Dose prediction system, dose prediction method, and dose prediction program

Abstract

This invention provides a dose prediction system, dose prediction method, and dose prediction program for accurately evaluating particle beam irradiation doses and supporting treatment using particle beams. [Solution] The support device 20 comprises an irradiation device 31 that irradiates with a particle beam, a detection device 32 that measures the irradiation area of ​​the particle beam, an imaging device 33 that photographs the light emission of the irradiation area, and a control unit 21 that predicts the irradiation dose by the irradiation device 31. The control unit 21 acquires the light emission distribution of the surface of the irradiated object irradiated with the particle beam, acquires the activity distribution of positron emission nuclei generated on the side surface of the irradiated object, and calculates a three-dimensional dose distribution using the light emission distribution and the activity distribution.

Description

Technical Field

[0001] The present disclosure relates to a dose prediction system, a dose prediction method, and a dose prediction program for assisting treatment using a particle beam.

Background Art

[0002] In some cases, treatment such as cancer treatment is performed using a high-energy and high-speed particle beam. One type of particle beam, the proton beam, loses a large amount of energy at a location just before the incident proton stops in the body. And a high-dose region called a "Bragg peak" is formed at that location. Therefore, by reducing the damage to normal regions, strong radiation can be intensively irradiated to the affected part in the body. In such irradiation of a particle beam (proton beam), the proton beam irradiation region is visualized by utilizing a nuclear fragmentation reaction that occurs between the incident proton nucleus and the target nucleus in the patient's body. Based on this visualization information, a technique for deriving the irradiation dose to a tumor has also been studied (see, for example, Non-Patent Document 1). The technique described in this document uses a "Beam ON-LINE Positron Emission Tomography system", which is a positron emission tomography device (PET device) that detects positron-emitting nuclei generated in the irradiation region in the patient's body by a nuclear fragmentation reaction in proton beam therapy. By installing this PET device in a proton beam rotating gantry irradiation chamber, the proton beam irradiation region is visualized. When performing treatment using radiation, in order to reduce the exposure dose of the patient, it is necessary to irradiate at an appropriate position with an appropriate radiation dose.

[0003] Furthermore, as a technique for deriving the irradiation dose to a tumor, a flash irradiation method has also been studied (see, for example, Non-Patent Document 2). In the flash irradiation method described in this document, radiation is irradiated at a dose rate (>40 Gy / s) higher than the normal treatment dose rate (about 0.03 Gy / s). In this case, it is possible to reduce the side effects on normal tissues while maintaining the conventional treatment effect. And studies on the implementation of cancer treatment using the flash irradiation method with a proton beam have also been started.

[0004] Furthermore, predictive support systems to assist in treatment using particle beam irradiation are also being considered (see, for example, Patent Document 1). The support device described in this document includes a control unit that predicts the irradiation state by a particle beam irradiation device. The control unit calculates the three-dimensional radioactivity distribution when at least one of the irradiation state and the patient state is changed, based on the irradiation state determined by the particle beam irradiation conditions, using simulation. Furthermore, it calculates measurement information obtained by measuring the three-dimensional radioactivity distribution in two dimensions. The control unit then generates a predictive model that predicts the three-dimensional radioactivity distribution when changes are made based on the measurement information. When the control unit obtains measurement results measured in two dimensions, it applies the predictive model to the measurement results to predict the three-dimensional radioactivity distribution corresponding to the measurement results. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-119445 [Non-patent literature]

[0006] [Non-Patent Document 1] Teiji Nishio, "High-precision proton beam therapy using irradiation area visualization based on nuclear spallation reactions", [online], 2011, Research Institute for Advanced Science and Technology, RIST News, No. 50, pp. 24-35, [Retrieved September 22, 2024], Internet<URL:http: / / www.rist.or.jp / rnews / 50 / 50s4.pdf> [Non-Patent Document 2] Hiroyama, Yota et al., "Measurement of the cell lethal effect and micronucleus formation rate in cultured cells irradiated with 60 MeV proton beam flash," [online], July 7, 2021, Japan Isotope Association, 58th Isotope and Radiation Research Conference, [Retrieved September 22, 2024], Internet<https: / / www.jstage.jst.go.jp / article / happyokai / 1 / 0 / 1_134 / _pdf / -char / ja> [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the technology described in Patent Document 1 performs two-dimensional measurements from the side, which can make it difficult to grasp the three-dimensional distribution. [Means for solving the problem]

[0008] A dose prediction system that solves the above problems comprises an irradiation device that irradiates with a particle beam, a detection device that measures the irradiation area of ​​the particle beam, an imaging device that captures the light emission of the irradiation area, and a control unit that predicts the irradiation dose by the irradiation device. The control unit acquires the light emission distribution of the surface of the irradiated object irradiated with the particle beam, acquires the activity distribution of positron emission nuclei generated on the side surface of the irradiated object, and calculates a three-dimensional dose distribution using the light emission distribution and the activity distribution. [Effects of the Invention]

[0009] This disclosure enables accurate evaluation of particle beam irradiation dose and supports treatment using particle beam irradiation. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram of the dose prediction system according to an embodiment. [Figure 2] This is an explanatory diagram of the hardware configuration of the embodiment. [Figure 3] This is an explanatory diagram illustrating the arrangement of the detection device according to the embodiment. [Figure 4] This is an explanatory diagram illustrating the arrangement of the imaging device in the embodiment. [Figure 5] This is an explanatory diagram of the data of the embodiment. [Figure 6] This is an explanatory diagram of the processing procedure of the embodiment. [Figure 7] This is an explanatory diagram of the radioactivity distribution, luminescence distribution, and dose distribution of the embodiment. [Modes for carrying out the invention]

[0011] The following describes one embodiment of the dose prediction system, dose prediction method, and dose prediction program, with reference to Figures 1 to 7. In this embodiment, we describe a case in which a proton beam, as a particle beam, is irradiated onto the affected area (target of irradiation) of a patient by a flash irradiation method to treat the affected area. In this case, in order to calculate the three-dimensional irradiation dose of the proton beam, a two-dimensional dose distribution measured on the side and a surface dose distribution measured on the three-dimensional surface are used.

[0012] Here, as shown in Figure 1, a treatment planning device 10, a support device 20, and a treatment device 30 are used, all connected via a network. (Example hardware configuration) Figure 2 shows an example of the hardware configuration of the information processing device H10, which functions as a treatment planning device 10, a support device 20, a treatment device 30, etc.

[0013] The information processing device H10 includes a communication device H11, an input device H12, a display device H13, a storage device H14, and a processor H15. Note that this hardware configuration is an example, and other hardware may be included.

[0014] Communication device H11 is an interface that establishes a communication path with other devices and performs data transmission and reception, such as a network interface or a wireless interface.

[0015] The input device H12 is a device that receives input from a user or the like, such as a mouse, a keyboard, or the like. The display device H13 is a display, a touch panel, or the like that displays various information.

[0016] The storage device H14 is a storage device that stores data and various programs for executing various functions of the treatment planning device 10, the support device 20, and the treatment device 30. Examples of the storage device H14 include a ROM, a RAM, a hard disk, and the like.

[0017] The processor H15 controls each process (for example, the process in the control unit 21 described later) in the treatment planning device 10, the support device 20, and the treatment device 30 by using the programs and data stored in the storage device H14. Examples of the processor H15 include a CPU, an MPU, and the like. This processor H15 expands the program stored in a ROM or the like into a RAM and executes various processes corresponding to various processes. For example, when the application programs of the treatment planning device 10, the support device 20, and the treatment device 30 are started, the processor H15 operates a process for executing each process described later.

[0018] The processor H15 is not limited to performing software processing for all processes it executes. For example, the processor H15 may include a dedicated hardware circuit (for example, an application-specific integrated circuit: ASIC) that performs hardware processing for at least a part of the processes it executes. That is, the processor H15 may be configured as follows.

[0019] (1) One or more processors that operate according to a computer program (2) One or more dedicated hardware circuits that execute at least a part of various processes (3) A circuit including a combination thereof A processor includes a CPU and memory such as RAM and ROM, where memory stores program code or instructions configured to cause the CPU to perform processing. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0020] (Functions of each information processing device) Next, we will explain the functions of the treatment planning device 10, the support device 20, and the treatment device 30. The treatment planning device 10 is a simulator for examining the method of radiation incidence to the affected area and confirming whether an appropriate dose is prescribed. This treatment planning device 10 acquires CT images (DICOM data) taken from a CT scanner at predetermined image intervals. The treatment planning device 10 then performs contour extraction on the DICOM data using a known method and generates CT contour information. This CT contour information is composed of DICOM ROI (Region Of Interest) data and is data consisting of a collection of points (coordinates) that constitute the contour of a predetermined area (body surface, bone, affected area, and organs at risk, etc.) identified in the CT images (tomographic images) taken at predetermined intervals. In this treatment planning device 10, the beam quality, incidence direction, irradiation range, prescribed dose, and number of irradiations are determined based on the body surface shape of the affected area, the shape and location of the affected area, and the positional relationship with organs at risk.

[0021] The support device 20 is a computer system for supporting treatment using particle beams (proton beams). This support device 20 comprises a control unit 21, a treatment information storage unit 22, and a conversion coefficient storage unit 23.

[0022] The control unit 21 performs the processing described later (including the calculation stage, acquisition stage, evaluation stage, etc.). By executing the dose prediction program for this purpose, the control unit 21 functions as a calculation unit 211, an acquisition unit 212, an evaluation unit 213, etc.

[0023] The calculation unit 211 performs irradiation simulation processing for the therapeutic beam (proton beam). The acquisition unit 212 performs processing to acquire various information such as radiation levels. The evaluation unit 213 performs an evaluation process of the irradiation conditions based on the measurement results.

[0024] The treatment information storage unit 22 records treatment management information regarding proton beam irradiation for the patient's treatment. This treatment management information is recorded when treatment plan information (irradiation plan information) is obtained from the treatment planning device 10. This treatment management information includes CT contour information and irradiation condition information, associated with the patient code and the scheduled treatment date.

[0025] A patient code is an identifier used to identify each patient. The scheduled treatment date is the date (year, month, day) on which proton beam irradiation treatment is scheduled for this patient in the treatment plan.

[0026] CT contour information includes positional information of the contours of specified areas (body surface, bone, affected area, and organs at risk, etc.) in the CT images of the affected area of ​​this patient. The irradiation condition information refers to the conditions under which the proton beam will be irradiated to this patient on the scheduled treatment date. The irradiation condition information includes information on the proton beam's irradiation position, irradiation direction, irradiation energy, irradiation dose, beam irradiation method, etc. In this embodiment, "flash irradiation" is used as the beam irradiation method.

[0027] The conversion coefficient storage unit 23 stores conversion coefficient information for calculating the irradiation dose. This conversion coefficient information is recorded when the patient's conversion coefficient is calculated through pre-irradiation. In this pre-irradiation, positron-emitting nuclei are detected by performing flash irradiation on a reference atom (Ca atom in this embodiment) in the patient's body under predetermined conditions. Then, a radioactivity conversion coefficient is calculated from the internal reference radioactivity distribution of the "bone location containing Ca atom" identified by the CT contour information to convert it to the irradiation dose at the bone location.

[0028] Furthermore, the imaging device 33 measures the luminescence distribution, including visible light, obtained by flash proton beam irradiation of Toughwater (a water equivalent substance with a composition similar to human soft tissue), Khufbone, and Toughlang plate materials (with compositions similar to bone and lungs). A luminescence conversion coefficient is then calculated from the luminescence distribution to the body surface dose distribution. Note that there is a correlation between the luminescence distribution and the body surface dose distribution. Additionally, the luminescence conversion coefficient is corrected according to the patient's body surface condition (e.g., skin moisture content). This conversion coefficient information includes information on the radioactivity conversion coefficient and the luminescence conversion coefficient for each patient code.

[0029] A patient code is an identifier used to identify each patient. The radioactivity conversion coefficient is information used to predict the radiation dose by the flash irradiation method based on the radioactivity distribution (activity distribution) in different parts of the patient's body.

[0030] The luminescence conversion coefficient is information used to predict the radiation dose by the flash irradiation method from the luminescence distribution on the patient's body surface. The treatment device 30 is a device that treats cancer and other diseases by irradiating the affected area with radiation. The treatment device 30 is equipped with a treatment table for the patient P1 to lie on their back, stomach, or side. The treatment device 30 also includes an irradiation device 31, a detection device 32, and an imaging device 33.

[0031] The irradiation device 31 is a device (gantry) that irradiates the patient P1 on the treatment table with a particle beam using a flash irradiation method. The detection device 32 is a positron emission tomography (PET) device that detects positron-emitting nuclei generated in the irradiated area of ​​the patient's body by the target nuclear spallation reaction during proton beam therapy. The irradiation depth can be determined by the emission position of these positron-emitting nuclei. The detection device 32 is equipped with measurement surfaces 321 and 322 that detect positron-emitting nuclei from the side in the direction of irradiation of the proton beam irradiated from the irradiation device 31.

[0032] As shown in Figure 3, for example, the case of irradiating the neck with a particle beam is explained. In this case, the particle beam is irradiated from the irradiation device 31 located behind the neck of patient P1. Then, the radioactivity distribution is measured in two dimensions by the measurement surfaces 321 and 322 of the detection devices 32 located on both sides of the head.

[0033] As shown in Figure 4, the measurement surfaces 321 and 322 are positioned on the side of patient P1. When radiation is applied to a substance, electromagnetic waves are generated that correspond to the transition energy associated with the excitation and ionization of electrons within the substance. If the wavelength of these electromagnetic waves is equivalent to visible light, they can be captured as light emission by the imaging device 33. Furthermore, with ultra-high dose rates of flash proton beams, which are 1000 times or more the proton beam intensity used in normal treatment, visible light that can be detected by the naked eye is generated. Because electromagnetic waves with visible light wavelengths are easily absorbed by substances such as the human body, the human body light emission phenomenon caused by flash proton beam irradiation can only be observed near the body surface. The distribution of light emission observed on the patient's body surface includes information on the irradiation energy for each actual proton beam irradiation position on the tumor inside the body, as viewed from the direction of proton beam irradiation.

[0034] As shown in Figure 4, three imaging devices 33 (331, 332, 333) simultaneously photograph the surface of the irradiated area tg1 on the body surface of patient P1 from different directions, thereby measuring the emission from the surface. For example, a cooled CMOS camera capable of observing electromagnetic waves in the 400-1000 nm wavelength band (corresponding to an energy of 1-3 eV) is used as the imaging device 33. In this case, by using multiple imaging devices 33, shape correction can be performed to identify the three-dimensional shape of the irradiated area tg1, which consists of a curved surface.

[0035] (Data used for irradiation adjustment) Figure 5 illustrates the data used for irradiation adjustment. Through simulation, spot irradiation, which focuses the particle beam to a single point, and volume irradiation, which scans the particle beam to cover a wide area, are performed. From the 3D dose distribution D1 of the irradiated proton beam within the body, the lateral dose distribution D2 and surface dose distribution D3 are calculated. Then, proton beam irradiation is performed under the simulated irradiation conditions. During this proton beam irradiation, the lateral radioactivity distribution D4 is measured by the detection device 32 and the surface emission distribution D5 is measured by the imaging device 33. Then, the lateral dose distribution D6 is predicted from the lateral radioactivity distribution D4 and the surface dose distribution D7 is predicted from the surface emission distribution D5. From the predicted lateral dose distribution D6 and surface dose distribution D7, the 3D dose distribution D8 is predicted. Then, irradiation adjustments are made according to a comparison of the 3D dose distribution D1, lateral dose distribution D2, and surface dose distribution D3 with the 3D dose distribution D8, lateral dose distribution D6, and surface dose distribution D7.

[0036] (Irradiation support processing) The irradiation support process will be explained using Figure 6. First, the control unit 21 of the support device 20 executes the process of acquiring a treatment plan (step S11). Specifically, the calculation unit 211 of the control unit 21 acquires treatment plan information from the treatment planning device 10, using the patient code of the patient who will receive proton beam irradiation treatment on the scheduled treatment day (the day), as the key, and records it in the treatment information storage unit 22. Then, the acquisition unit 212 identifies the proton beam irradiation range using the irradiation conditions (proton beam irradiation position, irradiation direction, irradiation energy) in the CT contour information. Spot irradiation or volume irradiation may be used here.

[0037] Next, the control unit 21 of the support device 20 performs a simulation of the three-dimensional dose distribution (step S12). Specifically, the calculation unit 211 of the control unit 21 performs a simulation of irradiation with a particle beam (pre-irradiation) using the irradiation conditions.

[0038] In this simulation, the irradiation energy is set to the irradiation energy at the irradiation location in the treatment plan. The irradiation dose (planned value) is within the prescribed dose in the treatment plan, is the minimum dose at which the detection device 32 can detect positron-emitting nuclei, and is the dose at which the imaging device 33 can emit light. In this case, a three-dimensional dose distribution is calculated for the patient model placed in the virtual space, taking into account the shape of the body surface and organs from the CT contour information.

[0039] Next, the control unit 21 of the support device 20 performs a simulation process of the lateral dose distribution (step S13). Specifically, the calculation unit 211 of the control unit 21 calculates a two-dimensional lateral dose distribution when the dose distribution inside the patient model's body is measured from the side.

[0040] Next, the control unit 21 of the support device 20 performs a simulation process of the surface dose distribution (step S14). Specifically, the calculation unit 211 of the control unit 21 calculates the surface dose distribution of the three-dimensional surface of the patient model as if the dose distribution on the body surface were measured at the surface.

[0041] Next, the control unit 21 of the support device 20 performs the irradiation process (step S15). Specifically, the acquisition unit 212 of the control unit 21 transmits a proton beam flash irradiation instruction to the treatment device 30. The irradiation conditions used in the simulation are used for this flash irradiation instruction. Then, the irradiation device 31 of the treatment device 30 irradiates each of the instructed flash irradiation positions with a proton beam according to the irradiation energy and flash irradiation dose.

[0042] In this case, the control unit 21 of the support device 20 performs a side measurement process (step S16). Specifically, the acquisition unit 212 of the control unit 21 detects the reference area and the radioactivity distribution inside the body, measured on the measurement surfaces 321 and 322, from the detection device 32 of the treatment device 30.

[0043] Next, the control unit 21 of the support device 20 performs a prediction process for the lateral dose distribution (step S17). Specifically, the evaluation unit 213 of the control unit 21 obtains the radioactivity conversion coefficient associated with the patient code of the treatment plan information from the conversion coefficient storage unit 23. Next, the evaluation unit 213 identifies the internal reference radioactivity distribution from the bone containing the internal reference atom (Ca atom) in the obtained radioactivity distribution. Next, the evaluation unit 213 calculates the irradiation dose (actual dose) of the reference region using the radioactivity conversion coefficient based on the Ca density of the reference region.

[0044] Next, the control unit 21 of the support device 20 performs surface measurement processing (step S18). Specifically, the evaluation unit 213 of the control unit 21 acquires the light emission distribution of the patient P1's body surface from the imaging devices 331, 332, and 333. In this case, the light emission distribution is acquired according to the three-dimensional shape of the body surface.

[0045] Next, the control unit 21 of the support device 20 performs surface dose distribution prediction processing (step S19). Specifically, the evaluation unit 213 of the control unit 21 obtains the emission amount conversion coefficient associated with the patient code of the treatment plan information from the conversion coefficient storage unit 23. Then, the evaluation unit 213 calculates the surface dose distribution according to the emission amount distribution using the emission amount conversion coefficient.

[0046] Next, the control unit 21 of the support device 20 performs irradiation adjustment processing (step S20). Specifically, the evaluation unit 213 of the control unit 21 predicts a three-dimensional dose distribution from the lateral dose distribution and surface dose distribution predicted by irradiation.

[0047] As shown in Figure 7, the 3D dose distribution D8 is predicted from the lateral radioactivity distribution D4 and the surface emission distribution D5. The evaluation unit 213 then compares this with the simulated 3D dose distribution and determines whether there is a match or a mismatch.

[0048] Furthermore, the agreement between the predicted lateral dose distribution and surface dose distribution based on irradiation and the lateral dose distribution and surface dose distribution calculated by simulation is evaluated. For example, the lateral dose distribution is used to determine the agreement in the irradiation depth of the particle beam (agreement in irradiation energy). The surface dose distribution is used to determine the agreement in the irradiation position of the particle beam (agreement in orientation and arrangement).

[0049] The evaluation unit 213 then outputs the calculated radiation dose to the treatment device 30. Furthermore, the evaluation unit 213 compares the calculated radiation dose distribution with the radiation dose and depth position of the treatment plan. If it determines that the distribution is outside the predetermined tolerance range and does not match the treatment plan, the evaluation unit 213 outputs an alarm to the treatment device 30 regarding the deviation in radiation dose or depth position.

[0050] Once the irradiation support processing for the pre-irradiation is complete, the irradiation conditions are adjusted and the subsequent irradiation is performed using the dose remaining after subtracting the pre-irradiation dose. Irradiation support processing is also performed during this subsequent irradiation. (Operation of this embodiment) When a particle beam is irradiated, the surface emits light in accordance with the dose, allowing for the measurement of the dose distribution in a plane perpendicular to the direction of irradiation.

[0051] (Effects of this embodiment) (1) In this embodiment, the conversion coefficient storage unit 23 stores conversion coefficient information for calculating the irradiation dose. This makes it possible to predict the irradiation dose from the radioactivity distribution using the radioactivity conversion coefficient. In addition, it is possible to predict the irradiation dose from the emission amount distribution using the emission amount conversion coefficient.

[0052] (2) In this embodiment, the control unit 21 of the support device 20 performs a treatment plan acquisition process (step S11) and a three-dimensional dose distribution simulation process (step S12). This makes it possible to calculate the dose distribution by a simulation that simulates the treatment plan.

[0053] (3) In this embodiment, the control unit 21 of the support device 20 performs simulation processing of the lateral dose distribution (step S13). This makes it possible to predict the dose distribution measured on the side.

[0054] (4) In this embodiment, the control unit 21 of the support device 20 performs a simulation process of the surface dose distribution (step S14). This makes it possible to predict the dose distribution measured on the surface.

[0055] (5) In this embodiment, the control unit 21 of the support device 20 performs irradiation processing (step S15). This makes it possible to perform particle beam irradiation while maintaining the therapeutic effect and reducing side effects on normal tissue.

[0056] (6) In this embodiment, the control unit 21 of the support device 20 performs a side measurement process (step S16) and a side dose distribution prediction process (step S17). This makes it possible to measure the radioactivity distribution in two dimensions at high speed over a wide time range starting from the order of milliseconds. Therefore, the dose distribution can be measured in flash irradiation, where irradiation ends instantaneously.

[0057] (7) In this embodiment, the control unit 21 of the support device 20 performs surface measurement processing (step S18) and surface dose distribution prediction processing (step S19). This makes it possible to predict the dose distribution on the patient's body surface in flash irradiation, where irradiation ends instantaneously.

[0058] (8) In this embodiment, the control unit 21 of the support device 20 performs irradiation adjustment processing (step S20). This makes it possible to confirm proton beam irradiation corresponding to the treatment plan. If a discrepancy occurs, the irradiation conditions can be adjusted.

[0059] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. In the above embodiment, the control unit 21 of the support device 20 performs irradiation adjustment processing (step S20). In this case, the agreement of the three-dimensional dose distribution, the lateral dose distribution, and the surface dose distribution is evaluated. It is not necessary to use all dose distributions for this evaluation; the "three-dimensional dose distribution" or a "combination of the lateral dose distribution and the surface dose distribution" may be used.

[0060] In the above embodiment, a proton beam is used as the particle beam. However, the particle beam is not limited to a proton beam; for example, a carbon beam can also be used. • In the above embodiment, the irradiation dose in flash irradiation is calculated, but the particle beam irradiation method is not limited to flash irradiation.

[0061] In the above embodiment, a Ca atom is used as the reference atom. However, it is not limited to a Ca atom; any atom present in the body is acceptable. In the above embodiment, a positron emission tomography (PTMO) device is used as the detection device 32 to detect positron-emitting nuclei generated in the irradiated area within the patient's body. However, detection of the irradiated area is not limited to the detection of positron-emitting nuclei. [Explanation of Symbols]

[0062] 10... Treatment planning device, 20... Support device, 21... Control unit, 211... Calculation unit, 212... Acquisition unit, 213... Evaluation unit, 22... Treatment information storage unit, 23... Conversion coefficient storage unit, 30... Treatment device, 31... Irradiation device, 32... Detection device, 33... Imaging device.

Claims

1. An irradiation device that irradiates with a particle beam, A detection device for measuring the irradiation area of ​​the particle beam, A camera for capturing light emission from the aforementioned irradiation area, A dose prediction system comprising a control unit for predicting the irradiation dose by the irradiation device, The control unit, The emission distribution on the surface of the irradiated object is obtained when the particle beam is irradiated. The activity distribution in which positron-emitting nuclei are generated on the side surface of the irradiated object is obtained. A dose prediction system characterized by calculating a three-dimensional dose distribution using the aforementioned light emission distribution and the aforementioned activity distribution.

2. The control unit, Multiple images of the surface of the irradiated object are acquired from different directions at the same time. The dose prediction system according to claim 1, characterized in that the emission amount distribution is calculated by shape correction using the aforementioned plurality of images.

3. The control unit, The state of the surface of the irradiated object is identified, The dose prediction system according to claim 1 or 2, characterized in that it corrects the intensity of the light emission distribution according to the aforementioned state.

4. The control unit, Using the irradiation conditions of the irradiation plan, a pre-irradiation with a particle beam is performed to obtain the three-dimensional dose distribution. The dose prediction system according to claim 1, characterized in that the irradiation conditions are adjusted by comparing the three-dimensional dose distribution with the irradiation range in the irradiation plan.

5. An irradiation device that irradiates with a particle beam, A detection device for measuring the irradiation area of ​​the particle beam, A camera for capturing light emission from the aforementioned irradiation area, A method for performing dose prediction using a dose prediction system comprising a control unit for predicting the irradiation dose by the aforementioned irradiation device, The control unit, The emission distribution on the surface of the irradiated object is obtained when the particle beam is irradiated. The activity distribution in which positron-emitting nuclei are generated on the side surface of the irradiated object is obtained. A dose prediction method characterized by calculating a three-dimensional dose distribution using the aforementioned light emission distribution and the aforementioned activity distribution.

6. An irradiation device that irradiates with a particle beam, A detection device for measuring the irradiation area of ​​the particle beam, A camera for capturing light emission from the aforementioned irradiation area, A program for performing dose prediction using a dose prediction system comprising a control unit for predicting the irradiation dose by the aforementioned irradiation device, The control unit, The emission distribution on the surface of the irradiated object is obtained when the particle beam is irradiated. The activity distribution in which positron-emitting nuclei are generated on the side surface of the irradiated object is obtained. A dose prediction program characterized by functioning as a means for calculating a three-dimensional dose distribution using the aforementioned light emission distribution and the aforementioned activity distribution.

Images