Radiation dose determination method, apparatus, device, and storage medium

Abstract

Embodiments of the present application provide a radiotherapy dose determination method and device, and a storage medium, relating to the technical field of medical information, the method comprising: performing three-dimensional grid division on a simulation region to obtain a plurality of voxels; performing parallel Monte Carlo simulation on a plurality of sampled particles in the simulation region to obtain simulation results of the plurality of particles; and determining the deposition dose of each voxel according to the simulation results. The present application can effectively shorten the time consumption of determining the radiotherapy dose in the entire radiotherapy simulation process and improve the efficiency of Monte Carlo simulation.

Description

Technical Field

[0001] This application relates to medical information technology, and more particularly to a method, apparatus, device, and storage medium for determining radiotherapy dose. Background Technology

[0002] To ensure the accuracy of radiotherapy, a radiotherapy simulation can be performed before treating the target patient to obtain the dose distribution of the target patient. This simulation can then be used as a reference to develop a matching radiotherapy plan for the target patient.

[0003] In related technologies, the serial Monte Carlo simulation method is mostly used in the process of radiotherapy simulation. Serial Monte Carlo simulation refers to simulating multiple sampled particles sequentially, with the simulation of the next particle only proceeding after the simulation of the previous one has been completed.

[0004] The long time required for serial Monte Carlo simulations also extends the time needed to develop a treatment plan, thus increasing the overall treatment time. Summary of the Invention

[0005] This application provides a method, apparatus, device, and storage medium for determining radiotherapy dose, thereby shortening the overall duration of the radiotherapy simulation process, reducing the time required to develop a treatment plan, and thus shortening the overall treatment process.

[0006] In a first aspect, embodiments of this application provide a method for determining radiotherapy dosage, including:

[0007] The simulation region is divided into three-dimensional meshes to obtain multiple voxels;

[0008] Parallel Monte Carlo simulations were performed on multiple sampled particles within the simulation region to obtain simulation results for the multiple particles;

[0009] Based on the simulation results, the deposition dose of each voxel is determined.

[0010] In one possible implementation example, the parallel Monte Carlo simulation of multiple sampled particles within the simulation region, to obtain simulation results for the multiple particles, includes:

[0011] For each particle, determine the incident angle and incident voxel of the corresponding particle entering the simulation region;

[0012] Based on the incident angle and the incident voxel, a buffer space is allocated to a portion of the voxels in the simulation region, and a Monte Carlo simulation is performed until the particle passes through the simulation region to obtain the simulation result; the buffer space is used to store the deposition energy of the particle in the corresponding voxel.

[0013] In one possible implementation example, the step of allocating buffer space for a portion of the voxels in the simulation region based on the incident angle and the incident voxel, and performing a Monte Carlo simulation until the particle exits the simulation region to obtain simulation results includes:

[0014] Based on the incident angle and the incident voxel, the deposition region corresponding to each voxel layer of the particle in the simulation region is determined sequentially.

[0015] Allocate corresponding cache space for each voxel in the deposition region corresponding to each voxel layer;

[0016] Monte Carlo simulation is performed based on the incident angle and the incident voxel until the particle passes through the simulation region, and the deposition energy of the particle in the corresponding voxel is stored in the buffer space.

[0017] The data in the cache space is transferred to the shared storage space to obtain the simulation results.

[0018] In one possible implementation example, the step of sequentially determining the deposition region corresponding to each voxel layer of the particle in the simulation region based on the incident angle and the incident voxel, and allocating corresponding buffer space for each voxel in the deposition region corresponding to each voxel layer, includes:

[0019] Based on the incident angle, the incident voxel and the voxels within a preset range surrounding the incident voxel in the first layer voxel are determined as the first layer deposition region of the particle corresponding to the first layer voxel.

[0020] Allocate corresponding cache space for each voxel in the first layer deposition region to store the deposition energy of each voxel in the first layer deposition region;

[0021] When the particle enters the next voxel, the region in the next voxel that corresponds to the first deposition region and the voxels within a preset range around it are determined as the second deposition region of the particle in the next voxel.

[0022] Allocate corresponding buffer space for each voxel in the second layer deposition region to store the deposition energy of each voxel in the second layer deposition region;

[0023] The deposition region of each voxel when the particle enters each voxel layer is determined sequentially, and a corresponding buffer space is allocated to store the deposition energy of each voxel in the corresponding deposition region.

[0024] In one possible implementation example, the step of transferring the data in the cache space to the shared storage space to obtain the simulation result includes:

[0025] When the particle enters the nth layer of the simulation region, the buffer space corresponding to each voxel in the deposition region of each voxel in the layers preceding the mth layer is released; where m is a positive integer less than n.

[0026] The data stored in the released cache space will be transferred to the shared storage space.

[0027] In one possible implementation example, the method further includes:

[0028] The uncertainty of the parallel Monte Carlo simulation is calculated based on the deposition energy of the Nth particle in the shared storage space, where N is equal to the number of particles.

[0029] In one possible implementation example, calculating the uncertainty of the parallel Monte Carlo simulation based on the deposition energy of the Nth particle in the shared memory space includes:

[0030] The uncertainty of the parallel Monte Carlo simulation is calculated based on the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel.

[0031] Wherein, the deposition energy of the Nth particle in a single voxel is the average deposition dose of the Nth particle in each corresponding voxel, and the energy variance of the Nth particle in a single voxel is the sum of the variances of the deposition energy of the Nth particle in each corresponding voxel and the average deposition energy.

[0032] Secondly, embodiments of this application may also provide a radiotherapy dose determination device, comprising:

[0033] The meshing module is used to divide the simulation area into three-dimensional meshes, resulting in multiple voxels;

[0034] The simulation module is used to perform parallel Monte Carlo simulations on multiple sampled particles within the simulation region to obtain simulation results for the multiple particles.

[0035] The determination module is used to determine the deposition dose of each voxel based on the simulation results.

[0036] Thirdly, embodiments of this application also provide a computer device, including: a memory and a processor, wherein the memory stores a computer program executable by the processor, and the processor executes the computer program to implement the radiotherapy dose determination method described in any of the first aspects above.

[0037] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when read and executed, implements the radiotherapy dose determination method described in any of the first aspects above.

[0038] The radiotherapy dose determination method, apparatus, device, and storage medium provided in this application embodiment can obtain multiple voxels by dividing the simulation area into a three-dimensional mesh, and perform parallel Monte Carlo simulations on multiple sampled particles within the simulation area to obtain simulation results for multiple particles. Then, based on the simulation results, the deposition dose of each voxel is determined. In other words, the radiotherapy dose determination method provided in this application embodiment is actually a method for determining radiotherapy dose through parallel Monte Carlo simulation. The Monte Carlo simulation method for multiple particles is executed in parallel, effectively shortening the time spent determining the radiotherapy dose during the entire radiotherapy simulation process, improving the efficiency of Monte Carlo simulation, shortening the time for treatment planning, and thus shortening the overall treatment process. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A flowchart illustrating a method for determining radiotherapy dosage provided in an embodiment of this application;

[0041] Figure 2 This application provides a flowchart of a method for determining radiotherapy dose using parallel Monte Carlo simulation.

[0042] Figure 3 A method flow chart for a Monte Carlo simulation process in a radiotherapy dose determination method provided in this application embodiment. Figure 1 ;

[0043] Figure 4 A method flow chart for a Monte Carlo simulation process in a radiotherapy dose determination method provided in this application embodiment. Figure 2 ;

[0044] Figure 5 This application provides a flowchart of a method for transferring data in a cache space in a radiotherapy dose determination method.

[0045] Figure 6 A schematic diagram of a radiotherapy dose determination device provided in an embodiment of this application;

[0046] Figure 7 This is a schematic diagram of a computer device provided in an embodiment of this application. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0048] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0049] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0050] Before describing the radiotherapy dose determination method provided in the embodiments of this application, the technical terms involved in the embodiments of this application will be explained below.

[0051] Monte Carlo simulation: As the most accurate algorithm in the field of radiotherapy, it can sample the emitted particles of the radiation source model using a preset probability distribution model, and then simulate the motion process of the particles in the region to be simulated according to the statistical law of microscopic particle motion, so as to obtain the radiation dose distribution of the sampled particles in the region to be simulated.

[0052] Compared with the traditional method of using serial Monte Carlo simulation for radiotherapy simulation, this application provides a method of using parallel Monte Carlo simulation for radiotherapy simulation to determine multiple possible implementations of the radiotherapy plan.

[0053] The device that executes the radiotherapy dose determination method provided in the embodiments of this application can be a computer device equipped with a radiotherapy dose determination application. The computer device can execute the corresponding radiotherapy dose determination method by running the radiotherapy dose determination application. The radiotherapy dose determination application can be a sub-functional module of a treatment plan system (TPS), which can also be called a Monte Carlo calculation module.

[0054] The following examples illustrate the radiotherapy dose determination method provided in the embodiments of this application. Figure 1 A flowchart illustrating a method for determining radiotherapy dosage provided in an embodiment of this application. Figure 1 As shown, methods for determining radiotherapy dose may include:

[0055] S101. Divide the simulation area into three-dimensional meshes to obtain multiple voxels.

[0056] The simulation region, also known as the computational region, can be a pre-defined three-dimensional region of the target object, which can be the object to be treated or a pre-defined phantom object. Since the simulation region is actually a three-dimensional region, its division can be achieved by creating a three-dimensional mesh within three-dimensional space based on the size of a pre-defined individual voxel, resulting in multiple voxels. This ensures that the simulation region has voxels a, b, and c on the three coordinate axes of a pre-defined three-dimensional coordinate system. For example, the pre-defined three-dimensional coordinate system could be an xyz coordinate system, with the three coordinate axes being the x-axis, y-axis, and z-axis, respectively.

[0057] S102. Perform parallel Monte Carlo simulations on multiple sampled particles within the simulation region to obtain simulation results for multiple particles.

[0058] Before performing parallel Monte Carlo simulations, the emitted particles from the source module can be sampled according to a preset probability distribution model to obtain multiple sampled particles. The preset probability distribution model can be, for example, a random probability distribution model or other probability distribution models; this embodiment does not limit this. With the sampled particles obtained, a parallel Monte Carlo simulation can be performed on the multiple particles within the simulation area. During the Monte Carlo simulation of each particle, the motion of the corresponding particle within the simulation area is simulated, and the deposited energy of the corresponding particle on each voxel is calculated during the motion simulation, thereby obtaining the simulation result for the corresponding particle.

[0059] S103. Based on the simulation results, determine the deposition dose of each voxel.

[0060] The simulation results for each particle may include the deposition energy of the corresponding particle on each voxel. In a possible implementation, the deposition dose of each voxel can be determined based on the simulation results of multiple particles, thus obtaining the radiation dose distribution of each voxel in the simulation area.

[0061] For example, in determining the deposition dose of each voxel based on the simulation results of multiple particles, the deposition energy for the same voxel in the simulation results of multiple particles can be combined to obtain the deposition dose of the corresponding voxel.

[0062] The radiotherapy dose determination method provided in this application embodiment can obtain multiple voxels by dividing the simulation area into a three-dimensional mesh, and perform parallel Monte Carlo simulations on multiple sampled particles within the simulation area to obtain simulation results for multiple particles. Then, based on the simulation results, the deposition dose of each voxel is determined. In other words, the radiotherapy dose determination method provided in this application embodiment is actually a method for determining radiotherapy dose through parallel Monte Carlo simulation. The Monte Carlo simulation method for multiple particles is executed in parallel, effectively shortening the time spent determining the radiotherapy dose during the entire radiotherapy simulation process, improving the efficiency of Monte Carlo simulation, shortening the time for treatment planning, and thus shortening the overall treatment process time.

[0063] Based on the radiotherapy dose determination method provided in the above embodiments of this application, this application also provides possible implementations of parallel Monte Carlo simulations for multiple particles through multiple embodiments. Figure 2 This is a flowchart illustrating a method for parallel Monte Carlo simulation in a radiotherapy dose determination method provided in an embodiment of this application. Figure 2 As shown in S102 above, parallel Monte Carlo simulations are performed on multiple sampled particles within the simulation region to obtain simulation results for multiple particles, which may include:

[0064] S201. Based on each particle, determine the incident angle and incident voxel of the corresponding particle entering the simulation area.

[0065] When multiple particles are sampled, the exit angle of each sampled particle from the source model is determined. Therefore, for each particle, based on the exit angle of the corresponding particle determined during the sampling process and the placement position of the simulation area relative to the source model, the incident angle and incident voxel of the corresponding particle entering the simulation area can be determined. This incident voxel is the voxel that the particle encounters within the simulation area from outside the simulation area; it can also be referred to as the voxel that the particle passes through on its trajectory within the simulation area.

[0066] For ease of description, assuming the particle incident angle is in the negative direction of the z-coordinate, it can be determined that the first voxel encountered by the particle in the simulation region is the c-th voxel along the positive direction of the z-coordinate. Therefore, it can be determined that the incident voxels include the first encountered voxel v(i, j, c) and other voxels that enter the simulation after passing through the first encountered voxel.

[0067] S202. Based on the incident angle and incident voxels, allocate buffer space for some voxels in the simulation region, and perform Monte Carlo simulation until the particles pass through the simulation region to obtain the simulation results.

[0068] The cache space is used to store the deposition energy of particles in the corresponding voxels.

[0069] In the specific implementation process, based on the determined incident angle and incident voxels of the particle, a Monte Carlo simulation is performed. During the simulation, corresponding buffer spaces are allocated to certain voxels in the simulation region until the particle's motion passes through the simulation region. The Monte Carlo simulation process for the particle is then completed, and the simulation result is obtained. The certain voxels in the simulation process can be: voxels associated with the particle's trajectory in the simulation region, which may include, for example, voxels passed through by the particle's trajectory in the simulation region, and voxels within a preset range around the particle's trajectory in the simulation region.

[0070] Allocating cache space for a subset of voxels in the simulation region means allocating a corresponding cache space for each voxel within that subset to store the deposited energy of the particles in that voxel. In a possible implementation example, the size of each cache space could be a cache area of ​​a preset number of bytes, such as a four-byte floating-point buffer.

[0071] Assume that the particles in the simulation region comprise k voxels, and in this process, k buffer spaces can be allocated to store the deposited energy of the particles in the k voxels respectively.

[0072] The radiotherapy dose determination method provided in this application can determine the incident angle and incident voxel for each particle entering the simulation region. Based on the incident angle and incident voxel, buffer space is allocated for some voxels in the simulation region, and Monte Carlo simulation is performed until the particle exits the simulation region to obtain the simulation result. The allocated buffer space is used to record the deposition energy of the particle in the corresponding voxel during the simulation. In other words, in the process of determining radiotherapy dose using parallel Monte Carlo simulation, the Monte Carlo simulation for each particle does not allocate corresponding buffer space for all voxels in the simulation region, but only allocates corresponding buffer space for some voxels associated with the particle in the simulation region to store the deposition energy of the particle in the corresponding voxel. This effectively reduces the memory resources required for the Monte Carlo simulation process for each particle in the parallel Monte Carlo simulation, thereby ensuring the parallel efficiency of Monte Carlo simulation for multiple particles, thus effectively shortening the overall calculation time for radiotherapy dose determination, shortening the time for treatment planning, and thus shortening the entire treatment process.

[0073] The following examples, with reference to the accompanying figures, illustrate various implementations of a Monte Carlo simulation process for a single particle, providing multiple possible implementations of the radiotherapy dose determination method. Figure 3 A method flow chart for a Monte Carlo simulation process in a radiotherapy dose determination method provided in this application embodiment. Figure 1 .like Figure 3 As shown in Figure S202 above, based on the incident angle and incident voxels, buffer space is allocated to some voxels in the simulation region, and a Monte Carlo simulation is performed until the particles pass through the simulation region. The simulation results may include:

[0074] S301. Based on the incident angle and incident voxel, determine the deposition area corresponding to each voxel layer in the simulation area in sequence.

[0075] In the specific execution process, the particle's movement can be simulated within the simulation area based on the incident angle and incident voxels. Then, based on the simulation results, the deposition regions corresponding to each voxel layer within the simulation area can be determined sequentially. A deposition region refers to a three-dimensional region composed of multiple voxels containing the particle's deposition energy. The simulation results may include, for example, the particle's trajectory within the simulation area, and the trajectories of secondary particles generated during the particle's movement within the simulation area. The particle's trajectory within the simulation area can be represented by the coordinate positions of the voxels it passes through, and similarly, the secondary particle's trajectory can be represented by the coordinate positions of the voxels it passes through.

[0076] S302. Allocate corresponding buffer space for each voxel in the deposition region corresponding to each voxel layer.

[0077] After determining the deposition region corresponding to each voxel layer, a corresponding buffer space can be allocated to each voxel within that region. That is, a buffer space is allocated for each voxel within the deposition region corresponding to each voxel layer. The number of voxels in the deposition regions corresponding to different voxel layers may differ; therefore, the number of buffer spaces allocated to the voxels in the deposition regions corresponding to different voxel layers will also differ.

[0078] The number of voxels in the deposition region corresponding to each voxel layer can be determined by considering at least one of the following parameters in the simulation region: voxel density, medium type, particle type, particle energy entering each voxel layer, incident angle, and free path corresponding to the medium type, combined with the physical motion laws of the particles. In other words, when particles move within each voxel layer, it is unnecessary to allocate buffer space for all voxels in the first voxel layer. Instead, buffer space is allocated only for the voxels associated with the particle's motion within each voxel layer—that is, for the voxels in the deposition region corresponding to each voxel layer in the first voxel layer. This significantly reduces the amount of buffer space required when particles move within each voxel layer in the simulation region.

[0079] Since the density, medium type, particle energy entering the voxel layer, incident angle, and path of freedom in the medium may vary in different voxel layers within the simulation area, the voxels in the deposition area corresponding to different voxel layers within the simulation area may be different.

[0080] Assuming that the deposition region corresponding to the first voxel layer includes k1 voxels, then k1 buffer spaces can be allocated to k1 voxels in the deposition region corresponding to the first voxel layer to store the deposition energy of the recorded particles in k1 voxels respectively; and the deposition region corresponding to the second voxel layer includes k2 voxels, then k2 buffer spaces can be allocated to k2 voxels in the deposition region corresponding to the second voxel layer to store the deposition energy of the recorded particles in k2 voxels respectively, and so on.

[0081] It should be noted that cache allocation is performed once a voxel layer is entered and the corresponding deposition region is identified. Before entering a new voxel layer, the deposition region cannot be determined, therefore no cache allocation is performed. The above example is provided merely to facilitate understanding of the relationship between voxels in the deposition regions of each voxel layer and the corresponding allocated cache space.

[0082] S303. Based on the incident angle and incident voxel, a Monte Carlo simulation is performed until the particle passes through the simulation area, and the deposition energy of the particle in the corresponding voxel is stored in the buffer space.

[0083] When a particle emerges from a certain voxel layer, a Monte Carlo simulation needs to be performed based on the incident angle and the incident voxel until the particle emerges from the entire simulation region. This completes the Monte Carlo simulation of the particle in the simulation region. During the simulation, the deposition energy of the particle in the corresponding voxel in the current voxel layer is stored in the buffer space of each voxel.

[0084] The buffer space allocated to each voxel in each deposition region can be used to store the deposition energy of the particle and / or its secondary particles in the corresponding voxel.

[0085] S304. Transfer the data in the cache space to the shared storage space to obtain the simulation results.

[0086] In one possible implementation, after the simulation process for a particle in the simulation region is completed, all data in the cache space for that particle can be transferred to the shared memory space to obtain the simulation result. Alternatively, during the simulation, some data in the cache space can be transferred to the shared memory space, and after the simulation process is completed, the data in the remaining cache spaces can be transferred to the shared memory space to obtain the simulation result. The shared memory space is the shared memory space for multiple parallel Monte Carlo processes involving multiple particles.

[0087] In the method provided in this embodiment, the deposition region corresponding to each voxel in the simulation region is determined sequentially, and a corresponding cache space is allocated to each voxel in the deposition region corresponding to each voxel. Monte Carlo simulation is performed on the particle until the particle passes through the simulation region. The deposition energy of the particle in the corresponding voxel is stored in the cache space, and then the data in the cache space is transferred to the shared storage space to obtain the simulation result of the particle. This provides a clear example of determining the deposition region for each particle in the Monte Carlo simulation process and allocating cache space for each voxel in the deposition region. It effectively ensures that in the Monte Carlo simulation process for each particle, it is not necessary to allocate cache space for all voxels, which effectively reduces the memory resource consumption in the Monte Carlo simulation process for each particle, thereby ensuring the parallel execution efficiency of the parallel Monte Carlo simulation process for multiple particles.

[0088] Based on the solutions provided in the above embodiments, this application also provides other possible implementations of a Monte Carlo simulation process for a single particle. Figure 4 A method flow chart for a Monte Carlo simulation process in a radiotherapy dose determination method provided in this application embodiment. Figure 2 .like Figure 4As shown above, in S301, based on the incident angle and the incident voxel, the deposition region corresponding to each voxel layer in the simulation region is determined sequentially. In S302, the corresponding buffer space is allocated to each voxel in the deposition region corresponding to each voxel layer. This can include:

[0089] S401. Based on the incident angle, the incident voxel and the voxels within a preset range surrounding the incident voxel in the first layer voxel are determined as the first layer deposition region corresponding to the particle in the first layer voxel.

[0090] In a possible implementation example, the voxels within a preset range surrounding the incident voxel in the first layer of voxels can be determined based on the incident angle. The incident voxel and the voxels within the preset range surrounding it are then defined as the first layer deposition region corresponding to the first layer voxel. That is, the voxels within the first layer deposition region include: the incident voxel and the voxels within the preset range surrounding it. The incident voxel can be the voxel through which the trajectory of the particle and / or secondary particle in the first layer of voxels passes. The voxels within the preset range surrounding the incident voxel can be the voxels within the preset range surrounding the trajectory of the corresponding particle in the first layer of voxels. The size of the preset range can be a three-dimensional region determined based on the incident voxel as a reference point.

[0091] S402. Allocate corresponding buffer space for each voxel in the first layer of deposition region to store the deposition energy of each voxel in the first layer of deposition region.

[0092] Continuing with the example above, if the incident angle of the particle is in the negative direction of the z-coordinate, when the particle enters the first voxel v(i, j, c) of the first voxel layer, a buffer space can be allocated for the incident voxel to store the deposited energy of the particle within the incident voxel; when the particle moves to the first adjacent voxel v(i+1, j, c) in the first voxel layer where the z-coordinate is still c, another buffer space can be allocated for the first adjacent voxel to store the deposited energy within the first adjacent voxel; when the particle continues to move to the second adjacent voxel v(i+1, j+1, c) in the first voxel layer where the z-coordinate is still c, another buffer space can be allocated for the second adjacent voxel to store the deposited energy within the second adjacent voxel.

[0093] Suppose that the particle's trajectory in the first voxel layer passes through voxel k11 with z-coordinate c, and voxels within the first voxel layer with z-coordinate c within a predetermined range surrounding the particle's trajectory are voxels k12. Then, the deposition region corresponding to the first voxel layer can be determined to include: the voxel k11 passed through by the trajectory, and the voxels k12 within the predetermined range surrounding the trajectory. Therefore, k1 buffer spaces can be allocated to the deposition region corresponding to the first voxel layer to store the deposition energy in voxels k1, where k1 = k11 + k12. In this example, the first voxel layer can be a single voxel layer with z-coordinate c; therefore, the z-coordinate of each voxel in the first deposition region corresponding to the first voxel layer determined from the first voxel layer is also c.

[0094] S403. When a particle enters the next voxel, the region in the next voxel that corresponds to the first deposition region and the voxels within the surrounding preset range are determined as the second deposition region corresponding to the particle in the next voxel.

[0095] When a particle enters the next voxel layer—that is, from the first voxel layer with z-coordinate c to the next voxel layer with z-coordinate c-1—the voxels along the particle's trajectory in the next voxel layer can be determined as the region corresponding to the first deposition region within that voxel layer. Combined with the voxels within a predetermined range surrounding the particle's trajectory, this is defined as the second deposition region corresponding to the particle in the next voxel layer. Here, the particle's trajectory refers to the trajectory of the particle and / or its secondary particles. In other words, the second deposition region includes: the voxels traversed by the particle's trajectory, and the voxels within a predetermined range surrounding the particle's trajectory.

[0096] S404. Allocate corresponding buffer space for each voxel in the second deposition region to store the deposition energy of each voxel in the second deposition region.

[0097] The specific implementation of allocating corresponding cache space to each voxel in the second deposition region can be similar to the implementation process of allocating cache space to each voxel in the first deposition region, and will not be repeated here.

[0098] When a particle moves from the first voxel with z coordinate c to the next voxel with z coordinate c-1, and the second deposition region corresponding to the next voxel with z coordinate c-1 includes voxel k2, then voxel k2 needs to be allocated to the second deposition region to store the deposition energy in voxel k2.

[0099] S405. Sequentially determine the deposition area when the particle enters each voxel layer, and allocate corresponding buffer space to store the deposition energy of each voxel in the corresponding deposition area.

[0100] Since the particle movement within the simulation region is continuous, the simulation continues after the particle exits the second voxel layer, sequentially determining the deposition region when the particle enters each voxel layer until it exits the simulation region. It should be noted that the specific implementation process for determining the deposition region of the next voxel layer when the particle moves from the previous voxel layer is similar to the process described above for determining the second deposition region when the particle moves from the first voxel layer to the second voxel layer; details are as described above and will not be repeated here. During the simulation, a corresponding buffer space is allocated to the voxels within the deposition region corresponding to each voxel layer to store the deposition energy of each voxel within that region.

[0101] The method provided in this embodiment determines the deposition region corresponding to the particle in each voxel layer, making the voxels in the corresponding deposition region of each voxel layer more accurate. This ensures the accurate determination of the deposition region corresponding to each voxel layer and the accuracy of the number of cache spaces allocated for voxels in the corresponding deposition region of each voxel layer. It effectively reduces the consumption of the number of cache spaces allocated during the Monte Carlo simulation of each particle in the simulation region, thereby effectively ensuring the parallel execution efficiency of the parallel Monte Carlo simulation process for multiple particles.

[0102] Based on the solutions provided in the above embodiments, this application also provides possible implementation methods for transferring data in the cache space to the shared storage space. Figure 5 This is a flowchart illustrating a method for transferring data from a cache space in a radiotherapy dose determination method provided in an embodiment of this application. Figure 5 As shown, in step S304 of the method described above, the data in the cache space is transferred to the shared storage space. The simulation results obtained may include:

[0103] S501. When a particle enters the nth layer of the simulation region, the buffer space corresponding to each voxel in the deposition region of each voxel in the layers before the mth layer is released.

[0104] Where m is a positive integer less than n. Since particles may scatter or deflect during transmission, they may enter the same voxel multiple times with a very low probability. To ensure the accuracy of the statistical results, the number of buffer layers cannot be too small, nor can it be arbitrarily set; otherwise, the probability of statistical errors will increase. Therefore, in this embodiment, the specific value of m can be determined based on the voxel parameters of the simulation region and the particle attribute parameters. The voxel parameters may include at least one of the following: voxel density, medium type in the voxel, and the free path corresponding to the medium type. The attribute parameters include at least one of the following: particle type, initial energy of the particle, and incident angle of the particle.

[0105] The method provided in this embodiment can buffer the deposited energy in voxels to the greatest extent possible within an acceptable range. That is, when a particle enters a certain layer, it will still generate deposited energy in voxels within a preset range of previous layers. Therefore, the data in the buffer space cannot be released directly in this situation. Instead, when a particle enters the nth layer of the simulation region, based on the voxel parameters of the simulation region and the particle's attribute parameters, it is determined that the particle will not deposit energy again in the mth layer voxel. Therefore, the buffer space corresponding to each voxel in the deposition region of each voxel before the mth layer can be released. For layers n-1 or n-2, etc., within the preset range before the nth layer, the scattered particles (also called secondary particles) of the particle entering the nth layer may return and affect the deposited energy in their voxels. Therefore, the buffer space corresponding to each voxel in the deposition region of each voxel between the nth and mth layers is not released temporarily, ensuring that the deposited energy generated by the scattered particles can still be recorded.

[0106] However, when the particle passes out of the simulation area, the particle will not generate deposition energy on the voxels in the simulation area. In this case, the buffer space corresponding to each voxel in the deposition area of ​​other layers of voxels can be released.

[0107] S502: Transfer the data stored in the released cache space to the shared storage space.

[0108] Once the data in the cache space is released, the data stored in the cache space can be used as the energy contribution of the particles and / or their generated secondary particles to the corresponding voxels in the simulation region, and then transferred to the shared storage space.

[0109] In the method provided in this embodiment, since the cache space corresponding to each voxel in the deposition region of each voxel before the mth layer can be released when the particle enters the nth layer, and the released data is transferred to the shared storage space, the accuracy of the statistical results is guaranteed, and the flexible use of cache resources is also guaranteed.

[0110] Since the multiple particles used in the Monte Carlo simulation during radiotherapy dose determination are sampled, the dose determined by performing parallel Monte Carlo simulations on multiple particles inevitably contains uncertainties. Therefore, based on the radiotherapy dose determination method provided in the above embodiments, this application also provides a possible implementation method for calculating uncertainty to assess the reliability of the simulation process. In this embodiment, the radiotherapy dose determination method may further include:

[0111] The uncertainty of the parallel Monte Carlo simulation is calculated based on the deposition energy of the Nth particle in the shared storage space, where N is the number of particles.

[0112] Here, the Nth particle refers to the last particle to release the buffer space, and the deposition energy of the Nth particle refers to the deposition energy statistical parameter obtained by statistically analyzing the deposition energy of each voxel in the corresponding layer deposition region of the N particles. The order of the N particles refers to the order in which they release the buffer space and transfer it to the shared storage space.

[0113] In a possible implementation example, the data stored in the cache space corresponding to each voxel in each deposition region is the deposition energy of each voxel in the corresponding deposition region of the particle. When the cache space for releasing data is the cache space for each voxel of the l-th particle in the corresponding deposition region, the deposition energy of each voxel of the l-th particle in the corresponding deposition region can be statistically analyzed to obtain the deposition energy of the l-th particle, and the statistical energy in the shared storage space is updated to the deposition energy of the l-th particle. That is to say, the deposition energy of the l-th particle in the shared storage space is the deposition energy statistical parameter after the l-th particle is transferred in.

[0114] When the cache space for released data is the cache space for each voxel in the corresponding layer deposition region of the first particle, the deposition energy of each voxel in the corresponding layer deposition region of the first particle can be statistically analyzed to obtain the deposition energy of the first particle, and the statistically analyzed deposition energy of the first particle can be stored in the shared storage space. When the cache space for released data is the cache space for each voxel in the corresponding layer deposition region of more than one particle, the deposition energy can be statistically analyzed again based on the deposition energy of the particles stored in the shared storage space and the deposition energy of each voxel in the corresponding layer deposition region of the particles in the currently released cache space, to obtain the deposition energy of the current particle, and the deposition energy statistical parameters in the shared storage space can be updated to the deposition energy of the current particle.

[0115] When l = N, which is the number of sampled particles, it can be determined that the parallel Monte Carlo simulation of multiple particles has ended. In this case, the deposited energy of the Nth particle stored in the shared storage space is the deposited energy of all sampled particles. At this time, based on the deposited energy of the Nth particle, the uncertainty of the parallel Monte Carlo simulation of multiple particles can be calculated.

[0116] In the method provided in this embodiment, when the deposition energy of the Nth particle is transferred to the shared storage space, that is, when the deposition energy of the last particle among the N particles is available, the uncertainty of the parallel Monte Carlo simulation can be calculated based on the deposition energy of the Nth particle. In other words, the uncertainty of the parallel Monte Carlo simulation only needs to be calculated based on the deposition energy of the Nth particle after the Monte Carlo simulation of all sampled particles has ended. During the Monte Carlo simulation of the particles, it is only necessary to statistically update the deposition energy of the new particles in the voxel cache space of the corresponding layer deposition region based on the released cache space. Based on the update result, the deposition energy of the particles in the shared storage space can be updated without calculating the uncertainty. Therefore, the method provided in this embodiment is actually a method that uses online statistical analysis of the deposition energy of particles to calculate the uncertainty. Compared with the previous method, calculating the uncertainty at once after obtaining the deposition energy of all particles can effectively improve the stability of the uncertainty calculation, reduce rounding errors in the uncertainty calculation process, and ensure the accuracy of the uncertainty calculation.

[0117] Secondly, in the method of this embodiment, the deposition energy of particles in the shared storage space refers to the statistical value of the deposition energy of voxels in the corresponding layer deposition region. Therefore, in the parallel Monte Carlo simulation, only the deposition energy of particles can be statistically analyzed. Only the corresponding buffer in the shared storage space needs to be allocated to store the statistical value of deposition energy. Only when all parallel Monte Carlo simulations have ended can the uncertainty of the parallel Monte Carlo simulation be calculated based on the deposition energy of particles recorded in the shared storage space. Therefore, in the process of calculating uncertainty, as few storage resources as possible can be used, which ensures the online real-time statistics of deposition energy and also ensures the use of as few storage resources as possible.

[0118] Regarding the calculation of uncertainties in parallel Monte Carlo simulations, embodiments of this application also provide a possible implementation method. For example, as shown above, calculating the uncertainties of a parallel Monte Carlo simulation based on the deposition energy of the Nth particle in the shared memory space may include:

[0119] The uncertainty of the parallel Monte Carlo simulation is calculated based on the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel.

[0120] Wherein, the deposition energy of the Nth particle in a single voxel is the average deposition dose of the Nth particle in each corresponding voxel, and the energy variance of the Nth particle in a single voxel is the sum of the variances of the deposition energy and the average deposition energy of the Nth particle in each corresponding voxel.

[0121] For example, the uncertainty of the parallel Monte Carlo simulation is calculated using the following formula (1) based on the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel.

[0122]

[0123] Where N is the number of sampled particles, i.e., the number of multiple particles, which is a positive integer greater than 1, u N S is the deposition energy of the Nth particle in a single voxel. N Let be the energy variance of the k-th particle in a single voxel.

[0124] In this embodiment, since the deposition energy of the Nth particle includes the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel, which are two energy statistical parameters for the Nth particle, only two storage areas are needed in the shared storage space to store these two energy statistical parameters respectively during the parallel Monte Carlo simulation. The two storage areas storing these two energy statistical parameters can be the same size.

[0125] The following example illustrates the process of updating the deposited energy of particles in the shared storage space, i.e., the two energy statistical parameters of the particles, during the calculation of uncertainty.

[0126] Assume that the deposition energy of the (N-1)th particle in a single voxel is u. N-1 Then, when the released buffer space is the buffer space of each voxel in the corresponding layer deposition region of the Nth particle, the average value of the deposition energy of each voxel in the corresponding layer deposition region of the Nth particle can be calculated based on the buffer space of each voxel in the corresponding layer deposition region of the Nth particle as the contribution energy xN of the Nth particle in a single voxel, as follows, the deposition energy u of the Nth particle in a single voxel can be calculated using the following formula (2). N .

[0127]

[0128] Assume the energy variance of the (N-1)th particle in a single voxel is S. N-1 S N -1 can be expressed as the following formula (3).

[0129]

[0130] Thus, based on the energy variance S of the (N-1)th particle in a single voxel... N-1 The energy contribution of the Nth particle in a single voxel is xN, and the deposition energy of the (N-1)th particle in a single voxel is u. N-1And the deposition energy u of the Nth particle in a single voxel. N The energy variance of the Nth particle in a single voxel is calculated using the following formula (4).

[0131]

[0132] In the method provided in this embodiment, the uncertainty of the parallel Monte Carlo simulation can be calculated based on the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel. Furthermore, both the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel are updated based on the corresponding energy statistical parameters of the previous particles in a single voxel. This effectively ensures the statistical accuracy and stability of the energy statistical parameters, effectively reduces the rounding error in the process of updating the deposition energy, and thus effectively ensures the accuracy of the uncertainty calculation.

[0133] The following describes the radiotherapy dose determination device, equipment, and storage medium provided in this application for implementation. The specific implementation process and technical effects are described above and will not be repeated below.

[0134] Figure 6 This is a schematic diagram of a radiotherapy dose determination device provided in an embodiment of this application, as shown below. Figure 6 As shown, the radiotherapy dose determination device 600 may include:

[0135] The meshing module 601 is used to perform three-dimensional meshing on the simulation area to obtain multiple voxels;

[0136] Simulation module 602 is used to perform parallel Monte Carlo simulations on multiple sampled particles within a simulation region to obtain simulation results for multiple particles;

[0137] The determination module 603 is used to determine the deposition dose of each voxel based on the simulation results.

[0138] Optionally, the simulation module 602 is specifically used to determine the incident angle and incident voxel of the corresponding particle entering the simulation region based on each particle; based on the incident angle and the incident voxel, allocate buffer space for some voxels in the simulation region, and perform Monte Carlo simulation until the particle passes through the simulation region to obtain the simulation result; the buffer space is used to store the deposited energy of the particle in the corresponding voxel.

[0139] Optionally, the simulation module 602 is specifically used to determine the deposition region corresponding to each voxel layer in the simulation region based on the incident angle and the incident voxel; allocate a corresponding buffer space for each voxel in the deposition region corresponding to each voxel layer; perform Monte Carlo simulation based on the incident angle and the incident voxel until the particle passes through the simulation region, and store the deposition energy of the particle in the corresponding voxel in the buffer space; transfer the data in the buffer space to the shared storage space to obtain the simulation results.

[0140] Optionally, the simulation module 602 is specifically used for: determining, based on the incident angle, the incident voxel and the voxels within a preset range surrounding the incident voxel in the first layer as the first layer deposition region corresponding to the particle in the first layer; allocating corresponding buffer space to each voxel in the first layer deposition region to store the deposition energy of each voxel in the first layer deposition region; when the particle enters the next layer voxel, determining the region in the next layer voxel corresponding to the first layer deposition region and the voxels within a preset range surrounding it as the second layer deposition region corresponding to the particle in the next layer voxel; allocating corresponding buffer space to each voxel in the second layer deposition region to store the deposition energy of each voxel in the second layer deposition region; sequentially determining the deposition region when the particle enters each layer voxel, and allocating corresponding buffer space to store the deposition energy of each voxel in the corresponding deposition region.

[0141] Optionally, the simulation module 602 is specifically used to: release the buffer space corresponding to each voxel in the deposition region of each voxel in the layers before the m-th layer when the particle enters the n-th layer of the simulation region; where m is a positive integer less than n; and transfer the data stored in the released buffer space to the shared storage space.

[0142] Optionally, the radiotherapy dose determination device 600 may also include:

[0143] The computation module is used to calculate the uncertainty of the parallel Monte Carlo simulation based on the deposition energy of the Nth particle in the shared storage space, where N equals the number of particles.

[0144] Optionally, a computation module is provided, specifically for calculating the uncertainty of the parallel Monte Carlo simulation based on the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel.

[0145] Wherein, the deposition energy of the Nth particle in a single voxel is the average deposition dose of the Nth particle in each corresponding voxel, and the energy variance of the Nth particle in a single voxel is the sum of the variances of the deposition energy and the average deposition energy of the Nth particle in each corresponding voxel.

[0146] The above-described device is used to perform the radiotherapy dose determination method provided in the foregoing embodiments. Its implementation principle and technical effects are similar, and will not be described again here.

[0147] These modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more digital signal processors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs). Alternatively, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together as a system-on-a-chip (SOC).

[0148] Figure 7 This is a schematic diagram of a computer device provided in an embodiment of this application. Figure 7 As shown, the computer device 700 includes a memory 701 and a processor 702. The memory 701 and the processor 702 are connected via a bus.

[0149] The memory 701 stores a computer program executable by the processor 702. When the processor 702 executes the computer program, it can perform the above-described method embodiments. The specific implementation and technical effects are similar, and will not be described again here.

[0150] Based on the above-described method for determining radiotherapy dose, this application embodiment may also provide a computer-readable storage medium for performing the above-described method for determining radiotherapy dose. This medium may be a non-volatile storage medium storing a computer program thereon, which may execute the above-described method embodiment when read and executed.

[0151] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0152] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0153] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0154] The integrated units implemented as software functional units described above can be stored in a computer-readable storage medium. These software functional units, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0155] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining radiotherapy dosage, characterized in that, include: The simulation region is divided into three-dimensional meshes to obtain multiple voxels; Parallel Monte Carlo simulations were performed on multiple sampled particles within the simulation region to obtain simulation results for the multiple particles; Based on the simulation results, the deposition dose of each voxel is determined; The process of performing parallel Monte Carlo simulations on multiple sampled particles within the simulation region to obtain simulation results for the multiple particles includes: For each particle, determine the incident angle and incident voxel of the corresponding particle entering the simulation region; Based on the incident angle and the incident voxel, a buffer space is allocated to a portion of the voxels in the simulation region, and a Monte Carlo simulation is performed until the particle exits the simulation region to obtain the simulation result; the portion of the voxels are the voxels associated with the trajectory of the particle in the simulation region, and the buffer space is used to store the deposited energy of the particle in the corresponding voxel.

2. The method according to claim 1, characterized in that, Based on the incident angle and the incident voxel, buffer space is allocated to a portion of the voxels in the simulation region, and a Monte Carlo simulation is performed until the particle exits the simulation region to obtain simulation results, including: Based on the incident angle and the incident voxel, the deposition region corresponding to each voxel layer of the particle in the simulation region is determined sequentially. Allocate corresponding cache space for each voxel in the deposition region corresponding to each voxel layer; Monte Carlo simulation is performed based on the incident angle and the incident voxel until the particle passes through the simulation region, and the deposition energy of the particle in the corresponding voxel is stored in the buffer space. The data in the cache space is transferred to the shared storage space to obtain the simulation results.

3. The method according to claim 2, characterized in that, Based on the incident angle and the incident voxel, the deposition region corresponding to each voxel layer in the simulation region is determined sequentially, and a corresponding buffer space is allocated to each voxel in the deposition region corresponding to each voxel layer, including: Based on the incident angle, the incident voxel and the voxels within a preset range surrounding the incident voxel in the first layer voxel are determined as the first layer deposition region of the particle corresponding to the first layer voxel. Allocate corresponding cache space for each voxel in the first layer deposition region to store the deposition energy of each voxel in the first layer deposition region; When the particle enters the next voxel, the region in the next voxel that corresponds to the first deposition region and the voxels within a preset range around it are determined as the second deposition region of the particle in the next voxel. Allocate corresponding buffer space for each voxel in the second layer deposition region to store the deposition energy of each voxel in the second layer deposition region; The deposition region of each voxel when the particle enters each voxel layer is determined sequentially, and a corresponding buffer space is allocated to store the deposition energy of each voxel in the corresponding deposition region.

4. The method according to claim 2, characterized in that, The step of transferring the data in the cache space to the shared storage space to obtain the simulation results includes: When the particle enters the nth layer of the simulation region, the buffer space corresponding to each voxel in the deposition region of each voxel in the layers preceding the mth layer is released; where m is a positive integer less than n. The data stored in the released cache space will be transferred to the shared storage space.

5. The method according to claim 4, characterized in that, The method further includes: The uncertainty of the parallel Monte Carlo simulation is calculated based on the deposition energy of the Nth particle in the shared storage space, where N is equal to the number of particles.

6. The method according to claim 5, characterized in that, The calculation of the uncertainty of the parallel Monte Carlo simulation based on the deposition energy of the Nth particle in the shared storage space includes: The uncertainty of the parallel Monte Carlo simulation is calculated based on the deposition energy of the Nth particle in a single voxel and the energy variance of the Nth particle in a single voxel. Wherein, the deposition energy of the Nth particle in a single voxel is the average deposition energy of the Nth particle in each corresponding voxel, and the energy variance of the Nth particle in a single voxel is the sum of the variances of the deposition energy of the Nth particle in each corresponding voxel and the average deposition energy.

7. A radiotherapy dose determination device, characterized in that, include: The meshing module is used to divide the simulation area into three-dimensional meshes, resulting in multiple voxels; The simulation module is used to perform parallel Monte Carlo simulations on multiple sampled particles within the simulation region to obtain simulation results for the multiple particles. A determination module is used to determine the deposition dose of each voxel based on the simulation results; Specifically, the simulation module is used to: determine the incident angle and incident voxel of each particle entering the simulation region; allocate buffer space for some voxels in the simulation region based on the incident angle and the incident voxel, and perform Monte Carlo simulation until the particle exits the simulation region to obtain simulation results; the partial voxels are voxels associated with the trajectory of the particle in the simulation region, and the buffer space is used to store the deposited energy of the particle in the corresponding voxel.

8. A computer device, characterized in that, include: A memory and a processor, wherein the memory stores a computer program executable by the processor, and the processor executes the computer program to implement the radiotherapy dose determination method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when read and executed, implements the radiotherapy dose determination method according to any one of claims 1-6.

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