JP2017080005A - Neutron capture therapy simulation system and neutron capture therapy simulation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simulation system for NCT (Neutron Capture Therapy) using a collimator in a three-dimensional shape.SOLUTION: A neutron capture therapy simulation system 10 comprises: a collimator shape storing part 11 that stores collimator shape data D103 showing a three-dimensional shape of a collimator 65 to be used in neutron capture therapy; a patient shape storing part 12 that stores patient shape data D104 showing a three-dimensional shape of a patient 53 undergoing the neutron capture therapy; and a simulation part 15 that performs a simulation calculation of a neutron distribution shown when the patient 53 is exposed to a neutron ray N through the collimator 65, on the basis of the collimator data D103 stored in the collimator shape storing part 11 and the patient shape data D104 stored in the patient shape storing part 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a neutron capture therapy simulation system and a neutron capture therapy simulation method.

  In recent years, attention has been paid to neutron capture therapy (NCT). In neutron capture therapy, a drug that accumulates in cancer cells and reacts with neutron radiation is administered to a patient in advance, and the patient is irradiated with neutron radiation to perform cancer treatment. In neutron capture therapy, a patient is irradiated with a neutron beam generated by a neutron source through a collimator that has an aperture and forms an irradiation field. In the conventional neutron capture therapy apparatus, a cylindrical collimator having a through-hole in the block body is used. However, in Patent Document 1 below, the shape of the opening provided in the collimator changes (adjusts) three-dimensionally. A possible neutron capture therapy device is described. This device is equipped with a collimator consisting of a plurality of leaf plates. By making at least a part of the leaf plates slidable in the direction of the irradiation axis of the neutron beam, a three-dimensional shape can be set for the collimator. It has become.

JP 2013-208257 A

  In this type of neutron capture therapy, a treatment plan is created prior to treatment to reduce the dose given to the patient's normal tissue and to improve the dose to the main tissue. In order to assist in the creation of a treatment plan, there is a program for simulating the treatment dose of neutron capture therapy, but this is only considered when a conventional cylindrical collimator is used. In other words, NCT simulation using a three-dimensional collimator is not taken into consideration, and a collimator in which the positions of many leaf plates change three-dimensionally cannot be simulated. It was difficult to create a treatment plan when using a collimator.

  An object of the present invention is to provide an NCT simulation system using a three-dimensional collimator.

  The neutron capture therapy simulation system of the present invention includes a collimator shape storage unit that stores collimator shape data indicating a three-dimensional shape of a collimator used in neutron capture therapy, and patient shape data indicating a three-dimensional shape of a patient in neutron capture therapy Based on the patient shape storage unit that stores data, the collimator shape data stored in the collimator shape storage unit, and the patient shape data stored in the patient shape storage unit, the patient was irradiated with neutrons via the collimator And a simulation unit for performing a simulation calculation of the distribution of the neutron beam.

  The neutron capture therapy simulation method of the present invention includes a collimator shape storage step for storing collimator shape data indicating a three-dimensional shape of a collimator used in neutron capture therapy, and patient shape data indicating a three-dimensional shape of a patient in neutron capture therapy The patient was irradiated with neutrons via the collimator based on the patient shape storage step for storing the data, the collimator shape data stored in the collimator shape storage step, and the patient shape data stored in the patient shape storage step And a simulation step for performing a simulation calculation of the distribution of the neutron beam.

  These systems and methods allow simulation based on the three-dimensional shape of the collimator and the three-dimensional shape of the patient.

  Moreover, the neutron capture therapy simulation system of the present invention is a space including a collimator and a patient by data synthesis processing of collimator shape data stored in the collimator shape storage unit and patient shape data stored in the patient shape storage unit. A data synthesizing unit that creates synthetic shape data indicating the three-dimensional shape of the data synthesizing unit may be provided, and the simulation unit may execute simulation calculation based on the synthetic shape data created by the data synthesizing unit.

  The neutron capture therapy simulation system of the present invention further includes a CT scanner device that acquires the CT image data of the collimator, and the collimator shape storage unit stores the CT image data acquired by the CT scanner device as collimator shape data. You may do it. According to this configuration, by using the CT scanning device, collimator shape data indicating the three-dimensional shape of the collimator can be obtained relatively easily.

  The neutron capture therapy simulation system of the present invention further includes an actual measurement data creation unit that creates actual collimator shape measurement data from the actually measured three-dimensional shape of the collimator, and the collimator shape storage unit is a collimator created by the actual measurement data creation unit. The actual shape data may be stored as collimator shape data.

  The neutron capture therapy simulation system of the present invention includes a collimator imaging unit that images the three-dimensional shape of the collimator, and the actual measurement data creation unit creates collimator shape actual measurement data based on the imaging data acquired by the collimator imaging unit. You may make it do.

  The collimator may be a multi-leaf collimator including a plurality of movable leaves, and at least some of the leaves may be slidable in the neutron beam irradiation direction in neutron capture therapy.

  According to the present invention, a simulation system for NCT using a three-dimensional collimator can be provided.

It is a block diagram which shows the neutron capture therapy simulation system of 1st Embodiment. (A) is collimator shape data, (b) is patient shape data, (c) is a conceptual diagram which shows synthetic | combination shape data, respectively. It is a block diagram which shows an example of a physical structure of a neutron capture therapy simulation system. It is a block diagram which shows the neutron capture therapy simulation system of 2nd Embodiment. It is a conceptual diagram which shows collimator CT image data. It is a figure which shows a BNCT apparatus. It is a conceptual diagram which shows the state by which the neutron beam which passes a collimator is irradiated to an irradiation target. (A) is a front view of a collimator, (b) is a side view of a collimator.

  Hereinafter, embodiments of a neutron capture therapy simulation system according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing functional elements of a neutron capture therapy simulation system 10 (hereinafter simply referred to as “simulation system 10” or “system 10”) in blocks. For example, in the neutron capture therapy illustrated in FIG. 6, the simulation system 10 calculates a treatment dose distribution of the neutron beam N irradiated toward the patient 53. In particular, the simulation system 10 is used for simulation of neutron capture therapy using a three-dimensional collimator 65 as described later. The neutron beam treatment apparatus 51 shown in FIG. 6 will be described later.

  As shown in FIG. 1, the simulation system 10 includes a CT scanner device 5 and an arithmetic processing unit 3. The CT scanner device 5 acquires CT image data, which is three-dimensional shape data of an object to be imaged, by computed tomography. A known CT scanner device can be used as the CT scanner device 5 of the simulation system 10. In the CT scanner device 5, the collimator 65 used in the neutron capture therapy is subjected to CT imaging, and collimator CT image data D 101 indicating the three-dimensional shape of the collimator 65 is obtained. The three-dimensional shape of the collimator 65 means that at least some of the leaf plates constituting the collimator move in the first direction (X direction in FIG. 8), and at least some other leaf plates. Is the shape of the collimator 65 in a state in which it moves in a second direction (Y direction in FIG. 8) perpendicular to the first direction. In the CT scanner device 5, neutron capture therapy patient 53 is CT-photographed, and patient CT image data D <b> 102 indicating the three-dimensional shape of the patient 53 is obtained. Note that imaging of the collimator 65 using the CT scanner device 5 (acquisition of collimator CT image data D101) and imaging of the patient 53 using the CT scanner device 5 (acquisition of patient CT image data D102) are performed separately. Is called. At this time, the CT scanner device 5 is not the same, and two different CT scanners may be used.

  The arithmetic processing unit 3 includes a collimator shape storage unit 11, a patient shape storage unit 12, a data synthesis unit 13, a data conversion unit 14, a simulation unit 15, and a result output unit 16.

  The collimator shape storage unit 11 stores collimator shape data D103 indicating the three-dimensional shape of the collimator 65. Here, the collimator shape storage unit 11 stores the collimator CT image data D101 obtained by the CT scanner device 5 as collimator shape data D103. The patient shape storage unit 12 stores patient shape data D104 indicating a three-dimensional shape of a part related to treatment of the patient 53. Here, the patient shape storage unit 12 stores the patient CT image data D102 obtained by the CT scanner device 5 as patient shape data D104. The collimator shape data D103 and the patient shape data D104 are described as, for example, a voxel model (for example, a cube model). At this time, for example, the collimator CT image data D101 and the patient CT image data D102 obtained in the DICOM format may be converted into, for example, a voxel model and used as the collimator shape data D103 and the patient shape data D104.

  The data synthesis unit 13 creates specific shape data D105 indicating the three-dimensional shape of the space including the collimator 65 and the patient 53 by data synthesis processing of the collimator shape data D103 and the patient shape data D104. The concept of the synthesis process is as follows. As shown in FIG. 2A, the collimator shape data D103 is composed of an actual data part D103a indicating the collimator 65 and a blank part D103b other than that. Similarly, as shown in FIG. 2B, the patient shape data D104 includes an actual data part D104a indicating the patient 53 and a blank part D104b other than that. The data synthesizing unit 13 synthesizes the two actual data parts D103a and D104a while appropriately processing the marginal parts 103b and 104b that interfere with each other as described above, and the actual data part D103a as shown in FIG. 2C. , D104a and the blank portion 105b, composite shape data D105 is obtained. The positional relationship between the actual data portion D103a and the actual data portion D104a on the composite shape data D105 is made to correspond to the positional relationship between the collimator 65 and the patient 53 in NCT.

  Such data composition processing can be executed by known three-dimensional data processing. The synthesized shape data D105 obtained here represents the three-dimensional shape of the entire object including the collimator 65 present in the neutron irradiation region of the NCT apparatus, the patient 53, and the air layer filling between them as one piece of data. Is. The air layer corresponds to the blank portion D105b. The composite shape data D105 is described as a voxel model, for example.

  As shown in FIG. 1, the data converter 14 performs data format conversion of the composite shape data D105. The data conversion unit 14 converts the composite shape data D105 into a data format that can be input to the simulation unit 15 described later. For example, the data conversion unit 14 converts the composite shape data D105 into a data format that can be input to the Monte Carlo radiation transport code. Note that the data conversion unit 14 is not essential, and the data conversion unit 14 can be omitted if the format of the composite shape data D105 can be input to the simulation unit 15 as it is.

  The simulation unit 15 executes simulation calculation according to a predetermined simulation program. The simulation unit 15 calculates the neutron beam treatment dose distribution when the patient 53 is irradiated with the neutron beam through the collimator 65 using the composite shape data D105 delivered from the data conversion unit 14 as input data. The simulation unit 15 further includes an irradiation time for the therapeutic dose to the affected part of the patient 53 to reach a necessary amount, an irradiation time for reaching the allowable upper limit dose to the patient 53, and each of the patients 53 in the irradiation time. Information such as the treatment dose distribution of the part may be calculated. A known Monte Carlo radiation transport code can be used as the simulation program. Examples of the Monte Carlo radiation transport code include MCNP, PHITS, and GEANT4.

  The result output unit 16 presents the result of the simulation calculation by the simulation unit 15 to the user, for example, by screen display or printout.

  Here, an example of a physical configuration of the arithmetic processing unit 3 will be described. FIG. 3 is a hardware configuration diagram of the arithmetic processing unit 3. As shown in the figure, the arithmetic processing unit 3 physically includes a CPU 211, a RAM 212 and a ROM 213 that are main storage devices, an auxiliary storage device 215 such as a hard disk, an input device 216 such as a keyboard and a mouse that are input devices, and a display. The computer system includes an output device 217 such as a network module and a communication module 214 which is a data transmission / reception device such as a network card. Each function described in FIG. 1 has a communication module 214, an input device 216, and an output device 217 under the control of the CPU 211 by reading predetermined computer software on the hardware such as the CPU 211 and the RAM 212 shown in FIG. This is realized by reading and writing data in the RAM 212 and the auxiliary storage device 215.

  The neutron capture therapy simulation method performed in the simulation system 10 as described above includes a CT scan step, a collimator shape storage step, a patient shape storage step, a simulation step, and a result output step described below.

  In the CT scan step, the collimator 65 is scanned by the CT scanner device 5 to obtain collimator CT image data D101, and the patient 53 is scanned by the CT scanner device 5 to obtain patient CT image data D102. In the collimator shape storage step, the collimator shape storage unit 11 stores the collimator CT image data D101 as collimator shape data D103 indicating the three-dimensional shape of the collimator 65. In the patient shape storage step, the patient shape storage unit 12 stores the patient CT image data D102 as patient shape data D104 indicating the three-dimensional shape of the patient 53. In the simulation step, the distribution of the neutron beam when the patient 53 is irradiated with the neutron beam via the collimator 65 based on the combined shape data D105 obtained based on the collimator shape data D103 and the patient shape data D104. Perform simulation calculations. In the result display step, the result of the simulation calculation by the simulation unit 15 is presented to the user, for example, by screen display or printout.

  According to the simulation system 10 and the simulation method described above, it is possible to simulate neutron capture therapy based on the three-dimensional shape of the collimator 65 and the three-dimensional shape of the patient 53, and for NCT using a three-dimensional shape collimator. Simulation becomes possible. In addition, the shape of the collimator 65 can be converted into data relatively easily by CT scan. For example, the situation can be modeled even when a hole exists in the collimator 65. Further, when the basic design of the collimator 65 is changed, the change can be easily handled. Further, since the collimator 65 and the patient 53 are handled together as one model by the Monte Carlo radiation transport code, a highly accurate simulation is possible.

  When moving at least a part of the leaf plate of the collimator 65 in the neutron beam irradiation direction, it is difficult to move the leaf plate by a mechanical drive mechanism such as a motor. In such a case, the leaf plate is moved manually. When the leaf plate is moved by a mechanical drive mechanism, the position of the leaf plate can be easily detected from the control value of the drive mechanism, but when the leaf plate is moved manually, the position of the leaf plate is changed. It is difficult to detect when the leaf plate is moving. Therefore, by using the CT scanner device, even if at least a part of the leaf plate is a collimator that moves in the irradiation direction of the neutron beam, it is possible to detect the position of the leaf plate and create a treatment plan.

(Second Embodiment)
Next, a neutron capture therapy simulation system 30 (hereinafter simply referred to as “simulation system 30” or “system 30”) according to the second embodiment will be described. FIG. 4 is a block diagram showing functional elements of the simulation system 30 in blocks. In the second embodiment, components that are the same as or equivalent to those in the first embodiment are given the same reference numerals in the drawings. In the following, the points of the second embodiment that are different from the first embodiment will be mainly described, and overlapping descriptions will be omitted.

  As shown in FIG. 4, the arithmetic processing unit 33 included in the simulation system 30 includes a first actual measurement data creation unit 41. The first actual measurement data creation unit 41 creates collimator shape actual measurement data D107 based on collimator CT image data D101 (imaging data) acquired by the CT scanner device 5 (collimator imaging unit). Specifically, the first actual measurement data creation unit 41 measures the dimensions of each part such as the width h of the opening of the collimator 65, and converts the three-dimensional shape of the collimator 65 into a geometric model (for example, a rectangular parallelepiped, a cube, Obtained as the collimator shape actual measurement data D107 described in a sphere or the like. As shown in FIG. 5, the actual measurement of the dimensions of each part of the collimator 65 is based on the actual data part D101a of the collimator CT image data D101, for example, the number of pixels of each part on the actual data part D101a ( For example, the number of pixels corresponding to the width h is counted.

  The arithmetic processing unit 33 may include a second actual measurement data creation unit 42 instead of the first actual measurement data creation unit 41. That is, as shown in FIG. 4, it is not essential for the arithmetic processing unit 33 to include both the first actual measurement data creation unit 41 and the second actual measurement data creation unit 42, and either one may be omitted. . The second actual measurement data creation unit 42 receives data input from the user. At this time, the user manually measures the dimensions of each part such as the width h of the actual opening of the collimator 65 and inputs the measured value. Then, the second actual measurement data creation unit 42, based on the input measurement value data, collimator shape actual measurement data in which the three-dimensional shape of the collimator 65 is described by a geometric model (for example, a rectangular parallelepiped, a cube, a sphere, etc.). Obtained as D107.

  The collimator shape storage unit 11 stores the collimator shape actual measurement data D107 obtained by the first actual measurement data creation unit 41 or the second actual measurement data creation unit 42 as collimator shape data D109. At this time, the positional relationship between the collimator position indicated by the collimator shape data D109 and the patient position indicated by the patient shape data D104 is made to correspond to the positional relationship between the collimator 65 and the patient 53 in the NCT.

  The data conversion unit 14 converts the collimator shape data D109 described as a geometric model and the patient shape data D104 described as a voxel model into a data format that can be input to the simulation unit 15 and passes it to the simulation unit 15. . Subsequent processing is executed in the same manner as in the first embodiment.

  Such a simulation system 30 also enables neutron capture therapy simulation based on the three-dimensional shape of the collimator 65 and the three-dimensional shape of the patient 53, as in the simulation system 10 described above. The simulation for the used NCT becomes possible. Further, since the shape data of the collimator 65 is handled as a geometric model, high-speed simulation can be performed with a small amount of memory. Even if the positional relationship between the collimator 65 and the patient 53 is changed by changing the irradiation direction, the modeling rework can be minimized.

  The simulation systems 10 and 30 of the first and second embodiments described above are used, for example, for calculating a treatment dose distribution in BNCT (Boron Neutron Capture Therapy) using a neutron beam therapy apparatus 51 as shown in FIG. Can be used for treatment planning.

The neutron beam treatment device 51 is a device that performs cancer treatment using boron neutron capture therapy (BNCT), and irradiates a patient 53 to which boron 10 ( ¹⁰ B) is administered with neutron beams N. The neutron beam treatment apparatus 51 includes an accelerator 55 (for example, a cyclotron), and the accelerator 55 accelerates charged particles (for example, protons) to generate and emit a charged particle beam P (for example, proton beam). The accelerator 55 here has, for example, the ability to generate a charged particle beam P having a beam radius of 40 mm and 60 kW (= 30 MeV × 2 mA).

  The charged particle beam P emitted from the accelerator 55 passes through the beam transport path 59 in which the electromagnet 57 is disposed, and is guided to the neutron beam output unit 61. In the neutron beam output unit 61, a neutron beam N is emitted by irradiating the target T made of beryllium (Be) with the charged particle beam P, for example. The neutron beam N is decelerated by the moderator 63 and irradiated to the patient 53 on the treatment table 67 through the opening of the collimator 65 fitted in the emission port 62 of the neutron beam output unit 61. The thermal neutron beam contained in the neutron beam N mainly reacts with the boron 10 taken in the tumor in the patient 53 and exhibits an effective therapeutic effect. The collimator 65 may be provided adjacent to the emission port 62 without being fitted into the emission port 62 of the neutron beam output unit 61.

  Next, the collimator 65 will be described with reference to FIGS. The collimator 65 is a multi-leaf collimator including a plurality of movable leaves, and at least some of the leaves are slidable in the neutron beam irradiation direction in neutron capture therapy. Strictly speaking, neutron beams do not travel straight, but travel so as to diffuse in various directions. In the present application, the extending direction of the opening of the collimator 65 (or the extending direction of the emission port 62 of the neutron beam output unit 61) is referred to as “neutron beam emission direction”. The collimator 65 sets an irradiation field of neutron beams by forming an opening F according to the region of the affected part S of the patient 53. Further, the collimator 65 has a variable three-dimensional shape. The collimator 65 can be deformed into a three-dimensional shape according to the curve of the body surface of the patient 53, and is set so as to be in close contact with the patient 53 with the gap with the patient 53 as small as possible. A specific structure of the collimator 65 is as follows.

  Hereinafter, as shown in FIGS. 6 to 8, an XYZ orthogonal coordinate system having the Z axis in the vertical direction, the Y axis in the irradiation direction of the neutron beam, and the X axis in the direction orthogonal to both the Z axis and the Y axis is taken. In some cases, X, Y, and Z are used to describe the positional relationship of each part. The collimator 65 has a rectangular parallelepiped outer shape. The collimator 65 has a plurality of leaf plates 71A and 71B stacked in the vertical direction (Z direction). In other words, the plurality of leaf plates 71A and 71B are arranged along the plate thickness direction. A plurality of leaf plates 71A and 71B may be arranged along the left-right direction (X direction). Each of the leaf plates 71A and 71B is made of polyethylene containing lithium fluoride and has a rectangular plate shape. The plurality of leaf plates 71 </ b> A and 71 </ b> B are held in a collimator holder 73 to form a leaf plate group 71.

  Between the collimator holder 73 and the leaf plate group 71, a guide member 77 having a plurality of protrusions 75 for guiding the leaf plates 71A and 71B is disposed. The end portions in the irradiation direction of the leaf plates 71 </ b> A and 71 </ b> B that are in contact with the guide member 77 have an uneven shape that can be fitted to the protrusions 75 of the guide member 77.

  In the collimator 65, the leaf plates 71A (upper and lower four pieces in the example of FIG. 3) arranged at the upper end portion and the lower end portion of the leaf plate group 71 are plate members divided into two in the X direction. The leaf plate 71B disposed at the intermediate portion excluding the upper end portion and the lower end portion of the leaf plate group 71 is composed of two divided leaf plates 79 and 80 on one side divided in the X direction. More specifically, the divided leaf plate 79 and the divided leaf plate 80 are juxtaposed in the X direction. The divided leaf plate 79 is disposed on the outer side (that is, near the collimator holder 73), and the divided leaf plate 80 is disposed on the inner side (that is, near the irradiation field) adjacent to the divided leaf plate 79. The divided leaf plate 79 and the divided leaf plate 80 are integrally slidable in the X direction. Thus, the leaf plate 71B is slidable in the X direction, so that the shape and size of the opening F (irradiation field) can be arbitrarily set. Note that the leaf plate 71A is not limited to being divided into two in the X direction, and may be divided into four, for example.

  Further, in the collimator 65, the divided leaf plate 80 of the leaf plate 71B is slidable in the Y direction. As shown in FIG. 7 and FIG. 8, a protruding portion 81 that protrudes in the X direction and extends in the Y direction is formed on the end face of the divided leaf plate 80 that contacts the divided leaf plate 79. On the other hand, a groove 82 extending in the Y direction is formed on the end surface of the divided leaf plate 79 that contacts the divided leaf plate 80. The divided leaf plate 79 and the divided leaf plate 80 are each slidable in the Y direction in a state where the protruding portion 81 is fitted in the groove portion 82.

  The collimator 65 having the above configuration is a two-axis slide type multi-leaf collimator that is slidable in the X direction and the Y direction. In the collimator 65, the outer shape of the leaf plate group 71 can be freely changed in the X direction and the Y direction.

  When the patient 53 is irradiated with a neutron beam, the positions of the leaf plates 71A and 71B are adjusted so as to follow the shape of the irradiation field. The positions of the leaf plates 71A and 71B are manually adjusted by, for example, an operator. Then, the irradiation part of the patient 53 is brought close to the collimator 65 whose position and shape have been adjusted, and a neutron beam is irradiated through the opening F of the collimator 65 with a predetermined neutron dose. Unlike other radiations, as described above, neutron beams travel while diffusing greatly in various directions. By sliding the leaf plate group 71 of the collimator 65 not only in the X direction but also in the Y direction, the gap between the leaf plate group 71 of the collimator 65 and the patient 53 is reduced, and neutron beam leakage from the gap is suppressed. It becomes possible.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to the said embodiment, You may change in the range which does not change the summary described in each claim. You may use combining the structure of each embodiment suitably. For example, instead of the CT scanner device 5 shown in FIG. 1 or FIG. 4, a 3D measuring device such as a 3D laser scanner is adopted, and the 3D shape data of the collimator 65 similar to the collimator CT image data D101 is acquired. May be.

  DESCRIPTION OF SYMBOLS 5 ... CT scanner apparatus (collimator imaging | photography part) 10,30 ... Neutron capture therapy simulation system, 11 ... Collimator shape memory | storage part, 12 ... Patient shape memory | storage part, 13 ... Data composition part, 15 ... Simulation part, 41 ... 1st Measured data creation unit, 42 ... second measured data creation unit, 53 ... patient, 65 ... collimator, 71A, 71B, 79,80 ... leaf plate, D101 ... collimator CT image data (imaging data), D103 ... collimator shape data, D104 ... Patient shape data, D105 ... Composite shape data, D107 ... Collimator shape actual measurement data.

Claims (7)

A collimator shape storage unit that stores collimator shape data indicating the three-dimensional shape of the collimator used in neutron capture therapy;
A patient shape storage unit for storing patient shape data indicating a three-dimensional shape of the neutron capture therapy patient;
Neutrons when the patient is irradiated with a neutron beam via the collimator based on the collimator shape data stored in the collimator shape storage unit and the patient shape data stored in the patient shape storage unit A simulation unit for performing a simulation calculation of the distribution of lines;
A neutron capture therapy simulation system. A three-dimensional shape of the space including the collimator and the patient is shown by a data synthesis process of the collimator shape data stored in the collimator shape storage unit and the patient shape data stored in the patient shape storage unit. It has a data composition unit that creates composite shape data,
The simulation unit
The neutron capture therapy simulation system according to claim 1, wherein the simulation calculation is executed based on synthetic shape data created by the data synthesis unit. A CT scanner device for acquiring CT image data of the collimator;
The collimator shape storage unit is
The neutron capture therapy simulation system according to claim 2, wherein the CT image data acquired by the CT scanner device is stored as the collimator shape data. An actual measurement data creation unit for creating collimator shape actual measurement data from the actually measured three-dimensional shape of the collimator,
The collimator shape storage unit is
The neutron capture therapy simulation system according to claim 2, wherein the collimator shape actual measurement data created by the actual measurement data creation unit is stored as the collimator shape data. A collimator imaging unit that images the three-dimensional shape of the collimator,
The actual measurement data creation unit
The neutron capture therapy simulation system according to claim 4, wherein the collimator shape actual measurement data is created based on imaging data acquired by the collimator imaging unit. The collimator is a multi-leaf collimator comprising a plurality of movable leaves,
The neutron capture therapy simulation system according to any one of claims 1 to 5, wherein at least some of the leaves are slidable in a neutron beam irradiation direction in the neutron capture therapy. A collimator shape storage step for storing collimator shape data indicating the three-dimensional shape of the collimator used in neutron capture therapy;
A patient shape storage step for storing patient shape data indicating a three-dimensional shape of the patient in the neutron capture therapy
Based on the collimator shape data stored in the collimator shape storage step and the patient shape data stored in the patient shape storage step, neutrons when the patient is irradiated with a neutron beam via the collimator A simulation step for performing a simulation calculation of the distribution of lines;
A neutron capture therapy simulation method comprising:

Images