Dose evaluation method, irradiation condition selection method and treatment plan generation apparatus

Abstract

The present application relates to a dose evaluation method, an irradiation condition selection method and a treatment plan generation apparatus. The dose evaluation method comprises: acquiring tissue material information; determining a conjugate flux corresponding to a tissue material according to the tissue material information; and on the basis of an irradiation condition in combination with the conjugate flux corresponding to the tissue material, obtaining a radiation absorption dose corresponding to the tissue material under the irradiation condition. By using the method, a radiation absorption dose corresponding to a tissue material can be quickly calculated, thereby improving the efficiency of dose calculation under a plurality of irradiation conditions, and radiation absorption doses corresponding to each tissue material under different irradiation conditions can be quickly evaluated, so as to facilitate the quick selection of a suitable irradiation condition from among the plurality of irradiation conditions, thereby greatly shortening the formulation time of a treatment plan.

Description

Dose evaluation method, irradiation condition selection method and treatment plan generation device TECHNICAL FIELD

[0001] The present application relates to the technical field of radiotherapy, in particular to a dose evaluation method, an irradiation condition selection method and a treatment plan generation device. BACKGROUND

[0002] Radiotherapy is a means for treating cancer by using radiation to deposit energy around cancer cells to kill the cancer cells. According to the type of radiation, radiotherapy can be divided into photon radiotherapy, electron radiotherapy, proton heavy ion radiotherapy and boron neutron capture therapy, etc.

[0003] In order to kill as many cancer cells as possible while reducing damage to normal cells, before treating a patient, an image scan is usually performed by using Computed Tomography (CT) or Positron Emission Computed Tomography (PET). According to the scan result, tissue material information of a to-be-irradiated body is obtained. A calculation model is established according to the tissue material information and a radiation source. A transport process of radiation particles in the to-be-irradiated body is simulated. Finally, a dose distribution of the radiation particles in the to-be-irradiated body is obtained. Then, a treatment plan with the optimal dose distribution for the patient is selected as a treatment scheme for the patient.

[0004] In the above treatment plan generation process, the dose distribution of the irradiated part of the patient plays a decisive role in the effect of radiotherapy. The dose distribution is usually calculated under a given irradiation condition. The selection of the irradiation condition is usually based on the experience of a physicist, which has great uncertainty. In the traditional technology, the dose distribution is mainly obtained by simulating the motion process of radiation particles by using the Monte Carlo method. By simulating the transport process of radiation particles in the to-be-irradiated body under different irradiation conditions, the dose distribution of the patient under different irradiation conditions is obtained. For traditional radiotherapy, the motion process of photons and electrons needs to be simulated. For other radiation therapy, the motion process of neutrons and photons needs to be simulated.

[0005] However, the simulation and calculation process of the above method is time-consuming and consumes a large amount of memory. Moreover, there are many given irradiation conditions. It will take a long time to simulate and calculate each given irradiation condition by using the above method. Therefore, it is difficult to select a suitable irradiation condition within a reasonable calculation time, which is not conducive to the optimization calculation of the treatment plan.

[0006] SUMMARY

[0007] Therefore, it is necessary to provide a dose evaluation method, an irradiation condition selection method and a treatment plan generation device capable of quickly evaluating a dose and quickly selecting appropriate irradiation conditions in order to solve the above technical problems.

[0008] In a first aspect, the present application provides a radiotherapy dose evaluation method, which comprises:

[0009] obtaining tissue material information;

[0010] determining a conjugate flux corresponding to the tissue material according to the tissue material information;

[0011] obtaining a radiation absorbed dose corresponding to the tissue material under the irradiation condition based on the irradiation condition and the conjugate flux corresponding to the tissue material.

[0012] In one embodiment, the determining of the conjugate flux corresponding to the tissue material according to the tissue material information comprises:

[0013] determining a flux-dose conversion factor corresponding to the tissue material according to element information of the tissue material in the tissue material information;

[0014] determining the conjugate flux corresponding to the tissue material according to the flux-dose conversion factor corresponding to the tissue material.

[0015] In one embodiment, the element information comprises element composition and element proportion, and the determining of the flux-dose conversion factor corresponding to the tissue material according to the element information of the tissue material in the tissue material information comprises:

[0016] obtaining densities of each nuclide in the tissue material according to the element composition and the element proportion;

[0017] obtaining a flux-dose conversion factor corresponding to each nuclide;

[0018] determining the flux-dose conversion factor corresponding to the tissue material by combining the flux-dose conversion factor corresponding to each nuclide and the density of each nuclide.

[0019] In one embodiment, the determining of the flux-dose conversion factor corresponding to the tissue material by combining the flux-dose conversion factor corresponding to each nuclide and the density of each nuclide adopts the following formula: Kerma =∑ρ i ·Kerma i ;

[0020] wherein, ρ i represents the density of the i-th nuclide, and Kerma i represents the flux-dose conversion factor corresponding to the i-th nuclide.

[0021] In one of the embodiments, the conjugate flux corresponding to the tissue material is determined according to a flux-dose conversion factor corresponding to the tissue material, and the following formula is used:

[0022] wherein, represents the conjugate flux, P1 and P2 represent different particle state parameters, represents the conjugate flux of the particles in the P1 state, Kerma represents the flux-dose conversion factor, K * represents the conjugate nucleus, K * (P2→P1) represents the probability of the particles reaching the P2 state from the P1 state through a collision reaction.

[0023] In one of the embodiments, the radiation absorbed dose corresponding to the tissue material under the irradiation condition is obtained based on the irradiation condition and in combination with the conjugate flux corresponding to the tissue material, and includes:

[0024] The source term distribution corresponding to the irradiation condition is determined based on the irradiation condition, wherein the source term distribution is used to represent a distribution function of the particle source under the irradiation condition;

[0025] The radiation absorbed dose corresponding to the tissue material is obtained according to the source term distribution and the conjugate flux corresponding to the tissue material.

[0026] In a second aspect, the present application further provides an irradiation condition selection method, which includes:

[0027] The radiation absorbed dose corresponding to each tissue material is obtained in combination with the irradiation condition and the conjugate flux corresponding to the tissue material;

[0028] At least one suitable irradiation condition is selected according to the radiation absorbed dose corresponding to each tissue material.

[0029] In one of the embodiments, at least one suitable irradiation condition is selected according to the radiation absorbed dose corresponding to each tissue material, and includes:

[0030] If the radiation absorbed dose corresponding to each tissue material meets the preset condition, the irradiation condition is accepted.

[0031] In one of the embodiments, the tissue material at least includes tumor tissue material and important organ tissue material, and if the radiation absorbed dose corresponding to each tissue material meets the preset condition, the irradiation condition is accepted, and includes:

[0032] If the radiation absorbed dose corresponding to the tumor tissue material is greater than a first preset threshold, and the radiation absorbed dose corresponding to the important organ tissue material is less than a second preset threshold, the irradiation condition is accepted.

[0033] In one embodiment, before obtaining the radiation absorbed dose corresponding to each tissue material in combination with the irradiation condition and the conjugate flux corresponding to the tissue material, the method comprises:

[0034] Determining the tissue material corresponding to the region of interest based on at least one preset region of interest.

[0035] In one embodiment, before obtaining the radiation absorbed dose corresponding to each tissue material in combination with the irradiation condition and the conjugate flux corresponding to the tissue material, the method comprises:

[0036] Determining the tissue material corresponding to the region of interest based on at least one preset region of interest in combination with the concentration distribution of the targeted element in the region of interest.

[0037] In one embodiment, selecting the appropriate irradiation condition according to the radiation absorbed dose corresponding to each tissue material, the method comprises:

[0038] Determining the radiation absorbed dose of the region of interest according to the radiation absorbed dose corresponding to all tissue materials in the region of interest;

[0039] Selecting the appropriate irradiation condition according to the radiation absorbed dose of the region of interest.

[0040] In a third aspect, the present application also provides a treatment planning method, which comprises:

[0041] Obtaining the radiation absorbed dose corresponding to each tissue material in combination with the irradiation condition and the conjugate flux corresponding to the tissue material;

[0042] Selecting at least one appropriate irradiation condition according to the radiation absorbed dose corresponding to each tissue material;

[0043] Generating the treatment plan according to the appropriate irradiation condition.

[0044] In one embodiment, selecting at least one appropriate irradiation condition according to the radiation absorbed dose corresponding to each tissue material, the method comprises:

[0045] If the radiation absorbed dose corresponding to each tissue material meets the preset condition, the irradiation condition is accepted.

[0046] In one embodiment, the tissue material at least comprises tumor tissue material and important organ tissue material, and if the radiation absorbed dose corresponding to each tissue material meets the preset condition, the irradiation condition is accepted, which comprises:

[0047] If the radiation absorbed dose corresponding to the tumor tissue material is greater than a first preset threshold, and the radiation absorbed dose corresponding to the important organ tissue material is less than a second preset threshold, the irradiation condition is accepted.

[0048] In one embodiment, before obtaining the radiation absorbed dose corresponding to each tissue material in combination with the irradiation condition and the conjugate flux corresponding to the tissue material, the method comprises:

[0049] Based on at least one preset region of interest, the tissue material corresponding to the region of interest is determined.

[0050] In one embodiment, before obtaining the radiation absorbed dose corresponding to each tissue material in combination with the irradiation condition and the conjugate flux corresponding to the tissue material, the method comprises:

[0051] Based on at least one preset region of interest, in combination with the concentration distribution of the targeted element in the region of interest, the tissue material corresponding to the region of interest is determined.

[0052] In one embodiment, according to the radiation absorbed dose corresponding to each tissue material, the appropriate irradiation condition is selected, which comprises:

[0053] According to the radiation absorbed dose corresponding to all tissue materials in the region of interest, the radiation absorbed dose of the region of interest is determined.

[0054] According to the radiation absorbed dose of the region of interest, the appropriate irradiation condition is selected.

[0055] In one embodiment, according to the appropriate irradiation condition, a treatment plan is generated, which comprises:

[0056] According to the appropriate irradiation condition, the corresponding flux is determined, and the dose distribution calculation is performed based on the flux using the Monte Carlo simulation program.

[0057] In a fourth aspect, the present application also provides a treatment plan generation device, which comprises:

[0058] A radiation source module is used to establish source item information according to different irradiation conditions;

[0059] A medical image data module is used to obtain tissue material information based on medical image data, and establish a three-dimensional voxel tissue model;

[0060] A dose evaluation module is used to determine the conjugate flux corresponding to the tissue material according to the tissue material information, and obtain the radiation absorbed dose corresponding to each tissue material in combination with the source item information and the conjugate flux corresponding to the tissue material;

[0061] An irradiation condition selection module is used to select at least one appropriate irradiation condition according to the radiation absorbed dose corresponding to each tissue material;

[0062] A treatment plan generation module is used to generate a treatment plan according to the appropriate irradiation condition.

[0063] In a fifth aspect, the present application provides a radiotherapy system, comprising:

[0064] a beam generating device for generating a treatment beam;

[0065] a beam adjusting device for adjusting the treatment beam generated by the beam generating device;

[0066] a treatment plan generating device for establishing source term information according to different irradiation conditions, obtaining tissue material information based on medical image data, establishing a three-dimensional voxel tissue model, determining a conjugate flux corresponding to the tissue material according to the tissue material information, combining the source term information and the conjugate flux corresponding to the tissue material to obtain a radiation absorption dose corresponding to each tissue material, selecting at least one appropriate irradiation condition according to the radiation absorption dose corresponding to each tissue material, and generating a treatment plan according to the appropriate irradiation condition;

[0067] a beam control device for calling the corresponding treatment plan from the treatment plan generating device and controlling the beam generating device to execute the treatment plan.

[0068] In a sixth aspect, the present application provides a radiotherapy system, comprising a memory and a processor;

[0069] the memory is configured to store a computer program;

[0070] the processor is configured to, when executing the computer program, implement the radiotherapy dose evaluation method provided in the first aspect of the present application, the irradiation condition selection method provided in the second aspect of the present application, or the treatment plan generation method provided in the third aspect of the present application.

[0071] In a seventh aspect, the present application provides a computer readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the radiotherapy dose evaluation method provided in the first aspect of the present application, the irradiation condition selection method provided in the second aspect of the present application, or the treatment plan generation method provided in the third aspect of the present application is implemented.

[0072] The radiotherapy dose evaluation method described above obtains tissue material information, determines a conjugate flux corresponding to the tissue material according to the tissue material information, and obtains a radiation absorption dose corresponding to the tissue material under an irradiation condition based on the irradiation condition and the conjugate flux corresponding to the tissue material. Since the evaluation of the radiation absorption dose based on the irradiation condition and the conjugate flux is relatively simple, the radiation absorption dose corresponding to the tissue material can be quickly evaluated by using the method described above.

[0073] Further, since the conjugate flux is irrelevant to the source term S, the calculation times are only related to the count target of the tissue material that needs to be considered. Regardless of the changes in the irradiation conditions, the conjugate flux corresponding to the tissue material is determined, and the radiation absorbed dose of the tissue material under multiple different irradiation conditions can be quickly obtained, and the radiation absorbed dose of each interested region under multiple different irradiation conditions can also be quickly obtained. Therefore, in the above irradiation condition selection method, when at least one suitable irradiation condition needs to be selected from multiple different irradiation conditions, the radiation absorbed dose of each tissue material or each interested region under multiple different irradiation conditions can be evaluated by calculating the conjugate flux several times, and the suitable irradiation condition can be quickly selected based on the radiation absorbed dose under multiple different irradiation conditions.

[0074] Further, in the above treatment plan generation method, the suitable irradiation condition can be quickly selected from multiple different irradiation conditions, thereby greatly shortening the time for formulating the treatment plan. BRIEF DESCRIPTION OF DRAWINGS

[0075] FIG. 1 is an application environment diagram in one embodiment;

[0076] FIG. 2 is a flow diagram of a radiotherapy dose evaluation method in one embodiment;

[0077] FIG. 3 is a flow diagram of an irradiation condition selection method in one embodiment;

[0078] FIG. 4 is a flow diagram of a treatment plan generation method in one embodiment;

[0079] FIG. 5 is a structural block diagram of a treatment plan generation device in one embodiment;

[0080] FIG. 6 is a structural block diagram of a radiotherapy system in one embodiment;

[0081] FIG. 7 is a structural block diagram of a radiotherapy system in another embodiment. DETAILED DESCRIPTION

[0082] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0083] The radiotherapy dose evaluation method, the irradiation condition selection method and the treatment plan generation method provided in the embodiments of the present application can be applied in an application environment as shown in FIG. 1. In the application environment, a terminal 102 communicates with a server 104 through a network, and a data storage system can store data required to be processed by the server 104. The data storage system can be integrated on the server 104, or can be placed on a cloud or other network server. The terminal 102 can be, but is not limited to, various personal computers, notebook computers, smart phones, tablet computers, Internet of Things devices and portable wearable devices. The Internet of Things device can be a smart speaker, a smart television, a smart air conditioner, a smart vehicle device, etc. The portable wearable device can be a smart watch, a smart bracelet, a head-mounted device, etc. The server 104 can be implemented by a single server or a server cluster composed of multiple servers.

[0084] It should be noted that the radiotherapy dose evaluation method, the irradiation condition selection method and the treatment plan generation method provided in the embodiments of the present application can generally be executed by the server 104. Correspondingly, the treatment plan generation apparatus provided in the embodiments of the present application can generally be arranged in the server 104. The radiotherapy dose evaluation method, the irradiation condition selection method and the treatment plan generation method provided in the embodiments of the present application can also be executed by a server or a server cluster different from the server 104 and capable of communicating with the terminal 102 or the server 104. Correspondingly, the treatment plan generation apparatus provided in the embodiments of the present application can also be arranged in a server or a server cluster different from the server 104 and capable of communicating with the terminal 102 or the server 104.

[0085] It should be understood that the number of terminal devices, networks and servers in FIG. 1 is only illustrative. According to the implementation needs, there can be any number of terminal devices, networks and servers.

[0086] The basic physical principle of radiotherapy technology is to irradiate tumor tissue with radiation, and to kill cancer cells by depositing the energy carried by the radiation to the cancer cells through the interaction between the radiation and the tumor tissue. The fundamental goal is to kill as many cancer cells as possible (give the tumor tissue as high a radiation absorption dose as possible) on the premise of protecting healthy tissue (give the healthy tissue as low a radiation absorption dose as possible).

[0087] The radiotherapy dose evaluation method, the irradiation condition selection method and the treatment plan generation method provided in the embodiments of the present application can be used for radiotherapy that uses radiation for treatment, such as traditional radiotherapy, proton radiotherapy, X-ray radiotherapy, electron beam radiotherapy, neutron capture therapy and boron neutron capture therapy, etc.

[0088] In radiation therapy technology, the Monte Carlo method can simulate the three-dimensional space nuclear particle collision track and energy distribution inside the irradiated body. In the simulation process, in order to determine the radiation dose distribution of the irradiated body under certain irradiation conditions, the traditional method uses computer technology to process medical image data, and establishes a grid model required by the Monte Carlo software, and then combines the Monte Carlo software to calculate the dose. In the Monte Carlo dose calculation program, the dose D is calculated by the following formula 1:

[0089] Wherein, D is the dose, is the flux, kerma is the flux dose conversion factor, P is the parameter representing the state of the particle, wherein the particle state parameter includes spatial position r, angle Omega, energy E.

[0090] Flux is calculated by formula 2:

[0091] Wherein, P1 and P2 represent different particle state parameters, S represents the source term, S(P1) represents the number of particles in P1 state under the initial source state, K is the transport nuclear parameter in the nuclear reaction database, and K(P2→P1) represents the collision probability of particles from P2 state to P1 state.

[0092] According to formula 2, the flux of particles in P1 state includes two parts, the first part is the number of particles in P1 state under the initial source state, and the second part is the number of particles in P1 state through collision reaction from other states (different from P1 state). Formula 2 integrates all P2, that is, all the number of particles in P1 state converted from P1 state.

[0093] In the above dose simulation calculation by Monte Carlo method, the calculation of flux is a relatively complex and time-consuming process, resulting in low efficiency of dose calculation. Moreover, in radiation therapy technology, it is often necessary to calculate the dose distribution of tissue materials under different irradiation conditions, so as to select appropriate irradiation conditions based on the dose distribution of tissue materials under different irradiation conditions. Different irradiation conditions are essentially different source terms S. According to the above formula 1 and the above formula 2, it can be seen that the flux is related to the source term S, that is, related to the irradiation condition. When calculating the dose D of tissue materials under different irradiation conditions by flux , for each irradiation condition, the flux corresponding to the irradiation condition needs to be calculated. However, the calculation of flux is complex and time-consuming, therefore, flux When calculating the dose, it often takes a lot of time to calculate the dose distribution of the tissue material under various irradiation conditions, which makes it difficult to select appropriate irradiation conditions in a short time.

[0094] Therefore, in order to quickly evaluate the radiation absorption dose of the tissue material, and quickly evaluate the radiation absorption dose of the tissue material under different irradiation conditions, so as to facilitate the selection of appropriate irradiation conditions, the present application provides a radiotherapy dose evaluation method. In one embodiment, as shown in FIG. 2, the method comprises the following steps:

[0095] Obtain tissue material information:

[0096] The tissue material information includes element information of the tissue material, such as element composition and element proportion of the tissue material. There are more than 60 elements in human tissue, more than 20 of which are essential elements, which are important for maintaining the normal physiological function of the body. The elements with relatively high content include carbon, hydrogen, oxygen, nitrogen, sodium, phosphorus, sodium, magnesium, potassium, calcium, and the like. In addition, the blood tissue contains a small amount of iron element, and the thyroid tissue contains a small amount of iodine element.

[0097] In addition, in some radiotherapy techniques, before controlling the irradiation of the treatment beam on the irradiation object, a targeted molecular drug is injected into the irradiation object, so as to use the selectivity of the targeted molecular drug to make the targeted element specifically gather in some tissues. For example, in boron neutron capture therapy, a drug containing boron ( 10 B) selectively gathers in tumor tissue, and uses the characteristic of boron element ( 10 B) having a high capture cross section for thermal neutrons to achieve the purpose of locally killing tumor cells. In this application scenario, the element composition of the tissue material can also include the targeted element, and the element proportion of the tissue material can also include the proportion of the targeted element.

[0098] In radiotherapy techniques, medical images such as magnetic resonance imaging (MRI) or computed tomography (CT) can provide detailed tissue geometric structure information for the characteristics in the irradiation object. Taking computed tomography as an example, the tissue material can be defined according to the CT value, also known as HU value (Hounsfield Unit). The HU value in a fixed interval range corresponds to the tissue material with a fixed element composition ratio. For example, the HU value between-100 and 20 can correspond to fat tissue with a fixed element composition ratio, the HU value between 20 and 100 can correspond to muscle tissue with a fixed element composition ratio, and the HU value between-951 and 120 can correspond to lung tissue with a fixed element composition ratio.

[0099] When the conversion between the medical image data and the tissue material and the tissue material information is implemented, the HU value range covered by some tissue materials can be wide, which can result in low accuracy of dose calculation. In this case, the tissue materials covering a wide HU value range can be further divided, for example, the lung tissue can be divided into low-density lung tissue and high-density lung tissue.

[0100] For the radiotherapy technology including a target element, the concentration distribution of the target element in part of the tissue materials or all the tissue materials can be assumed to be non-uniform, and the non-uniform target element distribution information can be obtained through Positron Emission Computed Tomography (PET) and other medical images, so that part of the tissue materials or all the tissue materials are further divided according to the target element distribution information, for example, the tumor tissue materials are further divided into multiple tissue materials based on the boron concentration, so as to more accurately evaluate the radiation absorption dose of the tumor tissue materials with different boron concentrations.

[0101] For tumors at different positions, different tissue materials need to be considered or calculated for dose calculation. For head and neck cancer, the tissue materials that need to be considered usually include skin, brain, brainstem, eye, mucosa, mandible, spinal cord, tumor and the like. According to the medical image of the body to be irradiated, the geometric space of the tissue materials that need to be considered can be outlined.

[0102] It should be noted that the tissue material information obtained in the embodiments of the present application specifically refers to the information of the target tissue material for subsequent dose evaluation.

[0103] It should be noted that the definition of the tissue material in the embodiments of the present application, that is, the conversion relationship between the medical image data and the tissue material is not specifically limited, and the tissue material that needs to be evaluated can be defined according to the accuracy requirement of actual dose evaluation and the position of the tumor.

[0104] It should be noted that the method for obtaining the tissue material information is not specifically limited in the embodiments of the present application. For example, in proton radiotherapy, the HU value can be converted into the corresponding tissue material element information in the TOPAS software according to a specific relationship, and then the tissue material element information defined by default in the TOPAS software can be obtained. For example, in boron neutron capture therapy, the tissue material information can be obtained by combining the material template library of the MCNP software and the PET medical image data or the blood boron concentration.

[0105] According to the tissue material information, the conjugate flux corresponding to the tissue material is determined:

[0106] The conjugate flux corresponding to the tissue material includes distribution information of the conjugate flux in the geometric space of the tissue material.

[0107] Exemplarily, after obtaining the tissue material information, the conjugate flux corresponding to the tissue material is determined according to the element information in the tissue material information, wherein the conjugate flux has nothing to do with the variable source term S, i.e., the parameter of the radioactive ray. Therefore, when the dose distribution under multiple irradiation conditions is calculated by using the radiotherapy dose evaluation method provided in the embodiments of the present application, the conjugate flux corresponding to one kind of tissue material needs to be calculated only once, that is, the number of times of calculation of the conjugate flux is only related to the number of types of tissue materials to be considered, and is irrelevant to the number of irradiation conditions.

[0108] Based on the irradiation condition and in combination with the conjugate flux corresponding to the tissue material, the radiation absorbed dose of the tissue material under the irradiation condition is obtained.

[0109] The irradiation condition includes the irradiation direction, the irradiation position and the beam parameter of the radioactive particle forming the beam, and different irradiation conditions are essentially different source terms S. Different radioactive particles have different distribution states under different irradiation conditions, and the source term S can be represented by the distribution function of the particles.

[0110] Exemplarily, after the conjugate flux corresponding to the tissue material is determined, the radiation absorbed dose of the tissue material under the irradiation condition can be determined based on the irradiation condition and in combination with the conjugate flux corresponding to the tissue material, for example, according to the conjugate flux corresponding to the tumor tissue and the given irradiation condition, the radiation absorbed dose of the tumor tissue under the irradiation condition is obtained.

[0111] In the radiotherapy technology, it is often necessary to calculate the dose distribution of the tissue material under different irradiation conditions, for example, in order to select a suitable irradiation condition from 100 irradiation conditions, the dose D of the radioactive particle corresponding to the 100 irradiation conditions needs to be calculated. In the case of calculating the dose D by using the flux In the case of calculating the dose D by using the flux The flux is calculated according to the formula two, and the flux is calculated according to the formula two, and the flux Only 100 irradiation conditions can get the dose D corresponding to the dose D; and the dose D calculated by the conjugate flux provided in the embodiment of the application is not related to the source term S, and the number of calculations is only related to the number of tissue materials to be considered, so for different irradiation conditions, the conjugate flux corresponding to the tissue material is the same, and the dose D calculated by the conjugate flux provided in the embodiment of the application only needs to calculate the conjugate flux several times, and then combine 100 irradiation conditions to calculate the dose D corresponding to the tissue material under each irradiation condition, wherein the specific number depends on the number of tissue materials to be considered, and is generally the number of tumor tissues and normal tissues, and the number of tissue materials is obviously much smaller than the number of irradiation conditions to be considered. And the calculation of the flux is a very complex process, while the calculation of the conjugate flux is relatively simple, and the calculation of the dose D combining the irradiation condition and the conjugate flux is also relatively simple, so the dose D under multiple irradiation conditions is calculated by the conjugate flux, which is obviously much faster than the dose D under multiple irradiation conditions calculated by the flux .

[0112] In the above radiotherapy dose evaluation method, first, the tissue material information is obtained, the conjugate flux corresponding to the tissue material is determined according to the tissue material information, and the radiation absorption dose corresponding to the tissue material under the irradiation condition is obtained based on the irradiation condition and the conjugate flux corresponding to the tissue material. Because the calculation of the conjugate flux is relatively simple, and the calculation of the radiation absorption dose combining the irradiation condition and the conjugate flux is also relatively simple, the above method can quickly evaluate the radiation absorption dose corresponding to the tissue material, and when the dose distribution under multiple irradiation conditions is evaluated by the above method, because the conjugate flux is not related to the source term S, and the number of calculations is only related to the number of tissue materials to be considered, so no matter how the irradiation condition changes, the conjugate flux corresponding to the tissue material is determined, and then the dose distribution under multiple irradiation conditions can be evaluated by the above radiotherapy dose evaluation method only by calculating the conjugate flux several times, thereby improving the efficiency of dose evaluation under multiple irradiation conditions.

[0113] In one embodiment, the conjugate flux corresponding to the tissue material is determined according to the tissue material information, including the following steps:

[0114] The flux dose conversion factor corresponding to the tissue material is determined according to the element information of the tissue material in the tissue material information:

[0115] Wherein, the flux dose conversion factor (Kerma) of a certain tissue material is determined by the element composition and element proportion of the tissue material, which can be found in the cross-section database according to the particle energy and the flux dose conversion factor of each nuclide under the corresponding energy.

[0116] In an implementation, the density of each nuclide in the tissue material is obtained according to the element composition and the element proportion in the tissue material, and the flux dose conversion factor corresponding to each nuclide is obtained, and the flux dose conversion factor corresponding to the tissue material is determined by combining the flux dose conversion factor corresponding to each nuclide and the density of each nuclide.

[0117] In an implementation, the flux dose conversion factor corresponding to the tissue material is determined by combining the flux dose conversion factor corresponding to each nuclide and the density of each nuclide, and the following formula is used: Kerma =∑ρ i ·Kerma i ; (Formula Three)

[0118] Wherein, ρ i represents the density of the i-th nuclide, Kerma i represents the flux dose conversion factor corresponding to the i-th nuclide.

[0119] According to the flux dose conversion factor corresponding to the tissue material, the conjugate flux corresponding to the tissue material is determined:

[0120] In an implementation, according to the flux dose conversion factor Kerma corresponding to the tissue material, the conjugate equation is constructed with the flux dose conversion factor Kerma corresponding to the tissue material as the source term by combining the above formula two, and the conjugate flux corresponding to the tissue material is determined by using the conjugate equation, and the conjugate equation is as follows:

[0121] Wherein, represents the conjugate flux, P1 and P2 represent different particle state parameters, represents the conjugate flux of particles in P1 state, Kerma represents the flux dose conversion factor, K * represents the conjugate nuclear parameter in the nuclear reaction database.

[0122] Wherein, the transport kernel K and the conjugate kernel K * satisfy the following relationship:

[0123] K (P2→P1) = K * (P1→P2); (Formula Five)

[0124] It can be seen that K * (P2→P1) and K (P1→P2) in the above formula four are equal, that is, the probability of particles from P1 state to P2 state through collision reaction.

[0125] In this embodiment, the flux dose conversion factor corresponding to the tissue material is determined by the element information of the tissue material in the tissue material information, and the conjugate flux corresponding to the tissue material is determined according to the flux dose conversion factor corresponding to the tissue material. Referring to Formula Four, the conjugate flux is irrelevant to the source term S, and is related to the flux dose conversion factor Kerma, and the flux dose conversion factor Kerma is corresponding to the tissue material. The density of the nuclide in different tissue materials is different, different nuclides correspond to different Kerma values, and the Kerma value corresponding to the tissue material can be obtained by combining the nuclide density of the tissue material and the Kerma value corresponding to each nuclide, and then the conjugate flux corresponding to the tissue material is determined according to Formula Four through the Kerma value corresponding to the tissue material.

[0126] In one embodiment, the radiation absorbed dose corresponding to the tissue material under the irradiation condition is obtained based on the irradiation condition and in combination with the conjugate flux corresponding to the tissue material, and includes:

[0127] The source term distribution corresponding to the irradiation condition is determined based on the irradiation condition:

[0128] The source term distribution is the source term S, which is used to represent the distribution function of the particle source under the irradiation condition.

[0129] The radiation absorbed dose corresponding to the tissue material is obtained according to the source term distribution and the conjugate flux corresponding to the tissue material:

[0130] Please combine Formula Two with and do the inner product, combine Formula Four with and do the inner product, and the following can be obtained:

[0131] According to Formula Five, Formula Six and Formula Seven, the two double integrals on the right side of the equal sign are equal, and the equal parts are eliminated to obtain:

[0132] Combining Formula One, Formula Two, Formula Four and Formula Eight, the following can be obtained:

[0133] Formula Nine shows that the dose can be obtained by the inner product of the flux and the flux dose conversion factor Kerma, and can also be obtained by the inner product of the conjugate flux and the source term S.

[0134] In this embodiment, the source term distribution function corresponding to the irradiation condition is determined through the irradiation condition, and the radiation absorbed dose corresponding to the region of interest is obtained by doing the inner product of the source term distribution function and the conjugate flux corresponding to the tissue material. The calculation of the flux is a complex and time-consuming process, and the conjugate flux The calculation of the flux The calculation of the flux The calculation of the dose D only needs to calculate several times of the flux Wherein, the specific number depends on the number of tissue materials to be considered, and then the flux The dose D corresponding to different sources can be obtained by performing 100 times of inner products of the flux and the source term distribution function, which can greatly save the dose evaluation time and improve the efficiency of dose evaluation.

[0135] Based on the same inventive concept, the embodiment of the present application also provides an irradiation condition selection method. The implementation scheme for solving the problem provided by the irradiation condition selection method is similar to the implementation scheme described in the above radiotherapy dose evaluation method, so the specific limitations in one or more irradiation condition selection method embodiments provided below can refer to the limitations of the radiotherapy dose evaluation method embodiments in the above, which will not be repeated here.

[0136] In one embodiment, as shown in FIG. 3, an irradiation condition selection method is provided, including the following steps:

[0137] The radiation absorption dose corresponding to each tissue material is obtained by combining the irradiation condition and the flux corresponding to the tissue material:

[0138] Wherein, when selecting a suitable irradiation condition, it is required that the high-dose radiation is delivered to the tumor target area as much as possible, and the damage to the surrounding organs (healthy tissue) is minimized. In order to better control the dose distribution in each organ or target area, the appropriate irradiation condition is selected to kill tumor cells while minimizing damage to surrounding normal tissues. The tissue materials of the embodiment of the present application can include tumor tissue and at least one important organ tissue in the surrounding.

[0139] In an implementation manner, a plurality of irradiation conditions can be determined in advance according to the tumor type, position and size, and the experience of a physicist. Sampling from the plurality of irradiation conditions, that is, selecting a certain irradiation condition, can be randomly selected or selected according to a pre-set order. The radiation absorption dose corresponding to each tissue material under the irradiation condition is obtained by combining the irradiation condition and the flux corresponding to each tissue material.

[0140] At least one suitable irradiation condition is selected according to the radiation absorption dose corresponding to each tissue material:

[0141] In an implementation, if the radiation absorbed dose corresponding to each tissue material satisfies the preset condition, the irradiation condition is accepted; if the radiation absorbed dose corresponding to each tissue material does not satisfy the preset condition, the irradiation condition is resampled, and the radiation absorbed dose corresponding to each tissue material under the resampled irradiation condition is evaluated.

[0142] Illustratively, the tissue materials include tumor tissue materials and important organ tissue materials, if the radiation absorbed dose corresponding to the tumor tissue materials is greater than a first preset threshold, and the radiation absorbed dose corresponding to the important organ tissue materials is less than a second preset threshold, the irradiation condition is accepted as a suitable irradiation condition.

[0143] In an implementation, a plurality of irradiation conditions are selected according to the radiation absorbed dose corresponding to each tissue material, so as to select at least one suitable irradiation condition.

[0144] Illustratively, for the radiation absorbed dose corresponding to each tissue material under each irradiation condition, irradiation conditions satisfying the preset condition are first selected, and then the plurality of irradiation conditions satisfying the preset condition are sorted and selected, wherein the selection can be performed by comparing the radiation absorbed dose corresponding to the tumor tissue under each irradiation condition, and comparing the radiation absorbed dose corresponding to other important organ tissue materials under each irradiation condition, or different weights can be given to different tissue materials according to actual conditions, and the embodiments of the present application are not limited herein.

[0145] It should be noted that the selection can be to select one optimal irradiation condition, or to select a plurality of relatively optimal irradiation conditions, and the optimal or relatively optimal irradiation condition is used as a suitable irradiation condition. Alternatively, when a plurality of relatively optimal irradiation conditions are selected, a Monte Carlo simulation program can be used to calculate more accurate dose distributions under the plurality of relatively optimal irradiation conditions according to the fluxes corresponding to the plurality of relatively optimal irradiation conditions, and then the suitable irradiation condition is determined by comparison.

[0146] In the embodiments, the radiation absorbed dose corresponding to each tissue material is obtained by combining the irradiation condition and the conjugate flux corresponding to the tissue material, and at least one suitable irradiation condition is selected according to the radiation absorbed dose corresponding to each tissue material. Since the conjugate flux is independent of the source term S, the number of calculations is only related to the count of the tissue materials to be considered, and therefore, no matter how the irradiation condition changes, the conjugate flux corresponding to the tissue material is determined, and therefore, the above irradiation condition selection method only needs to calculate the conjugate flux several times to evaluate the radiation absorbed dose of each tissue material under a plurality of irradiation conditions, improves the efficiency of dose calculation under a plurality of irradiation conditions, and can quickly evaluate the radiation absorbed dose corresponding to each tissue material under different irradiation conditions, so as to quickly select a suitable irradiation condition from a plurality of irradiation conditions.

[0147] In one embodiment, before obtaining the radiation absorbed dose corresponding to each tissue material based on the irradiation condition and the conjugate flux corresponding to the tissue material, the method comprises: determining the tissue material corresponding to the region of interest based on at least one preset region of interest.

[0148] The region of interest (ROI) can be a target region of particle deposition, such as a tumor region that needs to be treated, or a protection region around the target region, such as a region where important organ tissues are located, which can be a critical organ such as the eye, liver, etc., or an important tissue such as bone tissue, brain tissue, etc.

[0149] The embodiments of the present application can preset at least one ROI region that needs to be defined for different tumor types, for example, the ROI types that need to be concerned in the treatment of brain tumors can include air (Air), skin (Skin), carotid artery (Carotid), mucosa (Mucosa), brain tissue (Brain), eyeball (Eyeball), eye lens (Eyelens), gland (Gland), bone (Skeleton), soft tissue (Soft tissue), or brain tumor (Brain tumor), etc.

[0150] Based on medical image data such as HU values, the corresponding ROI boundary can be automatically defined, automatically read, or manually defined by an operator. By defining the ROI boundary, the three-dimensional medical image geometric model of the body to be irradiated is divided into the corresponding ROI region, that is, each voxel grid is divided into the corresponding ROI region.

[0151] After the at least one ROI region is preset, the embodiments of the present application determine the tissue material corresponding to each ROI region. For example, the HU value range corresponding to each ROI region, one or more tissue material types corresponding to different ROI regions, the HU value corresponding to the tissue material, and the element information corresponding to the tissue material are preset in the material template library.

[0152] For example, the HU value range covered by some ROI regions is relatively narrow, and one ROI region can correspond to one tissue material.

[0153] For example, the HU value range covered by some ROI regions is relatively wide, and the ROI region can be further divided into different tissue material types according to different HU value ranges to obtain multiple tissue materials corresponding to the ROI region.

[0154] It should be noted that in the application scenario of radiotherapy including a targeting element, the concentration distribution of the targeting element in the ROI region is assumed to be a uniform concentration distribution.

[0155] In the embodiment, by selecting at least one preset region of interest, the tissue material corresponding to the region of interest is determined based on the tissue density in the medical image data, and one or more tissue materials corresponding to the region of interest are obtained, so that the radiation absorbed dose of the tissue material can be more accurately evaluated.

[0156] In another embodiment, before obtaining the radiation absorbed dose corresponding to each tissue material in combination with the conjugate flux corresponding to the tissue material and the irradiation condition, the tissue material corresponding to the region of interest is determined based on at least one preset region of interest and in combination with the concentration distribution of the targeted element in the region of interest.

[0157] The embodiment is applied to a radiotherapy scene including a targeted element, and the concentration distribution of the targeted element in the ROI region is assumed to be partially or totally inhomogeneous.

[0158] For example, after a preset ROI region is selected, the initial tissue material of the ROI region can be determined based on the HU value of the ROI region, and then some or all of the initial tissue material can be further divided based on the inhomogeneous concentration distribution of the targeted element. For example, in boron neutron capture therapy, a certain ROI region is circled according to the HU value, and the tissue material corresponding to the ROI region is tumor tissue. Further, the inhomogeneous boron isotope concentration distribution information in the ROI region can be obtained through PET medical imaging, and the ROI region can be further divided into tumor 1 tissue material, tumor 2 tissue material, tumor 3 tissue material, and the like based on the inhomogeneous boron isotope concentration distribution information.

[0159] In the embodiment, the tissue material corresponding to the region of interest is determined in combination with the concentration distribution of the targeted element in the region of interest. Since the targeted element also has a flux dose conversion factor Kerma value in the radiation absorbed dose calculation of the tissue material, the inhomogeneous distribution of the targeted element can affect the flux dose conversion factor Kerma value corresponding to the tissue material, thereby causing deviation of the radiation absorbed dose of the tissue material. Therefore, the embodiment can further divide the tissue material in the region of interest according to the concentration distribution of the targeted element, so that the radiation absorbed dose of the tissue material can be more accurately evaluated.

[0160] In one embodiment, the appropriate irradiation condition is selected according to the radiation absorbed dose corresponding to each tissue material, including:

[0161] The radiation absorbed dose of the region of interest is determined according to the radiation absorbed dose corresponding to all the tissue materials in the region of interest:

[0162] Wherein, before obtaining the radiation absorption dose corresponding to each tissue material, in the case of selecting the region of interest, the total radiation absorption dose in the region of interest can be used to select the appropriate irradiation condition.

[0163] Exemplarily, when there is only one kind of tissue material in the region of interest, the total radiation absorption dose in the region of interest is the absorption dose of the tissue material corresponding to the region of interest.

[0164] Exemplarily, when the region of interest includes multiple kinds of tissue materials, the total deposited energy of all the tissue materials can be divided by the region mass of the region of interest to obtain the radiation absorption dose of the region of interest, that is, the total average dose of the region of interest is used as the radiation absorption dose of the region of interest. The radiation absorption dose of the region of interest can be obtained by the following formula:

[0165] Wherein, E i_deposite represents the total deposited energy corresponding to the i-th kind of tissue material, M i represents the mass of the i-th kind of tissue material, D i represents the radiation absorption dose corresponding to the i-th kind of tissue material.

[0166] According to the radiation absorption dose of the region of interest, the appropriate irradiation condition is selected.

[0167] In this embodiment, after the region of interest is selected and the tissue materials in the region of interest are divided, the radiation absorption dose corresponding to each tissue material is determined by the conjugate flux and the irradiation condition, the radiation absorption dose of the region of interest is determined by the radiation absorption dose corresponding to all the tissue materials in the region of interest and the mass of all the tissue materials, and the appropriate irradiation condition is selected by judging whether the radiation absorption dose of the region of interest meets the preset condition.

[0168] Based on the same inventive concept, the embodiments of the present application also provide a treatment plan generation method, which uses the above irradiation condition selection method to realize the generation of a treatment plan, obtains the radiation absorption dose corresponding to each tissue material in combination with the irradiation condition and the conjugate flux corresponding to the tissue material, selects at least one appropriate irradiation condition according to the radiation absorption dose corresponding to each tissue material, and generates a treatment plan according to the appropriate irradiation condition.

[0169] Wherein, the steps of obtaining the radiation absorption dose corresponding to each tissue material in combination with the irradiation condition and the conjugate flux corresponding to the tissue material, and selecting at least one appropriate irradiation condition according to the radiation absorption dose corresponding to each tissue material are the same as the implementation solutions described in the above irradiation condition selection method, so the specific limitations in one or more treatment plan generation method embodiments provided below can be referred to the limitations of the irradiation condition selection method described above, which will not be repeated here.

[0170] In one embodiment, the treatment plan generation method comprises: obtaining radiation absorbed dose corresponding to each tissue material based on the irradiation condition and the conjugate flux corresponding to the tissue material; selecting at least one appropriate irradiation condition based on the radiation absorbed dose corresponding to each tissue material; and generating a treatment plan based on the appropriate irradiation condition.

[0171] In one embodiment, the selecting at least one appropriate irradiation condition based on the radiation absorbed dose corresponding to each tissue material comprises: if the radiation absorbed dose corresponding to each tissue material satisfies a preset condition, accepting the irradiation condition.

[0172] In one embodiment, the tissue material comprises tumor tissue material and important organ tissue material, and the accepting the irradiation condition if the radiation absorbed dose corresponding to each tissue material satisfies a preset condition comprises: if the radiation absorbed dose corresponding to the tumor tissue material is greater than a first preset threshold value, and the radiation absorbed dose corresponding to the important organ tissue material is less than a second preset threshold value, accepting the irradiation condition.

[0173] In one embodiment, before the obtaining radiation absorbed dose corresponding to each tissue material based on the irradiation condition and the conjugate flux corresponding to the tissue material, the method further comprises: determining the tissue material corresponding to a region of interest based on at least one preset region of interest.

[0174] In one embodiment, before the obtaining radiation absorbed dose corresponding to each tissue material based on the irradiation condition and the conjugate flux corresponding to the tissue material, the method further comprises: determining the tissue material corresponding to a region of interest based on at least one preset region of interest and the concentration distribution of the targeted element in the region of interest.

[0175] In one embodiment, the selecting at least one appropriate irradiation condition based on the radiation absorbed dose corresponding to each tissue material comprises: determining the radiation absorbed dose of the region of interest based on the radiation absorbed dose corresponding to all tissue materials in the region of interest; and selecting the appropriate irradiation condition based on the radiation absorbed dose of the region of interest.

[0176] In one embodiment, the generating a treatment plan based on the appropriate irradiation condition comprises: determining the corresponding flux based on the appropriate irradiation condition; and performing dose distribution calculation based on the flux using a Monte Carlo simulation program.

[0177] It should be understood that although the steps in the flowcharts involved in the above embodiments are shown in sequence according to the arrows, the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other sequences. Moreover, at least some of the steps in the flowcharts involved in the above embodiments can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of the steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least part of other steps or stages.

[0178] Based on the same inventive concept, the embodiments of the present application also provide a treatment plan generation device for implementing the above-mentioned treatment plan generation method. The implementation scheme for solving the problem provided by the treatment plan generation device is similar to the implementation scheme described in the above treatment plan generation method, so the specific limitations in one or more treatment plan generation device embodiments provided below can refer to the limitations of the treatment plan generation method described above, which will not be repeated here.

[0179] In one embodiment, as shown in FIG. 5, a treatment plan generation device is provided, which includes a radiation source module 502, a medical influence data module 504, a dose evaluation module 506, an irradiation condition selection module 508 and a treatment plan generation module 510, wherein:

[0180] The radiation source module 502 is configured to establish source item information according to different irradiation conditions.

[0181] The medical image data module 504 is configured to obtain tissue material information based on medical image data, and establish a three-dimensional voxel tissue model.

[0182] The dose evaluation module 506 is configured to determine the conjugate flux corresponding to the tissue material according to the tissue material information, and obtain the radiation absorbed dose corresponding to each tissue material by combining the source item information and the conjugate flux corresponding to the tissue material.

[0183] The irradiation condition selection module 508 is configured to select at least one suitable irradiation condition according to the radiation absorbed dose corresponding to each tissue material.

[0184] The treatment plan generation module 510 is configured to generate a treatment plan according to the suitable irradiation condition.

[0185] The various modules in the treatment plan generation apparatus described above can be implemented in whole or in part by software, hardware, and combinations thereof. The various modules can be embedded in or independent of a processor in a computer device in hardware form, or stored in a memory in a computer device in software form, so as to be invoked by a processor to perform the operations corresponding to the various modules.

[0186] Based on the same inventive concept, the embodiments of the present application also provide a radiotherapy system, which provides a solution to the problem similar to the implementation solutions described in the treatment plan generation method or the treatment plan generation apparatus, and therefore the specific limitations in one or more radiotherapy system embodiments provided below can refer to the limitations of the treatment plan generation method or the treatment plan generation apparatus described above, which will not be repeated here.

[0187] In one embodiment, as shown in FIG. 6, a radiotherapy system is provided, which includes a beam generation apparatus 602, a beam adjustment apparatus 604, a treatment plan generation apparatus 606, and a beam control apparatus 608, wherein:

[0188] The beam generation apparatus 602 is configured to generate a therapeutic beam.

[0189] The beam adjustment apparatus 604 is configured to adjust the therapeutic beam generated by the beam generation apparatus 602.

[0190] The treatment plan generation apparatus 606 is configured to establish source term information according to different irradiation conditions, obtain tissue material information based on medical image data, establish a three-dimensional voxel tissue model, determine the conjugate flux corresponding to the tissue material according to the tissue material information, obtain the radiation absorption dose corresponding to each tissue material in combination with the source term information and the conjugate flux corresponding to the tissue material, select at least one appropriate irradiation condition according to the radiation absorption dose corresponding to each tissue material, and generate a treatment plan according to the appropriate irradiation condition.

[0191] The beam control apparatus 608 is configured to retrieve the corresponding treatment plan from the treatment plan generation apparatus 606 and control the beam generation apparatus 602 to execute the treatment plan.

[0192] Based on the same inventive concept, the embodiment of the present application further provides another radiotherapy system which can be a server, and an internal structure diagram of the server can be shown in FIG. 7. The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for running the operating system and the computer program in the non-volatile storage medium. The database of the computer device is configured to store data such as organizational material information. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to communicate with terminals outside through a network connection. The computer program is executed by the processor to implement the radiotherapy dose evaluation method, the irradiation condition selection method or the treatment plan generation method.

[0193] Those skilled in the art can understand that the structure shown in FIG. 7 is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the radiotherapy system to which the scheme of the present application is applied. Specifically, the radiotherapy system can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0194] In one embodiment, a radiotherapy system is provided, including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps in the above method embodiments.

[0195] In one embodiment, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0196] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing relevant hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. The volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0197] The technical features of the above embodiments can be combined in any way. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, but as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0198] The above embodiments only express several implementation manners of the present application, and the description is specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method of radiotherapy dose assessment, characterized by, The method comprises: obtaining tissue material information; determining the conjugate flux corresponding to the tissue material according to the tissue material information; obtaining the radiation absorbed dose corresponding to the tissue material under the irradiation condition based on the irradiation condition and the conjugate flux corresponding to the tissue material.

2. The method of claim 1, wherein, The determination of the conjugate flux corresponding to the tissue material according to the tissue material information comprises: determining the fluence-to-dose conversion factor corresponding to the tissue material according to the element information of the tissue material in the tissue material information; determining the conjugate flux corresponding to the tissue material according to the fluence-to-dose conversion factor corresponding to the tissue material.

3. The method of claim 2, wherein, The element information comprises element composition and element proportion, and the determination of the fluence-to-dose conversion factor corresponding to the tissue material according to the element information of the tissue material in the tissue material information comprises: obtaining the density of each nuclide in the tissue material according to the element composition and the element proportion; obtaining the fluence-to-dose conversion factor corresponding to each nuclide; determining the fluence-to-dose conversion factor corresponding to the tissue material based on the fluence-to-dose conversion factor corresponding to each nuclide and the density of each nuclide.

4. The method of claim 3, wherein, The flux dose conversion factor corresponding to the tissue material is determined by combining the flux dose conversion factor corresponding to each nuclide and the density of each nuclide, using the following formula: Kerma =∑ρ i ·Kerma i ; where, p i represents the density of the i-th nuclide, Kerma i represents the flux dose conversion factor corresponding to the i-th nuclide.

5. The method of claim 2, wherein, The corresponding flux of the tissue material is determined according to the flux dose conversion factor corresponding to the tissue material, using the following formula: wherein representing the conjugate flux, P1and P2represent different particle state parameters, Kerma represents the flux dose conversion factor, K * Kerma represents the flux dose conversion factor, K * (P2→P1) represents the probability of a particle reaching state P2 from state P1 by a collision reaction.

6. The method of claim 1, wherein, The obtaining of the radiation absorbed dose corresponding to the tissue material under the irradiation condition based on the irradiation condition and the conjugate flux corresponding to the tissue material comprises: determining the source term distribution corresponding to the irradiation condition based on the irradiation condition, wherein the source term distribution is used to represent the distribution function of the particle source under the irradiation condition; obtaining the radiation absorbed dose corresponding to the tissue material according to the source term distribution and the conjugate flux corresponding to the tissue material.

7. An irradiation condition selection method characterized by comprising: The method comprises: obtaining the radiation absorbed dose corresponding to each tissue material based on the irradiation condition and the conjugate flux corresponding to the tissue material; selecting at least one suitable irradiation condition according to the radiation absorbed dose corresponding to each tissue material.

8. The method of claim 7, wherein, The selection of at least one suitable irradiation condition according to the radiation absorbed dose corresponding to each tissue material comprises: if the radiation absorbed dose corresponding to each tissue material meets the preset condition, the irradiation condition is accepted.

9. The method of claim 8, wherein, The tissue material at least comprises tumor tissue material and important organ tissue material, and the selection of the irradiation condition according to the radiation absorbed dose corresponding to each tissue material comprises: if the radiation absorbed dose corresponding to the tumor tissue material is greater than a first preset threshold value, and the radiation absorbed dose corresponding to the important organ tissue material is less than a second preset threshold value, the irradiation condition is accepted.

10. The method of claim 7, wherein, Before the obtaining of the radiation absorbed dose corresponding to each tissue material based on the irradiation condition and the conjugate flux corresponding to the tissue material, the method comprises: determining the tissue material corresponding to at least one preset region of interest based on the region of interest.

11. The method of claim 7, wherein, Before the obtaining of the radiation absorbed dose corresponding to each tissue material based on the irradiation condition and the conjugate flux corresponding to the tissue material, the method comprises: determining the tissue material corresponding to at least one preset region of interest based on the concentration distribution of the targeted element in the region of interest.

12. The method according to claim 10 or 11, characterized in that, The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest.

13. A treatment plan generation apparatus characterized by comprising: The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest.

14. A radiotherapy system, characterized by, The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material is determined according to the corresponding radiation absorption dose of each tissue material in the region of interest. The radiation absorption dose of each tissue material

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