3D imaging with combined therapeutic and non-therapeutic beams

Abstract

The radiation delivery system of the present invention initiates a radiation therapy session in which a therapeutic radiation source delivers a therapeutic radiation beam to a target, then directs one or more x-ray radiation sources to deliver imaging radiation beams through the target to one or more x-ray detectors, and acquires image data related to the target during the delivery of the therapeutic radiation beam, and uses the acquired image data to construct one or more volumetric images.

Description

Related Applications

[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. patent application Ser. No. 17 / 364,527, filed June 30, 2021, the entire text of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to three-dimensional (3D) imaging using a combination of therapeutic and non-therapeutic beams. [Background technology]

[0003] Radiation delivery systems used in radiation therapy often utilize images for patient alignment, motion tracking, and verification of the dose administered to the subject. Three-dimensional volumetric images are most useful for visualizing and tracking the relative positions of the tumor (i.e., the radiation therapy target) and surrounding organs. Images constructed from data acquired simultaneously with the delivery of therapeutic radiation provide the best representation of the subject's appearance at the moment the radiation is delivered. [Brief explanation of the drawings]

[0004] The present invention can be more fully understood from the following detailed description (embodiments of the invention) and the accompanying drawings illustrating various embodiments of the present disclosure.

[0005] [Figure 1A] 1 is an explanatory diagram illustrating a helical radiation irradiation system according to an embodiment of the present invention.

[0006] [Figure 1B] FIG. 1 is an illustration of a robotic radiation delivery system that can be used in accordance with embodiments of the present invention.

[0007] [Figure 1C] 1 is an explanatory diagram illustrating a C-arm gantry-based radiation delivery system according to an embodiment of the present invention.

[0008] [Figure 2] FIG. 2 is an explanatory diagram showing an example of a radiation irradiation system that uses an X-ray radiation source to acquire image data during irradiation of a therapeutic radiation beam according to an embodiment of the present invention.

[0009] [Figure 3A] FIG. 1 is an explanatory diagram showing an example of a radiation source of a radiation irradiation system that initially (at a first time) generates a therapeutic radiation beam according to an embodiment of the present invention.

[0010] [Figure 3B] FIG. 4 is an illustration of an example radiation source of an irradiation system that generates an imaging radiation beam at a second time, in accordance with an embodiment of the present invention.

[0011] [Figure 4] FIG. 2 is an illustration showing an example of a multi-leaf collimator forming a target aperture and a fan beam aperture in accordance with an embodiment of the present invention.

[0012] [Figure 5] FIG. 1 is a flow diagram illustrating a method for constructing a volumetric image using image data acquired during a therapeutic radiation beam delivery, according to an embodiment of the present invention.

[0013] [Figure 6] FIG. 1 is a block diagram illustrating an example of a computing device that may perform one or more of the operations of the present disclosure, in accordance with some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE INVENTION In the following, the present disclosure describes embodiments for generating one or more three-dimensional (3D) images during delivery of a therapeutic radiation beam. A radiation delivery system includes one or more radiation sources that generate a therapeutic radiation beam to deliver a therapeutic dose of radiation to a target, such as a tumor, and may also include one or more imaging radiation beams that are used to acquire image data related to the target.

[0015] Some conventional radiation delivery systems construct a three-dimensional volumetric image of a volume of interest containing a target, where the volumetric image is constructed by a processing device using, for example, a series of two-dimensional (2D) images taken before delivery of the therapeutic radiation beam begins. In the present disclosure, a radiation therapy session can be defined as the time from when a patient enters a room to begin radiation therapy to when the patient leaves the room. Furthermore, delivery of a therapeutic radiation beam can be defined as the time from when the therapeutic radiation beam is first turned on to when it is finally turned off. Note that, in embodiments of the present invention, the therapeutic radiation beam may be turned on and off during the delivery period of the therapeutic radiation beam. However, because such volumetric images are constructed using 2D images that were not acquired during delivery of the therapeutic radiation beam, they may not accurately represent the volume of interest at the time of delivery of the therapeutic radiation beam, which can make it difficult to accurately track target motion and estimate the therapeutic dose delivered to the target and / or other structures proximate to the target, such as patient organs.

[0016] In one aspect of the present invention, the above-mentioned drawbacks and other deficiencies can be ameliorated by constructing a volumetric image during delivery of a therapeutic radiation beam. In one aspect of the invention, processing logic in a processing device of a radiation delivery system can initiate a radiation therapy session to deliver a therapeutic radiation beam to a target, and during delivery of the therapeutic radiation beam, the processing logic can generate an imaging radiation beam from a radiation source and direct it through the target to one or more x-ray detectors to acquire image data related to the target.

[0017] In one aspect of the invention, a radiation delivery system can utilize a single therapeutic radiation source to generate a therapeutic radiation beam and an imaging radiation beam, which can be used in combination with image data captured by an imaging system of the radiation delivery system. In one aspect of the invention, pulses of one or more imaging radiation beams may be alternated between pulses of one or more therapeutic radiation beams, for example, one imaging beam pulse may occur after two therapeutic radiation beam pulses, or two imaging beam pulses may occur after one therapeutic radiation beam pulse. In one aspect of the invention, any number of pulses of the therapeutic radiation beam may be alternated with any number of pulses of the imaging radiation beam. In one embodiment, the therapeutic radiation source may generate the therapeutic radiation beam and the imaging radiation beam simultaneously, as described in more detail in FIG. 4 below.

[0018] In one aspect of the invention, the radiation delivery system can utilize multiple radiation sources. For example, the radiation delivery system can include a therapeutic radiation source and one or more X-ray radiation sources. In one embodiment, the one or more X-ray radiation sources can be offset relative to the therapeutic radiation source along an arc trajectory about the target. In some embodiments, one of the one or more X-ray radiation sources can be positioned in alignment with the therapeutic radiation source (collinear with the target) to provide image data corresponding to a viewpoint of the therapeutic radiation source.

[0019] Processing logic according to one aspect of the present invention can utilize image data acquired during delivery of a therapeutic radiation beam to construct one or more volumetric images, which can correspond to a volume of interest that includes the target. In some embodiments, processing logic may construct a volumetric image using a set of image data that is not fully sampled. For example, such processing logic may utilize an image reconstruction algorithm to construct a volumetric image from image data of a limited arc line. In another example, the processing logic may execute an iterative reconstruction algorithm to construct a most probable volumetric image from a set of undersampled image data that may not be a continuous arc line. In some embodiments, the processing logic may utilize pre-treatment image data, treatment planning image data, or previously acquired image data in addition to imaging data acquired during delivery of the therapeutic radiation beam to construct the volumetric image, where pre-treatment image data may include image data acquired before a radiation treatment session as well as image data acquired during a radiation treatment session and before delivery of the therapeutic radiation beam. In some embodiments, the therapeutic radiation beam can also be used to acquire image data that is used to construct a volumetric image.

[0020] According to one aspect of the present invention, an improved radiation delivery system is provided by constructing a volumetric image from image data acquired during delivery of a therapeutic radiation beam. In embodiments, the volumetric image can be used to more accurately estimate the therapeutic dose delivered to a target or an object proximate to the target (e.g., a radiation-sensitive structure such as a patient's organ). In some embodiments, the volumetric image can be used to correct (adjust) the delivery of the therapeutic radiation to compensate for movement or other visual changes in the target, thereby ensuring that the appropriate therapeutic dose is delivered accurately to the target.

[0021] FIG. 1A illustrates a helical irradiation system 800 according to an embodiment of the present disclosure. The helical radiation delivery system 800 includes a LINAC (linear accelerator) 850 mounted on a ring gantry 820. The LINAC 850 can be used to generate a radiation beam (i.e., a treatment beam) by directing an electron beam toward an X-ray radiation target. The treatment beam will deliver radiation toward a target area (i.e., a tumor). The treatment system further includes a multi-leaf collimator (MLC) 860 connected to the distal end of the LINAC 850. The MLC includes a housing containing multiple movable leaves, which can be moved to adjust the aperture of the MLC to enable treatment beam formation. In embodiments, the MLC 860 is a binary MLC including multiple leaves arranged in two opposing banks, where the leaves of the two opposing banks are interleaved and can be opened and closed to form an aperture. In some embodiments, the MLC 860 can be an electromagnetically actuated MLC, although the MLC 860 can also be any other type of MLC. The ring gantry 820 has a toroidal shape, and the patient 830 passes through the bore of the ring / toroid. The LINAC 850 is mounted around the periphery of the ring and rotates about an axis through its center to target radiation delivered from one or more angles around the patient. During treatment, the patient 830 can simultaneously move through the bore of the gantry on the treatment couch 840.

[0022] The helical radiation delivery system 800 includes an imaging system with a LINAC 850 as an imaging source and an X-ray detector 870. The LINAC 850 can be used to generate megavoltage X-ray images (MVCT) of a region of interest (ROI) of a patient 830. In this case, the patient 830 is imaged by projecting a series of X-ray beams toward the ROI and striking an X-ray detector 870 on the opposite side of the LINAC 850, generating setup and pre-treatment images. In one embodiment, helical radiation delivery system 800 may also include a secondary imaging system consisting of a kV (kilovoltage) imaging source 810 mounted on a ring gantry 820 orthogonal to (e.g., 90 degrees away from) LINAC 850 and positioned to project an imaging x-ray beam toward a target region and illuminate the imaging plane of a detector after passing through patient 130.

[0023] FIG. 1B illustrates a radiation therapy system 1200 used in accordance with an alternative embodiment described herein. As shown in FIG. 1B, the radiation therapy system 1200 includes a LINAC (linear accelerator) 1201 that functions as a radiation therapy source, and a multi-leaf collimator (MLC) 1205 connected to the distal end of the LINAC 1201 to form a treatment beam. In one embodiment, the LINAC 1201 is mounted and positioned at the end of a robotic arm 1202 with multiple (e.g., five or more) degrees of freedom to send beams from many angles and planes in a working area around the patient to irradiate a pathological anatomy (e.g., target). Treatment may involve beam paths with a single isocenter, beam paths with multiple isocenters, or beam paths with a non-isometric approach.

[0024] By moving the robotic arm 1202, the LINAC 1201 can be positioned at multiple different nodes (predefined locations where the LINAC 1201 stops and delivers radiation) during treatment. At the nodes, the LINAC 1201 can deliver one or more radiation treatment beams to the target, where the shape of the radiation beam is determined by the position of the leaves in the MLC 1205. The nodes can be positioned in an approximately spherical distribution around the patient. The specific number of nodes, and the number of treatment beams applied to each node, may vary depending on the location and type of pathological anatomy to be treated.

[0025] In another embodiment, the robotic arm 1202, and the LINAC 1201 at its end, can move continuously between nodes while radiation is being delivered. The shape and two-dimensional intensity map of the radiation beam are determined by the rapid movement of leaves in the MLC 1205 while the LINAC 1201 operates continuously.

[0026] The radiation therapy system 1200 includes an imaging system 1210. The imaging system 1210 includes a processing unit 1230 connected to X-ray sources 1203A and 1203B (i.e., imaging sources) and fixed X-ray detectors 1204A and 1204B. Alternatively, if the x-ray sources 1203A, 1203B and / or x-ray detectors 1204A, 1204B are movable, they may be repositioned to maintain alignment with the target or to image the target from different directions, and many x-ray images may be acquired to reconstruct a three-dimensional (3D) cone-beam computed tomography (CT). In one embodiment, the X-ray source is not a point source, but rather an array of X-ray sources, as will be appreciated by those skilled in the art. In one embodiment, the LINAC 1201 functions as the imaging source, and the power level of the LINAC is reduced to a level suitable for imaging.

[0027] The imaging system 1210 may perform computed tomography (CT), such as cone-beam CT or helical megavoltage computed tomography (MVCT), and the images generated by the imaging system 1210 may be two-dimensional (2D) or three-dimensional (3D). Two X-ray sources 1203A and 1203B may be mounted in fixed positions on the ceiling of the operating room and positioned to project X-ray imaging beams from two different angular positions (e.g., 90 degrees apart) to intersect at the machine isocenter (referred to herein as the treatment center, which provides a reference point for positioning the patient on the treatment couch 1206 during treatment) and illuminate the imaging planes of the respective X-ray detectors 1204A and 1204B after passing through the patient. In one embodiment, the imaging system 1210 provides a volumetric image of the target and surrounding volume of interest (VOI). In other embodiments, imaging system 1210 may include more than two or less than two x-ray sources and more than two or less than two detectors, any of which may be movable rather than fixed, and in still other embodiments, the positions of the x-ray sources and detectors may be interchanged. In one embodiment, image data acquired from a fixed angle of the imaging system 1210 can be combined with a previous image, such as a planning image or a pre-treatment CT image. Image data acquired from a fixed angle during delivery of the therapeutic radiation beam may be used to transform the previous image into a volumetric image representative of the patient at the time of delivery of the therapeutic radiation beam. X-ray detectors 1204A and 1204B may be fabricated from a scintillation material (e.g., amorphous silicon) that converts X-rays into visible light. In this case, an array of CMOS (Complementary Metal Oxide Silicon) or CCD (Charge Coupled Device) imaging cells converts the light into a digital image, as is well known to those skilled in the art. This digital image can be compared to a reference image during an image registration process, in which the coordinate system of the digital image is transformed to that of the reference image. The reference image can be, for example, a digitally reconstructed radiograph (DRR), which is a virtual X-ray image created from a three-dimensional (3D) CT image and generated by simulating the X-ray image formation process through the CT image.

[0028] In one embodiment, radiation therapy system 1200, which is an IGRT (Image Guided Radiation Therapy) delivery system, also includes a secondary imaging system 1239. Secondary imaging system 1239 can be a CBCT (Cone Beam Computed Tomography) imaging system, or alternatively, other types of volumetric imaging systems. The secondary imaging system 1239 includes a rotating gantry 1240 (e.g., a ring) mounted on an arm and rail system (not shown). The arm and rail system moves the rotating gantry 1240 along one or more axes (e.g., along an axis extending from the head to the foot of the couch 1206). An imaging source 1245 and a detector 1250 are mounted on the rotating gantry 1240. The rotating gantry 1240 can rotate 360 ​​degrees about the axis extending from the head to the foot of the couch. Thus, the imaging source 1245 and the detector 1250 can be positioned at many different angles. In one embodiment, imaging source 1245 is an X-ray source and detector 1250 is an X-ray detector. In one embodiment, secondary imaging system 1239 includes two independently rotatable rings, where imaging source 1245 can be attached to the first ring and detector 1250 can be attached to the second ring. In one embodiment, the rotating gantry 1240 is stationary at the foot of the treatment couch to avoid collision with the robotic arm 1202 during delivery of the therapeutic radiation beam.

[0029] 1B, the image-guided radiation therapy system 1200 can be further associated with a treatment delivery workstation 150 (a computer-controlled system), which may be located remotely from the radiation therapy system 1200 in a room different from the treatment room in which the radiation therapy system 1200 and the patient are located. The treatment delivery workstation 150 includes a processing unit (which may be the processing unit 1230 or another processing unit) and memory that allows it to modify the delivery of treatment to the patient 1225 based on detection of target movement according to one or more image registrations, as described herein.

[0030] 1C illustrates a C-arm radiation delivery system 1400. In one embodiment, the C-arm radiation delivery system 1400 can adjust the beam energy of the LINAC during treatment, allowing the LINAC to be used for both x-ray imaging and radiation therapy. In another embodiment, the C-arm radiation delivery system 1400 may incorporate an on-board kV imaging system for producing x-ray images and a separate LINAC for producing higher energy therapeutic radiation beams. The C-arm radiation delivery system 1400 includes a C-arm gantry 1410, a LINAC 1420, an MLC 1470 coupled to the distal end of the LINAC 1420 for beamforming, and a portal imaging detector 1450. The C-arm gantry 1410 can be used to acquire an X-ray image of a VOI (Volume of Interest) of a patient 1430 on a treatment couch 1440 by rotating it to an angle corresponding to a selected projection. In embodiments including a portal imaging system, the LINAC 1420 generates an x-ray beam that passes through a target on the patient 1430 and strikes the portal imaging detector 1450 to generate an x-ray image of the target. After the x-ray image of the target is generated, the beam energy of the LINAC 1420 can be increased and the LINAC 1420 can generate a radiation beam to treat the target area of ​​the patient 1430. In another embodiment, the kV imaging system can generate an x-ray beam that passes through a target in the patient 1430 to generate an x-ray image of the target. In some embodiments, the portal imaging system can acquire portal images during treatment delivery (irradiation). The portal imaging detector 1450 can measure the exit dose after the beam passes through the patient 1430. This allows internal or external fiducials or anatomical structures (e.g., tumors, bones, etc.) to be localized within the portal image.

[0031] Additionally, the kV imaging source or portal imaging devices and operation methods described herein can be used with other types of gantry-based systems. In some gantry-based systems, the gantry rotates the kV imaging source and LINAC about an axis that passes through the isocenter. In other embodiments, the kV imaging source and LINAC rotate independently of each other but can simultaneously image and deliver therapeutic radiation to the same volume of interest. Gantry-based systems include a ring gantry having a roughly toroidal shape where the patient's body extends through the inner diameter (bore) of the ring / toroid, and the kV imaging source and LINAC are mounted on the outer periphery of the ring and rotate around an axis passing through the isocenter. Gantry-based systems may further include a C-arm gantry in which the kV imaging source and LINAC are cantilever-mounted and rotated about an axis through the isocenter. In another embodiment, the kV imaging source and LINAC can be used in a robotic arm based system to which the kV imaging source and LINAC are attached as previously described. Aspects of the present disclosure may also be used in other such systems, such as gantry-based LINAC systems, static imaging systems associated with radiation therapy and radiosurgery, proton therapy systems using integrated image guidance, interventional radiology and intraoperative X-ray imaging systems, and the like.

[0032] 2 is an illustration of an example radiation delivery system 200 that uses an X-ray radiation source to acquire image data during delivery of a therapeutic radiation beam in accordance with an embodiment of the present disclosure. In an embodiment, the radiation delivery system 200 may correspond to and include components of one of the radiation delivery systems described above in FIGS. 1A-C.

[0033] The radiation delivery system 200 includes a therapeutic radiation source 202 that generates a therapeutic radiation beam 210. In embodiments, the therapeutic radiation source 202 may correspond to the LINAC 850 of Figure 1A, the LINAC 1201 of Figure 1B, or the LINAC 1420 of Figure 1C. Irradiation system 200 also includes an X-ray radiation source 204 that generates an imaging radiation beam 212. In embodiments, X-ray radiation source 204 may correspond to kV imaging source 810 of Figure 1A, one of imaging sources 1203A or 1203B of Figure 1B, or the imaging system of irradiation system 1400 of Figure 1C. Irradiation system 200 further includes X-ray detector 208a and X-ray detector 208b, which, in embodiments, may correspond to X-ray detector 870 of Figure 1A, detector 1204a and detector 1204b of Figure 1B, or the X-ray detectors of irradiation system 1400 of Figure 1C.

[0034] In an embodiment, the X-ray radiation source 204 is positioned at an offset 216 relative to the therapeutic radiation source 202 along an arcuate trajectory 214 with the target as the axis of rotation. The arcuate trajectory 214 may correspond to the trajectory along which the X-ray radiation source 204 and / or the therapeutic radiation source 202 rotate relative to the target 206 during delivery of the therapeutic radiation beam. In one embodiment, the offset 216 corresponds to an angle between the therapeutic radiation source 202 and the x-ray radiation source 204. For example, the offset 216 may correspond to a 90 degree angle between the therapeutic radiation source 202 and the x-ray radiation source 204. In some embodiments, the X-ray radiation source 204 is positioned in alignment (collinear with the target) with the therapeutic radiation source 202. The offset 216 in this case may correspond to the axial offset of the X-ray radiation source 204 relative to the therapeutic radiation source 202. In such embodiments, the axial offset is between 0 and 40 centimeters (cm).

[0035] During delivery of the therapeutic radiation beam, the therapeutic radiation source 202 generates a therapeutic radiation beam 210 to provide a required radiation dose to the target 206. In an embodiment, the target 206 may correspond to a tumor or other structure to be treated by the therapeutic radiation beam 210. While (e.g., simultaneously with) the therapeutic radiation beam 210 is active, the x-ray radiation source 204 may generate an imaging radiation beam 212, which passes through the target 206 and impinges on the x-ray detector 208a to generate x-ray image data related to the target 206.

[0036] In some embodiments, the X-ray radiation source 204 may include a collimator 218. The collimator 218 is used to shape the imaging radiation beam 212 to correlate to the shape of the target 206 or the shape of a volume of interest associated with the target 206. The collimator 218 may be used to shape the imaging radiation beam 212 to improve the quality of the image data and reduce the imaging dose delivered to the patient. In some embodiments, the collimator 218 may be an MLC, as previously described. In one embodiment, the collimator 218 may be an iris collimator. In embodiments, the collimator 218 may correspond to any type of collimator that can be used to shape the imaging radiation beam 212.

[0037] In embodiments, the therapeutic radiation beam 210 may be used to acquire image data in addition to the imaging radiation beam 212. In such embodiments, a second detector (e.g., X-ray detector 208b) may be positioned on the opposite side of the target 206 from the therapeutic radiation source 202. The therapeutic radiation beam 210 may pass through the target 206 and impinge on the X-ray detector 208b to generate additional X-ray image data related to the target 206.

[0038] It should be noted that while radiation delivery system 200 is shown having a single therapeutic radiation source and a single X-ray radiation source, embodiments of the present disclosure may employ multiple X-ray and / or therapeutic radiation sources. For example, the radiation delivery system may include a single therapeutic radiation source and multiple X-ray radiation sources positioned at various locations along arc trajectory 214.

[0039] FIG. 3A is an illustration showing an example of the first time a radiation source of a radiation delivery system 300 generates a therapeutic radiation beam, according to an embodiment of the present disclosure. The radiation delivery system 300 may include similar components to the radiation delivery systems described above in Figures 1A-2. The radiation delivery system 300 may use a radiation source 302 to generate both a therapeutic radiation beam 304 and an imaging radiation beam (not shown). The imaging radiation beam can be used to acquire image data that can be used in conjunction with image data acquired using one or more X-ray radiation sources (not shown), as described below in FIG. 3B. In one embodiment, the radiation source 302 may alternate between one or more pulses of the therapeutic radiation beam 304 and one or more pulses of the imaging radiation beam during radiation treatment delivery. In other embodiments, the radiation source 302 may simultaneously generate the therapeutic radiation beam 304 and the imaging radiation beam, as described below in FIG.

[0040] In an embodiment, the radiation delivery system 300 may include a tunable X-ray detector 308. The tunable X-ray detector 308 may be selectively tuned to detect radiation beams within a particular range of energy levels. For example, if the therapeutic radiation beam 304 is a megaelectronvolt (MeV) radiation beam and the imaging radiation beam is a kiloelectronvolt (KeV) radiation beam, the tunable X-ray detector 308 may be selectively tuned to detect radiation beams within the KeV range of energy levels.

[0041] As shown in FIG. 3A, the radiation source 302 generates one or more therapeutic radiation beam pulses at an initial (first) time (T1) and supplies a therapeutic dose of radiation to the target 306. In some embodiments, the therapeutic radiation beam 304 can be used to generate image data, as described in FIG. 2 above. In such embodiments, the tunable x-ray detector 308 can be tuned to detect a radiation beam corresponding to the energy level of the therapeutic radiation beam 304 in order to generate image data when the therapeutic radiation beam 304 is incident on the tunable x-ray detector 308. For example, the tunable x-ray detector 308 may be adjusted to detect a radiation beam in MeV.

[0042] FIG. 3B is an explanatory diagram showing an example of a radiation source of a radiation irradiation system 350 that generates an imaging radiation beam at a second time, according to an embodiment of the present disclosure. The radiation irradiation system 350 may include components similar to those of the radiation irradiation systems described in FIGS. 1A to 3A above. The radiation irradiation system 350 further includes an x-ray radiation source 204 that generates an imaging radiation beam 212, as described in FIG. 2 above. This imaging radiation beam 212 passes through the target 306 and is incident on the x-ray detector 208a to obtain image data related to the target 306.

[0043] 3B , the radiation source 302 generates one or more pulses of the imaging radiation beam 352 at a second time (T2) to acquire image data related to the target 306. While the radiation source 302 is generating the one or more pulses of the imaging radiation beam 352, the tunable X-ray detector 308 is adjusted to detect a radiation beam corresponding to an energy level of the imaging radiation beam 352 and generates image data when the imaging radiation beam 352 is incident on the tunable X-ray detector 308. For example, the tunable X-ray detector 308 may be adjusted to detect a kV radiation beam. In an embodiment, the pulses of the imaging radiation beam 352 may be activated in one or more successive arcs to acquire image data related to the target 306.

[0044] In an embodiment, as described above in Figures 3A and 3B, the process of alternating pulses of the therapeutic radiation beam with pulses of the imaging radiation beam may be performed repeatedly as the radiation source 302 moves along an arcuate trajectory 354 around the target 306 during delivery of the therapeutic radiation beam.

[0045] FIG. 4 is an illustration showing an example of a multi-leaf collimator 400 forming a target (treatment) aperture and a fan beam aperture in accordance with an embodiment of the present disclosure. A multi-leaf collimator (MLC) 400 can be used to achieve dynamic source collimation of the radiation beam at the treatment plane, with fan beam apertures 404a and 404b positioned within or adjacent to the treatment aperture 402 to enable fan beam CT (fan beam computed tomography). The fan beam apertures 404a and 404b can be adjusted in size and position to obtain image data encompassing the target treatment region during the data acquisition interval.

[0046] In an embodiment, the leaves of MLC 400 can support an imaging mode in which all normally closed leaves become slit-like apertures forming fan beam apertures 404 a and 404 b, which can admit a small amount of fluence through narrow collimation that shapes the radiation beam into a fan beam to acquire target-related image data. Meanwhile, treatment aperture 402 can shape the radiation beam to provide a therapeutic dose of radiation to the target. In some embodiments, fan beam aperture 404a and fan beam aperture 404b can be positioned such that the fan beam image data is longitudinally centered across the treatment region. MLC 400 allows a therapeutic radiation source, such as radiation source 302 of FIGS. 3A and 3B, to simultaneously generate therapeutic and imaging radiation, with target aperture 402 as the union for therapeutic radiation and fan beam apertures 404 a and 404 b as the imaging apertures.

[0047] In embodiments, the contact surfaces of leaf pairs can have angled or toothed leaf tips to reduce leakage of closed leaves or to reduce the amount of radiation passing through leaves with open slivers (slits). Leaf windows near the edge of the treatment region may already experience radiation attenuation due to the angle between the radiation beam and the vertical leaf surface. Thus, sliver width can be set as a function of offset from the center of the treatment region (depending on relative position).

[0048] In some embodiments, a sliding imaging aperture can be used to acquire a circular orbit of the plane of interest. The imaging aperture slides at the speed of the radiation therapy system couch, but can slide in the opposite direction. The interval between acquired image slices can depend on the duration of the scan, the couch speed, and the recovery speed for resetting the aperture to its tip.

[0049] FIG. 5 is a flow diagram illustrating a method 500 for constructing a volumetric image using imaging data acquired during a therapeutic radiation beam delivery, according to an embodiment of the present disclosure. Method 500 may be performed by processing logic, which may be comprised of hardware (e.g., circuitry, dedicated logic, programmable logic, processor, processing device, central processing unit (CPU), system-on-chip (SoC), etc.), software (e.g., instructions executed / performed on a processing device), firmware (e.g., microcode), or a combination thereof. In an embodiment, various portions of method 500 may be performed by processing logic of a processing device of a radiation delivery system, as described above in FIGS. 1A-4.

[0050] 5, method 500 illustrates example functions used in various embodiments. Although specific functional blocks (“blocks”) are disclosed in method 500, these blocks are exemplary. That is, embodiments may substitute various other blocks for the blocks described in method 500 or make variations of the blocks. The blocks of method 500 may be performed in a different order than presented, and not all blocks of method 500 may be performed.

[0051] Method 500 begins at block 510 where processing logic initiates a radiation therapy session and delivers a therapeutic radiation beam from a therapeutic radiation source to a target.

[0052] In block 520, processing logic directs imaging x-ray radiation beams from one or more x-ray radiation sources through the target to one or more x-ray detectors during delivery of the therapeutic radiation beams to acquire image data related to the target, as described above in Figures 2-4.

[0053] At block 530, processing logic constructs one or more volumetric images using the acquired image data. In some embodiments, processing logic may construct the volumetric images using a set of image data that is not fully sampled. Also, in some embodiments, processing logic may construct the volumetric images using pre-treatment image data, treatment planning image data, previously acquired image data, in addition to image data acquired during delivery of the therapeutic radiation beam.

[0054] At block 540, processing logic estimates a dose of therapeutic radiation based on the one or more volumetric images. In embodiments, processing logic may estimate a therapeutic dose delivered to a target by a therapeutic radiation beam and / or an imaging radiation beam. For example, processing logic may estimate a therapeutic dose delivered to a tumor in a patient. In some embodiments, the processing logic may estimate a therapeutic dose delivered by the therapeutic radiation beam and / or the imaging radiation beam to an object proximate the target. For example, the processing logic may estimate a therapeutic dose delivered to an organ of the patient proximate to a tumor.

[0055] At block 550, processing logic corrects (adjusts) the delivery of therapeutic radiation for the radiation therapy session based on the one or more volumetric images to account for target motion. In an embodiment, the processing logic can correct (adjust) the delivery of therapeutic radiation by changing the shape of the collimator opening (e.g., target opening 402 in FIG. 4) or aperture to account for changes in shape and / or position due to target movement. In some embodiments, processing logic may modify the radiation treatment session by changing the amount of time that the therapeutic radiation beam and / or the imaging radiation beam are active during the radiation treatment session. In one embodiment, processing logic may modify the radiation treatment session by changing the energy levels of the therapeutic radiation beam and / or the imaging radiation beam. In an embodiment, processing logic may modify the radiation treatment session by changing the position of one or more radiation sources relative to the target along an arc trajectory. In one embodiment, the processing logic may change the shape of the collimator aperture of the therapeutic radiation beam to avoid the organ at risk, for example, if the organ at risk moves between the therapeutic radiation source and the target. In some embodiments, processing logic may modify other parameters associated with the radiation delivery system to accommodate target movement.

[0056] FIG. 6 is a block diagram of an example computing device 600 capable of performing one or more of the operations described herein, according to some embodiments. The computing device 600 may be connected to other computing devices by a LAN, an intranet, an extranet, and / or the Internet. The computing device may operate as a server machine in a client-server network environment and as a client in a peer-to-peer network environment. A computing device may be provided by a personal computer (PC), a set-top box (STB), a server, a network router, a switch, a bridge, or any machine that executes a set of instructions (sequential or otherwise) that specify operations to be performed by that machine. Further, although only a single computing device is illustrated, the term "computing device" is intended to include a collection of computing devices that individually or collectively execute a set (or sets) of instructions to perform the methods described herein.

[0057] The computing device 600 illustrated herein may include a processing unit (e.g., a general-purpose processor, a programmable logic device (PLD), etc.) 602, a main memory 604 (e.g., a synchronous dynamic random access memory (DRAM), a read-only memory (ROM)), a static memory 606 (e.g., a flash memory, and a data storage device 618), which may communicate with each other via a bus 630.

[0058] The processing unit 602 may be provided by one or more general-purpose processing units, such as a microprocessor, a central processing unit, or the like. As specific examples, the processing unit 602 may comprise a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or a processor implementing other instruction sets or combinations of instruction sets. The processing unit 602 may also include one or more application-specific processing units, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), a network processor, or the like. The processing unit 602 may also be configured to perform the operations and steps described herein in accordance with one or more aspects of the present disclosure.

[0059] Computing device 600 may further include a network interface device 608 capable of communicating with a network 620. Computing device 600 may also include a video display device 610 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 612 (e.g., a keyboard), a cursor control device 614 (e.g., a mouse), and an audio signal generator 616 (e.g., a speaker). In one embodiment, video display device 610, alphanumeric input device 612, and cursor control device 614 may be combined into a single component or device (e.g., an LCD touch panel).

[0060] The data storage device 618 may include a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) 628 on which may be stored one or more sets of instructions including a beam generation procedure 625 for performing the operations described herein in accordance with one or more aspects of the present disclosure. When executed by computing device 600, such instructions may reside, completely or at least partially, within primary memory 604 and / or processing unit 602, where primary memory 604 and processing unit 602 also constitute computer-readable media. Additionally, the instructions may also be transmitted to or received over network 620 via network interface unit 608.

[0061] Although computer-readable storage medium 628 is illustratively shown to be a single medium, the term "computer-readable storage medium" should be considered to include a single medium or multiple media (e.g., centralized or distributed databases and / or associated caches and servers) that store one or more sets of instructions. The term "computer-readable storage medium" also includes any medium capable of storing, encoding, or transmitting sets of instructions for execution by a machine, thereby causing the machine to perform the methods described herein. Thus, the term "computer-readable storage medium" includes, but is not limited to, solid-state memory, optical media, and magnetic media.

[0062] It should be noted that the methods and apparatus described herein are not limited to use in medical diagnostic imaging and treatment. In alternative embodiments, the methods and apparatus described herein may be used in applications outside of the medical technology field, such as industrial imaging and non-destructive testing of materials. In such applications, for example, "treatment" may generally refer to the performance of an operation controlled by a treatment planning system, which may include the application of a beam (e.g., radiation, sound, etc.). Also, "target" may refer to a non-anatomical object or region, rather than an anatomical object or region.

[0063] Although the foregoing description provides several examples of particular systems, components, methods, etc. to facilitate understanding of embodiments of the present invention, those skilled in the art may practice at least some embodiments of the present disclosure without the description of these examples. In addition, well-known components and methods may be omitted in detail or shown in simplified block diagram form in order to facilitate understanding of the present invention. Therefore, the disclosed content is merely exemplary, and one example may differ from other examples and still be included within the scope of the present invention.

[0064] The use of the phrase "one embodiment" or "an embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase "in one embodiment" or "an embodiment" in various places in this specification do not necessarily refer to the same embodiment.

[0065] Although the operations of the methods described herein are shown in a particular order, the order of the operations of each method may be changed, certain operations may be performed in reverse order, or at least some operations may be performed simultaneously with other operations. Different operations may be directed or sub-operations may be performed intermittently or alternately.

[0066] The above description of the embodiments of the present invention, including the description of the abstract concepts thereof, is not intended to limit the present invention. The embodiments and specific examples described in this specification are provided for the purpose of explaining the present invention, and various equivalent modifications can be made within the scope recognized by those skilled in the art. As used herein, the words "example" or "exemplary" are used to serve as an example or illustration. Any aspect or feature described as "example" or "exemplary" should not be construed as superior to other aspects or features. Use of the word "example" or "exemplary" is intended to present concepts in a concrete manner. The term "or" as used herein is intended to be construed as an inclusive "or" rather than an exclusive "or." That is, unless otherwise specified or clear from the context, the phrase "X includes A or B" refers to any of the natural inclusive permutations. That is, if X includes A, if X includes B, or if X includes both A and B, then in all of the foregoing cases, the condition "X includes A or B" is satisfied. Furthermore, the articles "a" and "an," as used in this specification and the appended claims, shall be construed to mean "one or more" unless the singular form is clear from the context, unless otherwise specified. Furthermore, when terms such as "first," "second," "third," and "fourth" are used in the specification, these terms are used as labels to distinguish different elements and do not necessarily indicate an order according to the numerical designation.

Claims

1. 1. A radiation delivery system comprising: a therapeutic radiation source; one or more sources of X-ray radiation; a processing device operably connected to the therapeutic radiation source and the one or more X-ray radiation sources; The processing device includes: initiating a radiation therapy session to deliver a therapeutic radiation beam consisting of a plurality of pulses from the therapeutic radiation source to a target; directing a first imaging radiation beam from the one or more x-ray radiation sources through the target to one or more first x-ray detectors and acquiring first image data related to the target during the radiation treatment session; directing a second imaging radiation beam of one or more pulses from the therapeutic radiation source through the target in alternating fashion with the therapeutic radiation beam of multiple pulses toward one or more second x-ray detectors to acquire second image data related to the target; and constructing one or more volumetric images using the acquired second image data.

2. 2. The radiation irradiation system according to claim 1, a first imaging radiation beam from one of the one or more X-ray radiation sources that is collinear with a therapeutic radiation beam from the therapeutic radiation source;

3. 2. The radiation irradiation system according to claim 1, A radiation delivery system wherein the first imaging radiation beam of one of the one or more X-ray radiation sources is offset relative to a therapeutic radiation beam from the therapeutic radiation source.

4. 2. The radiation irradiation system according to claim 1, A radiation delivery system wherein at least one of said one or more X-ray radiation sources is stationary.

5. 2. The radiation irradiation system according to claim 1, A radiation delivery system wherein the irradiation with the therapeutic radiation beam and the first imaging radiation beam is performed simultaneously.

6. 2. The radiation irradiation system according to claim 1, A radiation delivery system, wherein delivery of the therapeutic radiation beam and the first imaging radiation beam is performed alternately.

7. A radiation irradiation system according to claim 6, 10. A radiation delivery system, comprising: a first imaging radiation beam configured to deliver a therapeutic radiation beam to a target site; a second imaging radiation beam configured to deliver a therapeutic radiation beam to a target site; a third imaging radiation beam configured to deliver a therapeutic radiation beam to a target site;

8. A radiation irradiation system according to claim 6, A radiation delivery system, wherein the second imaging radiation beam is activated in one or more successive arcs, and construction of the one or more volumetric images is performed based on the second image data acquired from the one or more successive arcs.

9. 2. The radiation irradiation system according to claim 1, A radiation delivery system, wherein the one or more volumetric images are constructed using a fully desampled set of image data.

10. The radiation irradiation system according to claim 9, a radiation delivery system, wherein the one or more volumetric images are constructed using the fully unsampled image data as well as at least one of pre-treatment image data, treatment planning image data, or previous image data acquired during a radiation treatment session.

11. 2. The radiation irradiation system according to claim 1, the one or more second X-ray detectors are adjustable to selectively detect the second imaging radiation beam based on a first energy level of the second imaging radiation beam or to selectively detect the therapeutic radiation beam based on a second energy level of the therapeutic radiation beam to acquire the second image data.

12. 2. The radiation irradiation system according to claim 1, the second imaging radiation beam is projected from the therapeutic radiation source through the target to the one or more second X-ray detectors to obtain the second image data related to the target during the radiation treatment session; and wherein the one or more volumetric images are constructed using both the acquired second image data and the first image data acquired based on the first imaging radiation beam.

13. 2. The radiation irradiation system according to claim 1, The processing device further comprises: a multi-leaf collimator (MLC) configured to form an aperture that combines a first aperture that shapes a first portion of the therapeutic radiation beam to correspond to the target, and a second aperture that shapes a second portion of the therapeutic radiation beam into a fan beam to acquire image data that includes a treatment region of the target.

14. 2. The radiation irradiation system according to claim 1, The processing device further comprises: A radiation delivery system that estimates a therapeutic dose to be delivered to one or more of the target or objects proximate to the target based on the one or more volumetric images.

15. 2. The radiation irradiation system according to claim 1, The processing device further comprises: A radiation delivery system that corrects therapeutic radiation delivery in the current radiation therapy session based on the one or more volumetric images.

16. A method for operating a processing device in a radiation irradiation system, comprising the following steps a to d. The processing device a. initiating a radiation therapy session to deliver a therapeutic radiation beam consisting of multiple pulses from a therapeutic radiation source to a target; b. receiving, with one or more first x-ray detectors, first imaging radiation beams projected from one or more x-ray radiation sources through the target, and acquiring first image data related to the target during the radiation treatment session; c) receiving a second imaging radiation beam consisting of one or more pulses emitted from the therapeutic radiation source through the target, alternately with the therapeutic radiation beam consisting of multiple pulses, by one or more second X-ray detectors to acquire second image data related to the target; d) constructing one or more volumetric images using the acquired second image data.

17. The method of claim 16, The method of claim 1, wherein the first imaging radiation beam of one of the one or more X-ray radiation sources is collinear with a therapeutic radiation beam from the therapeutic radiation source.

18. The method of claim 16, The method, wherein the first imaging radiation beam of one of the one or more X-ray radiation sources is offset relative to a therapeutic radiation beam from the therapeutic radiation source.

19. The method of claim 16, A method wherein at least one of said one or more x-ray radiation sources is stationary.

20. The method of claim 16, A method wherein the one or more volumetric images are constructed using a fully desampled set of image data.

21. The method of claim 20, The method, wherein the one or more volumetric images are constructed using the fully unsampled image data as well as at least one of pre-treatment image data, treatment planning image data, or previous image data acquired during a radiation treatment session.

22. The method of claim 16, the one or more second X-ray detectors are adjustable to selectively detect the second imaging radiation beam based on a first energy level of the second imaging radiation beam or to selectively detect the therapeutic radiation beam based on a second energy level of the therapeutic radiation beam to acquire the second image data.

23. A non-transitory computer-readable storage medium storing instructions that, when executed by a processing device, cause the processing device to: a. Initiating a radiation therapy session to deliver a therapeutic radiation beam consisting of multiple pulses from a therapeutic radiation source to a target. b. directing a first imaging radiation beam from one or more x-ray radiation sources through the target and onto one or more first x-ray detectors, and acquiring first image data related to the target during the radiation treatment session. c) directing a second imaging radiation beam of one or more pulses from the therapeutic radiation source through the target in alternating fashion with the therapeutic radiation beam of multiple pulses toward one or more second x-ray detectors to acquire second image data related to the target. d. Constructing one or more volumetric images using the acquired second image data.

Images