Radiotherapy apparatus for delivering radiation to a subject

Abstract

This application relates to a radiotherapy device for delivering radiation to a subject. The device includes a radiation source configured to rotate about an isocenter and emit radiation in a radiation plane containing the isocenter. The device also includes a subject support surface configured such that a portion of the subject support surface is located substantially at the isocenter. The device further includes a subject support surface rotation mechanism configured to rotate the subject support surface about a rotation axis passing through the isocenter, wherein the subject support surface rotation mechanism is located outside the radiation plane.

Description

Technical Field

[0001] This disclosure generally relates to radiotherapy equipment, and more particularly to the positioning of a subject during the delivery or application of radiotherapy. Background Technology

[0002] Radiation therapy uses ionizing radiation to treat human or animal bodies. In particular, radiation therapy is commonly used to treat tumors in humans or animals. In such treatment, cells forming the tumor are irradiated with ionizing radiation to destroy or damage these cells. However, in order to deliver a prescribed dose of ionizing radiation to a target site or region, such as a tumor, the ionizing radiation typically also penetrates healthy tissue in the human or animal body. Therefore, radiation therapy has the desired result of irradiating and destroying the target area, but it can also have the undesirable result of irradiating and destroying healthy tissue. In radiation therapy, it is desirable to align the dose received by the target area with the prescribed dose and to minimize the dose received by the healthy tissue.

[0003] Modern radiotherapy uses techniques to reduce the radiation dose to healthy tissue, thus providing safe treatment. For example, one way to minimize the radiation dose received by healthy tissue surrounding the target area is to direct radiation to the target area from multiple different angles, such as by rotating a radiation source around the patient using a rotating gantry. In this case, the angle at which radiation is applied is chosen so that each beam passes through the target area. In this way, a cumulative radiation dose can be built up over the target area during the treatment arc, where the radiation source rotates at a certain angle. The radiation is emitted in a radiation plane that coincides with the plane of the gantry around which the radiation source rotates, so that regardless of the angle at which the radiation head rotates around the gantry, the radiation can be delivered to the radiation isocenter at the center of the gantry. Because radiation is applied from multiple different angles, the same high, cumulative radiation dose does not accumulate in the healthy tissue, as the specific healthy tissue through which the radiation passes varies with the angle. Therefore, the unit volume of healthy tissue receives a reduced radiation dose relative to the target area. Treatment utilizing gantry rotation in this way is called coplanar. However, after the radiation source has rotated 180°, it should be understood that any subsequent radiation beam begins to pass through areas of healthy tissue that have already been irradiated. This increases the radiation dose applied to the healthy tissue. Therefore, when using this method, the volume of healthy tissue available for distributing the radiation dose is relatively small, thus limiting the treatments that can be provided by such a device.

[0004] Therefore, an alternative approach to minimizing the radiation dose received by the healthy tissue surrounding the target area is to rotate the patient relative to the radiation plane. As the patient's angle changes relative to the plane of the gantry, the amount of healthy tissue through which the radiation passes also changes. To further reduce the radiation dose per unit volume relative to the target area, it is desirable to provide a treatment that combines both of these rotations. Figure 1 An example of a known device that combines rotation of the patient with rotation of the radiation source is shown. This demonstrates that the patient 140 (also referred to herein as patient support surface 114) supported on object support surface 114 can rotate, and the gantry 116 can also rotate about patient support surface 114. Figure 1 The gantry 116 shown is a C-arm gantry or an open gantry. A rotating mechanism 117 rotates the gantry 116 about a fixed axis 119. As the gantry 116 rotates, radiation emitted by the radiation source 106 can sweep out a circle. Radiation can be applied to the patient 140 from multiple angles around this circle. This circle can be described as lying in the radiation plane. The radiation axis lies in the radiation plane. The radiation axis forms a 90° angle with respect to the fixed axis 119.

[0005] The rotation mechanism 120 for the patient support surface 114 is located below the gantry 116 of the radiotherapy apparatus, while the rotation mechanism for the gantry 116 is located opposite the patient support surface 114. The rotation mechanism 120 for the patient support surface 114 is located below the gantry 116 such that the axis of rotation 111 of the patient support surface lies in the radiation plane. Specifically, the axis of rotation 111 of the patient support surface passes through the isocenter 124 of the radiotherapy apparatus, causing the patient support surface 114 to rotate about the isocenter 124. When the patient support surface 114 is in its neutral position, the axis of rotation 111 of the patient support surface is approximately vertical (perpendicular to the plane of the base plate), and this can also be referred to as the vertical axis 111. The longitudinal axis 113 is parallel to the long side of the patient support surface 114 in its neutral position, and the transverse axis 115 is parallel to the short end of the patient support surface 114 in its neutral position. The rotation mechanism 120 lies in the radiation plane. Treatment utilizing radiation and the rotation of the patient 140 is referred to as non-coplanar treatment.

[0006] Some recently developed radiotherapy devices include ring-based gantry (or perforated structures), such as... Figure 2As shown in the diagram. Typically, the aperture of the radiotherapy device is cylindrical. A patient support surface 114 is positioned within the aperture so that radiation can be directed toward a patient 140 positioned on the support surface 114. The aperture of the device can be formed by a frame, which may also be described as a base, shielding structure, outer shell, or housing. The frame defines the outer surface of the device as seen by the patient 140 upon entering the treatment room, and the inner surface of the aperture as seen by the patient 140 when positioned within the aperture. The frame also defines a hollow region of annular cross-section in which the gantry 116 can rotate and tilt. Thus, the patient 140 is shielded from the rotating gantry 116. The movement of the gantry 116 is concealed from the patient's line of sight, reducing the threat and distress that might arise if the patient 140 could see the rotation of the large gantry 116 (as they would for a patient with a large gantry 116). Figure 1 The open gantry shown can be rotated as is, and also reduces the likelihood that a patient could accidentally touch or interfere with the movement of gantry 116. This means that gantry 116 can be rotated quickly, efficiently, and safely. Ring-based gantry systems are also desirable because they increase device stability. Ring-based gantry systems are supported and rest on a base plate. However, the geometry of the ring-based gantry system and its connection to the base plate make it impossible for the patient support surface 114 to rotate about the isocenter 124.

[0007] Another problem that arises when attempting to minimize the radiation dose received by healthy tissue surrounding the target area can be found when precisely positioning the target area relative to the device. For example, patient movement can cause movement of unhealthy tissue, such as a tumor, thus potentially reducing the dose applied to the target area while increasing the dose applied to healthy tissue. In other words, if the patient moves during or before radiotherapy, this can lead to a high cumulative dose accumulating in healthy tissue areas rather than the target area. This reduces the effectiveness of radiotherapy for treating the target area and may damage other healthy tissues.

[0008] The deflection of the tabletop, the patient-supporting surface, also contributes to this problem when the tabletop extends into the device. In normal operation, the tabletop initially lies approximately outside the gantry plane to allow the patient easy positioning. It then extends into the gantry plane, specifically aligning the target area with the device's isocenter. In the extended position, the tabletop deflects with an amplitude depending on its position, the patient's position on the tabletop, and the patient's weight. Due to this tabletop deflection, the target area shifts relative to the isocenter, resulting in healthy tissue receiving a higher dose of radiation than necessary. Furthermore, during helical therapy targeting larger target areas, the tabletop is moved during treatment. Helical therapy involves moving the patient via tabletop movement while the radiation source moves around the gantry and emits radiation. Accordingly, the amount of tabletop deflection changes during treatment, thus altering the target area's position relative to the isocenter, resulting in healthy tissue receiving a higher dose of radiation than necessary. This problem occurs for all radiotherapy devices with extendable tabletops. However, this issue is particularly important for radiotherapy devices with perforated solutions, as these devices will typically have a longer surface extension. The longer the surface extension, the more surface deflection will occur, and the greater the change in the position of the target area will be.

[0009] Previous solutions to this problem included manually positioning the patient, for example, using a laser. However, this is particularly ineffective for automated and spiral treatments without repeated treatment stops, resulting in longer treatment times and lower efficiency. The location of the target area can be detected by taking images; however, this is harmful to the patient. It is desirable to know the location of the treatment area as accurately as possible throughout the treatment without needing to take additional images. Accurate knowledge of the target area's location allows radiation to be focused where it is needed, ideally within 1 mm of the target area, thereby minimizing the radiation dose received by the surrounding healthy tissue. Summary of the Invention

[0010] The invention is described in the claims. Attached Figure Description

[0011] The specific implementation method is now described by way of example only, with reference to the accompanying drawings, wherein:

[0012] Figure 1 A known radiotherapy device with a rotating mechanism located in the radiation plane is described;

[0013] Figure 2 A front view of a radiotherapy device is depicted;

[0014] Figure 3 An isometric view depicting an embodiment of a radiotherapy device;

[0015] Figure 4A An isometric view depicting an embodiment of a radiotherapy device including a curved track;

[0016] Figure 4B A plan view depicting an embodiment of a radiotherapy device including a curved track is shown;

[0017] Figure 5 A side elevation view of an embodiment of a radiotherapy device including a curved track is depicted, wherein the unloaded object support surface is in its non-extended position.

[0018] Figure 6 An isometric view depicting an embodiment of a radiotherapy device including two vertically aligned curved tracks;

[0019] Figure 7 An isometric view depicting an embodiment of a radiotherapy device connected to a base plate, the radiotherapy device including two vertically aligned curved tracks;

[0020] Figure 8 Detailed isometric views depicting an embodiment of a radiotherapy device including two vertically aligned curved tracks;

[0021] Figure 9 A side elevation view of an embodiment of a radiotherapy device is depicted, and the bending of the extendable tabletop of the patient support surface is shown, which is loaded and in its extended position.

[0022] Figure 10A A side elevation view of an embodiment of a radiotherapy device is depicted, and the object support surface in its loaded and unextended position is shown;

[0023] Figure 10B A close-up side view of an embodiment of a radiotherapy device is depicted, showing the position of the sensor relative to the object's supporting surface;

[0024] Figure 11 A side view of an embodiment of a radiotherapy device is depicted, showing the object support surface in its loaded and extended position. Detailed Implementation

[0025] Overview

[0026] Several benefits are provided by providing a radiotherapy device for delivering radiation to a subject, comprising a subject-supporting surface and a rotating mechanism for the subject-supporting surface. The subject-supporting surface is configured such that a portion of it is approximately at the isocenter, and the rotating mechanism is configured to rotate the subject-supporting surface about a rotation axis passing through the isocenter, wherein the rotating mechanism is located outside the radiation plane. This device provides means for minimizing the dose received by healthy tissue during radiotherapy treatment. By rotating the subject-supporting surface, for example, when a patient is positioned on it, radiation can be distributed through healthy tissue while rotating about the isocenter, ensuring that the maximum amount of radiation still passes through the target area. This maximizes treatment efficiency and allows for reduced treatment time. However, if the rotating mechanism were located within the radiation plane to allow the recliner to rotate about the isocenter, it would be impossible to use a recliner and rotating mechanism in a radiotherapy device using apertures, as the gantry and rotating mechanism would obstruct each other. For the wide variety of radiotherapy devices with different geometries, positioning the rotating mechanism of the subject-supporting surface outside the radiation plane allows for minimizing the dose received by the healthy tissue of the subject during radiotherapy. For example, these benefits can be achieved in radiotherapy devices that include openings for accommodating objects.

[0027] Several benefits are offered by providing a system for positioning an object within a radiotherapy device. This system includes an object support surface and a processor. The object support surface has an extendable table and one or more sensors configured to measure the vertical position of the extendable table. The processor is configured to use the measured position to determine the deflection of the extendable table and, based on the deflection, control the treatment with the radiotherapy device. Using this system to determine the deflection profile allows for precise execution of treatments, such as helical therapy, without requiring re-imaging of the patient during treatment. This reduces the amount of imaging radiation exposed to the patient, thereby reducing harm to the patient. Eliminating the requirement for re-imaging increases the speed at which treatment can be performed, thereby increasing patient throughput and improving the efficiency of the radiotherapy device. The system also enables the location of the target area to be known with greater certainty and accuracy, allowing for treatment to be performed with greater accuracy and confidence during treatment of the target area. This also minimizes radiation received by healthy tissue.

[0028] Detailed description

[0029] When a radiotherapy device including a radiation source 106 configured to rotate around an isocenter 124 and emit radiation in a radiation plane containing the isocenter 124 treats a subject or patient 140, rotating the subject around the isocenter 124 allows for minimization of the dose received by healthy tissue during radiotherapy. This can be achieved by providing a subject support surface rotation mechanism 120 connected to a subject support surface 114 and configured to rotate the subject support surface around the isocenter 124. Rotating the subject support surface 114 about an axis of rotation passing through the isocenter 124 ensures that radiation will pass through the same point, regardless of the rotation angle of the subject support surface 114. This is advantageous because, for example, by positioning the target region of the patient 140 at the isocenter 124, it can be ensured that radiation passes through the target region for all rotation angles of the subject support surface 114. By rotating the object support surface 140 (and thus the patient 140), radiation can be distributed through healthy tissue while rotating around the isocenter 124. This ensures that the maximum amount of radiation still passes through the target area, maximizing treatment efficiency and allowing for reduced treatment time. For the wide variety of radiotherapy devices with different geometries, positioning the object support surface rotation mechanism 120 outside the radiation plane allows for minimizing the dose received by the healthy tissue of the object 140 during radiotherapy. In particular, the radiotherapy device includes an aperture for receiving the object 140. As a background, in known devices, the rotation mechanism is located in the radiation plane, such as... Figure 1 As shown, this makes them unsuitable for radiotherapy devices that include holes.

[0030] According to one embodiment, Figure 3 A radiotherapy device suitable for delivering a radiation beam to a patient during radiotherapy treatment is described. To provide useful accompanying information for the invention, the device and its components will be generally described. Figure 3 The apparatus described herein is based on this disclosure and is suitable for use with the disclosed systems and devices, although not all features are required, or as... Figure 3 As depicted in [the text]. Although Figure 3 The device described is an MR-linac, but embodiments of this disclosure can be any radiotherapy device, such as a linear accelerator (linac) device. Figure 3 Features shared with known devices (especially, for example, Versa HD™), and features involved in the generation of the therapeutic beam 110. According to the invention, by providing an object support surface rotation mechanism 120, modifications are made relative to known devices. Figure 3 The embodiments shown are described in more detail below.

[0031] Figure 3The device shown is an MR-linac. This device includes both an MR imaging unit 112 and a radiotherapy (RT) unit, which may include a linear accelerator unit. In operation, the MR scanner generates MR images of the patient 140, which can be used to determine the position of the patient 140 on a recliner 114 and the position of a target region (e.g., a tumor) within the patient 140, such that the position of the target region relative to the recliner 114 can be determined. The linear accelerator unit generates and shapes the radiation beam and guides it toward the target region within the patient's body according to the radiotherapy treatment plan. In a commercial environment such as a hospital, the usual "casing" covering the MR imaging unit 112 and the RT unit is not included. Figure 3 It is depicted in the text.

[0032] Figure 3 The MR-linac device depicted includes a radiation source 106. Radiation source 106 may include beam-generating devices such as one or more of the following: a radio frequency source 102, a circulator 118, an electron source 105, a waveguide 104, and a target (not shown). The MR-linac may also include a collimator 108 (e.g., a multi-leaf collimator) configured to collimate and shape the beam, an MR imaging device 112, and a patient support surface 114. The device also includes a housing that, together with the circumferential gantry, defines an aperture. The movable object support surface 114 can be used to move a patient or other object into the aperture when an MR scan and / or radiotherapy is about to begin or during treatment. The MR imaging device 112, the RT device, and the object support surface actuator are communicatively coupled to a controller or processor. The controller is also communicatively coupled to a memory device including computer-executable instructions executable by the controller.

[0033] The RT device includes a radiation source 106 and a radiation detector (not shown). Typically, the radiation detector is positioned radially opposite the radiation source 106. The radiation detector is adapted and configured to generate radiation intensity data. In particular, the radiation detector is positioned and configured to detect the intensity of radiation that has passed through an object. The radiation detector can also be described as a radiation detection device and can form part of an illumination field imaging system.

[0034] Radiation source 106 defines the point at which the treatment beam 110 is introduced into the aperture. Radiation source 106 may include a beam generation system, which may include an RF energy source 102, an electron gun 105, and a waveguide 104. The beam generation system is attached to a rotatable gantry 116 so as to rotate together with the gantry 116. In this way, radiation source 106 can rotate around patient 140, allowing the treatment beam 110 to be applied from different angles around gantry 116. In a preferred embodiment, gantry 116 can rotate continuously. In other words, gantry 116 can rotate 360 ​​degrees around patient, and in fact, can continue to rotate beyond 360 degrees. Gantry 116 rotates about a mechanical isocenter, which is the spatial point around which gantry 116 rotates, and about a fixed axis 119. Radiation isocenters can be defined as the points where radiation beams intersect. These two isocenters 124 need not be identical, although they can be. In this disclosure, the term isocenter 124 can refer to one or both of these. The isocenter 124 is located within the radiation plane. The frame 116 can be annular. In other words, the frame 116 can be an annular frame with openings. The frame 116 can also be non-annular, but can be, for example... Figure 1 The open rack shown.

[0035] A radio frequency (RF) source 102 (e.g., a magnetron) is configured to generate RF waves. The RF source 102 is coupled to a waveguide 104 via a circulator 118 and configured to pulse the RF wave into the waveguide 104. The RF wave can travel from the RF source 102 through an RF input window and into an RF input connection conduit or tube. An electron source 105 (e.g., an electron gun) is also coupled to the waveguide 104 and configured to inject electrons into the waveguide 104. In the electron source, electrons are thermally emitted from the cathode filament as it is heated. The temperature of the filament controls the number of injected electrons. The injection of electrons into the waveguide 104 is synchronized with the pumping of the RF wave into the waveguide 104. The design and operation of the RF source 102, the electron source, and the waveguide 104 are such that the RF wave accelerates the electrons to very high energies as they propagate through the waveguide 104.

[0036] Radiation source 106 is configured to direct therapeutic radiation beam 110 toward a patient positioned on patient support surface 114. Radiation source 106 may include a heavy metal target toward which high-energy electrons exiting a waveguide are directed. When electrons strike the target, X-rays are generated in various directions. A master collimator may block X-rays traveling in certain directions and allow only forward-traveling X-rays to pass through to generate therapeutic beam 110. X-rays may be filtered and may pass through one or more ion chambers for dose measurement. Before the beam enters the patient's body as part of radiotherapy, it may be shaped in various ways by beam-shaping devices, such as by using a multi-leaf collimator 108.

[0037] In some embodiments, the radiation source 106 is configured to emit an X-ray beam or an electron particle beam. Such an embodiment allows the device to provide electron beam therapy, i.e., an external beam therapy, in which electrons, rather than X-rays, are directed toward a target region. A "swap" can be made between a first mode emitting X-rays and a second mode emitting electrons by adjusting components of the linear accelerator. Essentially, the switching between the first and second modes is achieved by moving a heavy metal target into or out of the electron beam path and replacing the heavy metal target with a so-called "electron window." The electron window is substantially transparent to the electrons and allows the electrons to exit the flight tube.

[0038] Figure 3 The radiotherapy device / apparatus depicted also includes an MR imaging device 112. The MR imaging device 112 is configured to acquire images of an object positioned (i.e., located) on an object support surface 114. The MR imaging device 112 may also be referred to as an MR imager. The MR imaging device 112 may be a conventional MR imaging device 110 that operates in a known manner to acquire MR data (e.g., MR images). Those skilled in the art will understand that such an MR imaging device 112 may include a main magnet, one or more gradient coils, one or more receiving coils, and an RF pulse applicator. The operation of the MR imaging device is controlled by a controller.

[0039] A controller is a computer, processor, or other processing device. A controller may be formed from several discrete processors; for example, a controller may include an MR imaging device processor that controls the MR imaging device 112; an RT device processor that controls the operation of the RT device; and an object support surface processor that controls the operation and actuation of the object support surface. The controller is communicatively coupled to memory, i.e., a computer-readable medium.

[0040] As those skilled in the art will understand, linear accelerator devices also include several other components and systems. For example, appropriate shielding is provided to ensure that the linear accelerator does not leak radiation.

[0041] A patient support surface 114 may be used to support an object. The object may be a human body (e.g., a patient), an animal body, or a material sample. The object support surface 114 is configured to move parallel to a longitudinal axis 113 between a first position generally outside the aperture and a second position generally inside the aperture. In the first position, the patient 140 or the object may mount the object support surface 114. The object support surface 114 and the patient 140 may then extend within the aperture to the second position to image the patient 140 via an MR imaging device 112 and / or to image or treat the patient 140 using an RT device. Movement of the object support surface 114 is achieved and controlled by an object support surface actuator, which may be described as an actuation mechanism. The actuation mechanism is configured to move the object support surface 114 in a direction parallel to and defined by the longitudinal axis of the object support surface 114. The terms object and patient are used interchangeably herein, such that the object support surface 114 may also be described as a patient support surface 114. The object support surface 114 may also be referred to as a movable or adjustable recliner or table.

[0042] The present invention differs from known devices as follows: The object support surface 114 is connected to the object support surface rotation mechanism 120. The rotation mechanism 120 can be attached to the base plate shown, or, for example, to the device housing or frame 116 (e.g., as shown in the image). Figure 4A (As shown in the diagram). The rotation mechanism 120 is configured to rotate the patient support surface 114 such that its axis of rotation passes through the isocenter 124 of the frame 116. The patient support surface 114 or a portion thereof may rotate about (around) the longitudinal axis 113 (roll), about the lateral axis 115 (pitch), or about an axis perpendicular to the base plate 111 (yaw), or any combination thereof.

[0043] Despite Figure 3In the diagram, the plane of rotation of the patient support surface 114 is shown parallel to the base plate (as defined by the xy plane, which corresponds to the plane in which the patient support surface 114 is in its neutral position, where x is the longitudinal axis 113 and y is the transverse axis 115), wherein the rotation is a yaw about axis 111. However, as an example, the angle of the plane of rotation relative to the base plate can be 3, 15, 45, or 90 degrees with respect to the base plate. However, for patient comfort, the angle will generally be kept quite low. The tilt can also be changed before or during treatment. The object support surface rotation mechanism is configured to rotate the object support surface about the object support surface rotation axis by + / - 40-20 degrees, more preferably 35-25 degrees, and most preferably 30 degrees. The rotation mechanism 120 and / or the patient support surface 114 may also be connected to an additional rotation mechanism (not shown) configured to rotate the rotation mechanism 120 and / or the patient support surface 114 in different planes, wherein the rotation axis also passes through the isocenter 124. In this way, the patient support surface 114 can be connected to more than one rotation mechanism, each configured to move the patient support surface 114 in different planes. Alternatively, a single rotation mechanism 120 can be configured to rotate the patient support surface 114 in more than one plane, with the axis of rotation of each plane of rotation of the patient support surface 114 passing through the isocenter 124. The main consideration is that the center of rotation (around any axis) is located at or near the isocenter 124. As a result, the treatment beam can be consistently focused on the area requiring treatment.

[0044] By rotating the recliner around the isocenter, and thus the patient around the isocenter, the radiation dose can diffuse through healthy tissue, minimizing the radiation dose received by the healthy tissue surrounding the target area. This improves the health of patient 140. If the rotation of the recliner 114 is not around the isocenter 124, then the position of the target area will shift relative to the isocenter 124 (and the focal point of radiation), thus resulting in an increased radiation dose received by the healthy tissue. Furthermore, this would lead to a longer treatment time because the target area would not receive the expected dose of radiation.

[0045] This disclosure provides a rotational device for rotating a patient support surface about an isocenter 124 while positioning the patient support surface rotation mechanism 120 outside the radiation plane. This is particularly useful for annular gantry / aperture solutions or devices where the gantry 116 rotates 360°, for which positioning the rotation mechanism 120 within the radiation plane without disturbing the gantry 116 is problematic. However, this disclosure is applicable to any radiotherapy device. While this disclosure is not limited to aperture solutions (annular gantry), aperture solutions offer improved device stability. Furthermore, aperture solutions are less imposed or disturbing to the patient. Therefore, aperture solutions may be desirable. This disclosure provides a device for supplying non-coplanar treatment (where both the gantry 116 and the patient support surface 114 rotate) in a radiotherapy device with an aperture solution.

[0046] This disclosure provides a rotating device located outside the plane of the frame 116, and therefore outside the radiation plane or contour lines. Positioning the rotating device 120 outside the radiation plane minimizes radiation interference.

[0047] An example of a specific link and structure for rotating an object support surface about a rotation axis passing through an isocentric point will now be described, wherein the object support surface rotation mechanism is located outside the radiation plane.

[0048] exist Figure 4A , Figure 4B and Figure 5An embodiment is illustrated from three different perspectives. These figures show a patient support surface 114 (which can also be described as a recliner or patient positioning system) supported and connected to a rotating mechanism 120. The recliner 114 is directly connected to the rotating mechanism 120, or connected via an intermediate element, and can be connected by any suitable means, such as a mechanical connection. The recliner 114 may include several rollers, a tabletop 144, a base, or other components. In these figures, the rotating mechanism 120 is connected to a frame 116, but it may also be alternatively or additionally connected to a base plate, wall, or other support structure. The rotating mechanism 120 shown here utilizes two curved guides or tracks 122, the centers of curvature of which may be approximately located at an isocenter 124. For example, the center of curvature (and the center of rotation of the patient support surface 114) can be within 0.005 to 0.015 mm, more preferably 0.01 mm; 0.05 mm to 0.15 mm, more preferably 0.1 mm; 0.15 mm to 0.25 mm, more preferably 0.2 mm; 0.25 to 0.35 mm, more preferably 0.3 mm; 0.35 mm to 0.45 mm, more preferably 0.4 mm; 0.45 mm to 0.55 mm, more preferably 0.5 mm; 0.5 mm to 1.5 mm, more preferably 1 mm; or another distance from the isocenter 124. Ideally, the center of curvature of each curved track 122 and the center of rotation of the recliner 114 will be as close as possible to the isocenter 124. There can be one curved track 122 or any larger number. In one example with two curved tracks 122, the two curved tracks 122 have the same radius. In another example, the two curved tracks 122 have different radii, but the centers of curvature of the two curved tracks 122 are still the same.

[0049] The rotating mechanism 120 itself can be in any direction (e.g., as shown in the image). Figure 4A The patient support surface 114 can move up and down (vertically as shown in the diagram). The patient support surface 114 can move in any direction. Alternatively, or additionally, the patient support surface 114 may include a tabletop 144 that is capable of moving independently of the rest of the patient support surface 114 (e.g., a table base) and in any direction (e.g., a longitudinal direction (along the longitudinal axis 113 of the patient support surface 114), a lateral direction (along the lateral axis 113 of the patient support surface 114), a vertical direction (along the vertical axis 111, which is an axis perpendicular to the base plate), or a direction inclined to any of these directions). In some embodiments, the longitudinal direction 113 may be described as the Y direction 113. The lateral or transverse direction 115 may be described as the X direction 115. The vertical direction 111 may be described as the Z direction 111. Rotational, vertical, or other movements may be manually driven or driven by, for example, one or more motors.

[0050] exist Figure 4A , Figure 4B and Figure 5 In the example shown, the plane of rotation of the recliner 114 is shown parallel to the base plate. This may be the case, but is not limited to. The curved track 122 itself may be tilted and fixed to the base plate, or the tilt may actually change before, during, or after the recliner 114 rotates. Furthermore, the recliner 114 may include a tabletop 144, which is itself configured to rotate, for example, about the axis of the aperture or the longitudinal axis 113. This is also used to minimize the radiation dose received by healthy tissue surrounding the target area.

[0051] Rotation of the patient support system 114 can occur before, during, or after treatment. Rotation can be continuous or discrete / static. Rotation of the recliner 114 can also occur with or without the table 144 extended. Rotation of the recliner 114 can also occur simultaneously with the table 144 extended. In one example, the patient 140 lies on the recliner 114 in its non-extended position. The recliner 114 then extends, and the patient is scanned and exposed to radiation. Radiation is then stopped, and the recliner 114 is manually rotated (yawed) by sliding it along the curved track 122, and the patient is then exposed to further radiation. In another example, radiation is not stopped, and rotation of the recliner 114 occurs automatically, while the patient is simultaneously exposed to radiation.

[0052] The rotation can be controlled by a processor, which may be included in the patient support surface 114 or found elsewhere. For example, the processor can control the rotation speed, rotation angle, or amount of rotation. The processor can also be used to control radiation emission, radiotherapy treatment, or other operations of the radiotherapy device. This allows the rotation of the recliner 114 to be synchronized with the operation of the radiotherapy device or the implementation of radiotherapy treatment.

[0053] In solutions for holes, for example as shown in Figure 4 and Figure 4A As shown, the rotation of the recliner 114 can be prevented at certain angles by the frame 116 or the frame cover. For example, the recliner 114 can rotate + / - 30 degrees from the neutral position. 0 The neutral position is when the recliner 114 is aligned with the axis of the hole and parallel to the base plate. When the patient support system 114 is fully extended into the hole, rotation may be less compared to when the patient support system 114 is not extended or only partially extended into the hole. As a result, this system is particularly suitable for the treatment of the head and neck.

[0054] One or more curved tracks 122 may be made of the same or different materials. For example, each curved track 122 may be made of metal (e.g., steel). The curved track 122 may be fixed to a base plate or another support surface. The track includes a slide rail and a slider. The slider may be attached to a table or frame. The sliding position may be controlled by a linear motor, timing belt, or direct drive. Direct drive is a separate toothed track or a toothed track integrated into the track. To help prevent the slider from drifting between tracks, some deflection may be used to compensate for tolerances.

[0055] Alternatively, the rotation mechanism 120 may not actually include the curved track 122, but may include one or more curved grooves whose centers of curvature are approximately located at the isocenter 124, wherein the one or more curved grooves are used to guide the rotation of the patient support surface 114 about the isocenter 124. Alternatively, the rotation mechanism 120 may include one or more curved tracks 122 and one or more curved grooves, both of which have their centers of curvature approximately located at the isocenter 122. When the center of curvature is referred to as being approximately located at the isocenter 122, this includes falling at any point approximately along the vertical axis passing through the isocenter 122 and the isocenter 122 itself. Accordingly, it will be apparent that the specific means for guiding the rotation can be varied, and the important concept is that the center of curvature of the rotation guide is approximately located at the isocenter 124.

[0056] At the same time or at different times, synchronously or separately from the patient support surface 114, the radiation source or gantry 116 itself may also rotate partially about the transverse axis of the short end of the patient support surface 114 in its neutral position, although not necessarily when the patient support surface 114 is in its neutral position.

[0057] By using a rotating mechanism 120 comprising a curved track as described, pure isocentric rotation of the patient support system 114 can be induced without the rotating mechanism 120 sharing a common mechanical axis with the gantry 116. In other words, isocentric rotation and its associated benefits are achieved while keeping the rotating mechanism 120 outside the radiation unit, without interfering with gantry rotation or radiation delivery. Accordingly, this disclosure allows for minimizing the dose received by healthy tissue during radiotherapy treatment.

[0058] exist Figure 6 , Figure 7 and Figure 8Another embodiment is shown from three different perspectives. These figures illustrate a patient support surface 114 supported by and connected to a rotating mechanism 120. The recliner 114 is directly connected to the rotating mechanism 120, or connected via an intermediate element, and can be connected by any suitable means, such as a mechanical connection. The recliner 114 may include several rollers, a tabletop 144, a base, or other components. In these figures, the rotating mechanism 120 is connected to the base plate, particularly to a recess 121 forming part of the base plate, but it may alternatively or additionally be connected to a frame 116, a wall, or other support structure. The rotating mechanism 120 is shown as being partially included within the recess 121, but it may be formed entirely within the recess 121. Figure 6 , Figure 7 and Figure 8 The rotating mechanism shown is the same as described above. Figure 4A , Figure 4B and Figure 5 The rotating mechanism shown is similar. For example, rotating mechanism 120 utilizes two curved tracks 122, the centers of curvature of which are approximately located at isocenter 124. However, in this embodiment, the curved tracks 122 are stacked on top of each other, that is, they are parallel to each other but spaced apart from each other in the vertical direction (e.g., along the vertical axis). The vertical axis 111 is the axis of rotation. Rotating mechanism 120 is shown as being included within frame 123.

[0059] In this embodiment, the recliner 114 is connected to the curved track 122 via an arm 125. The arm 125 can be connected to the curved track 122 using any suitable means. For example, the arm 125 may include a first groove and a second groove for engaging with the first and second curved tracks 122. The first and second grooves may be straight or curved (with a radius of curvature designed to match the radius of curvature of the curved track 122). In this example, the arm 125 also serves as the base of the recliner 114, but the arm 125 may be separate from the base of the recliner 114. In one example, a curved groove is used instead of the curved track 122. Any other suitable curved guide may also be used instead of the curved track 122 mentioned in this disclosure. In another example, the curved groove is used in conjunction with the curved track 122, both having the same center of curvature and located at an isocenter 124 (or along a point on a vertical axis passing through the isocenter 124). In another example, the curved track 122 has a different radius than the curved groove, but the centers of curvature of the curved track 122 and the curved groove remain the same.

[0060] By vertically separating the curved track 122 (or the curved track 122 and the curved groove), the rotating mechanism 120 can remain compact, thus saving horizontal space.

[0061] As described above, the patient support surface 114 may include an extendable tabletop 144, which is movable independently of the rest of the patient support surface 114 (e.g., a table base) and in any direction (e.g., the longitudinal direction (along the longitudinal axis 113 of the patient support surface 114)). This can extend from a first position to a second position, the first position being, for example, a position outside the plane of the rack 116 (e.g., ...). Figure 10A As shown in the diagram, the second position is, for example, a position that causes a portion of the recliner 114 or tabletop 144 to lie within the plane of the frame 116. This serves a variety of purposes, including enabling the patient 140 to easily climb onto the recliner 114 when in the first position, and then positioning the patient 140 to receive the treatment bundle 110 in the second position. This stretching can also be performed to compensate for movement of the recliner 114. This stretching can also be performed as part of a spiral therapy, as described in the background section.

[0062] like Figure 9 As shown, when the tabletop 144 is in the second (extended) position, the weight of the patient 140, the tabletop 144 itself, or both cause the tabletop 144 to flex (or bend or deflect as may be used herein). For illustrative purposes, Figure 9 The amount of deflection described is exaggerated. Embodiments of the invention provide a system that allows for compensation of the curvature of the platform 144 in such a way that radiation can be more precisely focused onto the target region. This will be explained with reference to the structure and operation of the system below.

[0063] Figure 10A Figure 10B and Figure 11 A system for positioning a subject (e.g., patient 140) within a radiotherapy device is shown. The radiotherapy device is similar to the one described above. Figure 3 The described radiotherapy device, however, includes an object support surface 114 that also includes one or more sensors 146 configured to measure the vertical position of the table surface 144. In one embodiment, as... Figure 10A , Figure 10BAs depicted, the object support surface 114 is connected to the frame 116 and also includes a rotation mechanism 120 (in this case, one or more curved tracks 122) within the object support surface 114, although it does not necessarily include any rotation mechanism 120. In this way and with reference to these figures, the object support surface 114 refers to everything that supports and positions the table 144 in such a way as to position the object 140 to receive the treatment bundle 110, including the rotation mechanism 120 (if present). The object support surface 114 may not be connected to the frame 116, but instead to a support surface (e.g., a base plate). As previously stated, one or more motors can be used to extend the table 144 along the longitudinal axis 113, and these one or more motors may be electric motors with an absolute encoder or other encoders, although any other suitable drive mechanism may be used instead of one or more of these motors. The table 144 itself is supported in exactly the same way in the external (first, non-extended) position and the internal (second, extended) position, such that the absolute deflection of the table 144 will be the same throughout the entire stroke (the entire range of extension of the table 144).

[0064] Figure 10B An enlarged view of the area including sensor 146 is shown. Sensor 146 is located near the entrance to the aperture in rack 116. Although in Figure 9 , Figure 10A , Figure 10B and Figure 11 The embodiment depicted is a radiotherapy device with holes, but the system may also be without holes, and instead may have an open rack.

[0065] Sensor 146 is communicatively coupled to the processor and configured to send data to the processor directly or indirectly. In one example, sensor 146 includes a linear variable differential transformer (LVDT) configured to convert mechanical motion into current. LVDT sensors are known technology, and their operating modes will not be described in great detail here. However, physically, an LVDT structure is a hollow metal cylinder in which a smaller diameter shaft moves freely along the long axis of the cylinder. Sensor 146 also includes a pressure wheel that is always in contact with the underside of the platform 144 in a first position, a second position, and between these positions. When the platform 144 extends, it flexes, as described above. This causes the pressure wheel to compress, causing the shaft of the LVDT with the smaller diameter to move within the larger cylinder, which in turn results in a current corresponding to the displacement of one cylinder relative to the other. Thus, sensor 146 is used to measure the deflection of the platform 144. Other suitable sensors may also be used. In particular, other sensors are known for providing accurate and easy measurement. For example, an alternative sensor could be a laser triangulation device of a type known to those skilled in the art, provided it is radiation-resistant, since the sensor is close to the beam in the scattering region. Alternatively, the sensor could include one or more ultrasonic sensors. The compression of sensor 146 is related to the position of platform 144, which in turn is related to the deflection or bending of platform 144. Any of these values, or an electrical signal capable of calculating any of these values, is then transmitted to a processor, enabling the processor to determine the deflection of platform 146.

[0066] Sensor 146 is included in the object support surface 114 so as to measure only the deflection of the tabletop 144. Sensor 146 is located outside the imaging / radiation volume and attached to the recliner 114 such that when the patient 140 moves into the opening along with the tabletop 144, structural deflection of the rest of the recliner 114 is disregarded. In this way, only the deflection of the tabletop 144 is measured. Although only one sensor 146 is depicted, it should be understood that multiple sensors 146 may be used, for example, to provide redundancy. The same lateral position is measured to avoid any variation in the measurement caused by lateral movement and / or the uneven underside of the tabletop 144.

[0067] When the tabletop 144 is in the second longitudinal position (i.e., the extended position), the measured bending is smaller compared to when it is in the first longitudinal position (i.e., the non-extended position). When the tabletop 144 is loaded, i.e., when the patient 140 is on the tabletop 144, the amount of bending at both longitudinal positions will increase. In the loaded state, the patient's weight increases the bending moment on the tabletop 144. The tabletop 144 is actually a cantilever supported at two points toward one end of the tabletop. The bending moment is zero at the free end and becomes maximum toward the supported end. Relative deflection, deflection change, and / or deflection increase can be determined by measuring the deflection of the tabletop 144 in its first position and in its second position. It should be understood that deflection is a value equivalent to relative position, and this value is calculated based on the change in position of the tabletop 144 in the vertical 111 direction at the position of the sensor 146 along the longitudinal axis 113 between the first and second positions and / or between the unloaded reference state and the loaded state, or as will be described below. Furthermore, although for simplicity, the deflection relative to the first and second positions is discussed here, the position of the tabletop 144 can be measured at more than two positions. For example, the position of the tabletop 144 can be measured at 5, 10, 100, 1000, or some other number of positions along the longitudinal axis 113 of the tabletop 144's extension. As another example, the position of the tabletop 144 can be measured at different extension levels along the longitudinal axis 113 (e.g., at intervals of 50 mm, 10 mm, 1 mm, or other intervals). Thus, the position of the tabletop 144 in the vertical direction relative to the first position (also referred to as deflection) can be determined for several different positions, each corresponding to a specific extension of the tabletop 144 on a scale from no extension to full or maximum extension (this can refer to the maximum extension used for a particular treatment rather than the maximum possible extension). In one example, the measurement area is the entire treatment area, and the deflection is measured at at least three different positions to determine the tilt angle of the tabletop 144. When the treatment area is longer, more measurements can be taken because the tilt angle will vary.

[0068] During operation, with the tabletop 144 in its non-extended position, the patient 140 climbs onto the object support system 114. The tabletop 144, with the patient 140 on it, then extends into the orifice, and the deflection of the tabletop 144 is measured at several locations during its delivery into the orifice. The amount of deflection (or the vertical position of the tabletop 144 at the location of the sensor 146) is measured at each location by the sensor 146 and stored in memory associated with the processor. In this way, the processor can generate and record a deflection profile. For example, this profile may resemble a portion of a negative exponential curve or some other shape, such as... Figure 9 As shown in the image.

[0069] The object 140 is then imaged to locate the target region, allowing the treatment beam 110 to be focused on that region. The object support surface 114 can also be controlled and extended in the vertical 111 or horizontal 115 direction, such that the target region is located at or near the radiation isocenter 124 or other desired location.

[0070] Then, a spiral treatment is performed, in which the table 144 retracts (opposite to the previous extension) while the treatment bundle 110 is applied. As the table 144 retracts, its deflection decreases. The deflection profile, determined by the processor, is used to predict the vertical position of the target area based on the current level of extension (or amount of retraction). It is known that the target area does not move (retract) exactly parallel to the axis of the aperture 113, but instead follows a specific (e.g., banana-shaped) profile relative to the axis of the aperture, which allows the treatment to be adjusted accordingly.

[0071] For example, treatment can be deflected in such a way that the radiation isocenter 124 can be precisely maintained within the target area during treatment, over the entire distance the table 144 moves along the longitudinal axis 113. In one example, the vertical position of the table 144 can be raised or lowered along the vertical axis 111 to coordinate the absolute vertical position of the table 144 with the deflection profile, thereby maintaining the target area approximately at the isocenter and optimizing treatment by reducing the amount of healthy tissue exposed to harmful radiation. This vertical movement is initiated and controlled by the object support surface 114, which, as described above, is configured to extend the table 144 along the vertical axis 111. In other words, treatment can be correlated with and used with a predicted deflection profile during the retraction of the table 144, which is the inverse of the deflection profile determined during the extension of the table 144. The processor that determines the deflection profile can be used to synchronize treatment according to the deflection profile, or it can provide the information necessary to do so to another processor for controlling the treatment. This allows for precise spiral therapy to be performed while only initial images are being captured, rather than during the treatment itself. This reduces the harmful effects of imaging while also increasing the speed of treatment.

[0072] In one example, a lung spiral therapy is performed using the disclosed device. The therapy is performed by scanning the treatment beam 110 over the target area, starting from the end of the patient 140, which includes the patient's head, and moving 500 mm down the patient's body. As will now be explained, the scanning is achieved by physically moving the patient 140 on the table 144 to pass through the treatment beam 110. In one example, the treatment beam is also moved. For example, a tilted beam can be used.

[0073] To position the patient 140, the patient 140 first climbs onto the tabletop 144 in a first non-extended longitudinal position. The tabletop 144 is connected to the recliner 114 via two connection points (also referred to as tabletop attachment points 148) (although the number may be larger or smaller). These two tabletop attachment points 148 are fixed to the tabletop 144 such that the tabletop 144 is attached in both the first and second positions via the same two points 148. However, the connection 148 to the object support surface 114 can be moved relative to the object support surface 114 from the first longitudinal position to the second longitudinal position. This longitudinal movement can be achieved using any suitable means. For example, the tabletop 144 can be connected to the recliner 114 in such a way that it is configured to move along a set of rollers, sliders, or tracks in the longitudinal direction. Movement along the longitudinal axis 113 from the first position to the second position can be manually driven, but can also be driven by, for example, one or more electric motors or by any other suitable means.

[0074] The weight of the patient 140 on the table 144, especially if the patient 140 is large, will cause the table 144 to deflect by, for example, an amount of 3 mm. The table 144 is considered to be in a loaded state when an object 140 is located on it. The amount of deflection will vary along the length of the table 144, becoming even greater further away from the table attachment point 148. However, once the patient 140 is on the table 144, the absolute amount of deflection of the table 144 will not change during treatment or as the table 144 is extended, unless the patient moves relative to the table 144. The table 144 may include additional devices to prevent the patient 140 from moving on it during treatment or transport into the orifice, such as belts, blocks, hoops, or other suitable devices. In other words, the overall deflection of the table 144 does not change with the extension of the table 144, but is only the amount of deflection measured relative to a specific longitudinal point (i.e., relative to sensor 146).

[0075] Before the patient 140 is positioned on the tabletop 144, the sensor 146 provides a first reference value or signal. This value or signal generated by the sensor 146, and subsequent values ​​or signals, can be considered to represent the height of the tabletop 144 at the position of the sensor 146 in the unloaded state. When the patient 140 is positioned on the tabletop 144 in its first (non-extended) position (i.e., loaded state), the tabletop 144 flexes and the sensor 146 is compressed, causing an electrical signal or change in electrical signal to be communicated to the processor, allowing the processor to determine the new height of the tabletop 144, and thus the amount of deflection caused by the specific patient 140 along the tabletop 144 in the first position. For example, the sensor 146 can determine that when comparing the height of the tabletop 144 in its first position with the patient 140 on it to the height of the tabletop 144 in its first position without the patient 140 on it, the height of the tabletop 144 has changed by 3 mm (in other words, deflection).

[0076] In this example, the platform 144 then extends along the longitudinal axis 113 into the aperture to position the lower end of the target area outside the location that will be the radiation center during treatment. At this point, the approximate location of the target area is known due to the prior diagnosis. The approximate location of the target area can be physically marked on the patient 140 using a pen or tattoo. This can be used to assist in moving the patient 140 to the approximate correct position to receive the start of treatment, for example, manually by an operator. This can be assisted by using laser positioning. However, due to swelling or other reasons, the actual location of the target area may shift inside the patient 140 relative to the marked position on the outside of the patient 140. To accurately know the location of the target area during or close to treatment, so that the patient can be precisely positioned to reduce any unnecessary exposure of healthy tissue to the treatment beam, the patient 140 is scanned using an MR imaging device 112 to obtain initial CBCT images. This allows for precise location of the target area, enabling further adjustment of the recliner 114, for example, by extension in the vertical 111, lateral 115, or longitudinal 113 directions, to precisely position the patient 140, and particularly the target area, relative to the isocenter or isocenter 124. For example, the target area may be located within 3 mm, 1 mm, or 0.1 mm of the desired location. In one example, it is desired that the target area be within 1 mm of the desired location. The table extension in this position will be referred to as the second (extended) position, although the second position may also be at a greater extension than that suitable for initiating treatment. When the table 144 is in the second position, the sensor 146 provides a second height measurement of the table 144, which, when compared with a reference value, determines the deflection of the table 144 in the second position at the location of the sensor 146. This second deflection can be compared by the processor with a first deflection to determine the change in deflection between the first and second longitudinal positions. Because in the second longitudinal position, the sensor 146 measures the height of the platform 144 at the end of the platform 144 near the platform attachment point 148, the deflection determined for the second longitudinal position is expected to be less than the deflection determined for the first longitudinal position.

[0077] Between the first and second positions, the deflection will vary by an unknown amount, which will depend on the proximity of that position to the attachment point 148 of the table 144, and cannot be easily calculated without knowing the centroid of the object 140. This is something that varies between objects 140 and is difficult to determine. As a result, sensor 146 is used to measure the height of the table 144 at one or more positions between the first and second positions (corresponding to different levels of extension of the table 144 along the longitudinal axis 113). The first position is typically a non-extended position, while the second position is typically a position of maximum extension (for this treatment). In this example, sensor 146 measures the height of the table 144 every 1 mm for the first 1000 mm extension. The sensor 146 data is then used to determine the amount of deflection per 1 mm, and in this way, a deflection profile is generated by the processor. This deflection profile can be generated during or after the table 144 is transported into the orifice (or the patient 140 is loaded).

[0078] After the patient 140 is precisely positioned using CBCT images and the recliner 114 and table 144, treatment begins. As previously described, the treatment beam 110 is activated. Either continuously during the application of the treatment beam, or at one or more intervals between applications, the table 144 retracts a distance corresponding to the desired length of the target region receiving the treatment beam, in this case 500 mm. The deflection profile stored in memory associated with the processor can be used to predict the amount of deflection of the table 144, and thus predict the change in the vertical position of the target region at any given time / location of retraction. For example, if the deflection is 5 mm, the vertical movement will raise the recliner 114 or table 144 by 5 mm to compensate for the deflection.

[0079] As the table 144 moves from the second longitudinal position back to the first longitudinal position (or other positions in between corresponding to the ends of the target region, also referred to herein as the third longitudinal position), this allows for optimization of treatment by compensating for changes in the height of the target region. Treatment can be adjusted by a processor that determines the deflection profile, or the deflection profile can be transmitted to a separate processor configured to adjust the vertical height based on the deflection profile.

[0080] Once the table 144 has reached the third longitudinal position, treatment is stopped by completely closing the bundle. The table 144 is then fully retracted to the first longitudinal position so that the patient 140 can easily get off the recliner 114.

[0081] In one example, the processor is also configured to perform deflection measurements while the table 144 is retracting. These measurements can be compared to measurements taken during extension to see if the deflection has changed, which can indicate that the patient 140 has moved. The change in deflection value can be calculated by comparing the deflection at a specific point during table 144 retraction with the corresponding measurement at the same point during table 144 extension. In one example, the processor is configured to stop radiation if the change in deflection value is greater than a change in a deflection safety threshold. In one example, after radiation has been stopped in response to a change in deflection value greater than a change in the deflection safety threshold, the processor is configured to instruct a CBCT scan to accurately examine the position of the patient 140 and, for example, recalibrate the position of the target area accordingly. In another example, in response to a change in deflection value greater than a change in the deflection safety threshold, the processor is configured to modify the treatment in a manner that compensates for, for example, the change in deflection caused by movement of the patient 140.

[0082] The sensor 146 measuring the position and deflection of the table 144 needs to be fast and accurate. For example, the sensor may have an accuracy of approximately 0.1 mm or better to help ensure that the tolerances are at a reasonable level. As mentioned above, an LVDT sensor in which a magnet moves within a coil can be used. LVDTs have no electronics near the sensor and are simple. As mentioned above, an LVDT, such as an induSENSOR LVDT, may include a pressure roller or standard roller built into the LVDT. Alternatively, a triangulation sensor or proximity sensor can be used. Any other suitable type of sensor can also be used as sensor 146, as long as it can accurately determine the position or deflection of the table 144. Multiple sensors 146 can also be used to provide redundancy, to increase the reliability of the measurement and deflection profile, or for any other reason. In one example, multiple sensors 146 are positioned along the lateral axis 115 of the recliner 114 and configured to determine the deflection of the table 144 in the lateral direction. If multiple sensors 146 are used, these sensors 146 can be of the same kind or can be different from each other. In one example, one or more sensors 146 are selected to be radiation-resistant to prevent damage over time from scattered radiation from the linear accelerator and CBCT.

[0083] The countertop 144 is made of one or more rigid materials, such as steel, aluminum, titanium, composite materials, or any other suitable material. The countertop 144 may also include a softer material (e.g., foam) designed to improve the comfort or support of the patient 140. The countertop 144 may also include multiple layers, one of which includes plastic. In one example, these materials are chosen to be radiation-resistant to prevent them from becoming damaged or brittle after repeated exposure to emitted radiation.

[0084] While the material chosen for the tabletop 144 will be selected to provide a sufficient degree of rigidity, the disclosed system allows for the use of materials with less rigidity than required in a radiotherapy device without tabletop 144 bending compensation. This is because the bending caused by choosing a less rigid material can still be compensated for by adjusting the radiotherapy or other treatments, as described above. This results in a wider range of materials suitable for the tabletop 144. For example, materials with less rigidity but less radiation interference can be used. This, in turn, reduces the amount of radiation that must be generated, thereby saving power and minimizing damage to any healthy tissue exposed to radiation. Furthermore, rigid materials are typically expensive, and reducing the rigidity requirement makes cheaper or more commonly used materials available for the tabletop 144.

[0085] Additional sensors can be installed to also measure the deflection of the main body supporting the object's support surface 114, but this deflection will not be as large as the tabletop deflection. Structural deflection will depend on the longitudinal position 113 of the recliner 116 / tabletop 144. Deflection will exist in the main structure of the recliner 116, which is related to the rigidity of the material used in its construction—this is why rigid materials are needed. However, most of the deflection still comes from the deflection of the tabletop 144. In one example, markings are added to the tabletop 144, and this is then measured with a camera. For example, one or more cameras can be placed on the base plate and looking upwards at the underside of the tabletop 144, or they can be viewed from the side to determine the deflection. The camera needs to process high-resolution images to obtain measurement accuracy and a determination of the deflection within 0.1 mm. In another example, a C-Rad scanner system is used to measure the deflection.

[0086] The processor can also be configured to use data from memory that stores information such as the dimensions and configuration of components, so that this information can be used in calculations to control the movement of various components and to prevent, for example, the recliner 114 from colliding with the rack 116.

[0087] It should be noted that various embodiments can be implemented in hardware, software, or a combination thereof. Various embodiments and / or components, such as components and controllers used therein, can also be implemented as part of one or more computers or processors or field-programmable gate arrays (FPGAs). A computer or processor or FPGA may include computing devices, input devices, display units, and interfaces, for example, for accessing the Internet. A computer or processor may include a microprocessor. The microprocessor may be connected to a communication bus. A computer or processor or FPGA may also include memory. Memory may include random access memory (RAM) and read-only memory (ROM). A computer or processor or FPGA may also include a storage device, which may be a hard disk drive or a removable storage drive, such as an optical disk drive. The storage device may also be other similar means for loading computer programs or other instructions into the computer or processor.

[0088] As described above, this system allows for the precise execution of treatments such as spiral therapy without the need for re-imaging of the patient 140 during treatment (e.g., re-imaging the patient 140 after the table 144 has been partially retracted, which might otherwise be necessary). The system is also useful for long-field therapy, where table movement needs to be able to radiate the entire target area, as it improves the accuracy of the understanding of the target area's location when the table 144 moves from one position to another. Directly positioning the recliner 114 in the correct position before performing a CBCT scan saves time, thus eliminating the need for table calibration after the CBCT scan. The system is also well-suited for recliners 116 that do not have six degrees of freedom of motion. Re-imaging the patient 140 is harmful to the patient, therefore reducing the need for re-imaging reduces harm to the patient 140, thereby improving his or her health. Moreover, re-imaging may require stopping table movement and adds additional time and cost to the treatment. Eliminating the need for re-imaging thus increases the speed at which treatment can be performed, thereby increasing patient 140 throughput and improving the efficiency of the radiotherapy equipment. This system also enables the location of the target area to be determined with greater certainty and accuracy, allowing for more accurate and reliable treatment during the treatment of the target area. This also minimizes radiation received by healthy tissue.

Claims

1. A radiotherapy device for delivering radiation to a subject, the device comprising: A radiation source configured to rotate about an isocenter and emit radiation in a radiation plane containing the isocenter; An object support surface, configured such that a portion of the object support surface is approximately located at the isocenter; as well as An object support surface rotation mechanism is configured to rotate the object support surface about a rotation axis passing through the isocenter, wherein the object support surface rotation mechanism is located outside the radiation plane; and The object support surface rotation mechanism includes a first bending guide, the center of curvature of which is located at a vertical axis passing through the isocenter; and The radiotherapy device includes a frame, wherein the first curved guide is connected to the frame.

2. The radiation therapy device of claim 1, wherein, The axis of rotation is at least one of a longitudinal axis, a transverse axis, or a vertical axis.

3. The radiation therapy device of claim 1, wherein, The object support surface rotation mechanism is configured to rotate the object support surface before, after, or during treatment.

4. The radiotherapy device according to claim 1, wherein, The radiotherapy device includes a hole for accommodating the object.

5. The radiotherapy device according to claim 1, wherein, The object support surface rotation mechanism further includes a second bending guide, wherein the center of curvature of the second bending guide is located at a vertical axis passing through the isocenter.

6. The radiotherapy device according to claim 5, wherein, Each of the first bending guide and the second bending guide is aligned in a horizontal plane perpendicular to the vertical axis.

7. The radiotherapy device according to claim 5, wherein, Each of the first bending guide and the second bending guide is spaced apart from each other in the vertical direction.

8. The radiotherapy device according to claim 7, wherein, The first bending guide and the second bending guide are aligned along the vertical axis.

9. The radiotherapy device according to any one of claims 5 to 8, wherein, The first bending guide and the second bending guide are a first bending guide rail and a second bending guide rail.

10. The radiotherapy device according to any one of claims 5 to 8, wherein, The first bending guide and the second bending guide are a first bending groove guide and a second bending groove guide.

11. The radiotherapy device according to claim 9, wherein, The first curved guide rail and the second curved guide rail are connected to the frame.

12. The radiotherapy device according to any one of claims 1 to 8, wherein, The object support surface rotation mechanism is configured to rotate the object support surface by + / - 40-20 degrees around the object support surface rotation axis.

13. The radiotherapy device according to any one of claims 1 to 8, wherein, The object support surface rotation mechanism is configured to rotate the object support surface by + / - 35-25 degrees around the object support surface rotation axis.

14. The radiotherapy device according to any one of claims 1 to 8, wherein, The object support surface rotation mechanism is configured to rotate the object support surface by + / - 30 degrees around the object support surface rotation axis.

15. The radiotherapy device according to any one of claims 1 to 8, wherein, The object support surface includes: Extendable countertop; and A sensor configured to measure the vertical position of the extendable platform. The radiotherapy device includes: The processor, configured as follows: The deflection of the extendable platform is determined using the measured position; and The treatment of the radiotherapy device is controlled according to the deflection.

16. A method for controlling an object support surface in a radiotherapy apparatus, the radiotherapy apparatus including a radiation source configured to rotate about an isocenter and emit radiation in a radiation plane containing the isocenter, the method comprising: Provide an object support surface, the object support surface being configured such that a portion of the object support surface can be located approximately at the isocenter; as well as An object support surface rotation mechanism connected to the object support surface is used to rotate the object support surface about a rotation axis passing through the isocenter, wherein the object support surface rotation mechanism is located outside the radiation plane; and The object support surface rotation mechanism includes a first bending guide, the center of curvature of which is located at a vertical axis passing through the isocenter; and The radiotherapy device includes a frame, wherein the first curved guide is connected to the frame.

Images