Method and device for obtaining boron neutron capture multi-angle irradiation time coefficient, storage medium, terminal and computer program product

Abstract

The present invention discloses a method and device for obtaining boron neutron capture multi-angle irradiation time coefficients, a storage medium, a terminal, and a computer program product. The method includes obtaining all set irradiation angles, all critical regions, and the maximum tolerable dose corresponding to each critical region; performing Monte Carlo transport simulations for each set irradiation angle to obtain the equivalent biological dose distribution in the target object when irradiated alone at each set irradiation angle; and obtaining the irradiation time proportion coefficients of all set irradiation angles through a column generation algorithm based on the equivalent biological dose distribution in the target object when irradiated alone at each set irradiation angle. The present invention can ensure that the dose received by the normal tissues of the target object is within a reasonable safety threshold, so that the equivalent biological dose obtained by tumor cells after irradiation at each irradiation angle based on the irradiation time proportion coefficient per unit time is as high as possible, and the dose calculation error caused by using a static uniform boron concentration distribution model is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of boron neutron capture, and particularly to a method and device for obtaining a multi-angle irradiation time coefficient of boron neutron capture, a storage medium, a terminal, and a computer program product. Background Art

[0002] Boron Neutron Capture Therapy (BNCT) is a radiotherapy technique that can achieve targeted irradiation of tumor cells through a single irradiation, killing tumor cells while minimizing the irradiation of normal tissues as much as possible. BNCT utilizes the principle that boron has a very large reaction cross-section with thermal neutrons. After absorbing neutrons, the boron-10 nuclide will undergo the 10B(n,α)7Li reaction. This neutron capture reaction produces high Linear Energy Transfer (LET) radiation because the ranges of the α particles and 7Li+ particles generated by the reaction in tissue are comparable to the cell diameter. Therefore, the energy released by this reaction can kill tumor cells without affecting other cells.

[0003] During the BNCT treatment process, the boron concentration in the human body changes with time and is non-uniformly distributed. In existing methods, the boron concentrations in tumors and normal tissues and the boron concentration in blood are usually regarded as fixed values in T / N (tumor boron concentration / normal tissue boron concentration) and T / B (tumor boron concentration / blood boron concentration). However, the distribution of boron concentration in the human body changes with time and is non-uniformly distributed. Using a static and uniform boron concentration distribution will result in a deviation between the dose results obtained by Monte Carlo simulation and the dose received by the human body during actual irradiation.

[0004] In addition, the non-uniform distribution of neutron flux will lead to the non-uniform distribution of the equivalent biological dose in the tumor, that is, the tumor cells receive a higher dose where the thermal neutron flux is high, and a lower dose where the thermal neutron flux is low. This usually manifests as a higher dose in the part of the tumor close to the neutron exit and a lower dose in the part far from the exit. In the single-dose BNCT treatment, the non-uniform distribution of the equivalent biological dose in the target object's body may occur, which may further lead to the inability to achieve the treatment effect in the tumor area. The multi-angle irradiation BNCT treatment depends on the irradiation time proportion coefficient of each angle. To a certain extent, the irradiation time proportion coefficient of each angle reflects the maximum dose that can be achieved in the target area after irradiation at each irradiation angle per unit time. At present, the weight of each irradiation field (i.e., the proportion of the irradiation time of each irradiation angle) in the multi-angle irradiation BNCT treatment is manually set. Further, the irradiation time proportion coefficient of each irradiation angle used as an auxiliary coefficient reference has not been calculated and verified. Therefore, when doctors set the optimal irradiation plan based on the irradiation time proportion coefficient of each irradiation angle and the total irradiation duration, there is still a problem that cancer cells cannot be killed because the prescribed dose set by doctors cannot be achieved in the target area within a limited time, which will further affect the treatment effect. Therefore, it is very necessary to optimize the irradiation time proportion coefficient of each angle. Summary of the Invention

[0005] The purpose of this application is to provide a method and device for obtaining the multi-angle irradiation time coefficient of boron neutron capture, a storage medium, and a terminal, which are used to solve the problem that in the current multi-angle irradiation BNCT treatment process, the irradiation time proportion coefficient of each irradiation angle is manually set and not calculated and verified, resulting in the inability to reach the maximum dose per unit time under the set irradiation angle conditions in the BNCT treatment process.

[0006] In the first aspect, this application provides a method for obtaining the multi-angle irradiation time coefficient of boron neutron capture, including:

[0007] Obtain all set irradiation angles, all critical regions, and the maximum tolerance dose corresponding to each critical region;

[0008] Conduct Monte Carlo transport simulations for each set irradiation angle respectively to obtain the equivalent biological dose distribution in the target object's body when each set irradiation angle irradiates alone;

[0009] Based on the equivalent biological dose distribution in the target object's body when each set irradiation angle irradiates alone, obtain the irradiation time proportion coefficient of all set irradiation angles through the column generation algorithm;

[0010] Among them, in obtaining the irradiation time proportion coefficients of all the set irradiation angles through the column generation algorithm, the maximum dose received by the target area is the main problem, and the doses received by each critical area being less than the corresponding maximum tolerance dose are used as constraint conditions. Initial basic variables are obtained based on the irradiation per unit time for each set irradiation angle alone.

[0011] In an embodiment of the present application, based on the non-uniform dynamic boron concentration distribution model, Monte Carlo transport simulations are respectively performed for each of the set irradiation angles to obtain the equivalent biological dose distribution in the target object when irradiated alone for each of the set irradiation angles.

[0012] In an embodiment of the present application, the process of obtaining the non-uniform dynamic boron concentration distribution model is as follows:

[0013] Obtain the CT image of the target object and the target area delineation file. Based on the target area delineation file, obtain the position information and regional volume size of the well-perfused area, the position information and regional volume size of the non-well-perfused area, and the position information and regional volume size of the target area from the CT image;

[0014] Substitute the regional volume sizes of the well-perfused area, the non-well-perfused area, and the target area into the preset three-compartment boron pharmacokinetic model to obtain the boron concentration-time change curve of the well-perfused area, the boron concentration-time change curve of the non-well-perfused area, and the boron concentration-time change curve of the target area;

[0015] Based on the CT image, construct a three-dimensional model of the boron concentration distribution, and fill the boron concentration-time change curve of the well-perfused area into the three-dimensional model of the boron concentration distribution based on the position information of the well-perfused area, fill the boron concentration-time change curve of the non-well-perfused area into the three-dimensional model of the boron concentration distribution based on the position information of the non-well-perfused area, and fill the boron concentration-time change curve of the target area into the three-dimensional model of the boron concentration distribution based on the position information of the target area to obtain the non-uniform dynamic boron concentration distribution model.

[0016] In an embodiment of the present application, when the target area is located in the non-well-perfused area, the preset three-compartment boron pharmacokinetic model includes a central compartment representing the well-perfused area, a peripheral compartment representing the non-well-perfused area, and a specific compartment representing the target area. Boron exchange occurs between the central compartment and the peripheral compartment, and boron exchange occurs between the peripheral compartment and the specific compartment.

[0017] In an embodiment of the present application, when the target region is located in the non - well - perfused region, the preset three - compartment boron pharmacokinetic model is as follows: the expressions of the boron concentration change curves with time in the well - perfused region, the non - well - perfused region, and the target region are respectively:

[0018]

[0019]

[0020]

[0021] Among them, C1(t) represents the curve of boron concentration change with time in the well - perfused region, C2(t) represents the curve of boron concentration change with time in the non - well - perfused region, C3(t) represents the curve of boron concentration change with time in the target region, V1 represents the volume of the well - perfused region, V2 represents the volume of the non - well - perfused region, V3 represents the volume of the target region, K1 represents the transport rate of boron from the well - perfused region to the non - well - perfused region, K2 represents the transport rate of boron from the non - well - perfused region to the well - perfused region, K3 represents the transport rate of boron from the target region to the non - well - perfused region, K4 represents the transport rate of boron from the non - well - perfused region to the target region, K5 represents the total rate of boron absorption, metabolism, and excretion in the well - perfused region, I(t) represents the function of injection boron intensity change with time, and f is the mass percentage of boron element in the boron drug.

[0022] In an embodiment of the present application, when the target region is located in the well - perfused region, the preset three - compartment boron pharmacokinetic model includes a central compartment representing the well - perfused region, a peripheral compartment representing the non - well - perfused region, and a specific compartment representing the target region. Boron exchange occurs between the central compartment and the specific compartment, and boron exchange also occurs between the peripheral compartment and the central compartment.

[0023] In an embodiment of the present application, when the target region is located in the well - perfused region, the preset three - compartment boron pharmacokinetic model is as follows: the expressions of the boron concentration change curves with time in the well - perfused region, the non - well - perfused region, and the target region are respectively:

[0024]

[0025]

[0026]

[0027] Among them, C1(t) represents the curve of the boron concentration in the well-perfused area changing with time, C2(t) represents the curve of the boron concentration in the non-well-perfused area changing with time, C3(t) represents the curve of the boron concentration in the target area changing with time, V1 represents the volume size of the well-perfused area, V2 represents the volume size of the non-well-perfused area, V3 represents the volume size of the target area, K1 represents the transport rate of boron transported from the well-perfused area to the non-well-perfused area, K2 represents the transport rate of boron transported from the non-well-perfused area to the well-perfused area, K6 represents the transport rate of boron transported from the target area to the well-perfused area, K7 represents the transport rate of boron transported from the well-perfused area to the target area, K5 represents the total rate of absorption, metabolism and excretion of boron in the well-perfused area, I(t) represents the function of the injection boron intensity changing with time, and f is the mass percentage of boron element in the boron drug.

[0028] In an embodiment of the present application, constructing a three-dimensional model of boron concentration distribution based on the CT image includes:

[0029] Constructing a three-dimensional model of boron concentration distribution based on the CT image, and setting the boron concentrations in the air area, bone area and bedplate area in the three-dimensional model of boron concentration distribution to 0.

[0030] In an embodiment of the present application, based on the equivalent biological dose distribution in the target object's body when irradiated separately at each of the set irradiation angles, obtaining the irradiation time ratio coefficients for all the set irradiation angles through the column generation algorithm includes:

[0031] Taking the maximum dose received by the target area as the main problem, taking the dose received by each critical area being less than the corresponding maximum tolerance dose as the constraint condition, and obtaining the initial basic variables based on the irradiation per unit time at each set irradiation angle;

[0032] Solving the current main problem with a preset irradiation angle vector to obtain the current irradiation time vector, and solving the shadow price of the main problem based on the dual problem of the main problem;

[0033] Solving whether the current test number is greater than zero based on the shadow price. If there is a new irradiation angle with the current test number greater than zero, adding the new irradiation angle to the current preset irradiation angle vector to form a new preset irradiation angle vector, and re-solving the current main problem based on the new preset irradiation angle vector. If there is no new irradiation angle with the current test number greater than zero, taking the current irradiation time vector as the optimal irradiation time vector;

[0034] Obtaining the irradiation time proportion coefficients for all the set irradiation angles based on the optimal irradiation time vector;

[0035] Among them, the initial state of the preset irradiation angle vector is obtained based on all the set irradiation angles.

[0036] In an embodiment of the present application, the expression of the inspection number is:

[0037]

[0038] Among them, represents the degree of the target area receiving dose in the new irradiation angle, represents the vector of the degree of the target area receiving dose of all irradiation angles in the current preset irradiation angle vector, represents the coefficient vector of the current new irradiation angle split into all irradiation angles in the preset irradiation angle vector, represents the dose rate vector of all current critical regions under the individual irradiation of all irradiation angles in the preset irradiation angle vector.

[0039] In a second aspect, the present application further provides a device for obtaining the boron neutron capture multi-angle irradiation time coefficient, including an initial parameter acquisition module, an equivalent biological dose distribution acquisition module, and an irradiation time ratio coefficient acquisition module;

[0040] The initial parameter acquisition module is used to acquire all set irradiation angles, all critical regions, and the maximum tolerable dose corresponding to each critical region;

[0041] The equivalent biological dose distribution acquisition module is used to perform Monte Carlo transport simulation on each set irradiation angle based on the non-uniform dynamic boron concentration distribution model to obtain the equivalent biological dose distribution in the target object's body when each set irradiation angle is irradiated alone;

[0042] The irradiation time ratio coefficient acquisition module is used to obtain the irradiation time ratio coefficients of all the set irradiation angles through a column generation algorithm based on the equivalent biological dose distribution in the target object's body when each set irradiation angle is irradiated alone;

[0043] Among them, when obtaining the irradiation time ratio coefficients of all the set irradiation angles through the column generation algorithm, the maximum dose received by the target area is used as the main problem, and the condition that the dose received by each critical region is less than the corresponding maximum tolerable dose is used as a constraint condition, and the initial basic variables are obtained based on the individual irradiation per unit time of each set irradiation angle.

[0044] In a third aspect, the present application further provides a storage medium, on which a computer program is stored, and when the program is executed by a processor, the method for obtaining the boron neutron capture multi-angle irradiation time coefficient as described above is implemented.

[0045] Fourthly, the present application also provides a terminal, which is characterized by comprising a processor and a memory, and the memory is communicatively connected to the processor;

[0046] The memory is used for storing a computer program, and the processor is used for executing the computer program stored in the memory, so that the terminal executes the boron neutron capture multi-angle irradiation time coefficient acquisition method as described above.

[0047] Compared with the prior art, one or more of the above embodiments may have the following advantages or beneficial effects:

[0048] By applying the boron neutron capture multi-angle irradiation time coefficient acquisition method provided by the embodiment of the present invention, the problem of irradiation from different angles in the BNCT treatment plan can be optimized, so that the irradiation time proportion coefficient changes from manually setting the irradiation time proportion of each irradiation angle to the irradiation time proportion coefficient optimized by machine calculation, reducing the time consumed by doctors in designing the irradiation time proportion coefficient. At the same time, the constraint conditions of the column generation algorithm adopted can ensure that the dose received by the normal tissues of the target object is within a reasonable safety threshold, so that the equivalent biological dose obtained by tumor cells after irradiation at each irradiation angle per unit time is as high as possible. At the same time, the present invention also obtains the boron concentration time change curve corresponding to each region based on the designed preset boron pharmacokinetic three-compartment model, and adds the boron concentration time change curve corresponding to each region to the corresponding position in the three-dimensional model of the target object to obtain a non-uniform dynamic boron concentration distribution model, eliminating the dose calculation error caused by using a static uniform boron concentration distribution model, and more accurately simulating the dose received by the target object during the BNCT treatment process, so as to better evaluate the irradiation time proportion coefficient.

[0049] Other features and advantages of the present invention will be described in the following specification, and will become apparent in part from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0051] Figure 1 It shows a schematic flow chart of the boron neutron capture multi-angle irradiation time coefficient acquisition method described in the embodiment of the present application.

[0052] Figure 2 It shows a schematic diagram of the acquisition process of the non-uniform dynamic boron concentration distribution model in the boron neutron capture multi-angle irradiation time coefficient acquisition method described in the embodiment of the present application.

[0053] Figure 3 It shows a schematic diagram of a preset three-compartment model of boron pharmacokinetics where the target area is located in a non-well-perfused area in the boron neutron capture multi-angle irradiation time coefficient acquisition method described in the embodiments of the present application.

[0054] Figure 4 It shows a schematic diagram of a preset three-compartment model of boron pharmacokinetics where the target area is located in a well-perfused area in the boron neutron capture multi-angle irradiation time coefficient acquisition method described in the embodiments of the present application.

[0055] Figure 5 It shows a schematic diagram of the structure of the boron neutron capture multi-angle irradiation time coefficient acquisition device described in the embodiments of the present application.

[0056] Figure 6 It shows a schematic diagram of the structure of the terminal described in the embodiments of the present application. Detailed implementation manners

[0057] The following will combine the drawings and embodiments to detail the implementation manners of the present invention, so as to fully understand how the present invention uses technical means to solve technical problems and achieve the implementation process of technical effects and implement accordingly. It should be noted that as long as there is no conflict, the various embodiments in the present invention and the various features in each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

[0058] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. Therefore, only the components related to the present application are shown in the diagrams, rather than being drawn according to the number, shape and size of the components in actual implementation. The types, numbers and proportions of the actual components in implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0059] The following will elaborate on the principle and implementation manners of a boron neutron capture multi-angle irradiation time coefficient acquisition method, device, storage medium and terminal of this embodiment in detail with reference to the drawings, so that those skilled in the art can understand the boron neutron capture multi-angle irradiation time coefficient acquisition method, device, storage medium and terminal of this embodiment without creative labor.

[0060] As Figure 1 shown, this embodiment provides a boron neutron capture multi-angle irradiation time coefficient acquisition method, including the following steps.

[0061] Step S101, obtain all set irradiation angles, all critical areas, and the maximum tolerable dose corresponding to each critical area.

[0062] Specifically, multiple irradiation angles for the target area of the target object are set based on the actual situation of the target area, and each irradiation angle for the target area is used as the set irradiation angle. At the same time, the critical areas involved in the boron neutron capture diagnosis and treatment process are obtained, and the maximum tolerable dose is set for each critical area. Among them, the target object can be set as a cancer patient, the target area can be set as the tumor area of the cancer patient, and the critical area is generally reflected in units of organs.

[0063] Step S102: Perform Monte Carlo transport simulations for each set irradiation angle to obtain the equivalent biological dose distribution in the target object when irradiated individually at each set irradiation angle.

[0064] In this embodiment, a non-uniform dynamic boron concentration distribution model can be used to perform Monte Carlo transport simulations for each set irradiation angle to obtain the equivalent biological dose distribution in the target object when irradiated individually at each set irradiation angle. Or an existing uniform dynamic boron concentration distribution model can be used to perform Monte Carlo transport simulations for each set irradiation angle to obtain the equivalent biological dose distribution in the target object when irradiated individually at each set irradiation angle. This embodiment specifically discloses a method for obtaining a non-uniform dynamic boron concentration distribution model. The non-uniform dynamic boron concentration distribution model can also be obtained through other existing methods for obtaining non-uniform dynamic boron concentration distribution models. This embodiment does not impose a fixed limitation on it here.

[0065] Refer to as Figure 2 shown, the process for obtaining the non-uniform dynamic boron concentration distribution model disclosed in this embodiment includes: first, read the CT image of part or the whole body of the target object, and the CT image should include the target area, the well-perfused area, and the non-well-perfused area. Then, obtain the target area delineation file drawn by the doctor, and the target area delineation file should correspond to the CT image so that the target area, the well-perfused area, and the non-well-perfused area in the CT image can be determined based on the target area delineation file. Next, based on the target area delineation file, determine the position information and regional volume size of the well-perfused area, the position information and regional volume size of the non-well-perfused area, and the position information and regional volume size of the target area in the CT image. Finally, substitute the obtained regional volume size of the well-perfused area into the preset boron pharmacokinetic three-compartment model to obtain the boron concentration-time curve of the well-perfused area; substitute the obtained regional volume size of the non-well-perfused area into the preset boron pharmacokinetic three-compartment model to obtain the boron concentration-time curve of the non-well-perfused area; and substitute the obtained regional volume size of the target area into the preset boron pharmacokinetic three-compartment model to obtain the boron concentration-time curve of the target area.

[0066] It should be noted that the target area can be located in a well-perfused area or a non-well-perfused area, that is, certain tissue lesions in the well-perfused area or non-well-perfused area form a tumor area (i.e., the target area). At this time, when dividing the well-perfused area or non-well-perfused area, the target area is separately divided as the target area. Further, the target area is not included in the well-perfused area or non-well-perfused area during the division.

[0067] Furthermore, three-dimensional reconstruction is performed based on the read CT images, that is, the materials and densities corresponding to the Monte Carlo calculations are restored based on the CT images, and a basic human body model required for Monte Carlo simulation is established as the three-dimensional model of boron concentration distribution. Then, the air area, bone area, and bed board area in the three-dimensional model of boron concentration distribution are selected according to the material values, and the boron concentrations in the air area, bone area, and bed board area are all set to 0 to avoid the influence of the air area, bone area, and bed board area on the accuracy of the boron concentration distribution of the finally obtained non-uniform dynamic boron concentration distribution model.

[0068] Finally, based on the obtained position information of the well-perfused area, the time-varying curve of boron concentration in the well-perfused area is filled into the corresponding position in the three-dimensional model of boron concentration distribution. At the same time, based on the obtained position information of the non-well-perfused area, the time-varying curve of boron concentration in the non-well-perfused area is filled into the corresponding position in the three-dimensional model of boron concentration distribution. Also, based on the obtained position information of the target area, the time-varying curve of boron concentration in the target area is filled into the corresponding position in the three-dimensional model of boron concentration distribution. Finally, the time-varying curves of boron concentration in the above three areas are filled into the completed three-dimensional model of boron concentration distribution as the non-uniform dynamic boron concentration distribution model. Combining with the non-uniform dynamic boron concentration distribution model obtained by CT image conversion, the dose received by the patient during BNCT treatment can be accurately simulated to better evaluate the radiotherapy plan.

[0069] The above process introduces a preset three-compartment model of boron pharmacokinetics. The traditional boron pharmacokinetic model is usually a two-compartment model. The two-compartment model can only simulate the change curves of boron concentration in the well-perfused area and non-well-perfused area, but cannot simulate the target area that can specifically absorb boron drugs. However, in BNCT treatment, the boron concentration in the target area is particularly critical, and the boron concentration in the target area seriously affects the treatment effect of BNCT. Therefore, in this embodiment, a three-compartment expansion is performed on the basis of the two-compartment model to simulate the results of the change of boron concentration in the target area.

[0070] When the target area is located in the non-well-perfused compartment and the well-perfused compartment, there are differences in the established preset three-compartment model of boron pharmacokinetics. Therefore, the following will be separately described with reference to the accompanying drawings.

[0071] When the target region is located in a non-well-perfused region (for example, when the tumor is located in the brain), the preset three-compartment model of boron pharmacokinetics includes a central compartment representing the well-perfused region, a peripheral compartment representing the non-well-perfused region, and a specific compartment representing the target region. There is boron exchange between the central compartment and the peripheral compartment, and boron exchange between the peripheral compartment and the specific compartment. Further, the structure of the preset three-compartment model of boron pharmacokinetics is as shown in Figure 3 shown, where the central compartment represents the well-perfused region, such as tissues and organs with blood, kidneys, skin, etc.; the peripheral compartment represents the non-well-perfused region, such as the brain; the specific compartment represents the target region that can specifically absorb boron drugs. At this time, the expression of the boron concentration change curve with time in the well-perfused region is the following formula (1), the expression of the boron concentration change curve with time in the non-well-perfused region is the following formula (2), and the expression of the boron concentration change curve with time in the target region is the following formula (3).

[0072]

[0073]

[0074]

[0075] Among them, C1(t) represents the boron concentration change curve with time in the well-perfused region, C2(t) represents the boron concentration change curve with time in the non-well-perfused region, C3(t) represents the boron concentration change curve with time in the target region, V1 represents the volume of the well-perfused region, V2 represents the volume of the non-well-perfused region, V3 represents the volume of the target region, K1 represents the transport rate of boron from the well-perfused region to the non-well-perfused region, K2 represents the transport rate of boron from the non-well-perfused region to the well-perfused region, K3 represents the transport rate of boron from the target region to the non-well-perfused region, K4 represents the transport rate of boron from the non-well-perfused region to the target region, K5 represents the total rate of boron absorption, metabolism, and excretion in the well-perfused region, I(t) represents the function of the injection boron intensity changing with time, and f is the mass percentage of boron element in the boron drug.

[0076] When the target region is located in the well-perfused region, the preset three-compartment model of boron pharmacokinetics includes a central compartment representing the well-perfused region, a peripheral compartment representing the non-well-perfused region, and a specific compartment representing the target region. There is boron exchange between the central compartment and the specific compartment, and boron exchange between the peripheral compartment and the central compartment. Further, the structure of the preset three-compartment model of boron pharmacokinetics is as shown in Figure 4As shown, where the central compartment represents the well-perfused region; the peripheral compartment represents the non-well-perfused region; and the specific compartment represents the target region that can specifically absorb the boron drug. At this time, the expression of the curve of boron concentration changing with time in the well-perfused region is the following formula (4), the expression of the curve of boron concentration changing with time in the non-well-perfused region is the following formula (5), and the expression of the curve of boron concentration changing with time in the target region is the following formula (6).

[0077]

[0078]

[0079]

[0080] Among them, C1(t) represents the curve of boron concentration changing with time in the well-perfused region, C2(t) represents the curve of boron concentration changing with time in the non-well-perfused region, C3(t) represents the curve of boron concentration changing with time in the target region, V1 represents the volume of the well-perfused region, V2 represents the volume of the non-well-perfused region, V3 represents the volume of the target region, K1 represents the transport rate of boron from the well-perfused region to the non-well-perfused region, K2 represents the transport rate of boron from the non-well-perfused region to the well-perfused region, K6 represents the transport rate of boron from the target region to the well-perfused region, K7 represents the transport rate of boron from the well-perfused region to the target region, K5 represents the total rate of absorption, metabolism, and excretion of boron in the well-perfused region, I(t) represents the function of injection boron intensity changing with time, and f is the mass percentage of boron element in the boron drug.

[0081] After obtaining the non-uniform dynamic boron concentration distribution model according to the non-uniform boron pharmacokinetics, this embodiment mainly optimizes the treatment plan by using rays at different angles. Under the condition of ensuring that the critical region and normal tissues are within the limit range, the dose at the tumor cells is made as large as possible to improve the treatment effect of the treatment plan. Specifically, it is necessary to first perform a Monte Carlo transport simulation for each set irradiation angle based on the non-uniform dynamic boron concentration distribution model to obtain the equivalent biological dose distribution in the target object's body when irradiated alone at each set irradiation angle.

[0082] Step S103, based on the equivalent biological dose distribution in the target object's body when irradiated alone at each set irradiation angle, obtain the optimal irradiation time for each set irradiation angle through the column generation algorithm.

[0083] In this embodiment, the goal of dose optimization is as follows: while ensuring that the dose received by the critical region does not exceed the maximum tolerable dose, the equivalent biological dose received by the target region is maximized as much as possible. In the process of obtaining the optimal irradiation time for each set irradiation angle through the column generation algorithm, in this embodiment, the maximum dose received by the target region is used as the master problem, and the constraint is that the dose received by each critical region is less than the corresponding maximum tolerable dose. Then, based on the initial basis variables obtained by irradiating the unit time separately for each set irradiation angle.

[0084] In this embodiment, the dose value exceeding the minimum acceptable dose of the tumor is used to represent the degree of the dose received by the tumor (i.e., the target region), and the positions that have not reached are set to 0. Assume that the voxel of the target region (Gross Tumor Volume, abbreviated as GTV) is i, and its set is GTV; the voxel of the critical region (Organs At Risk, abbreviated as OAR) is j, and its set is OAR. Then the degree of the dose received by the target region at a set irradiation angle is:

[0085] c = ∑max(0, D i -T i ), i ∈ GTV (7)

[0086] Among them, T i represents the minimum acceptable dose of the target region voxel, D i represents the dose of a voxel in the target region, and the subscript represents different voxels, and the unit is Gy for all.

[0087] The constraint that a critical region needs to comply with at a set irradiation angle is:

[0088] ∑D j ≤ b, j ∈ OAR (8)

[0089] Among them, b represents the maximum tolerable dose of this critical region, D j is the dose of a voxel in the critical region, and the subscript represents different voxels, and the unit is Gy for all. The dose of the voxel is obtained based on the equivalent biological dose distribution in the target object when irradiated separately at the corresponding set irradiation angle.

[0090] Assume that the irradiation time for each angle is x min, and the equivalent biological dose distributions in the patient's body under different angle irradiations can be superimposed. Then the master problem of the multi-angle dose optimization model can be expressed as:

[0091]

[0092]

[0093] Among them, The subscripts represent different irradiation angles, and n represents the number of irradiation angles used in the treatment. The subscripts represent different critical regions, and m represents the number of critical regions. a mn means the dose rate of the m-th critical region under the single irradiation of the n-th irradiation angle, with the unit of Gy / min. The dose rate of the critical region is obtained by summing up and averaging the voxel dose rates within the critical region, that is

[0094] The dual problem of the main problem is:

[0095]

[0096]

[0097] Among them, when obtaining the optimal solution, is the shadow price of the main problem Its mathematical meaning is the influence of the unit change of b i on z.

[0098] In this embodiment, the initial basic variables are obtained based on the single irradiation per unit time for each set irradiation angle. That is, the initial basic variables are composed of the single irradiation for each angle, and the irradiation time of the angle is the treatment time of that angle. If it is set to 1, the initial basic variables are:

[0099] Based on the above settings, the process of obtaining the optimal irradiation time arrangement plan for all specific set irradiation angles is as follows: First, solve the current main problem with the preset irradiation angle vector to obtain the current irradiation time vector; that is, based on the current irradiation angle situation, determine the vector of the degree of dose received by the target regions of all irradiation angles in the current preset irradiation angle vector Then solve the main problem to obtain the current irradiation time vector Then solve the shadow price of the main problem based on the dual problem of the main problem (that is, based on formula 11) The preset irradiation angle vector is the vector formed by all the current irradiation angles for irradiation. During the process of obtaining new irradiation angles, the preset irradiation angle vector can include actual irradiation angles and non-actual irradiation angles. The initial state of the preset irradiation angle vector is obtained based on all set irradiation angles, that is, all set irradiation angles are used as the initial irradiation angles, and the preset irradiation angle vector in the initial state is obtained based on all set irradiation angles.

[0100] Then solve whether the current test number is greater than zero based on the shadow price, and further judge whether there are new irradiation angles that can be added to the basic variables. The test number expression is:

[0101]

[0102] Indicates the degree of the dose received by the target area at the new irradiation angle. Indicates the vector of the degrees of the doses received by the target areas at all the irradiation angles in the current preset irradiation angle vector. Indicates the coefficient vector of splitting the current new irradiation angle into all the irradiation angles in the preset irradiation angle vector. Indicates the dose rate vector of all the critical areas under the individual irradiations at all the irradiation angles in the preset irradiation angle vector, and

[0103] The corresponding subproblem becomes the following formula:

[0104]

[0105] s.t.l i ≤1(15)

[0106] If there is such that the reduced cost is greater than 0, it indicates that there exists a new irradiation angle that makes the current reduced cost greater than zero.

[0107] If there exists a new irradiation angle that makes the current reduced cost greater than zero, it indicates that this new irradiation angle can make the target area receive a higher dose. Add the coefficient vector of the new irradiation angle to the basic variables, and at the same time update and A, and add the new irradiation angle to the current preset irradiation angle vector to form a new preset irradiation angle vector, and return the solution steps for the current main problem with the preset irradiation angle vector based on the new preset irradiation angle vector until there is no reduced cost greater than 0. If there does not exist a new irradiation angle that makes the current reduced cost greater than zero, it is considered that there is no better irradiation angle. Take the current irradiation time vector as the optimal irradiation time vector, take the current basic variables as the optimal basic variables, and obtain the irradiation time proportion coefficients of all the set irradiation angles based on the optimal irradiation time vector and the optimal basic variables. Since in addition to multiple set irradiation angles, the newly obtained irradiation angles each time are not the actual irradiation angles, after obtaining the irradiation time of each angle in the current preset irradiation angle based on the optimal irradiation time vector and the optimal basic variables, it is also necessary to equivalently substitute the irradiation time of the non-actual irradiation angles in the current preset irradiation angle to each set irradiation angle based on the coefficient vector in the optimal basic variables, so as to obtain the final irradiation time of each set irradiation angle, and finally take the ratio of the final irradiation times of each set irradiation angle to obtain the irradiation time proportion coefficients of each set irradiation angle.

[0108] The method for obtaining the boron neutron capture multi-angle irradiation time coefficient provided by the embodiment of the present invention can optimize the problem of irradiation from different angles in the BNCT treatment plan, so that the irradiation time proportion coefficient changes from manually setting the irradiation time proportion of each irradiation angle to the irradiation time proportion coefficient optimized by machine calculation, reducing the time-consuming for doctors to design the irradiation time proportion coefficient. At the same time, the constraint conditions of the column generation algorithm adopted can ensure that the dose received by the normal tissues of the target object is within a reasonable and safe threshold, so that the equivalent biological dose obtained by tumor cells after irradiation based on the irradiation time proportion coefficient at each irradiation angle per unit time is as high as possible. At the same time, the present invention also obtains the boron concentration time change curve corresponding to each region based on the designed preset boron pharmacokinetic three-compartment model, and adds the boron concentration time change curve corresponding to each region to the corresponding position in the three-dimensional model of the target object to obtain a non-uniform dynamic boron concentration distribution model, eliminating the dose calculation error caused by using a static uniform boron concentration distribution model, and more accurately simulating the dose received by the target object during the BNCT treatment process, so as to better evaluate the irradiation time proportion coefficient.

[0109] As Figure 5 shown, the embodiment of the present application also provides a device for obtaining the boron neutron capture multi-angle irradiation time coefficient, including an initial parameter acquisition module, an equivalent biological dose distribution acquisition module, and an irradiation time proportion coefficient acquisition module.

[0110] The initial parameter acquisition module is used to acquire all set irradiation angles, all critical regions, and the maximum tolerance dose corresponding to each critical region.

[0111] The equivalent biological dose distribution acquisition module is used to perform Monte Carlo transport simulation for each set irradiation angle to obtain the equivalent biological dose distribution in the target object when irradiated alone at each set irradiation angle.

[0112] The irradiation time proportion coefficient acquisition module is used to obtain the optimal irradiation time arrangement plan for all set irradiation angles based on the equivalent biological dose distribution in the target object when irradiated alone at each set irradiation angle through the column generation algorithm.

[0113] Among them, in the optimal irradiation time arrangement plan for all set irradiation angles obtained by the column generation algorithm, the maximum dose received by the target region is the main problem, and the dose received by each critical region being less than the corresponding maximum tolerance dose is used as the constraint condition, and the initial basic variables are obtained based on the irradiation per unit time when irradiated alone at each set irradiation angle.

[0114] The device for obtaining the boron neutron capture multi-angle irradiation time coefficient provided by the embodiment of the present invention can optimize the problem of irradiation from different angles in the BNCT treatment plan, so that the irradiation time proportion coefficient changes from manually setting the irradiation time proportion of each irradiation angle to the irradiation time proportion coefficient optimized by machine calculation, reducing the time consumed by doctors in designing the irradiation time proportion coefficient. At the same time, the constraint conditions of the column generation algorithm adopted can ensure that the dose received by the normal tissues of the target object is within a reasonable and safe threshold, so that the equivalent biological dose obtained by tumor cells after irradiation at each irradiation angle per unit time is as high as possible. At the same time, the present invention also obtains the boron concentration time change curve corresponding to each region based on the designed preset boron pharmacokinetic three-compartment model, and adds the boron concentration time change curve corresponding to each region to the corresponding position in the three-dimensional model of the target object to obtain a non-uniform dynamic boron concentration distribution model, eliminating the dose calculation error caused by using a static uniform boron concentration distribution model, and more accurately simulating the dose received by the target object during the BNCT treatment process, so as to better evaluate the irradiation time proportion coefficient.

[0115] The embodiment of the present application also provides a computer-readable storage medium. Those of ordinary skill in the art can understand that all or part of the steps in the method of the above embodiments can be completed by instructing a processor through a program. The program can be stored in a computer-readable storage medium. The storage medium is a non-transitory medium, such as random access memory, read-only memory, flash memory, hard disk, solid-state drive, magnetic tape, floppy disk, optical disc, and any combination thereof. The above storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrating one or more available media. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a digital video disc (DVD)), or a semiconductor medium (such as a solid-state disk (SSD)).

[0116] As Figure 6 shown, the embodiment of the present application provides a terminal.

[0117] The terminal of this embodiment includes a processor and a memory connected to each other; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal can implement all or part of the steps in the method of the above embodiments when executed.

[0118] The beneficial effects of all or part of the steps of the method in the above embodiments are the same as those obtained by the terminal provided in the embodiments of the present invention, and thus will not be elaborated herein.

[0119] It should be noted that the memory may include a random access memory (RAM) and may also include a non-volatile memory, such as at least one disk memory. Similarly, the processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0120] The present application also provides a computer program product, where the computer program product stores computer-readable instructions that can be executed by at least one processor, so that the at least one processor executes all or part of the steps of the method in the above embodiments.

[0121] The beneficial effects of all or part of the steps of the method in the above embodiments are the same as those obtained by the computer program product provided in the embodiments of the present invention, and thus will not be elaborated herein.

[0122] Although the disclosed embodiments of the present invention are as above, the above content is only an embodiment adopted for facilitating the understanding of the present invention and is not used to limit the present invention. Any person skilled in the art within the technical field to which the present invention pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the protection scope of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A method for obtaining a multi-angle irradiation time coefficient of boron neutron capture, comprising: Obtaining all set irradiation angles, all endangered areas, and the maximum tolerated dose corresponding to each endangered area; Performing Monte Carlo transport simulation on each of the set irradiation angles respectively to obtain equivalent biological dose distribution in the target object when each of the set irradiation angles is irradiated separately; Based on the equivalent biological dose distribution in the target object when each of the set irradiation angles is irradiated separately, the irradiation time proportional coefficients of all the set irradiation angles are obtained by a column generation algorithm, including: The maximum dose received by the target area is the main problem, and the dose received by each endangered area is less than the corresponding maximum tolerated dose as a constraint. The initial basic variables are obtained based on the unit time of each set irradiation angle. Solving the current main problem with a preset irradiation angle vector to obtain a current irradiation time vector, and solving the shadow price of the main problem based on the dual problem of the main problem; Based on the shadow price, whether the current test number is greater than zero is solved. If there is a new illumination angle whose current test number is greater than zero, the new illumination angle is added to the current preset illumination angle vector to form a new preset illumination angle vector, and the current main problem is solved again based on the new preset illumination angle vector. If there is no new illumination angle whose current test number is greater than zero, the current illumination time vector is used as the optimal illumination time vector; Acquire the irradiation time proportional coefficients of all the set irradiation angles based on the optimal irradiation time vector; Wherein, the initial state of the preset illumination angle vector is acquired based on all the set illumination angles.

2. The acquisition method according to claim 1, characterized in that Based on the non-uniform dynamic boron concentration distribution model, Monte Carlo transport simulation is performed on each of the set irradiation angles to obtain the equivalent biological dose distribution in the target object when each of the set irradiation angles is irradiated separately.

3. The acquisition method according to claim 2, characterized in that The process of obtaining the non-uniform dynamic boron concentration distribution model is as follows: Acquire a CT image and a target area delineation file of the target object, and acquire position information and area volume size of a well-perfused area, position information and area volume size of a poorly perfused area, and position information and area volume size of a target area from the CT image based on the target area delineation file; Substituting the regional volume size of the well-perfused area, the regional volume size of the poorly perfused area, and the regional volume size of the target area into a preset boron pharmacokinetic three-compartment model, respectively, to obtain a boron concentration-time variation curve of the well-perfused area, a boron concentration-time variation curve of the poorly perfused area, and a boron concentration-time variation curve of the target area; Construct a three-dimensional model of boron concentration distribution based on the CT image, and fill the time-varying curve of boron concentration in the well-perfused region into the three-dimensional model of boron concentration distribution based on the position information of the well-perfused region, fill the time-varying curve of boron concentration in the non-well-perfused region into the three-dimensional model of boron concentration distribution based on the position information of the non-well-perfused region, and fill the time-varying curve of boron concentration in the target region into the three-dimensional model of boron concentration distribution based on the position information of the target region, so as to obtain a non-uniform dynamic boron concentration distribution model.

4. The obtaining method according to claim 3, characterized in that, When the target region is located in the non-well-perfused region, the preset three-compartment boron pharmacokinetic model includes a central compartment representing the well-perfused region, a peripheral compartment representing the non-well-perfused region, and a specific compartment representing the target region. Boron exchange occurs between the central compartment and the peripheral compartment, and boron exchange occurs between the peripheral compartment and the specific compartment.

5. The obtaining method according to claim 3, wherein When the target region is located in the well-perfused region, the preset three-compartment boron pharmacokinetic model includes a central compartment representing the well-perfused region, a peripheral compartment representing the non-well-perfused region, and a specific compartment representing the target region. Boron exchange occurs between the central compartment and the specific compartment, and boron exchange occurs between the peripheral compartment and the central compartment.

6. The acquisition method according to claim 3, wherein Constructing a three-dimensional model of boron concentration distribution based on the CT image includes: Construct a three-dimensional model of boron concentration distribution based on the CT image, and set the boron concentrations in the air region, bone region, and bedplate region in the three-dimensional model of boron concentration distribution to 0.

7. A device for obtaining the multi-angle irradiation time coefficient of boron neutron capture, characterized in that, It includes an initial parameter acquisition module, an equivalent biological dose distribution acquisition module, and an irradiation time proportion coefficient acquisition module; The initial parameter acquisition module is used to acquire all set irradiation angles, all critical regions, and the maximum tolerance dose corresponding to each critical region; The equivalent biological dose distribution acquisition module is used to perform Monte Carlo transport simulations for each set irradiation angle based on the non-uniform dynamic boron concentration distribution model to obtain the equivalent biological dose distribution in the target object's body when each set irradiation angle irradiates alone; The irradiation time proportion coefficient acquisition module is used to obtain the irradiation time proportion coefficients of all set irradiation angles through a column generation algorithm based on the equivalent biological dose distribution in the target object's body when each set irradiation angle irradiates alone, including: Taking the maximum dose received by the target region as the main problem, taking the dose received by each critical region being less than the corresponding maximum tolerance dose as the constraint condition, and obtaining the initial basic variables based on the unit time of each set irradiation angle irradiating alone; Solving the current main problem with a preset irradiation angle vector to obtain the current irradiation time vector, and solving the shadow price of the main problem based on the dual problem of the main problem; Solve whether the current reduced cost is greater than zero based on the shadow price. If there is a new irradiation angle with a current reduced cost greater than zero, add the new irradiation angle to the current preset irradiation angle vector to form a new preset irradiation angle vector, and re-solve the current master problem based on the new preset irradiation angle vector. If there is no new irradiation angle with a current reduced cost greater than zero, use the current irradiation time vector as the optimal irradiation time vector; Obtain the irradiation time proportionality coefficients of all the set irradiation angles based on the optimal irradiation time vector; Among them, the initial state of the preset irradiation angle vector is obtained based on all the set irradiation angles.

8. A storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the method for obtaining the boron neutron capture multi-angle irradiation time coefficient according to any one of claims 1 to 6.

9. A terminal, characterized in that, Including: A processor and a memory, the memory is communicatively connected to the processor; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory so that the terminal executes the method for obtaining the boron neutron capture multi-angle irradiation time coefficient according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the method for obtaining the boron neutron capture multi-angle irradiation time coefficient according to any one of claims 1 to 6.

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