Simulation method for performing radiotherapy by focusing particle beams based on Monte Carlo method

Abstract

The invention relates to the technical field of medicine, in particular to a simulation method for performing radiotherapy by focusing a particle beam based on a Monte Carlo method, and the method comprises the steps: obtaining a pre-constructed virtual physical model used for simulating a particle beam radiotherapy process; adjusting a magnetic field gradient combination corresponding to the quadrupole magnet and the deflection magnet in the virtual physical model, and obtaining a dose distribution result of a particle beam penetrating through the water phantom in a radiotherapy process according to the magnetic field gradient combination; extracting a plurality of groups of target dose distribution results from the dose distribution results according to the longitudinal depth of the target region, and combining the plurality of groups of target dose distribution results with different weights to determine target irradiation doses which are longitudinally and uniformly distributed in the target region; and simulating and executing radiotherapy operation of the target region based on the target irradiation dose. Therefore, the problem of how to accurately control the dose distribution of the focusing beam in the human body is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medicine, in particular to a simulation method for radiotherapy based on a Monte Carlo method focused particle beam. BACKGROUND

[0002] With the continuous improvement of economic level and the rapid development of science and technology, the medical technology level has been significantly improved. However, cancer is still one of the main obstacles threatening human health, and the number of deaths caused by it is increasing year by year. At present, radiotherapy is the main means of cancer treatment.

[0003] In order to effectively use high-energy electron beam to treat tumors, the key is to control the dose distribution of the beam in the human body to ensure that the dose can be accurately concentrated on the tumor position while reducing the damage to the surrounding healthy tissues. Therefore, when designing a high-energy electron beam radiotherapy device, it is necessary to accurately calculate the dose distribution of the beam in the target area after being focused by the quadrupole magnet and deflected by the deflection magnet. Due to the long construction period, high construction cost and high medical treatment device acceptance standard of the treatment device, a large number of simulations need to be performed when designing a high-energy electron beam radiotherapy device to ensure that the design of the treatment device meets the standard. Although the Monte Carlo method has been widely used to simulate the dose distribution in the process of radiotherapy, there is a lack of a comprehensive simulation method to support the whole process from the design of the focused particle beam device to the dose optimization to meet the growing demand for accurate radiotherapy. SUMMARY

[0004] The present application provides a simulation method for radiotherapy based on a Monte Carlo method focused particle beam to solve the problem of how to accurately control the dose distribution of the focused beam in the human body.

[0005] The first aspect of the present application provides a simulation method for radiotherapy based on a Monte Carlo method focused particle beam, comprising the following steps: obtaining a pre-constructed virtual physical model for simulating the process of particle beam radiotherapy, wherein the virtual physical model is constructed in the Monte Carlo code; adjusting the magnetic field gradient combination corresponding to the quadrupole magnet and the deflection magnet in the virtual physical model, and obtaining the dose distribution result of the particle beam passing through the water phantom in the process of radiotherapy according to the magnetic field gradient combination; extracting a plurality of target dose distribution results from the dose distribution result according to the longitudinal depth of the target region, and combining a plurality of target dose distribution results with different weights to provide a target irradiation dose with uniform longitudinal distribution for the target region, wherein the longitudinal depth of the target region is the depth of the region to be treated in the human body along the particle beam incident direction from the entrance surface to the exit surface of the region to be treated; and simulating the execution of the radiotherapy operation of the target region based on the target irradiation dose.

[0006] Optionally, the combining the multiple sets of target dose distribution results with different weights to provide the target irradiation dose with longitudinal uniform distribution in the target region comprises: determining a dose calculation interval according to a maximum dose and a minimum dose in the selected multiple sets of target dose distribution results; calculating a maximum dose position on a longitudinal axis of the target position in the target region according to each set of target dose distribution result, and determining a position coverage range according to the maximum dose position; interpolating randomly in the position coverage range and the dose calculation interval, so that the uniformity of the superimposed dose in the position coverage range reaches a preset standard, and determining the weight of each set of target dose distribution result; determining the irradiation dose of the corresponding position in the longitudinal distribution in the target region according to the weight of each set of target dose distribution result, and generating the target irradiation dose with longitudinal uniform distribution in the target region according to the irradiation dose at each position.

[0007] Optionally, the obtaining the virtual physical model for simulating the particle beam radiotherapy process comprises: constructing an initial physical model for simulating the particle beam radiotherapy process, wherein the physical model comprises one or more components of a quadrupole magnet, a deflection magnet and a water phantom; setting a distance between the quadrupole magnet, the deflection magnet and the water phantom, and an initial magnetic field gradient of the quadrupole magnet and the deflection magnet, and running the virtual physical model according to the distance and the initial magnetic field gradient to obtain a dose distribution result of the particle beam after passing through the water phantom in the radiotherapy process; and simulating adjustment of the initial physical model to obtain the virtual physical model according to the dose distribution result and a preset target dose distribution of the water phantom.

[0008] Optionally, the simulating adjustment of the initial physical model to obtain the virtual physical model according to the dose distribution result and the preset target dose distribution of the water phantom comprises: simulating adjustment of the distance between the quadrupole magnet, the deflection magnet and the water phantom, and a magnetic field gradient within a magnet gradient range that meets magnet processing according to the dose distribution result and the preset target dose distribution of the water phantom, until a preset condition of the target dose distribution is met, to determine a design position of one or more components in the initial physical model; and optimizing the initial physical model to obtain the virtual physical model based on the design position.

[0009] Optionally, the preset condition of the target dose distribution comprises at least one of the following: a water phantom inlet dose is a first target dose; a water phantom outlet dose is a second target dose; a deviation between a maximum dose position and the target position is less than or equal to a preset distance; and a particle beam size of the target position is less than or equal to a target size.

[0010] The second aspect embodiment of the application provides a simulation device for radiotherapy based on a Monte Carlo method focused particle beam, comprising: an acquisition module configured to acquire a pre-constructed virtual physical model for simulating a particle beam radiotherapy process, wherein the virtual physical model is constructed based on a Monte Carlo method; a collection module configured to adjust a magnetic field gradient combination corresponding to a quadrupole magnet and a deflection magnet in the virtual physical model, and acquire a dose distribution result of the particle beam passing through a water phantom in the radiotherapy process according to the magnetic field gradient combination; a providing module configured to extract a plurality of target dose distribution results from the dose distribution result according to a longitudinal depth of a target region, and combine the plurality of target dose distribution results with different weights to provide a target irradiation dose with longitudinal uniform distribution for the target region, wherein the longitudinal depth of the target region is a depth of a region to be treated in a human body along a particle beam incident direction, from an entrance surface to an exit surface of the region to be treated; and a simulation module configured to simulate a radiotherapy operation of the target region based on the target irradiation dose.

[0011] Optionally, the providing module is further configured to determine a dose calculation interval according to a maximum dose and a minimum dose in the selected plurality of target dose distribution results; calculate a dose maximum position on a longitudinal axis of a target position in the target region according to each selected target dose distribution result, and determine a position coverage range according to the dose maximum position; randomly interpolate in the position coverage range and the dose calculation interval, so that the uniformity of the superimposed dose in the position coverage range reaches a preset standard, and determine a weight of each target dose distribution result; and determine the target irradiation dose of a corresponding position on the longitudinal distribution in the target region according to the weight of each target dose distribution result, and generate the target irradiation dose with longitudinal uniform distribution in the target region according to the target irradiation dose at each position.

[0012] Optionally, the acquisition module is further configured to construct an initial physical model for simulating the particle beam radiotherapy process, wherein the physical model comprises one or more components of a quadrupole magnet, a deflection magnet, and a water phantom; set a distance between the quadrupole magnet, the deflection magnet, and the water phantom, and an initial magnetic field gradient of the quadrupole magnet and the deflection magnet, and run the virtual physical model to acquire a dose distribution result of the particle beam passing through the water phantom in the radiotherapy process according to the distance and the initial magnetic field gradient; and simulate adjustment of the initial physical model to obtain the virtual physical model according to the dose distribution result and a pre-set target dose distribution of the water phantom.

[0013] Optionally, the obtaining module is further configured to simulate adjustment of the spacing between the quadrupole magnet, the deflection magnet, and the water phantom, respectively, and the magnetic field gradient within the magnet gradient range that conforms to the magnet processing, according to the dose distribution result and the preset target dose distribution of the water phantom, until a preset condition of the target dose distribution is met, to determine the design position of one or more components in the initial physical model; and optimize the initial physical model based on the design position to obtain the virtual physical model.

[0014] Optionally, the preset condition of the target dose distribution includes at least one of the following: the water phantom inlet dose is a first target dose; the water phantom outlet dose is a second target dose; a deviation between a dose maximum position and the target position is less than or equal to a preset distance; and a particle beam size at the target position is less than or equal to a target size.

[0015] The third aspect of the present application provides a physical design method of a treatment device, including the following steps: obtaining a target user's to-be-treated region; identifying a target position with the deepest longitudinal depth in the to-be-treated region; determining a design position of one or more treatment components and a magnetic field gradient combination for radiation treatment according to the target position, wherein the design position and the magnetic field gradient are simulated by the simulation method of the radiation treatment of the focused particle beam based on the Monte Carlo method, and performing physical design on the treatment device based on the design position of the one or more treatment components and the magnetic field gradient combination.

[0016] The fourth aspect of the present application provides a simulation platform, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the program to implement the simulation method of the radiation treatment of the focused particle beam based on the Monte Carlo method as described in the above embodiments.

[0017] The fifth aspect of the present application provides a computer readable storage medium having a computer program or instructions stored thereon, and the computer program or instructions are executed to implement the simulation method of the radiation treatment of the focused particle beam based on the Monte Carlo method as described in the above embodiments.

[0018] The sixth aspect of the present application provides a computer program product, including a computer program or instructions, and the computer program or instructions are executed to implement the simulation method of the radiation treatment of the focused particle beam based on the Monte Carlo method as described in the above embodiments.

[0019] Therefore, the present application has at least the following beneficial effects:

[0020] The embodiment of the present application simulates the particle beam radiotherapy process based on the virtual physical model constructed, obtains the dose distribution results under different conditions by adjusting the magnetic field gradient combination of the quadrupole magnet and the deflection magnet, extracts multiple groups of target dose distribution from the results according to the longitudinal depth of the target region, determines the target irradiation dose for realizing the longitudinal dose distribution uniformity in the target region, and finally simulates the execution of the radiotherapy operation based on the target irradiation dose, so as to ensure accurate and effective treatment on the treatment region while minimizing the impact on the surrounding healthy tissues.

[0021] Additional aspects and advantages of the present application will be made apparent by the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 A flowchart of a simulation method for radiotherapy of focused particle beams based on a Monte Carlo method according to an embodiment of the present application;

[0024] Figure 2 A flowchart of a method for expanding the dose distribution interval of particle beams in a target region during radiotherapy according to an embodiment of the present application;

[0025] Figure 3 A flowchart of a model design and dose optimization method for focused particle beam radiotherapy based on a Monte Carlo method according to an embodiment of the present application;

[0026] Figure 4 A flowchart of dose distribution optimization according to an embodiment of the present application;

[0027] Figure 5 A schematic diagram of a designed virtual model according to an embodiment of the present application;

[0028] Figure 6 An example diagram of a simulation device for radiotherapy of focused particle beams based on a Monte Carlo method according to an embodiment of the present application;

[0029] Figure 7 A structural schematic diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described below in detail with reference to the accompanying drawings, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0031] The simulation method, device, electronic equipment and storage medium for radiotherapy based on Monte Carlo method focused particle beam of embodiments of the present application are described below with reference to the accompanying drawings. In view of the problems mentioned in the above background art, the present application provides a simulation method for radiotherapy based on Monte Carlo method focused particle beam, in which the Monte Carlo code is run based on the constructed virtual physical model to simulate the particle beam radiotherapy process, the dose distribution results under different conditions are obtained by adjusting the magnetic field gradient combination of the quadrupole magnet and the deflection magnet, and multiple sets of target dose distribution are extracted from these results according to the longitudinal depth of the target region, so as to determine the target irradiation dose for realizing longitudinal dose distribution uniformity in the target region, and finally simulate the execution of radiotherapy operation based on the target irradiation dose, so as to ensure accurate and effective treatment for the treatment area, while minimizing the impact on the surrounding healthy tissues.

[0032] Specifically, Figure 1 A flowchart of a simulation method for radiotherapy based on Monte Carlo method focused particle beam provided by embodiments of the present application is shown.

[0033] As Figure 1 shown, the simulation method for radiotherapy based on Monte Carlo method focused particle beam includes the following steps:

[0034] In step S101, a pre-constructed virtual physical model for simulating the particle beam radiotherapy process is obtained, wherein the virtual physical model is constructed in the Monte Carlo code.

[0035] In an embodiment of the present application, obtaining the pre-constructed virtual physical model for simulating the particle beam radiotherapy process includes: constructing an initial physical model for simulating the particle beam radiotherapy process based on the Monte Carlo method, wherein the physical model includes one or more components of the quadrupole magnet, the deflection magnet and the water phantom; setting the distance between the quadrupole magnet, the deflection magnet and the water phantom, and the initial magnetic field gradient of the quadrupole magnet and the deflection magnet, and running the virtual physical model according to the distance and the initial magnetic field gradient to obtain the dose distribution result of the particle beam after passing through the water phantom in the radiotherapy process; and simulating adjustment of the initial physical model to obtain the virtual physical model according to the dose distribution result and the pre-set target dose distribution of the water phantom.

[0036] The Monte Carlo method is widely used in dose calculation of radiotherapy because it can handle complex geometries and material properties. According to specific experimental requirements or clinical cases, appropriate electron beam parameters (such as energy, current, energy dispersion, and emission degree) are selected as input parameters. The Monte Carlo method is a particle beam simulation method that sets up a model in the code and uses the Monte Carlo method to simulate the dose distribution of the beam irradiating the water phantom based on the set model.

[0037] It can be understood that a preliminary physical model is constructed in the Monte Carlo code, which includes key components such as quadrupole magnets, deflection magnets, and water phantoms. The functions of these magnets are to focus and deflect the particle beam so that it passes through the water phantom along a specified path. In actual execution, the relative positional relationship between the quadrupole magnets, the deflection magnets, and the water phantom, as well as the deflection magnet field gradients B1, B2, the quadrupole magnet field gradients T1, T2,..., Tn (n = 3, 4,...), different spacings, and magnetic field gradient settings will result in different dose distribution results. By adjusting the distances between these elements (L1, L2,..., Ln+3, (n = 3, 4,...)), the path of the particle beam and its distribution in the water phantom can be affected. The initial model parameters, deflection magnet field gradients B1, B2, quadrupole magnet field gradients T1, T2,..., Tn (n = 3, 4,...), and element spacings L1, L2,..., Ln+3 (n = 3, 4,...) are used as input parameters to run the virtual physical model to calculate the dose distribution of the particle beam passing through the water phantom.

[0038] It should be noted that the particle beam mentioned in the embodiments of the present application can be an electron beam, or other particle beams that need to be focused and deflected according to requirements, without specific limitation. The initial setup of the simulation platform for simulating the particle beam radiotherapy process is based on focusing and deflecting high-energy electrons, but it can also be used for focusing protons and other particle beams, without specific limitation.

[0039] Further, the initial physical model is adjusted to obtain a virtual physical model according to the dose distribution result and the pre-set target dose distribution of the water phantom, including: adjusting the spacings between the quadrupole magnets, the deflection magnets, and the water phantom, respectively, and the magnetic field gradients within the magnet gradient range that meets the magnet processing, until the pre-set conditions of the target dose distribution are met, to determine the design positions of one or more components in the initial physical model; and optimizing the initial physical model based on the design positions to obtain the virtual physical model.

[0040] The preset conditions of the target dose distribution include at least one of the following: the water phantom entrance dose is a first target dose; the water phantom exit dose is a second target dose; the deviation between the dose maximum position and the target position is less than or equal to a preset distance; and the particle beam size of the target position is less than or equal to a target size.

[0041] Specifically, the dose distribution result obtained by the embodiment of the present application can be compared with a preset target dose distribution. The target dose distribution specifies the first target dose at the water phantom entrance, the second target dose at the exit, and the specific requirement that the deviation between the dose maximum position and the target position is less than or equal to a preset distance; and the particle beam size of the target position is less than or equal to a target size. The preset distance and the target size can be set according to actual conditions and are not specifically limited. The model size of the water phantom set in the Monte Carlo code can be adjusted. The water phantom is only used as a target body for a preliminary model. The water phantom can also be converted into a target body of other materials and shapes that more accurately reflect the patient's anatomical structure. For example, in order to be close to a clinical experiment, a CT image, a DICOM file or the like containing a case can be imported into a simulation platform for irradiation.

[0042] In another embodiment, after the target region using the specific patient's anatomical structure or the specific material is determined, the dose distribution needs to be recalculated and optimized to ensure the effectiveness and safety of the treatment.

[0043] In the embodiment of the present application, if the dose distribution under the current model fails to meet the above conditions of the target dose distribution, adjustment needs to be made. According to the difference in the dose distribution, the distance (L1, L2,...Ln+3) between the quadrupole magnet, the deflection magnet and the water phantom, and the magnetic field gradient within the magnet gradient range that meets the magnet processing are adjusted to change the particle beam path and its energy deposition in the water phantom, thereby affecting the final dose distribution. After each adjustment, the Monte Carlo code is re-run to obtain a new dose distribution result, which is compared with the target dose distribution again. If the above conditions are all met, all the parameters and results obtained in this simulation are stored; if any of the above conditions does not meet the requirements, the input parameters are changed for the next calculation. When the number of iterations meets the set number of times, the iteration loop is ended, and all the data results that meet the requirements are compared, and the optimal result is selected for output.

[0044] Further, when the dose distribution result meets the preset conditions (such as the entrance dose reaching the target dose 1, the exit dose reaching the target dose 2, the maximum dose position error meeting the requirements, etc.), it is considered that the design position of one or more components is found, and the quadrupole magnet, the deflection magnet and the positions of the elements corresponding to the optimization result are fixed to obtain the final virtual physical model.

[0045] In step S102, the magnetic field gradient combination corresponding to the quadrupole magnet and the deflection magnet in the virtual physical model is adjusted, and the dose distribution result of the particle beam passing through the water phantom in the radiotherapy process is obtained according to the magnetic field gradient combination.

[0046] In order to further optimize the dose distribution, the embodiments of the present application can change the magnetic field gradient of the quadrupole magnet and the deflection magnet. Different magnetic field gradients will cause different focusing and deflection effects of the particle beam, thereby affecting the final dose distribution. After changing the magnetic field gradient each time, the virtual physical model simulation is updated to obtain a new dose distribution result, and a plurality of dose distribution results of the particle beam passing through the water phantom under different magnetic field gradient settings can be obtained.

[0047] In step S103, a plurality of target dose distribution results are extracted from the dose distribution result according to the longitudinal depth of the target region, and the plurality of target dose distribution results with different weights are combined to provide the target irradiation dose with longitudinal uniform distribution for the target region. The longitudinal depth of the target region is the depth of the region to be treated in the human body along the particle beam incident direction from the entrance surface to the exit surface of the region to be treated.

[0048] On the basis of the dose distribution results obtained in the above embodiments under a plurality of different magnetic field configurations, the plurality of dose distribution results are superimposed to form a dose uniform region by assigning different weights. The embodiments of the present application can use the selected plurality of dose distribution results to expand the dose maximum value region according to the specific longitudinal depth (i.e. the distance from the entrance to the exit) of the target tumor in the human body, form a dose uniform region in the longitudinal interval, and ensure that the tumor is sufficiently and uniformly irradiated, thereby achieving more precise and safer radiotherapy effect, while reducing the risk to the surrounding healthy tissues. The dose uniform region refers to the dose value in a specific longitudinal interval along the axial direction after the above operation, which is as consistent as possible or fluctuates within a small set range. This means that the longitudinal irradiation position is determined, and the tumor tissue receives relatively uniform radiation dose in the target region through which the beam passes, avoiding the situation that some parts receive excessive dose while other parts receive insufficient dose.

[0049] It should be noted that the dose maximum value region is expanded using the selected dose distribution result, and the dose maximum value refers to the dose maximum value position on the longitudinal axis of the target position in the target region. The expansion method is to use a plurality of dose distribution curves with dose maximum values on the same axis, superimpose and use different dose distribution results by assigning different weights to the dose maximum value region along the longitudinal direction.

[0050] In an embodiment of the present application, the method for generating a longitudinal uniform target irradiation dose in a target region by combining target dose distribution results with different weights comprises: determining a dose calculation interval according to the maximum dose and the minimum dose in the target dose distribution results; calculating the position of the maximum dose on the longitudinal axis of the target region according to each target dose distribution result, and determining the position coverage range according to the position of the maximum dose; randomly interpolating in the position coverage range and the dose calculation interval, so that the uniformity of the superimposed dose in the position coverage range reaches a preset standard, and determining the weight of each target dose distribution result; determining the target irradiation dose at the corresponding position in the longitudinal distribution in the target region according to the weight of each target dose distribution result, and generating the longitudinal uniform target irradiation dose in the target region according to the target irradiation dose at each position.

[0051] It can be understood that, as shown in Figure 2 The embodiment of the present application can determine the dose calculation interval, that is, compare each dose distribution, find the maximum dose as the total maximum dose, and find the minimum dose as the total minimum dose. Randomly interpolate in the range of the position corresponding to the maximum dose and the dose interval, randomly set the weight of each dose distribution, change the weight combination so that the dose uniformity in the position coverage interval reaches the target uniformity, calculate the total dose and the uniformity, and output the weight of each dose distribution.

[0052] Specifically, the embodiment of the present application finds the position of the maximum dose in the selected longitudinal interval based on each target dose distribution result, to determine the most effective radiation concentration point in each dose distribution curve. Based on the positions of the maximum doses in all selected dose distribution results, a coverage range containing all the positions of the maximum doses is determined, random interpolation is performed in the determined position coverage range and the dose calculation interval, so that the superimposed dose distribution in the region is as uniform as possible, different weights are assigned to different dose distributions, and the target irradiation dose at each position in the longitudinal distribution in the target region is calculated based on each target dose distribution result and the corresponding weight, so as to accurately control the dose distribution of the particle beam in the human body and ensure that the entire tumor region can be uniformly and effectively irradiated.

[0053] In step S104, the radiotherapy operation of the target region is simulated based on the target irradiation dose.

[0054] In the embodiment of the present application, the target dose target irradiation dose provided for the target region realizes accurate simulation and optimization of the radiotherapy process in a virtual environment, provides scientific basis and technical support for actual clinical application, and greatly improves the accuracy and safety of radiotherapy.

[0055] The following will be described in combination with Figure 3The simulation method for radiotherapy using a focused particle beam based on the Monte Carlo method according to an embodiment of the application is described in detail, including the following steps:

[0056] S1: In the initial virtual model constructed by the Monte Carlo method, a model including a quadrupole magnet, a deflection magnet, a water phantom, and electron beam parameters is set.

[0057] S2: Set the dose distribution target in the water phantom: the inlet dose of the water phantom is the target dose 1, the outlet dose of the water phantom is the target dose 2, and the position of the maximum dose is the target position.

[0058] S3: Figure 4 As shown in the figure, the initial model parameters of the deflection magnet magnetic field B1, B2, the quadrupole magnet magnetic field T1, T2, ..., Tn, (n = 3, 4, ...), and the spacing between each element L1, L2, ..., Ln+3, (n = 3, 4, ...) are used as input parameters, and the model is run to obtain the corresponding dose distribution in the water phantom. Among them, the number of quadrupole magnets can be increased or decreased according to the parameters of the input electron beam, the magnet processing cost, and the feasibility of the magnetic field. The target can be defined according to the needs. The specific working principle of the virtual physical model is as follows. Figure 5 shown.

[0059] S4: Figure 4 As shown, the dose distribution in the water phantom is read for judgment. The judgment conditions are as follows: whether the entrance dose meets the requirement of target dose 1, whether the exit dose meets the requirement of target dose 2, whether the error between the maximum dose position and the target position meets the requirement of position error, and whether the beam size at the target position meets the requirement of target size.

[0060] S5: Figure 4 As shown in the figure, if all the above conditions are met, all parameters and results obtained from this simulation are stored. If any of the above conditions are not met, the input parameters are changed and the next round of calculation is performed. When the number of iterations meets the set number, the iteration cycle ends and all the data results that meet the requirements are compared to obtain the optimization result.

[0061] S6: Fix the positions of the quadrupole magnet, deflection magnet, and various components corresponding to the optimization results, and change the magnetic fields of the quadrupole magnet and deflection magnet to collect the corresponding dose distribution results in the water phantom.

[0062] S7: Based on the depth position of the target area, the collected dose distribution results are used to widen the dose maximum area to form a dose uniform area in the longitudinal section.

[0063] The simulation method for radiotherapy based on the Monte Carlo method focuses particle beams according to the embodiment of the present application, simulates and optimizes the particle beam radiotherapy process based on the virtual physical model constructed by the Monte Carlo method, obtains the dose distribution results under different conditions by adjusting the magnetic field gradient combination of the quadrupole magnet and the deflection magnet, and extracts a plurality of target dose distribution results from the results according to the longitudinal depth of the target region, so as to determine the target irradiation dose for realizing the longitudinal dose distribution uniformity in the target region, and finally simulates the execution of the radiotherapy operation based on the target irradiation dose, so as to ensure accurate and effective treatment on the treatment region, while minimizing the impact on the surrounding healthy tissues.

[0064] Secondly, the simulation device for radiotherapy based on the Monte Carlo method focuses particle beams according to the embodiment of the present application is described with reference to the accompanying drawings.

[0065] Figure 6 is the block schematic diagram of the simulation device for radiotherapy based on the Monte Carlo method focuses particle beams according to the embodiment of the present application.

[0066] As shown in Figure 6 , the simulation device for radiotherapy based on the Monte Carlo method focuses particle beams 10 includes an acquisition module 100, a collection module 200, a provision module 300 and a simulation module 400.

[0067] The acquisition module 100 is configured to acquire a pre-constructed virtual physical model for simulating the particle beam radiotherapy process, wherein the virtual physical model is constructed in the Monte Carlo code; the collection module 200 is configured to adjust the magnetic field gradient combination corresponding to the quadrupole magnet and the deflection magnet in the virtual physical model, and obtain the dose distribution results of the particle beam passing through the water phantom in the radiotherapy process according to the magnetic field gradient combination; the provision module 300 is configured to extract a plurality of target dose distribution results from the dose distribution results according to the longitudinal depth of the target region, and combine the plurality of target dose distribution results with different weights to provide the target irradiation dose with longitudinal uniform distribution for the target region, wherein the longitudinal depth of the target region is the depth of the treatment region in the human body along the particle beam incident direction from the entrance surface to the exit surface of the treatment region; and the simulation module 400 is configured to simulate the execution of the radiotherapy operation of the target region based on the target irradiation dose.

[0068] In an embodiment of the present application, the module 300 is further configured to determine a dose calculation interval according to the maximum dose and the minimum dose in each of the selected groups of target dose distribution results; determine a dose maximum position on a longitudinal axis of the target position in the target volume according to each of the selected groups of target dose distribution results, and determine a position coverage range according to the dose maximum position; randomly interpolate within the position coverage range and the dose calculation interval, so that the uniformity of the superimposed dose within the position coverage range reaches a preset standard, and determine a weight of each of the selected groups of target dose distribution results; determine a target irradiation dose of a corresponding position on the longitudinal distribution in the target volume according to the weight of each of the selected groups of target dose distribution results, and generate a target irradiation dose with a uniform longitudinal distribution in the target volume according to the target irradiation dose at each position.

[0069] In an embodiment of the present application, the obtaining module 100 is further configured to construct an initial physical model for simulating a particle beam radiotherapy process, wherein the physical model comprises one or more components of a quadrupole magnet, a deflection magnet and a water phantom; set a distance between the quadrupole magnet, the deflection magnet and the water phantom, and an initial magnetic field gradient of the quadrupole magnet and the deflection magnet, run the virtual physical model according to the distance and the initial magnetic field gradient to obtain a dose distribution result of the particle beam after passing through the water phantom in the radiotherapy process; and simulate adjustment of the initial physical model to obtain the virtual physical model according to the dose distribution result and a preset target dose distribution of the water phantom.

[0070] In an embodiment of the present application, the obtaining module 100 is further configured to simulate adjustment of the distance between the quadrupole magnet, the deflection magnet and the water phantom, and the magnetic field gradient within a magnet gradient range that meets magnet processing according to the dose distribution result and the preset target dose distribution of the water phantom, until a preset condition of the target dose distribution is met, to determine a design position of the one or more components in the initial physical model; and optimize the initial physical model based on the design position to obtain the virtual physical model.

[0071] In an embodiment of the present application, the preset condition of the target dose distribution comprises at least one of the following: a water phantom inlet dose is a first target dose; a water phantom outlet dose is a second target dose; a deviation between a dose maximum position and the target position is less than or equal to a preset distance; and a particle beam size of the target position is less than or equal to a target size.

[0072] It should be noted that the foregoing explanation and description of the embodiment of the simulation method for radiotherapy of the focused particle beam based on the Monte Carlo method also applies to the embodiment of the simulation device for radiotherapy of the focused particle beam based on the Monte Carlo method, which will not be described here.

[0073] The simulation device for radiotherapy based on the Monte Carlo method focuses particle beams, and simulates and optimizes the particle beam radiotherapy process based on a virtual physical model constructed based on the Monte Carlo method. The dose distribution results under different conditions are obtained by adjusting the magnetic field gradient combination of the quadrupole magnet and the deflection magnet, and a plurality of target dose distributions are extracted from the results according to the longitudinal depth of the target region, so as to determine the target irradiation dose for realizing the longitudinal dose distribution uniformity in the target region. Finally, the radiotherapy operation is simulated and executed based on the target irradiation dose, so as to ensure accurate and effective treatment on the treatment region, and minimize the influence on the surrounding healthy tissues.

[0074] The physical design method of the treatment device provided in the embodiments of the present application includes the following steps: obtaining a target user's treatment region; identifying a target position with the deepest longitudinal depth in the treatment region, determining the design position and the magnetic field gradient combination of one or more treatment components for radiotherapy according to the target position, wherein the design position and the magnetic field gradient are simulated based on the simulation method of the radiotherapy based on the Monte Carlo method focusing particle beams in the above embodiments, and the treatment device is physically designed based on the design position and the magnetic field gradient combination of the one or more treatment components.

[0075] It can be understood that the embodiments of the present application can obtain the region (such as a tumor region) that needs to be treated of a target user through medical images (such as CT, MRI, etc.), which is usually referred to as a target region, and the target position refers to the position from the body surface to the deepest position of the target region.

[0076] Figure 7 The simulation platform provided in the embodiments of the present application is shown in the structural schematic diagram. The simulation platform can include:

[0077] The memory 701, the processor 702, and the computer program stored in the memory 701 and executable on the processor 702.

[0078] The processor 702 implements the simulation method of the radiotherapy based on the Monte Carlo method focusing particle beams provided in the above embodiments when executing the program.

[0079] Further, the simulation platform further includes:

[0080] The communication interface 703 is used for communication between the memory 701 and the processor 702.

[0081] The memory 701 is used for storing the computer program executable on the processor 702.

[0082] The memory 701 can include a high-speed RAM (Random Access Memory) memory, and can also include a nonvolatile memory, such as at least one disk memory.

[0083] If the memory 701, the processor 702 and the communication interface 703 are implemented independently, the communication interface 703, the memory 701 and the processor 702 can be connected to each other through a bus and complete communication between each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For convenience of representation, Figure 7 In the figure, only one thick line is used to represent the bus, but it does not mean that there is only one bus or only one type of bus.

[0084] Optionally, in a specific implementation, if the memory 701, the processor 702 and the communication interface 703 are integrated on a chip, the memory 701, the processor 702 and the communication interface 703 can complete communication between each other through an internal interface.

[0085] The processor 702 can be a plurality of CPUs (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit) or one or more integrated circuits configured to implement the embodiments of the present application.

[0086] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the simulation method for radiotherapy based on a focused particle beam according to the Monte Carlo method.

[0087] The embodiments of the present application also provide a computer program product, which includes a computer program or instructions, and the computer program or instructions are executed to implement the simulation method for radiotherapy based on a focused particle beam according to the Monte Carlo method according to the above embodiments.

[0088] In the description of the application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the description of the application, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or N embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the description and the features of the different embodiments or examples, without contradiction.

[0089] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "N" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0090] Any process or method descriptions in flow charts or otherwise described herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions (or steps) in the process, and the various embodiments of the application include additional implementations in which the order of steps can differ from those shown or discussed, including a step can occur at substantially the same time with other steps or can be performed in reverse order, and additional steps can be included, all of which have been contemplated to be within the scope of the application.

[0091] It should be understood that parts of the application can be implemented in hardware, software, firmware or a combination thereof. In the above described embodiments, the N steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As in another embodiment, if implemented in hardware, any of the following technologies known in the art or their combination can be used: discrete logic circuit with logic gate circuit for implementing logic functions on data signals, application specific integrated circuit with suitable combination logic gate circuit, programmable gate array, field programmable gate array, etc.

[0092] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above described embodiment method can be completed by a program instructing the relevant hardware, and the program can be stored in a computer readable storage medium, which includes one or a combination of the steps of the method embodiment when executed.

[0093] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A simulation method for radiotherapy using a focused particle beam based on the Monte Carlo method, characterized in that: The following steps are involved: obtaining a pre-built virtual physical model for simulating a particle beam radiotherapy process, wherein the virtual physical model is built in a Monte Carlo code; adjusting a magnetic field gradient combination corresponding to a quadrupole magnet and a deflection magnet in the virtual physical model, and obtaining a dose distribution result of a particle beam passing through a water phantom during radiotherapy according to the magnetic field gradient combination; Extracting multiple groups of target dose distribution results from the dose distribution results according to the longitudinal depth of the target area, and combining the multiple groups of target dose distribution results with different weights to provide a target irradiation dose with uniform longitudinal distribution within the target area, wherein the longitudinal depth of the target area is the depth of the area to be treated in the human body from the entrance surface to the exit surface of the area to be treated along the incident direction of the particle beam; A radiotherapy operation of the target area is performed based on the target irradiation dose simulation.

2. The method for simulating radiotherapy using a focused particle beam using the Monte Carlo method according to claim 1, wherein: Combining multiple groups of target dose distribution results with different weights to provide a longitudinally uniform target irradiation dose for the target area includes: determining a dose calculation interval according to the maximum dose and the minimum dose in the selected multiple groups of target dose distribution results; Calculating the dose maximum position on the longitudinal axis of the target position in the target area according to each selected group of target dose distribution results, and determining the position coverage range according to the dose maximum position; Randomly interpolating within the position coverage range and the dose calculation interval so that the uniformity of the superimposed dose within the position coverage range meets a preset standard, and determining the weight of each group of target dose distribution results; According to the weight of each group of target dose distribution results, the irradiation dose at the corresponding position in the longitudinal distribution within the target area is determined, and according to the irradiation dose at each position, a target irradiation dose with uniform longitudinal distribution within the target area is generated.

3. The method for simulating radiotherapy using a focused particle beam using the Monte Carlo method according to claim 1, wherein: The method of obtaining a pre-built virtual physical model for simulating a particle beam radiotherapy process includes: constructing an initial physical model for simulating a particle beam radiotherapy process, wherein the physical model includes one or more components of a quadrupole magnet, a deflection magnet, and a water phantom; setting the distances between the quadrupole magnet, the deflection magnet, and the water phantom, and the initial magnetic field gradients of the quadrupole magnet and the deflection magnet, respectively, and running the virtual physical model according to the distances and the initial magnetic field gradients to obtain a dose distribution result after the particle beam passes through the water phantom during radiotherapy; According to the dose distribution result and the preset target dose distribution of the water phantom, the initial physical model is simulated and adjusted to obtain the virtual physical model.

4. The method for simulating radiotherapy using a focused particle beam using the Monte Carlo method according to claim 3, wherein: The method comprises: simulating and adjusting the initial physical model according to the dose distribution result and the preset target dose distribution of the water phantom to obtain the virtual physical model, comprising: Simulating and adjusting the distances between the quadrupole magnet, the deflection magnet, and the water phantom, and the magnetic field gradient within a magnet gradient range consistent with magnet processing according to the dose distribution result and the preset target dose distribution of the water phantom, until the preset conditions of the target dose distribution are met, and determining the design positions of one or more components in the initial physical model; The initial physical model is optimized based on the design position to obtain the virtual physical model.

5. The method for simulating radiotherapy using a focused particle beam using the Monte Carlo method according to claim 4, wherein: The preset conditions of the target dose distribution include at least one of the following: The water phantom inlet dose is a first target dose; The outlet dose of the water phantom is a second target dose; The deviation between the dose maximum position and the target position is less than or equal to the preset distance; The particle beam size at the target location is smaller than or equal to the target size.

6. A simulation device for radiotherapy based on a focused particle beam using the Monte Carlo method, characterized in that: include: an acquisition module, configured to acquire a pre-built virtual physical model for simulating a particle beam radiotherapy process, wherein the virtual physical model is built in a Monte Carlo code; a collecting module, configured to adjust a magnetic field gradient combination corresponding to the quadrupole magnet and the deflection magnet in the virtual physical model, and obtain a dose distribution result of a particle beam passing through the water phantom during radiotherapy according to the magnetic field gradient combination; Providing a module for extracting multiple groups of target dose distribution results from the dose distribution results according to the longitudinal depth of the target area, and combining the multiple groups of target dose distribution results with different weights to provide a target irradiation dose with uniform longitudinal distribution for the target area, wherein the longitudinal depth of the target area is the depth of the area to be treated in the human body from the entrance surface to the exit surface of the area to be treated along the incident direction of the particle beam; A simulation module is used to simulate and perform a radiotherapy operation on the target area based on the target irradiation dose.

7. A physical design method for a therapeutic device, characterized in that: The following steps are involved: Obtain the target user's area to be treated; Identify the target position with the deepest longitudinal depth in the area to be treated, and determine the design position and magnetic field gradient combination of one or more treatment components for radiotherapy based on the target position, wherein the design position and magnetic field gradient are simulated based on the simulation method for performing radiotherapy with a focused particle beam based on the Monte Carlo method as described in any one of claims 1 to 5. The treatment device is physically designed based on the planned positions of the one or more treatment components and the magnetic field gradient combination.

8. A simulation platform, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the simulation method for radiotherapy based on a Monte Carlo method focused particle beam according to any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed, the simulation method for radiotherapy based on a focused particle beam using a Monte Carlo method according to any one of claims 1 to 5 is implemented.

10. A computer program product comprising: A computer program or instruction, characterized in that when the computer program or instruction is executed, it implements the simulation method of radiotherapy based on the Monte Carlo method focusing particle beam according to any one of claims 1 to 5.

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