers (1606) may be within 5 mm of each other along the longitudinal axis (i.e., X-axis).

[0121] As shown in FIG. 16A, each dosimeter slot (1608) may be disposed at a predetermined depth of its corresponding step (e.g., substantially in the plane of its corresponding step (1604)). The dosimeter slots (1608) may be approximately parallel to the longitudinal axis (i.e., X-axis) and aligned along a vertical axis (i.e., Z-axis). In some variations, one or more dosimeter slots may be used to measure beam scatter of the radiation source (1630). For example, the vertical dosimeter slot (1609) may be positioned parallel or approximately parallel to the vertical axis. For example, the vertical dosimeter slot (1609) may be angled at about 2 degrees to about 10 degrees with respect to the vertical axis (i.e., Z-axis). The slots (1608, 1609) may comprise one or more shapes, including rectangular, square, trapezoidal, oval or elliptical, arc-shaped (e.g., semicircular, semispherical, semicylinder), combinations thereof, and the like. The slots (1608, 1609) may define an opening having a sufficient height to hold a radiography sheet at a predetermined depth of the phantom (1602). In some variations, one or more radiography sheets (e.g., radiography films) may be placed between one or more of the dosimeter slots (1608, 1609). The radiography sheet may be used to obtain radiation dosimetry. Data from the radiography sheet may have high spatial resolution and may be digitized for analysis. For example, the radiography sheet may be used to calculate the dose applied to the phantom (1602) and / or used to generate a dose map. The dose map may be compared to a predicted dose to identify any dose deviations. In some variations, a calibration curve may be generated using dose data from the radiography sheet such that operation of one or more of the linac, gantry, and multi-leaf collimator may be justified and / or characterized based on radiation dose data and / or dose maps acquired using the radiography sheet and / or radiation detector.

[0122] FIG. 17 depicts a cross-sectional side view of another variation of a patient platform (1720) comprising a phantom (1702) for a radiation therapy system (1700). For example, FIG. 17 depicts a radiation therapy system (1700) comprising a phantom (1702) coupled (e.g., mounted) to an underside of the patient platform (1720). The patient platform (1720) may have a patient support surface configured to hold a patient thereon (e.g., a surface of the platform facing the radiation detector (1740) in FIG. 17) with an underside (e.g., a surface of the platform facing the radiation source (1730) in FIG. 17) disposed opposite the patient support surface. The patient platform (1720) may define a longitudinal axis parallel to the X-axis. The patient platform (1720) is not drawn to scale for illustrative purposes (e.g., the patient area (1750) is relatively short in FIG. 17). The radiation source (1730) and radiation detector (1740) may be positioned on a gantry (not shown for clarity) relative to the patient platform (1720) to generate a beam that intersects the patient platform (1720) and the phantom (1702). The phantom (1702) may be positioned within a phantom region (1760) of the patient platform (1720) outside of the patient region (1750). That is, the patient region (1750) and not the phantom region (1760) may be positioned such that it intersects the beam plane of the radiation source (1730) during a treatment session. The patient region has a longitudinal length that exceeds the longitudinal length of the phantom region (FIG. 17 is not drawn to scale and the phantom region is enlarged). The patient platform (1720) may be advanced such that the beam plane intersects the phantom region (1760) only during quality assurance procedures. In some variations, the patient platform may have a patient region that is distal to the phantom region, and the patient region and phantom region do not overlap.

[0123] The phantom (1702) may comprise a housing having a plurality of regions arranged along a longitudinal axis. For example, the phantom (1702) may comprise a housing having two or more regions with different attenuation characteristics that are used to generate dose data corresponding to at least two or more pre-determined depths of the water-filled phantom when an individual beam (1732) passes through each region. The dose data of the regions may be used for absolute and / or relative dosimetry calculations. In some variations, the dose data generated by the detector (1740) may be calibrated against one or more of dose data generated using the ionization chamber (1712), dose data generated using radiographic film, and / or dose data generated using other dosimeters. In some variations, the density regions (1704, 1706, 1708, 1710) may be spaced apart along either the longitudinal axis (i.e., along the X-axis) or the transverse axis (i.e., along the Y-axis) of the patient platform (1720).

[0124] As shown in FIG. 17, the phantom (1702) may include a first region (1704), a second region (1706), a third region (1708), and a fourth region (1710) having distinct densities (A, B, C, D). In some variations, the phantom (1702) may include 2, 3, 4, 5, 6, 7, or more density regions. For example, the phantom (1702) may include four or five regions, each having the same thickness, but including different density materials. In one variation of the phantom including four regions of the same thickness, the first region (1704) has a density of about 1.5 g / cm 2 and the second region (1706) may have a mass per area of ​​about 5 g / cm 2 and the third region (1708) may have a mass per area of ​​about 10 g / cm 2 and the fourth region (1710) may have a mass per area of ​​about 20 g / cm 2 In another variation of the phantom with three regions of equal thickness, the first region (1704) may have a mass per area of ​​about 1.5 g / cm 2and the second region (1706) may have a mass per area of ​​about 10 g / cm 2 and the third region (1708) may have a mass per area of ​​about 20 g / cm 2 Alternatively, each region may have a different density and thickness than other regions of the phantom (1702).

[0125] Each density region may have a thickness (i.e., along the Z axis) of at least about 5 mm or more. The phantom (1702) may have a width (i.e., along the Y axis) of at least about 2 cm. Each region of the phantom (1702) may have a length of about 2 cm to about 5 cm. The variable density regions of the phantom (1702) may include materials such as lead, copper, steel, acrylic, tungsten, uranium, combinations thereof, and the like. In one variation, the first region (1704) may include acrylic, the second region (1706) may include aluminum, the third region (1708) may include copper or steel, and the fourth region (1710) may include lead. In some variations, the region with the highest density material may be located a greater distance away from other regions so that scattered radiation from the highest density region does not interfere with the dose data of the other regions.

[0126] In some variations, the phantom (1702) may further comprise a plurality of radiation detectors (1712, 1714) arranged along a longitudinal axis. For example, as depicted in FIG. 17, each density region (1704, 1706, 1708, 1710) has a separate ionization chamber (1712) and dosimeter slot (1714). The ionization chamber (1712) and dosimeter slot (1714) may be similar to those described herein with respect to FIGS. 16A-16B. In some of these variations, the dosimeter slot (1714) may be arranged to intersect its corresponding ionization chamber (1712). In some of these variations, an ionization chamber plug may be inserted into the ionization chamber (1712) when the radiography sheet is loaded into the dosimeter slot (1714) and the ion chamber (1710). In other variations, the dosimeter slots (1714) and ionization chambers (1712) of the density regions (1704, 1706, 1708, 1710) may be spaced apart along the vertical and / or horizontal axes. In some variations, the radiation detectors (1712, 1714) may be positioned in a region of the phantom (1702) that includes a material, such as acrylic (e.g., polymethylmethacrylate (PMMA)), that may be dosimetrically similar to water. The radiation detectors (1712, 1714) may be positioned above, below, and / or between the density regions (1704, 1706, 1708, 1710). In some variations, each density region (1704, 1706, 1708, 1710) may have a predetermined depth (e.g., approximately 5 cm) and provide different attenuation for the beam (1732) emitted from the radiation source (1730), thereby generating dose data corresponding to the different depths.

[0127] The phantoms described herein may have various shapes, such as cylindrical, disk-shaped, elongated, etc., as may be desired. In some variations, the phantom may be disposed on a patient support surface of a patient platform. In some variations, the ionization chamber (1712) may comprise a parallel plate chamber, a cylindrical chamber, a well-type chamber, a free air chamber, a vented chamber, a sealed chamber, combinations thereof, and / or the like. The slots (1714) may comprise one or more shapes, including a rectangular, square, trapezoidal, oval or elliptical, arc-shaped (e.g., semicircular, hemispherical, semicylindrical), combinations thereof, and the like. The slots (1714) may define an opening having a height sufficient to hold a radiographic sheet at a predetermined depth of the phantom (1702). In some variations, one or more radiographic sheets (e.g., radiographic films) may be disposed between one or more of the dosimeter slots (1714).

[0128] In some variations, the patient platform may comprise a phantom that may be used to measure the contrast resolution and ability of the radiation detector (e.g., MV detector) of the radiation therapy system to resolve high contrast edges. For example, the phantom may comprise a set of patterns with variable separation and / or contrast gradient that may allow the operator and / or the radiation therapy system to determine the upper limit of the spatial frequency and contrast resolution of the detector. In one variation, the phantom may comprise a first region with high contrast stripes with varying spatial frequencies and a second region with shapes with varying intensity or contrast relative to the background intensity. That is, the first region may comprise a pattern (e.g., a series of stripes with varying distance between them and / or varying stripe thickness) with a constant intensity or contrast level but with a variable spatial frequency to measure the ability of the detector to resolve edges. The second region may comprise a pattern (e.g., ovals of the same size) with a constant spatial frequency but with variable intensity or contrast level relative to the background intensity to measure the ability of the detector to resolve differences in intensity or contrast. In this manner, the spatial frequency and contrast resolution of one or more detectors (e.g., MV and / or kV) may be determined. The measured resolution may be compared to an expected (e.g., calibrated) detector resolution. As discussed in more detail herein, a fault signal may be generated when the measured resolution differs from the reference resolution by a pre-determined criterion. In some variations, the phantom may be mounted to the underside of the patient platform in a similar manner as described herein with respect to FIGS. 16A-16B and 17.

[0129] The phantom (1800) may include patterns that are within and exceed (e.g., above and below) the upper resolution limit of the radiation detector to be verified and / or calibrated. FIG. 18 depicts a plan view of a variation of the phantom (1800) having a housing (1802) with a first repeating pattern (1810) having a spatial frequency range and a second repeating pattern (1820) having a contrast range. In particular, the spatial frequency range may be configured to be within and exceed the upper spatial frequency limit of the radiation detector, and the contrast range may be configured to be within and exceed the upper contrast limit of the radiation detector. The first repeating pattern (1810) and the second repeating pattern (1820) may be spaced apart along the longitudinal axis (i.e., the X-axis) of the phantom (1800). The housing (1802) may include a material, such as acrylic (e.g., polymethylmethacrylate (PMMA)), that may be morphologically similar to water.

[0130] The first repeating pattern (1810) and the second repeating pattern (1820) may each comprise a set of contrasting shapes spaced at different intervals. When imaged by a radiation detector, the set of bars and ellipsoids may generate detector data (e.g., image data). In some variations, the first repeating pattern (1810) may comprise a set of rectangular bars with variable separation along the longitudinal axis of the phantom (1800). In some variations, the second repeating pattern (1820) may comprise a first shape (e.g., a dark ellipsoid) having a first thickness and a second shape (e.g., a lighter ellipsoid) having a second thickness different from the first thickness. Additionally or alternatively, the first shape (e.g., a dark ellipsoid) may have a first density and the second shape (e.g., a lighter ellipsoid) may have a second density different from the first density. The first and second shapes may include materials such as lead, copper, steel, acrylic, tungsten, uranium, combinations thereof, and the like.

[0131] In some variations, the repeating pattern may comprise one or more shapes, including a rectangle, a square, a trapezoid, an oval or ellipse, an arc shape (e.g., a semicircular arc, a semisphere, a semicylinder), combinations thereof, and the like. The housing (1802) may have a variety of shapes, and may be cylindrical, disc-shaped, elongated, etc., as may be desired. In some variations, the phantom (1800) may be disposed on a patient support surface of a patient platform.

[0132] In some variations, the phantom (1800) may comprise one, two, three, four, five, or more repeating patterns. For example, the phantom (1800) may comprise four repeating patterns to allow spatial frequency resolution and contrast resolution to be determined for MV CT and kVCT detectors. In some variations, the phantom (1800) may comprise a width (i.e., along the Y axis) of about 2 cm to about 5 cm. For example, the phantom (1800) may comprise a width of about 3 cm to about 4 cm. In some variations, the phantom (1800) may comprise a length (i.e., along the X axis) of about 10 cm to about 25 cm. For example, the phantom (1800) may comprise a length of about 15 cm to about 20 cm. In some variations, the phantom (1800) may comprise a height (i.e., along the Z axis) of at least about 0.2 cm. For example, the housing (1802) of the phantom (1800) may have a height of about 0.5 cm to about 2 cm.

[0133] In some variations, the width of the phantom (i.e., along the Y axis) may be aligned parallel to the length of the patient platform. In this manner, a single beam emitted from a radiation source (not shown) may be used to image both the first and second repeating patterns (1810, 1820) of the phantom (1800).

[0134] In some variations, a phantom as described herein (e.g., phantoms (1602, 1702, 1800)) may be used for energy measurement, calibration, and / or validation procedures using one or more radiation detectors and types. Any of the phantoms and associated systems described herein may be used in the methods described herein. A phantom as described herein may be placed above or below a patient platform. In some variations, the phantom may slide out laterally using a mount that is placed below the patient platform. The mount may allow an operator to prepare the phantom for a calibration procedure and may be configured to slidably position the phantom relative to the patient platform. For example, the mount may comprise a set of manually retractable and / or motor-driven rails. In some variations, the mount may comprise an electrical and / or mechanical interlock configured to prevent movement of the patient platform and / or radiation source when the phantom is retracted relative to the phantom. For example, a set of ionization chambers may be connected to an electrometer, a set of radiography sheets may be inserted into corresponding dosimeter slots, and the phantom may be filled with water. In some variations, one or more ionization chambers may be loaded from the side of the phantom. Radiography sheets placed in individual slots may form a stack that allows depth dosimetry to be obtained. In other variations, the phantom may be fixed relative to the patient platform.

[0135] After configuring (e.g., loading) the phantom, the patient platform may be moved to a predetermined position relative to the radiation source and detector. The radiation source and detector may be positioned at a predetermined gantry angle relative to the patient platform and phantom. For example, FIG. 16A illustrates a radiation source (1630) and a radiation detector (1640) and a patient platform positioned such that a beam (1632) emitted by the radiation source (1630) irradiates a first stage (1604) of the phantom (1602). Dose data acquired by the detector (1640) based on the beam (1632) may be stored in the memory of the controller along with data including the patient platform position, gantry position, stage depth, and corresponding reference data. After acquiring dose data in the first phantom using one or more radiation detectors, the patient platform (1620) may be moved longitudinally to generate dose data at other phantom depths and / or using other radiation detectors.

[0136] In some variations, dose data (e.g., dose-to-water values) may be acquired by a radiographic sheet placed in a slot of the phantom and compared to a set of reference dose data for calibration. For example, the calibrated dose intensity values ​​may correspond to the dose received by the patient and used in offline or online dose reconstruction. In a variation of a phantom with a set of variable density regions, the detector data may be used to generate a beam width intensity profile. The peak value of the intensity profile may be set as the dose value of the corresponding ion chamber. A TPR value may be calculated and compared to a reference TPR value. The reference TPR value may be determined during machine acceptance testing and / or beam commissioning. The tissue-phantom ratio does not depend on absolute calibration of the radiation detector because variations in the calibration factor and / or radiation detector gain may offset. Additionally or alternatively, the dose data may be used to characterize the stability of the radiation therapy beam. For example, the beam stability may be determined during daily quality assurance procedures.

[0137] A fault signal may be generated when the measured dose data deviates from the reference dose data based on a pre-determined criterion. For example, a fault signal may be generated by the processor when the dose data measured by the detector, the ionization chamber, and / or the radiographic sheet exceed a threshold parameter. The radiation therapy system may respond in one or more ways in response to the generation of the fault signal. For example, the system may deactivate one or more of the radiation source and the radiation detector, output a fault signal to the operator, prevent the radiation therapy treatment procedure, and calibrate the system using the calibration data. In some variations, the system may verify the fault signal and then recalibrate the system if necessary. One or more radiation detectors may be calibrated by the processor using the dose data.

[0138] In variations of the phantom comprising one or more repeating patterns, the dose data generated by the radiation detector may be used to generate an image of each repeating pattern using a single beam. An operator and / or processor may identify the smallest discernible difference between shapes within the first repeating pattern (1810) and the second repeating pattern (1820), thereby determining the high and low contrast resolution of the radiation detector.

[0139] In some variations, one or more visual, audio, and tactile sensory output systems coupled to the system may be used to output the fault signal and / or detector resolution to a user, such as an operator. For example, a display coupled to the system may display the fault signal, dose data calculations, and resolution to an operator, while an audio device may output an audible set of fault beeps and / or verbal messages. Additionally or alternatively, the fault signal and / or detector resolution may be stored in memory and / or transmitted over a network for output and / or display to one or more of a remote operator, a system vendor, a regulatory agency, and / or stored in a database. (Handheld Controller)

[0140] Generally, the patient platform system described herein may include a handheld portable controller for controlling movement of the patient platform. FIG. 5 is a cross-sectional side view of a patient platform system (500). The system (500) may include a patient platform (502) coupled to a base (510). A patient (504) may be provided on the patient platform (502). The system (500) may include a gantry (520) having a first radiation source (522) and a second radiation source (530). The first radiation source (522) may be coupled to a multi-leaf collimator (524) and may be provided opposite a first detector (528). The first radiation source (522) may be configured to emit a first beam (526). The second radiation source (530) may be provided opposite a second detector (534) and may be configured to emit a second beam (532). For example, the first radiation source (522) may be a radiotherapy source and the second radiation source (530) may be an imaging source.

[0141] The handheld controller (540) is coupled to the system (500) and may comprise a first switch (542) and a docking port (544). The first switch (542) may be configured to generate a movement signal for the patient platform (502). In some variations, the first switch (542) may comprise at least one of a button, an analog stick, a trackball, a touch screen, a directional pad, a jog dial, a motion detector, an image sensor, and a microphone.

[0142] In other variations, the controller (540) may further comprise a proximity sensor (548) configured to detect the proximity of the controller (540) to the patient platform (502) or a pre-determined location. In some of these variations, the patient platform (502) may be configured to move using the movement signal and the detected proximity. For example, control of the patient platform system (500) by the controller (540) may be limited to the room in which the system (500) is located and / or a specific area within the room.

[0143] The docking port (544) may be dockable with one or more of the gantry (520), the patient platform (502), and the user console. The controller (540) may be configured to generate different sets of output signals using the docking state of the controller (540). For example, the controller (540) may output gantry movement signals only when undocked from the system (500), and a radiation therapy treatment may be performed only when the docking port (544) of the controller (540) is docked to the system (500).

[0144] In some other variations, the controller (540) may include a wireless transmitter that outputs the movement signals (550). In other variations, the controller (540) may be hardwired to the system (500) to transmit the movement signals (550). In some of these variations, the movement signals (550) may control movement in at least four degrees of freedom, and may include yaw and / or pitch rotations.

[0145] Additionally or alternatively, the controller (540) may include a tether (552) for physically coupling the controller (540) to the system (500). It should be understood that the controller (540) may include multiple switches. Furthermore, some portions of the controller (540) may be handheld and / or portable, while other portions may be fixed. For example, the controller (540) may include a second switch (546), such as a step switch or foot pedal within the housing, separate from the first switch (542). The second switch (546) may, in some variations, be a safety switch that must be engaged before the movement signal of the first switch (542) can be output by the controller (540). In other variations, the controller (540) may include a housing having the first switch (542) on a first side of the housing and the second switch (546) on a second side of the housing opposite the first side. For example, controller (540) may be configured for one-handed activation, with a thumb on first switch (542) and a finger on second switch (546). It should be understood that the shape of controller (540) is not particularly limited. For example, controller (540) may be in the form of a pendant. (Head fixation device)

[0146] Generally, the head fixation devices described herein may fix or temporarily hold a patient's head in a desired position during a radiation therapy treatment. Figures 6A-6B are side views of a patient platform system (600) including a head fixation device (610) and a patient platform (602). The head fixation device (610) may include a hinge (614) coupled to a base (612), a head rest (616) coupled to the hinge (614), and a drive system (618) coupled to the head rest (616). The head rest (616) may be configured to hold the patient's head in a plurality of angled positions. In some variations, the head rest (616) may rotate about the hinge (614) such that the head rest (616) may tilt and orient relative to the base (612).

[0147] In some variations, the hinge (614) may include a lock with multiple detents and pins that form multiple lockable positions. Thus, the head rest (616) may be locked to the base (612). In some variations, the patient may manually adjust the position of their head by neck flexion.

[0148] In other variations, the patient and / or operator may control the drive system to reposition and lock the head rest (616) at a desired position. The head rest (616) and drive system (618) may each include radiolucent materials. In some variations, the drive system (618) may include pneumatic elements. In other variations, the drive system (618) may include electromechanical or hydraulic elements. In still other variations, the drive system (618) may be coupled to an actuator (620) and a controller (not shown). For example, the actuator (620) may be coupled to the first end (603) of the patient platform (602). As shown in FIGS. 6A-6B, extension of the drive system (618) in a direction generally perpendicular to the base (612) may angle the head to a desired position. The patient and / or operator may use a handheld controller to control the drive system (618) to control the speed of movement and position of the head rest (616) until the desired position is reached. Additionally or alternatively, a patient torso and / or patient shoulders may be coupled to the base (612). The base (612) may be removably attached or fixed to the patient platform (602). (controller)

[0149] In some variations, the systems described herein may include a controller configured to perform one or more steps of a radiation therapy procedure. The controller may be coupled to one or more of the patient platform and the gantry. In some variations, the controller may be disposed in one or more of the patient platform, the user console, and the like. For example, the controller may be configured to determine the subsidence of the patient platform, control the movement and positioning of the patient platform, and perform one or more steps of a radiation therapy procedure. The controller may include one or more processors and one or more machine-readable memories in communication with the one or more processors. The processor may incorporate data received from the memory and patient inputs and control the system. The memory may further store instructions for causing the processor to execute modules, processes, and / or functions associated with the system. The controller may be configured to control one or more components of the system, such as a drive system, a conformable substrate, an imaging system, a treatment system, and the like.

[0150] The controller may be implemented consistent with numerous general purpose or special purpose computing systems or configurations. Various exemplary computing systems, environments, and / or configurations that may be suitable for use with the systems and devices disclosed herein may include, but are not limited to, software or other components embodied within or on user consoles, servers or server computing devices such as routing / connectivity components, multiprocessor systems, microprocessor-based systems, distributed computing networks, personal computing devices, network appliances, portable (e.g., handheld), and the like.

[0151] The processor may be any suitable processing device configured to run and / or execute a set of instructions or code, and may include one or more data processors, image processors, graphic processing units, physical processing units, digital signal processors, and / or central processing units. The processor may be, for example, a general-purpose processor, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or the like. The processor may be configured to run and / or execute application processes and / or other modules, processes, and / or functions associated with the system and / or its associated network. The underlying device technology may be provided in a variety of component types, including metal oxide semiconductor field effect transistor (MOSFET) technology such as complementary metal oxide semiconductor (CMOS), bipolar technology such as emitter coupled logic (ECL), polymer technology (e.g., silicon conjugated polymer and metal conjugated polymer-metal structures), mixed analog and digital, combinations thereof, or the like.

[0152] In some variations, the memory may include a database (not shown), which may be, for example, a random access memory (RAM), a memory buffer, a hard drive, an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), a read-only memory (ROM), a flash memory, a combination thereof, or the like. As used herein, a database refers to a data storage resource. The memory may store instructions for causing the processor to execute modules, processes, and / or functions associated with the system, such as subsidence determination and / or compensation, patient platform movement, and the like. In some variations, the storage may be network-based and accessible for one or more authorized users. The network-based storage may be referred to as a remote data storage or a cloud data storage. The sensor signal and attachment data stored in the cloud data storage (e.g., a database) may be accessible to individual users via a network, such as the Internet. In some variations, the database may be a cloud-based FPGA.

[0153] Some variations described herein relate to computer storage products with non-transient computer-readable media (which may also be referred to as non-transient processor-readable media) having thereon instructions or computer code for performing various computer-implemented operations. The computer-readable media (or processor-readable media) is non-transient in the sense that it does not itself include a transitory propagating signal (e.g., a propagating electromagnetic wave that carries information over a transmission medium such as space or cable). The media and computer code (which may also be referred to as code or algorithms) may be designed and constructed for one or more specific purposes.

[0154] Examples of non-transitory computer readable media include, but are not limited to, magnetic storage media such as hard disks, floppy disks, and magnetic tapes, optical storage media such as compact disks / digital video disks (CD / DVDs), compact disk read only memories (CD-ROMs), holographic devices, magneto-optical storage media such as optical disks, solid-state storage devices such as solid-state drives (SSDs) and solid-state hybrid drives (SSHDs), carrier signal processing modules, and hardware devices specially configured to store and execute program code such as application specific integrated circuits (ASICs), programmable logic devices (PLDs), read only memories (ROMs), and random access memory (RAM) devices. Other variations described herein relate to computer program products, which may include, for example, the instructions and / or computer code disclosed herein.

[0155] The systems, devices, and methods described herein may be implemented by software (executed on hardware), hardware, or a combination thereof. Hardware modules may include, for example, a general-purpose processor (or microprocessor or microcontroller), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or the like. Software modules (executed on hardware) may be expressed in various software languages ​​(e.g., computer code), including C, C++, Java, Python, Ruby, Visual Basic, and / or other object-oriented, procedural, or other programming languages ​​and development tools. Examples of computer code include, but are not limited to, microcode or microinstructions, machine instructions such as those produced by a compiler, code used to generate web services, and files containing high-level instructions executed by a computer using an interpreter. Additional examples of computer code include, but are not limited to, control signals, encryption code, and compression code.

[0156] Examples of wireless communications within a wireless network include, but are not limited to, cellular, radio, satellite, and microwave communications. Wireless communications include, but are not limited to, Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), High Speed ​​Downlink Packet Access (HSDPA), Wideband Code Division Multiple Access (W-CDMA), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Bluetooth, Near Field Communication (NFC), Radio Frequency Identification (RFID), Wireless Fidelity (Wi-Fi) (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE 802.11nb ... 802.11n), Voice over Internet Protocol (VoIP), Wi-MAX, protocols for email (e.g., Internet Message Access Protocol (IMAP), Post Office Protocol (POP)), instant messaging (e.g., Extensible Messaging and Presence Protocol (XMPP), Instant Messaging, Session Initiation Protocol for Presence-enabled Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)), Short Message Service (SMS), or any other suitable communication protocol. Some wireless network deployments combine networks from multiple cellular networks or use a mix of cellular, Wi-Fi, and satellite communications.

[0157] In some variations, wireless networks may connect to wired networks to interface with the Internet, other carrier voice and data networks, business networks, and personal networks. Wired networks are typically carried over copper twisted pair, coaxial cable, and / or fiber optic cable. There are many different types of wired networks, including wide area networks (WANs), metropolitan area networks (MANs), local area networks (LANs), Internet area networks (IANs), campus area networks (CANs), global area networks (GANs) such as the Internet, and virtual private networks (VPNs). As used herein, a network refers to any combination of wireless, wired, public, and private data networks that are typically interconnected through the Internet to provide a unified networking and information access system. II. Method (Methods of administering radiation therapy)

[0158] Generally, methods for performing radiation therapy are described herein. Any of the systems and devices described herein may be used in the radiation therapy procedures described below. FIG. 7 is a flow chart generally illustrating a radiation therapy process (700), including subsidence determination and compensation. The process (700) may include loading a patient onto a patient platform (702). In some variations, patient loading may include securing one or more parts of the patient relatively comfortably so that the patient remains in a generally fixed position relative to the patient platform. As further discussed in FIG. 10, a conformable substrate of the patient platform may be controlled to couple the patient to the patient platform and increase patient compliance with the radiation therapy treatment. In some variations, the height of the conformable substrate may be independently controlled to contour the patient platform to the shape of the patient (e.g., FIGS. 2A-2C). Patient platform settings for each patient may be stored in memory and reapplied for efficiency and repeatability across one or more patient platforms and / or radiation therapy systems and across treatment sessions.

[0159] Additionally or alternatively, the patient platform may be contoured to the patient's body shape through heating and cooling of the thermoelectric layer. In yet another variation, the patient's head may be coupled to the patient platform in a fixed position by a head fixation device, as discussed with respect to Figures 6A-6B and further in Figure 14. During adjustment of the head fixation device, the patient may control pivoting of the head through neck flexion to improve patient comfort and compliance.

[0160] Once the patient is loaded onto the patient platform, the patient platform may be moved into the patient area of ​​the gantry (704). In some variations, as discussed with respect to Figures 3A-3D and further in Figures 11A-11B, the patient platform may comprise multiple sections that may move or extend axially relative to one another. The upper section of the patient platform may be formed from a radiolucent material, while the lower section may be formed from a more rigid material that is radiopaque and exhibits less subsidence than the radiolucent material. The patient platform may be moved into the patient area such that the radiopaque section does not intersect the plane of the imaging beam and / or the therapy beam when either or both of these beams are activated. Thus, the length of the radiolucent upper section that is cantilevered from the base may be shortened to reduce the amount of subsidence of the patient platform. In some variations, the upper section may have a length of 0.25 to 2.0 meters.

[0161] In other variations, as further discussed in Figures 12 and 13A-13E, the patient platform may be moved to align one or more regions of interest (e.g., lesions, tumors) of the patient with the isocenter of the gantry to ensure that the radiation dose is delivered to the region of interest. As used herein, particularly with reference to imaging and radiation oncology, an isocenter is a point in space through which multiple beamlets intersect, and which are emitted from multiple gantry locations by a rotating radiation source. The patient platform may translate (axially and / or laterally) and rotate (tilt and / or steer) to position the region of interest on the isocenter to provide the desired radiation dose.

[0162] In yet other variations, as discussed in more detail below, patient platform subsidence may be determined (706), compensated for (708), and used to determine and correct treatment beam parameters such as power, duration, location, etc. (e.g., treatment plan) (710). In some variations, as discussed with respect to FIGS. 1A-1F, an imaging beam may be emitted toward the submerged patient platform and used to determine the difference between the unweighted and weighted positions of the patient platform. For example, the patient platform may be imaged prior to loading the patient to determine the position of the unweighted patient platform. The change in location of the patient platform may be determined and then used to determine the change in location of the patient and one or more regions of interest. In some instances, the change in location of the patient platform may be used to compensate for the patient platform subsidence (708). For example, the treatment plan may be modified, adjusted, and / or updated to compensate for the determined subsidence. Alternatively, or in addition, the height and / or position of the patient platform may be adjusted (eg, raised or lowered) to compensate for subsidence of the patient platform in the treatment beam plane.

[0163] Once the patient platform is in the desired position and the treatment plan parameters have been updated or adjusted (if needed) to compensate for subsidence, the treatment beam may be delivered according to the treatment plan 712. After execution of the treatment plan, the patient platform may be removed from the patient region of the gantry 714. (Determine Patient Platform Subsidence)

[0164] FIG. 8 is a flow chart of one variation of a patient platform subsidence determination process (800). The method may be used, for example, with the system depicted in FIGS. 1A-1F, where the patient platform is coupled to an extension element and / or optical marker. The process may include emitting a first beam by a radiation source through a collimator to illuminate an extension element coupled to the patient platform (802). The first beam may be directed toward the extension element without crossing the patient to limit exposure to the patient. The first beam may be received by a detector located on the opposite side of the radiation source and collimator (804). Alternatively, an optical sensor may receive light reflected from the optical marker. The controller using the received detector data may then determine a first location of the extension element in the imaging beam plane that corresponds to the unweighted patient platform. In some variations, the patient platform subsidence determination may be performed prior to the patient receiving a radiation therapy treatment. However, the patient platform subsidence determination may be determined during the radiation therapy treatment as needed for recalibration.

[0165] FIG. 9 is a flow chart of one variation of the process (900) that describes in more detail the step of determining the location of the elongation elements and / or optical markers (806) using a Winston-Lutz based method. The elongation elements and / or optical markers may be detected at multiple angles (902) to generate detector data indicative of the location of the elongation elements and / or optical markers. For example, the elongation elements may be imaged at a set of primary angles (e.g., 0°, 180°, 270°) and / or other angles. The image data may be analyzed by a processor to identify the elongation elements and / or optical markers (904). The image data may then be compared to reference data corresponding to the elongation elements and / or optical markers of an unweighted platform (906).

[0166] Such reference data may be acquired, for example, before the patient is loaded onto the platform, and / or may be reference data acquired and stored during a calibration and / or setup procedure. The difference between the data may be used to determine the location of the extension elements and / or optical markers (908) and the extent to which the extension elements and / or optical markers have changed from the reference location (i.e., subsidence). Referring back to FIG. 8, the relationship between the location of the extension elements and / or optical markers and the patient platform may be known or determined in advance. Thus, a change in patient platform location (808) between an unweighted state and a weighted state may be determined. Thus, a change in location of one or more regions of interest on the patient may be determined based on the subsidence of the patient platform. Additionally or alternatively, the patient platform position and / or treatment plan may be modified to compensate for the subsidence of the patient platform (810). (Loading the patient onto the patient platform)

[0167] FIG. 10 is a flow chart of one variation of a patient platform loading process (1000). This method may be used in conjunction with the system depicted in FIG. 2C. The method (1000) may include the step of heating (1002) a thermoelectric layer of the patient platform. The thermoelectric layer may be heated to form a flexible configuration for the patient to lie on. The thermoelectric layer of the patient platform may then be modified through the patient weight to form an ergonomic surface. In other variations, the patient platform may comprise a conformable substrate having a plurality of enclosures. In some variations, the loading process (1000) may begin with the height of the plurality of enclosures being set to a predetermined height (1004) based on a previous fit for the patient or based on predetermined data for the patient's height and weight. The patient may then be loaded onto the patient platform (1006). In some instances, the patient lies on the patient platform in a predetermined orientation outside the patient area of ​​the gantry. It should be appreciated that determination and setting of the patient configuration of the patient platform may occur outside of the gantry (e.g., in a patient setup or waiting area), reducing the time the patient spends in the gantry, thereby allowing for more efficient use of the radiation therapy system.

[0168] Once a patient is loaded onto the patient platform, pressures of the multiple enclosures may be measured (1008) using pressure sensors coupled to the patient platform. The pressure may include multiple enclosure pressures. The height of each of the multiple enclosures may be independently controlled (1010) using the multiple enclosure pressures such that the patient platform contours to the shape of the patient. Additionally or alternatively, the thermoelectric layer may be cooled (1012) to transition from a flexible configuration to a rigid configuration. In some cases, heating of the thermoelectric layer may be stopped. In other cases, the thermoelectric layer may be actively cooled to form a rigid configuration. It should be understood that the heating and cooling steps (1002, 1012) may not be performed if the patient platform does not have a thermoelectric layer.

[0169] In some variations, a patient configuration may be determined (1014) corresponding to the height of each of the multiple enclosures. The patient configuration may comprise at least one of the pressure and / or height of the multiple enclosures. The patient configuration may be stored (1016) in memory and / or transferred to one or more other patient platforms and / or radiation therapy systems. The height of the multiple enclosures may then be readjusted (1018) using the stored patient configuration. Thus, patient positioning time may be reduced to increase efficiency and improve imaging and / or treatment consistency. (Moving the Patient Platform)

[0170] 11A-11B are flow charts of variations of a process (1100, 1150) for moving a patient platform into a gantry and reducing and / or determining subsidence. In some variations, the method may be performed by a patient platform coupled to a base. In FIG. 11A, the patient platform may comprise an upper portion and a lower portion coupled to the upper portion, and the upper portion and the lower portion may move relative to each other. The lower portion may have a higher rigidity than the upper portion. In some variations, the upper portion may include a radiolucent first material and the lower portion may include a radiopaque second material. The lower portion may include any material that is sufficiently rigid to support the upper portion, regardless of its radiopacity and / or radiolucency.

[0171] The process (1100) of FIG. 11A may include moving a lower portion of a patient platform relative to a patient region of the gantry (1102). The upper portion may move relative to the lower portion (1104). An imaging beam may be emitted (1106). In some variations, the imaging beam may be emitted by an imaging radiation source in an imaging plane perpendicular to a longitudinal axis of the patient platform. The movement of the lower and upper portions may be such that the lower portion does not intersect the imaging plane and the upper portion intersects the imaging plane. In some of these variations, moving the upper portion into the imaging plane includes positioning the lower portion such that a leading edge of the lower portion is located a predetermined first distance away from the imaging plane. The platform may move longitudinally through (e.g., stepwise through) the imaging beam, traversing a distance corresponding to a length of a radiolucent upper portion cantilevered from the lower portion. The imaging beam may capture an image of a portion of the patient located along the length of the upper portion cantilevered from the lower portion.

[0172] In other variations, the process (1100) may include moving the lower portion relative to the base (1108) and moving the upper portion relative to the lower portion (1110). A treatment beam may be emitted from a therapeutic radiation source coupled to the multi-leaf collimator in a treatment plane perpendicular to a longitudinal axis of the patient platform (1112). The lower and upper portions may be moved such that the lower portion does not intersect the treatment plane and the upper portion intersects the treatment plane. In some of these variations, moving the upper portion into the treatment plane includes positioning the lower portion such that a leading edge of the lower portion is located a predetermined second distance away from the treatment plane.

[0173] FIG. 11B illustrates another variation of process (1150) that may be performed by a patient platform coupled to a base. The patient platform may include an upper portion and a lower portion secured to the upper portion. The lower portion of the patient platform may be coupled to the base such that the lower portion may move relative to the base. In some variations, the lower portion may have a higher stiffness than the upper portion. The upper and lower portions may include materials having different degrees of radiolucency. For example, the upper portion may include a first material that is radiolucent and the lower portion may include a second material that is radiopaque.

[0174] The process (1150) of FIG. 11B may include moving (1152) the patient platform relative to the base. An imaging beam may be emitted by the therapeutic radiation source in an imaging plane perpendicular to the longitudinal axis of the patient platform (1154). In some variations, the patient platform is moved (1156) such that only an upper portion of the patient platform intersects the imaging beam. For example, the movement of the lower and upper portions may be such that the lower portion does not intersect the imaging plane and the upper portion intersects the imaging plane. In some of these variations, the lower portion may be moved such that a leading edge of the lower portion is located a predetermined first distance away from the imaging plane. The upper portion may be moved relative to the lower portion to intersect the imaging plane.

[0175] In one variation, the process (1150) may include moving (1158) the patient platform relative to the base. A treatment beam may be emitted by a therapeutic radiation source coupled to the multi-leaf collimator in a treatment plane perpendicular to a longitudinal axis of the patient platform (1160). In some variations, the patient platform may be moved (1162) such that only an upper portion of the patient platform intersects the treatment beam. For example, the patient platform may be moved such that the lower portion does not intersect the treatment plane and the upper portion intersects the treatment plane. In some of these variations, the lower portion may be moved such that a leading edge of the lower portion is located a predetermined second distance away from the treatment plane. The upper portion may be moved relative to the lower portion to intersect the treatment plane. (Move the region of interest to the isocenter)

[0176] For radiation therapy procedures, it may be desirable to position the center of a region of interest at the isocenter of the gantry. In the process described below, one or more regions of interest may be moved to align with the isocenter, such as through movement of the patient platform. FIG. 12 is a flow chart of one variation of a patient platform movement process (1200). In some variations, the process (1200) may include a step of determining (1202) a location of a first region of interest of a patient on the patient platform. In some of these variations, a location of a second region of interest may be determined (1204). The patient platform may then be moved (1206) into the patient region of the gantry, as illustrated in the exemplary FIG. 13A. The gantry may define an isocenter point about which the gantry rotates, and an isocenter axis that comprises the isocenter point and extends parallel to the longitudinal axis of the patient region. FIG. 13A illustrates a patient platform system (1300) comprising a patient platform (1310) moved into a patient region of a gantry (1330). The gantry (1330) may comprise a radiation source (1332) coupled to a multi-leaf collimator (1334). A treatment beam (1336) may be emitted by the radiation source (1332). A patient (1320) may be loaded onto the patient platform (1310) and may comprise a first region of interest (1322) having a first longitudinal axis (1323) and a second region of interest (1324) having a second longitudinal axis (1325). As shown in FIG. 13A, an isocenter axis (1338) is approximately parallel to both the first and second regions of interest (1322, 1324).

[0177] Referring back to FIG. 12, the patient platform may be moved laterally along the Y axis to position the first region of interest on the isocenter axis (1208). In some variations, the patient platform may be moved in one or more of pitch and yaw rotations and lateral directions. To further refine the radiation therapy treatment, the patient platform may be moved to align the longitudinal axis of the first region of interest on the isocenter axis (1210). As shown in FIG. 13B, the patient platform (1310) may be moved laterally along the Y axis to align the first longitudinal axis (1323) on the isocenter axis (1338). A radiation beam may be emitted from the radiation source to the first region of interest on the isocenter axis (1212).

[0178] After treating the first region of interest, the patient platform may be moved (1214) to position a second region of interest on the isocenter axis. In some variations, the patient platform may be moved (1216) to align a longitudinal axis of the second region of interest on the isocenter axis. As shown in FIG. 13C, the patient platform (1310) may be moved laterally along the Y axis to align a second longitudinal axis (1325) on the isocenter axis (1338). A radiation beam may be emitted (1218) from the radiation source to the second region of interest on the isocenter axis. Of course, the patient platform (1310) may be moved to treat any number of regions of interest on the patient (1320).

[0179] If the region of interest changes position at any time before, during, or after the radiation therapy treatment due to patient movement on the patient platform (due to breathing, patient discomfort, and the like), the patient platform may be moved to compensate for the change in patient position using the patient platform controller. For example, if the patient rolls in one direction on the patient platform, the position of the patient platform may be adjusted or rolled in the opposite direction to compensate for the patient movement. In some variations, the methods described with respect to Figures 12 and 13A-13D may be implemented using the systems described with respect to Figures 4A-4E.

[0180] FIG. 13D illustrates another variation in which the longitudinal axis (1323) of the region of interest (1322) of the patient (1320) is non-parallel to the isocenter axis (1338). The patient platform (1310) may be rotated about the Z axis to align the longitudinal axis (1323) with the isocenter axis (1338), as shown in FIG. 13E. In some non-limiting exemplary variations, the patient platform (1310) may be rotated about the Z axis by up to about 15°. Although not shown, it should be understood that the pitch of the patient platform may be varied to align the longitudinal axis of the region of interest with the isocenter axis. (Positioning the patient's head)

[0181] FIG. 14 is a flow chart of one variation of a patient head positioning process (1400). In some variations, the process (1400) may include loading a patient onto a patient platform (1402). A head fixation device may be provided on the patient platform such that the patient head may be coupled to a head rest of the head fixation device (1404). In some variations, the patient head may be held or secured to the head rest. The head may then be pivoted about a hinge of the head fixation device (1406). The head rest may tilt and orient relative to the patient platform. The pivoting may be provided by a head rest drive system coupled to the head rest and / or by patient neck flexion. For example, a radiolucent pneumatic element may be extended to tilt the head rest approximately vertically and position the patient head at a desired angle. Once the head is in the desired position, the head rest may be locked (1408). One or more portions of the patient's body may optionally be coupled to the platform 1410. For example, the patient's torso and / or shoulders may be coupled to the head immobilization device and / or the patient platform.

[0182] Although the foregoing variations have been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be apparent that certain changes and modifications may be practiced and are intended to fall within the scope of the appended claims. In addition, it should be understood that the components and features of the systems and devices described herein may be used in any combination. The description of an element or feature with respect to a specific figure is not intended to be limiting, nor should it be construed to suggest that the element cannot be used in combination with any of the other described elements. With respect to all of the variations described above, the steps of the method may not be performed sequentially. Some steps are optional, such that not all steps of the method may be performed.

Claims

[Claim 1] An apparatus, system or method.

Images