Radiation treatment plan for delivering high dose rate to spots in target

Abstract

Information describing a target (408) inside a patient to be radiation treated is accessed from a computer system (410) memory. An arrangement of spots (506) inside the target is determined. Each spot corresponds to a location inside the target where a corresponding beam (412) is directed during radiation treatment of the patient. A dose rate is determined for each of the beams. The dose rate for each beam can be a dose delivered to the spot corresponding to that beam in less than one second. For example, each beam can deliver at least four Gray (GY) in less than one second, and can deliver as much as 20 Gy to 50 Gy or 100 Gy or more in less than one second. A radiation treatment plan is stored in the computer system memory, the plan including the spot arrangement and the dose rate for each of the beams.

Description

Background Technology

[0001] The use of radiation therapy to treat cancer is well-known. Typically, radiation therapy involves directing a beam of high-energy proton, photon, ion, or electron radiation (“therapeutic radiation”) onto a target or target volume (e.g., the volume containing a tumor or lesion).

[0002] Before a patient receives radiation therapy, a treatment plan is developed specifically for that patient. This plan uses simulations and optimizations based on past experience to define various aspects of the treatment. Generally, the goal of the treatment plan is to deliver sufficient radiation to unhealthy tissues while minimizing radiation exposure to surrounding healthy tissues.

[0003] The planner's goal is to find the optimal solution relative to multiple clinical objectives, which may be contradictory in that improving one objective might adversely affect the achievement of another. For example, a treatment plan that avoids exposing the liver to a certain dose of radiation might result in the stomach receiving excessive radiation. These types of trade-offs lead to an iterative process in which the planner creates different plans to find the one best suited to achieve the desired outcome.

[0004] A recent radiobiology study demonstrated the effectiveness of delivering a full, relatively high therapeutic radiation dose to a target in a single, short time. For example, each beam can deliver at least 4 Gy in less than one second, and up to 20 Gy to 50 Gy or up to 100 Gy or more can be delivered in less than one second. This type of treatment is generally referred to in this article as FLASH radiation therapy (FLASH RT).

[0005] Evidence to date suggests that FLASH RT advantageously protects normal, healthy tissue from damage when exposed to high radiation doses for only a very short period. Therefore, FLASH RT introduces an important limitation that has not been considered or achieved in conventional radiation therapy programs. Summary of the Invention

[0006] This invention provides a computer system as defined in claim 1. Optional features are specified in the dependent claims.

[0007] A corresponding dose rate or corresponding minimum prescribed dose rate can be received for each of the multiple beams and / or the corresponding spot in the patient's target. Some or all of the corresponding dose rates or corresponding minimum prescribed dose rates may differ from each other.

[0008] In addition to the dose rate or minimum prescribed dose rate, or as an alternative, the maximum prescribed dose rate may be received and used by the computer system.

[0009] According to one embodiment, a computer system is provided, comprising:

[0010] Processor; and

[0011] A memory coupled to the processor and including instructions, which, when executed, cause the processor to perform operations for a method of radiation therapy planning, the operations including:

[0012] Access information from memory, including the outline of the target volume inside the patient to be irradiated;

[0013] Determine the arrangement of spots within the contour, wherein each spot corresponds to the location within the target volume where a corresponding beam of radiated radiation is guided during the patient's radiation therapy;

[0014] Determine the dose rate for each of a plurality of beams, wherein the dose rate for each beam is the dose delivered to the corresponding spot of each beam in less than one second; and

[0015] The radiation therapy plan, including the speckle arrangement and dose rate for each beam in the beam, is stored in memory.

[0016] According to another embodiment, a computer system is provided, comprising:

[0017] Processor; and

[0018] A memory coupled to the processor and including instructions, which, when executed, cause the processor to perform operations for generating a radiation therapy plan, the operations including:

[0019] Access the minimum prescribed dose rate from the memory to be delivered by the beam to the spot in the patient target;

[0020] Determine the arrangement and number of spots in the target; and

[0021] A beam energy is determined for each beam in the beam, wherein the beam energy for each beam in the beam is determined such that each spot receives the minimum prescribed dose rate.

[0022] According to another embodiment, a computer system is provided, comprising:

[0023] Processor; and

[0024] A memory coupled to the processor and including instructions, which, when executed, cause the processor to perform operations for generating a radiation therapy plan, the operations including:

[0025] Access the value of the parameter from the memory, wherein the parameter includes the beam energy for the beam within the arrangement of spots guided into the patient target;

[0026] Access information specifying limitations for the radiation therapy plan, wherein the limitations include minimum limits on the dose rate for each spot in the treatment area; and

[0027] Adjust the parameter values ​​until the dose rate for each spot meets the minimum dose rate limit.

[0028] An improved radiation therapy planning method for FLASH radiation therapy (FLASH RT) and an improved radiation therapy based on the plan are provided according to embodiments of the present invention.

[0029] In this embodiment, information describing a target inside a patient to be irradiated is accessed from computer system memory. The arrangement of spots within the target is determined. Each spot corresponds to a location within the target where a corresponding radiation beam is guided during the patient's irradiation. The dose rate for each beam is determined. The dose rate for each beam is the dose delivered to the spot corresponding to that beam in less than one second. For example, each beam may deliver at least four Gy in less than one second, and may deliver up to 20 to 50 or 100 or more in less than one second. A irradiation plan, including the arrangement of spots and the dose rate for each beam, is stored in computer system memory.

[0030] Embodiments of the invention improve radiation therapy planning and the treatment itself by extending FLASH RT to a wider range of treatment modalities and combinations thereof (e.g., spatially segmented grid radiation therapy in addition to intensity-modulated radiation therapy such as intensity-modulated particle therapy). Compared to conventional techniques, treatment plans generated as described herein are better at avoiding radiation exposure to normal tissue by designing to reduce (if not minimize) the amount of dose to normal tissue (outside the target) (and, in some cases, the integral). Combining the normal tissue preservation of FLASH radiation therapy with the tumor-killing power of spatially segmented grid radiation therapy allows for increased radiation dose in most tumors without the associated toxicities of conventional radiation therapy and increases the number of indications treatable by the FLASH dose rate. While finding a balance between competing and relevant parameters remains a complex task, treatment planning has been simplified compared to conventional plans.

[0031] In summary, embodiments of this disclosure relate to generating and implementing treatment plans that are most effective (relative to other plans) and have the fewest (or most acceptable) side effects (e.g., lower dose rates outside the treated area). Therefore, embodiments of the invention specifically improve the field of radiation therapy planning, and generally improve the field of radiation therapy. Embodiments of the invention allow for the rapid generation of more effective treatment plans. Furthermore, embodiments of the invention contribute to improved computer capabilities because, for example, by reducing the complexity of generating treatment plans, fewer computational resources are required and consumed, which also means that computer resources are freed up to perform other tasks.

[0032] Those skilled in the art will recognize these and other objects and advantages of the invention after reading the following detailed description illustrated in the various accompanying drawings.

[0033] This summary is provided to introduce a set of concepts further described in the following detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Attached Figure Description

[0034] The accompanying drawings illustrate embodiments of the present disclosure and, together with the detailed description, serve to explain the principles of the present disclosure. The drawings are incorporated in and form a part of this specification, and like reference numerals depict like elements therein.

[0035] Figure 1 It is a block diagram of an example computer system on which the embodiments described herein can be implemented.

[0036] Figure 2 This is a block diagram illustrating an example of an automated radiation therapy treatment planning system according to an embodiment of the present invention.

[0037] Figure 3 A knowledge-based planning system according to an embodiment of the present invention is shown.

[0038] Figure 4A This is a block diagram illustrating selected components on which a radiation therapy system according to an embodiment of the present invention can be implemented.

[0039] Figure 4B This is a block diagram illustrating selected components on which a radiation therapy system according to an embodiment of the present invention can be implemented.

[0040] Figure 4C A spatially segmented radiotherapy frame that can be used in an embodiment of the present invention is shown.

[0041] Figure 5 An example of a beam eye view of a target volume according to an embodiment of the present invention is shown.

[0042] Figure 6 A cross-sectional view of the target volume according to an embodiment of the present invention is shown.

[0043] Figure 7 , Figure 8 and Figure 9 This is a flowchart illustrating an example of computer-implemented operations for radiation therapy planning according to an embodiment of the present invention.

[0044] Figure 10 This is a flowchart illustrating an example of a computer-implemented radiation therapy method according to an embodiment of the present invention. Detailed Implementation

[0045] Reference will now be made in detail to various embodiments of this disclosure, examples of which are illustrated in the accompanying drawings. While described in conjunction with these embodiments, it is to be understood that they are not intended to limit the disclosure to these embodiments. Rather, this disclosure is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of this disclosure as defined in the appended claims. Furthermore, numerous specific details are set forth in the following detailed description of this disclosure to provide a thorough understanding of the disclosure. However, it should be understood that this disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail to avoid unnecessarily obscuring aspects of this disclosure.

[0046] Some parts of the following detailed description are presented based on programs, logic blocks, processes, and other symbolic representations of operations on data bits within computer memory. These descriptions and representations are means used by those skilled in the art of data processing to most effectively convey the substance of their work to those skilled in the art. In this application, programs, logic blocks, processes, etc., are considered as a self-consistent sequence of steps or instructions that lead to a desired result. These steps are those that utilize physical operations on physical quantities. Typically, although not essential, these quantities take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and otherwise manipulated in a computer system. Primarily for reasons of general use, it has proven convenient to sometimes refer to these signals as transactions, bits, values, elements, symbols, characters, samples, pixels, etc.

[0047] However, it should be remembered that all these and similar terms will be associated with appropriate physical quantities and are merely convenient labels applied to those quantities. Unless otherwise specifically stated clearly from the discussion below, it will be understood that throughout this disclosure, discussions using terms such as “determine,” “access,” “generate,” “represent,” “apply,” “instruct,” “store,” “use,” “regulate,” “include,” “calculate,” etc., refer to computer systems or similar electronic computing devices or processors (e.g., Figure 1The actions or processes of the computer system 100 (e.g., Figures 7-10 (Flowchart). A computer system or similar electronic computing device manipulates and converts data represented as physical (electronic) quantities within the computer system's memory, registers, or other such information storage, transmission, or display devices. Terms such as "dose," "dose rate," or some other parameter or attribute typically refer to dose values, dose rate values, attribute values, or parameter values, respectively; the use of these terms will become clear from the context of the surrounding discussion.

[0048] The following detailed descriptions are presented and discussed in the form of methods. Although the diagrams describing the operations of these methods (e.g., Figures 7-10 The steps and their order are disclosed in the document, but these steps and orderings are merely examples. Embodiments are well-suited to performing various other steps or variations thereof as described in the flowcharts of this accompanying drawing, and in a different order than depicted and described herein.

[0049] The embodiments described herein can be discussed in the general context of computer-executable instructions residing on some form of computer-readable storage medium, such as a program module, which is executed by one or more computers or other devices. By way of example and not limitation, the computer-readable storage medium may include non-transitory computer storage media and communication media. Typically, a program module includes routines, programs, objects, components, data structures, etc., that perform a particular task or implement a particular abstract data type. In various embodiments, the functionality of the program module may be combined or distributed as needed.

[0050] Computer storage media includes volatile and non-volatile, removable and non-removable media implemented using any method or technology for storing information such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory or other memory technologies, optical disc ROM (CD-ROM), digital versatile disc (DVD) or other optical storage, cassette tape, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible for retrieval of that information.

[0051] Communication media may contain computer-executable instructions, data structures, and program modules, and include any information delivery medium. By way of example, and not limitation, communication media includes wired media such as wired networks or direct wired connections, and wireless media such as acoustic, radio frequency (RF), infrared, and other wireless media. Any combination of the above may also be included within the scope of computer-readable media.

[0052] Figure 1A block diagram of an example computer system 100 on which embodiments described herein may be implemented is shown. In its most basic configuration, system 100 includes at least one processing unit 102 and memory 104. This most basic configuration in Figure 1 The image is shown by dashed line 106. System 100 may also have additional features and / or functions. For example, system 100 may also include additional storage devices (removable and / or non-removable), including but not limited to disks, optical discs, or magnetic tapes. Such additional storage... Figure 1 The system is illustrated by removable storage device 108 and non-removable storage device 120. System 100 may also include communication connections(s)122 that allow the device to communicate with other devices, for example, in a networked environment using a logical connection to one or more remote computers.

[0053] System 100 also includes multiple input devices 124, such as keyboards, mice, pens, voice input devices, touch input devices, etc. It also includes multiple output devices 126, such as display devices, speakers, printers, etc.

[0054] exist Figure 1 In the example, memory 104 includes computer-readable instructions, data structures, program modules, etc., associated with the "optimizer model" 150. However, optimizer model 150 may instead reside in any computer storage medium used by system 100, or may be distributed across a combination of computer storage media, or may be distributed across a combination of networked computers. The functionality of optimizer model 150 is described below.

[0055] Figure 2 This is a block diagram illustrating an example of an automated radiation therapy treatment planning system 200 according to an embodiment of the present invention. System 200 includes an input interface 210 for receiving patient-specific information (data) 201, a data processing component 220 implementing an optimizer model 150, and an output interface 230. System 200 may be implemented wholly or partially on / using computer system 100. Figure 1 Software programs, hardware logic, or combinations thereof on a device.

[0056] exist Figure 2 In the example, patient-specific information is provided to and processed by optimizer model 150. Optimizer model 150 produces predictions. Treatment plans can then be generated based on these predictions.

[0057] Figure 3 A knowledge-based planning system 300 according to an embodiment of the present invention is shown. Figure 3In the example, system 300 includes a knowledge base 302 and a treatment planning toolset 310. The knowledge base 302 includes patient records 304 (e.g., radiation therapy plans), treatment types 306, and statistical models 308. Figure 3 The example treatment planning toolset 310 includes a current patient record 312, treatment type 314, medical image processing module 316, optimizer model (module) 150, dose distribution module 320, and final radiation therapy plan 322.

[0058] Treatment planning toolset 310 searches the knowledge base 302 (via patient records 304) for previous patient records similar to the current patient record 312. Statistical model 308 can be used to compare the predictions of the current patient record 312 with the statistical patient data. Using the current patient record 312, the selected treatment type 306, and the selected statistical model 308, toolset 310 generates a radiation therapy plan 322.

[0059] More specifically, based on past clinical experience, the most commonly used treatment type may exist when a patient presents with a specific diagnosis, stage, age, weight, sex, comorbidities, etc. The first-step treatment type 314 can be selected by choosing the treatment type the planner has previously used on similar patients. Patient outcomes can be included in the treatment planning process, and these outcomes may include the probability of normal tissue complications as a function of dose rate and patient-specific treatment type outcomes. The medical image processing module 316 provides automatic contour drawing and automatic segmentation of two-dimensional cross-sectional slides (e.g., from any imaging modality, such as, but not limited to, computed tomography (CT), positron emission tomography-CT, magnetic resonance imaging, and ultrasound) to form a three-dimensional (3D) image using medical images from the current patient record 312. The dose and dose rate distribution module 320 can utilize the optimizer model 150 to calculate dose distribution maps and dose rate distribution maps.

[0060] In an embodiment of the invention, optimizer model 150 uses a dose prediction model to provide, for example, 3D dose distribution, flux and dose rate, and associated dose-volume histograms, dose-rate-volume histograms and radiation time-volume histograms.

[0061] Figure 4A This is a block diagram illustrating selected components on which a radiation therapy system 400 according to an embodiment of the present invention can be implemented. Figure 4A In the example, the radiation therapy system 400 includes a beam system 404 and a nozzle 406.

[0062] Beam system 404 generates and delivers a beam. This beam can be a proton beam, electron beam, photon beam, ion beam, or nuclear beam (e.g., carbon, helium, and lithium). In embodiments, depending on the type of beam, beam system 404 includes components that guide (e.g., bend, deflect, or direct) the beam in a direction toward nozzle 406 and into nozzle 406.

[0063] In intensity-modulated radiation therapy (IMRT), such as intensity-modulated particle therapy (IMPT), the intensity of the beam is different at each treatment area (target) of the patient. In an embodiment, the radiation therapy system 400 also includes a beam energy modulator 405, which can be used to modulate (e.g., reduce or modulate) the energy of the beam entering the nozzle 406. In an embodiment, the beam energy modulator 405 is part of the nozzle 406. Here, the term "beam energy modulator" is used as a general term for one or more components that influence the beam energy to control the range of the beam (e.g., the extent to which the beam penetrates the target), control the dose delivered by the beam, and / or control the depth-dose profile of the beam (depending on the type of beam). For example, for a proton or ion beam with a Bragg peak, the beam energy modulator 405 can control the position of the Bragg peak in the target volume 408 within the patient 410 supported by a patient support device (e.g., a chair or table) in the treatment room (see below). Figure 6 (Discussion). In various embodiments, the beam energy modulator 405 includes a range modulator, a range shifter, or both a range modulator and a range shifter.

[0064] The target volume 408 can be an organ, a portion of an organ (e.g., a volume or region within an organ), a tumor, diseased tissue, or a patient profile. The target volume can include both unhealthy tissue (e.g., a tumor) and healthy tissue.

[0065] Figure 4A The control system 410 receives and implements the prescribed radiation therapy plan. In an embodiment, the control system 410 includes a computer system having a processor, memory, input devices (e.g., a keyboard), and possibly a display device in a known manner. The control system 410 can receive data regarding the operation of the radiation therapy system 400. The control system 410 can control parameters of the beam system 404, nozzle 406, and patient support device (not shown) based on the received data and the prescribed radiation therapy plan, including parameters such as the energy, intensity, direction, size, and / or shape of the beam.

[0066] exist Figure 4AIn one embodiment, nozzle 406 is used to aim beam 412 at different locations (e.g., spots 504 and 506) within target volume 408 according to a prescribed radiation therapy plan and under the control of control system 410. In another embodiment, nozzle 406 includes a scanning magnet (not shown) that can be used to control the direction of beam 412. As will be described, beam 412 can be sequentially directed into spots (e.g., one beam is directed into spot 504, then another beam into spot 506, and so on).

[0067] Figure 4B This is a block diagram illustrating selected components on which a radiation therapy system 450 according to an embodiment of the present invention can be implemented. Figure 4A In contrast, the radiation therapy system 450 includes a spatially segmented radiotherapy block 455 between the system 450 and the target volume 408. The spatially segmented radiotherapy block 455 may be, for example, a grid frame or a multi-leaf collimator (MLC), and may be part of the nozzle 406 or a separate component located between the nozzle and the target volume 408.

[0068] Figure 4C The image shows an example beam eye view of grid block 460. Generally, a portion of beam 422 ( Figure 4B The beam 423 passes through openings 462 in grid blocks 460, while the remainder of the beam 422 is blocked or attenuated by the grid blocks. The openings 462 in grid blocks 460 are positioned such that they can be aligned with spots (e.g., spots 504 and 506) in target volume 408, or the beam 423 can be aligned with spots (e.g., spots 504 and 506) in target volume 408. Similarly, the leaves of the MLC (not shown) can be positioned such that they partially obscure the beam and align the unobscurified portion of the beam 422 with the positions of spots in target volume 408.

[0069] Figure 5 An example of a beam eye view of a target volume 408 according to an embodiment of the invention is shown. The target volume 408 may conform to the shape of the object being treated (e.g., the outline of the target volume may conform to the outline of a tumor), the target volume may be larger than the object being treated, or the target volume may correspond to a portion (sub-volume) of the object being treated.

[0070] In an embodiment of the invention, the target volume 408 comprises an arrangement of spots (e.g., spots 504 and 506). Reference Figure 4ANozzle 406 is configured to emit a beam 412n (one of the beams 412) as a pencil beam, also known as a spot-scanning beam. The target volume 408 can be irradiated by grating scanning (two-dimensional emission) with the pencil beam. Generally, a first pencil beam is aligned with a first spot 504 in the target volume 408, and a dose rate is delivered to that spot; then a second pencil beam is aligned with a second spot 506 in the target volume, and a dose rate is delivered to the second spot, and so on. Thus, in an embodiment implemented using the radiation therapy system 400, the beams 412 are delivered sequentially. More specifically, the beam is delivered to the first spot in the target volume (on), then closed, then the beam is delivered to the second spot in the target volume (on), then closed, and so on. Because the beams 412 are delivered sequentially, different doses and dose rates can be delivered to each spot if desired. This type of delivery and treatment can be referred to as Spatial Segmented Grid Radiation Therapy (SFGRT).

[0071] Each beam 412n may be turned on for only a fraction of a second. In embodiments according to the invention, each beam 412n delivers a relatively high dose rate (a relatively high dose over a relatively short period of time) to the target within that fraction of a second. For example, each beam 412n may deliver at least four (4) Gy in less than a second, and may deliver up to 20 Gy to 50 Gy or 100 Gy or more in less than a second.

[0072] refer to Figure 4B Nozzle 406 is configured to fire a beam 422 toward and into spatially segmented radiotherapy block 455. The dose rate is delivered to spots (e.g., spots 504 and 506) in target volume 408 through the portion of beam 422 not blocked by spatially segmented radiotherapy block 450 (beam 423). Therefore, in embodiments implemented using radiotherapy system 450, beam 423 can be delivered simultaneously. Despite simultaneous delivery of beam 423, spatially segmented radiotherapy block 455 can be configured such that different doses and dose rates can be delivered to each spot if desired. As in the embodiments described above, each beam 423n of beam 423 delivers a relatively high dose rate (a relatively high dose over a relatively short time period) to the target at a rate of fractions of a second. For example, each beam 423n can deliver at least 4 Gy in less than a second, and can deliver up to 20 Gy to 50 Gy or 100 Gy or more in less than a second. This type of delivery and treatment can also be called SFGRT.

[0073] Figure 6 A cross-sectional view of the target volume 408 according to an embodiment of the present invention is shown. Figure 6In the example, beam 412n / 423n is directed and passes through spot 504 and enters target volume 408. Beam energy modulator 405 can be used to change the intensity of beam 412n / 423n to control the beam's range (e.g., the extent to which the beam penetrates the target), control the dose delivered by the beam, and / or control the depth-dose profile of the beam (depending on the type of beam). For example, for a proton or ion beam with a Bragg peak, beam energy modulator 405 can control the position of the Bragg peak such that it is located at point 603, then at point 602, then at point 601 (and vice versa).

[0074] Figure 7 , Figure 8 and Figure 9 Flowcharts 700, 800, and 900 are examples of computer-implemented operations for radiation therapy planning according to embodiments of the present invention. Flowcharts 700, 800, and 900 can be implemented residing on some form of computer-readable storage medium (e.g., in...). Figure 1 Computer-executable instructions (e.g., in the memory of the computer system 100) are stored in the computer's memory. Figure 1 Optimizer model 150).

[0075] As described above, in IMRT (e.g., IMPT), beam intensity varies across each treatment region (target) of the patient, and in SFGRT, the beam can be segmented spatially and temporally. Depending on the treatment morphology, available degrees of freedom include beamforming (collimation), beam weighting (spot scanning), beam intensity or energy, beam orientation, dose rate, and the number and arrangement of spots. Parameters that can affect the dose rate are also considered. These parameters include, but are not limited to, the number of irradiations of the target volume, the duration of each irradiation (irradiation time), and the dose deposited in each irradiation. Parameters may also include the time period of irradiation application (e.g., multiple irradiations applied over a time period such as one hour, where each irradiation within that time period is separated from the next irradiation by another time period) and the time interval between each irradiation time period (e.g., one day between each hour-long time period). If the target volume is divided into sub-volumes or voxels, the values ​​of the parameters can be based on each sub-volume or each voxel (e.g., values ​​per sub-volume or voxel). These degrees of freedom result in a virtually unlimited number of potential treatment plans, making it beyond human capacity to consistently and effectively generate and evaluate high-quality treatment plans. This relies on the use of computer systems, especially considering the time constraints associated with using radiation therapy to treat diseases such as cancer, and the large number of patients receiving or needing radiation therapy at any given time.

[0076] The following discussion involves beam, target volume, dose, dose rate, and other elements or values. This discussion takes place within the context of modeled elements and calculated values ​​in the treatment planning toolset 310 and optimizer model 150, unless otherwise stated or explicitly stated in the discussion.

[0077] refer to Figure 7 as well as Figure 1 , Figure 4A , Figure 4B and Figure 5 In box 702, information (e.g., data or images) including a description of the outline of the target volume 408 inside the patient 410 to be irradiated is accessed from the memory of computer system 100.

[0078] In box 704, the arrangement of spots within the contour of target volume 408 is defined. Each spot corresponds to a position within target volume 408 that will guide the corresponding beam 412n or 423n during the patient's radiation therapy.

[0079] In block 706, the dose rate of each beam 412n / 423n of beams 412 / 423 is determined. For all beams 412 / 423, the dose rate of each beam may be the same, or it may be different on some or all beams. That is, generally, each spot in the target does not necessarily receive the same dose and dose rate. The dose rate of each beam is the dose delivered to the spot corresponding to that beam in less than one second. For example, each beam may deliver at least 4 Gy in less than one second, and up to 20 Gy to 50 Gy or 100 Gy or more in less than one second. In embodiments, the ratio of the maximum dose rate or maximum dose inside each spot to the maximum dose rate or maximum dose in the outer region is at least 1.5. The outer region includes... Figure 5 The region 510 may include regions outside the target volume; that is, the region outside the spot in the target volume may be inside or outside the target 408.

[0080] In box 708, a radiation therapy plan including the speckle arrangement and dose rate of each beam is stored in the computer system memory. In addition to determining and using the dose rate of each beam 412n / 423n, or as an alternative, a minimum (or maximum) dose rate of each beam 412n / 423n can be determined and used.

[0081] Now for reference Figure 8 And continue to refer to Figure 1 , Figure 4A , Figure 4B and Figure 5In block 802, the minimum prescribed dose rate of spots (e.g., spots 504 and 506) to be delivered by the sequence of beams 412 or beams 423 to the target (e.g., target volume 408) is accessed from the memory of computer system 100.

[0082] In box 804, the number and arrangement of spots in the target volume 408 are determined.

[0083] In box 806, the beam energy of each of the beams 412 or 423 is determined. The beam energy of each of the beams is determined such that each spot receives the minimum prescribed dose rate of that beam. In addition to determining and using the minimum prescribed dose rate of each of the beams 412 / 423, or as an alternative, the maximum dose rate of each of the beams 412 / 423 may be determined and used.

[0084] In box 808, a radiation therapy plan is stored in the computer system memory, which includes the number and arrangement of spots and the beam energy of each beam in the beam.

[0085] Now for reference Figure 9 And continue to refer to Figure 1 , Figure 4A , Figure 4B and Figure 5 In box 902, parameter values ​​are accessed from the memory of computer system 100. These parameters include the beam energy in the arrangement of spots (e.g., spots 504 and 506) that guide beam 412 / 423 into the patient target.

[0086] In box 904, access information on the limitations of the specified radiation therapy plan. These limitations include the minimum dose rate limit for each spot.

[0087] In box 906, adjust the parameter value until the dose rate for each spot meets the minimum limit for that spot's dose rate. In addition to obtaining and using the minimum limit for spot dose rate, or as an alternative, the maximum dose rate for each spot can be determined and used.

[0088] In box 908, a radiation therapy plan is stored in the computer system memory. This radiation therapy plan includes the arrangement of spots, the beam energy of the beam, and the values ​​of parameters (from box 906).

[0089] Figure 10 This is a flowchart 1000, an example of a computer-implemented radiation therapy method according to an embodiment of the present invention. Flowchart 1000 can be implemented as computer-executable instructions residing on some form of computer-readable storage medium (e.g., using...). Figure 4A or Figure 4B Control system 410).

[0090] exist Figure 10 In box 1002, also refer to Figure 1 The radiation therapy plan is accessed from the memory of the computer system 100. In an embodiment of the invention, the radiation therapy plan is based on the method discussed above (especially...). Figure 7 , 8 The plan is generated using the methods described above (and 9), and includes information determined according to the methods discussed above.

[0091] In box 1004, based on the above combination Figure 4A , Figure 4B , Figure 5 and Figure 6 The treatment plan directs the beam to spots within a target volume. In an embodiment, after each spot in the target volume is irradiated as described above, a uniform dose rate is applied across the entire target volume, including the area between spots. The uniform dose rate can be at the FLASH level (e.g., at least 4 Gy in less than one second, and up to 20 to 50 Gy or 100 Gy or higher in less than one second).

[0092] Although Figures 7-10 The operations in the system are presented as occurring in a series and a specific order, but the invention is not limited thereto. These operations can be performed in different orders and / or in parallel, and they can also be performed iteratively. As mentioned above, due to the different parameters that need to be considered, the range of values ​​of these parameters, the interrelationships of these parameters, the need for a treatment plan that is effective for the patient but minimizes risk, and the need to rapidly generate high-quality treatment plans, the use of computer system 100 ( Figure 1 It is important to use the optimizer model 150 that is consistently executed on the radiotherapy plan disclosed in this paper.

[0093] In summary, embodiments of the invention improve radiation therapy planning and the treatment itself by extending FLASH RT to a wider range of treatment modalities and combinations thereof (e.g., SFGRT in addition to IMRT and IMPT). Treatment plans resulting from designs that reduce (if not minimize) the amount of dose to normal tissue (outside the target) (and, in some cases, the integral), as described herein, are better at avoiding radiation exposure to normal tissue compared to conventional techniques. Combining the normal tissue preservation of FLASH RT with the tumor-killing power of SFGRT allows for increased radiation doses in most tumors without the associated toxicities of conventional RT and increases the number of indications treatable at FLASH dose rates. While finding a balance between competing and relevant parameters remains a complex task, treatment planning has been simplified compared to conventional plans.

[0094] When used with FLASH dose rate, it simplifies the management of patient movement because the dose is applied in a short time (e.g., less than one second).

[0095] The techniques described herein can be used in stereotactic radiosurgery and stereotactic body-assisted radiotherapy with single or multiple transfers.

[0096] Although the subject matter has been described in language specific to structural features and / or methodological actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms for implementing the claims.

Claims

1. A computer system, comprising: processor; as well as A memory coupled to the processor and including instructions, which, when executed, cause the processor to perform operations to generate a radiation therapy plan, the operations including: Receive the minimum prescribed dose rate to be delivered by each of the multiple beams to a corresponding spot in a plurality of spots in a patient target; as well as A control value is determined for each of the beams, wherein the control value for each of the beams is determined such that each of the spots receives the minimum prescribed dose rate. The control value for each of the beams is a dose rate for each of the beams, and the dose rate for each of the beams is a dose delivered to a corresponding spot in the spot within less than one second.

2. The computer system of claim 1, wherein the control value for each of the beams is the beam energy of each of the beams.

3. The computer system of claim 2, wherein the beam energy for each beam is determined using parameters including the number of radiations for a corresponding spot of each beam, the duration of each radiation for the corresponding spot, and the dose deposited in each radiation for the corresponding spot.

4. The computer system of claim 1, wherein the dose rate for each beam is determined using parameters including the number of irradiations for the corresponding spot, the duration of each irradiation for the corresponding spot, and the dose deposited in each irradiation for the corresponding spot.

5. The computer system of claim 4, wherein the operation further comprises determining the arrangement of the spots in the target and the number of the spots.

6. The computer system of claim 5, wherein determining a control value for each of the beams comprises accessing a value of a control parameter from the memory, and adjusting the value of the parameter until the dose rate for each spot satisfies the minimum prescribed dose rate, wherein the control parameter comprises the beam energy of a beam within an arrangement of spots in the target to be directed to the patient.

7. The computer system according to any one of claims 1 to 6, wherein the operation further comprises: Access information from the memory, the information including the outline of the volume of the target inside the patient to be radiated; The arrangement of the spots within the contour is determined, wherein each spot corresponds to a position within the volume of the target where a corresponding beam of the radiating beam is directed during the patient's radiation therapy.

8. The computer system of claim 7, wherein the operation further comprises storing a radiation therapy plan, including the arrangement of the spots and the dose rate for each of the beams, into the memory.

9. The computer system according to any one of claims 1 to 6, wherein the minimum prescription dose rate is 4 Gray per second.

10. The computer system according to any one of claims 1 to 6, wherein the minimum prescription dose rate is 20 Gy per second.

11. The computer system according to any one of claims 1 to 6, wherein the ratio of the dose rate inside the spot to the dose rate outside the spot is at least 1.

5.

12. The computer system according to any one of claims 1 to 6, wherein the beam comprises a beam type selected from the group consisting of: protons; electrons; photons; atomic nuclei; and ions.

13. The computer system according to claim 3 or 4, wherein the parameters further include: The duration of the radiation application, and the time interval between each period of radiation.

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