Neutron irradiation positioning parameter determination method, electronic equipment and storage medium

Abstract

The invention relates to the technical field of parameter positioning, and particularly provides a neutron irradiation positioning parameter determination method, electronic equipment and a storage medium, and the method comprises the steps: determining an initial irradiation angle and an initial source skin distance based on the position relation between an organ tissue and a tumor target region in a CT image and the interference relation between a skin outer contour and a treatment head, and then a dose depth curve library is constructed based on reaction characteristics of neutrons and substances, the simulated dose of the target region is determined based on the CT image and the dose depth curve library, and optimal neutron irradiation positioning parameters are determined by comparing the simulated irradiation time at multiple angles with the ideal dose of the tumor target region. According to the method, the urgent requirements that the exposure dose endangering organs is reduced as much as possible and the exposure dose of tumor tissues is increased as much as possible are considered, the optimal irradiation positioning scheme is obtained through iterative calculation evaluation at different irradiation angles, and the time for making a neutron irradiation plan for the first time is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of parameter positioning, and specifically provides a method for determining neutron irradiation positioning parameters, an electronic device and a storage medium. Background Art

[0002] Neutron capture therapy is a better cancer treatment option than traditional radiation. For example, Boron Neutron Capture Therapy (BNCT) is an advanced radiotherapy method that uses high-energy particles produced by the reaction of boron-10 isotopes and neutrons to accurately kill tumor cells. The formulation of neutron treatment plans is a complex and delicate process. In the treatment planning system, physicists often plan the irradiation path and range of the neutron beam based on the location, size, shape of the tumor and the location of surrounding important organs. Since each patient's tumor condition and physical condition are different, the treatment plan needs to be personalized according to the patient's specific situation.

[0003] Neutron therapy is different from photon radiotherapy. Neutron therapy is generally fixed-beam therapy. Since the irradiation angle of the treatment head itself is limited, it requires high flexibility in patient positioning. In addition, the physical process of particle transport in neutron therapy is more complicated and the dose composition is more diverse than that of photoelectron radiotherapy, which makes the full-space dose calculation based on CT images very time-consuming. A calculation often takes several hours. Therefore, before dose calculation, it is necessary to reasonably plan the neutron irradiation path and give relatively reasonable incident angles and distances to avoid the uncertainty caused by manual settings as much as possible.

[0004] Traditional methods mainly rely on manual experience to set neutron irradiation positioning parameters (incident angle and source-skin distance), and mainly set the positioning parameters based on the relative position of the tumor and the organ at risk. However, due to the complex tissue structure of the patient, the elemental composition of each tissue, the complex biological effects of each tissue and the relative biological effects of each element are all different, and it is often difficult to obtain better positioning parameters through manual setting.

[0005] Therefore, it is necessary to propose a method for determining neutron irradiation positioning parameters that can overcome the lack of traditional manual experience. Summary of the invention

[0006] In order to overcome the above-mentioned defects, the method for determining neutron irradiation positioning parameters proposed in the present invention solves the technical problems of traditional reliance on manual experience for parameter setting and inability to achieve automatic parameter optimization.

[0007] In a first aspect, the present invention provides a method for determining neutron irradiation positioning parameters, the method comprising:

[0008] Step S1: determining the initial irradiation angle and the initial source-skin distance based on the positional relationship between the organ tissue and the tumor target area in the CT image and the interference relationship between the skin outer contour and the treatment head;

[0009] Step S2: determining an irradiation parameter set based on the initial irradiation angle, the initial source-skin distance and the interference relationship, wherein the irradiation parameter set includes a plurality of sets of one-to-one corresponding irradiation angles and source-skin distances;

[0010] Step S3: traverse all the irradiation angles in the irradiation parameter set, obtain the ideal dose of the tumor target area at each irradiation angle by executing the preset operation to form an ideal dose set of the tumor target area, and take the irradiation angle and source-skin distance corresponding to the maximum dose value in the ideal dose set of the tumor target area to determine as the final neutron irradiation positioning parameters;

[0011] The preset operation includes: selecting a set of one-to-one corresponding irradiation angles and source-skin distances from the irradiation parameter set as the current irradiation angle and the current source-skin distance, determining a simulated dose per unit time based on the CT image, the current source-skin distance and a pre-constructed library of dose depth curves for different tissues, determining the shortest simulated irradiation time based on the simulated dose per unit time and a preset prescription dose threshold, and calculating the ideal dose of the tumor target area at the current irradiation angle based on the shortest simulated irradiation time and the simulated dose per unit time.

[0012] In some embodiments, the step S1 of determining the initial irradiation angle and the initial source-skin distance based on the positional relationship between the organ tissue and the tumor target area in the CT image and the interference relationship between the skin outer contour and the treatment head includes:

[0013] Step 11: extracting the coordinates of the contour points of the tumor and each organ at risk on each CT layer of the CT image;

[0014] Step 12: determining the center of gravity of the tumor based on the coordinates of the contour points, and traversing all points of the skin outer contour on each layer of CT layer layer by layer based on the center of gravity of the tumor to determine the nearest incident point;

[0015] Step 13: determining an initial value of the irradiation angle based on the tumor center of gravity and the incident point, and calculating the distance from the beam port center to the skin based on the interference relationship between the skin outer contour and the treatment head and the safe distance between the treatment head and the patient, and recording it as the initial value of the source-skin distance;

[0016] Step 14: Determine an initial illumination angle and an initial source-skin distance based on the initial value of the illumination angle, the initial value of the source-skin distance, and the interference relationship.

[0017] Furthermore, in step 14, determining the initial illumination angle and the initial source-skin distance based on the initial value of the illumination angle, the initial value of the source-skin distance and the interference relationship includes:

[0018] Step a1: judging whether interference occurs when the irradiation angle is taken as the initial value based on the interference relationship between the skin outer contour and the treatment head, if yes, updating the irradiation angle according to the preset angle step and executing step a2, otherwise determining the initial irradiation angle and the initial source-skin distance according to the initial value of the irradiation angle and the initial value of the source-skin distance;

[0019] Step a2: determine whether the updated illumination angle interferes, if yes, execute step a3, otherwise determine the initial illumination angle and the initial source-skin distance according to the updated illumination angle and the initial value of the source-skin distance;

[0020] Step a3: determine whether the updated illumination angle reaches the limit, if yes, execute step a4, otherwise update the illumination angle according to the preset angle step and execute step a2;

[0021] Step a4: adjusting the illumination angle to the initial value of the illumination angle, and updating the source-skin distance according to a preset distance step length based on the initial value of the source-skin distance;

[0022] Step a5: judging whether interference occurs based on the updated source-skin distance, if yes, executing step a6, otherwise determining the initial illumination angle and the initial source-skin distance according to the initial value of the illumination angle and the updated source-skin distance;

[0023] Step a6: Determine whether the updated source-skin distance reaches the preset source-skin distance threshold. If yes, prompt positioning failure. Otherwise, update the source-skin distance according to the preset distance step and execute step a5.

[0024] In some embodiments, determining the irradiation parameter set based on the initial irradiation angle, the initial source-skin distance and the interference relationship in step S2 includes:

[0025] Step 21: using the initial irradiation angle as the current irradiation angle, and using the initial source-skin distance as the current source-skin distance;

[0026] Step 22: judging whether interference occurs at the current illumination angle based on the interference relationship, if interference occurs, executing step 23, otherwise executing step 25;

[0027] Step 23: Update the current source-skin distance based on the preset length increment, and determine whether interference occurs. If interference occurs, execute step 24; if no interference occurs, execute step 25;

[0028] Step 24: determine whether the updated source-skin distance reaches the source-skin distance threshold, if yes, the current irradiation angle and the current source-skin distance are not included in the irradiation parameter set, and execute step 25, otherwise continue to execute step 23;

[0029] Step 25: taking the current irradiation angle and the current source-skin distance as a set of parameters in one-to-one correspondence and counting them into the irradiation parameter set;

[0030] Step 26: Update the current illumination angle based on the preset angle increment, and return to step 22.

[0031] In some embodiments, the method further includes: constructing a library of dose depth curves for different tissues based on the reaction characteristics of neutrons and matter, wherein the library of dose depth curves for different tissues includes a U-segment hydrogen dose depth curve, a U-segment nitrogen dose depth curve, a U-segment gamma dose depth curve associated with the source-skin distance, and a U-segment boron dose depth curve associated with the source-skin distance and boron concentration, wherein U is a positive integer obtained by dividing according to the CT value.

[0032] In some embodiments, determining the simulated dose per unit time based on the CT image, the current source-skin distance and a pre-built library of different tissue dose depth curves in step S3 includes:

[0033] Based on the CT image, all pixels on the central axis of the neutron beam from the skin entrance point to the skin exit point at the current irradiation angle are counted to obtain the CT value, ROI attribute and different component equivalent factors corresponding to each pixel, wherein the different component equivalent factors include boron CBE, hydrogen RBE, nitrogen RBE and gamma RBE;

[0034] Based on the current source-skin distance, a U-segment hydrogen dose depth curve, a U-segment nitrogen dose depth curve, and a U-segment gamma dose depth curve corresponding to the current source-skin distance are extracted from a pre-built different tissue dose depth curve library, and a U-segment boron dose depth curve corresponding to the current source-skin distance and boron concentration is extracted;

[0035] Based on the CT value of each pixel and the extracted U-segment hydrogen dose depth curve, the U-segment nitrogen dose depth curve, the U-segment gamma dose depth curve, and the U-segment boron dose depth curve, the boron dose, hydrogen dose, nitrogen dose, and gamma dose of each pixel are counted;

[0036] The simulated dose per unit time is determined based on the ROI attribute of each pixel, the different component equivalent factors, and the corresponding boron dose, hydrogen dose, nitrogen dose, and gamma dose.

[0037] Further, the determining of the simulated dose per unit time based on the ROI attribute of each pixel, the equivalent factors of different components, and the corresponding boron dose, hydrogen dose, nitrogen dose, and gamma dose includes:

[0038] Counting the number of ROIs on the central axis of the neutron beam based on the ROI attribute of each pixel, wherein the ROI includes a ROI for characterizing an organ at risk and a ROI for characterizing a tumor target area;

[0039] The simulated dose per unit time of each ROI is calculated based on the different component equivalent factors and the boron dose, hydrogen dose, nitrogen dose and gamma dose.

[0040] In some embodiments, determining the shortest simulated irradiation time based on the simulated dose per unit time and a preset prescription dose threshold in step S3 includes:

[0041] Obtain the prescription dose threshold corresponding to each ROI;

[0042] A plurality of simulated irradiation times are calculated based on the prescription dose threshold of each ROI and the simulated dose within the unit time, and the minimum value is selected as the shortest simulated irradiation time.

[0043] In a second aspect, the present invention provides an electronic device comprising at least one processor and at least one memory, wherein the memory is suitable for storing multiple program codes, and the program codes are suitable for being loaded and run by the processor to execute the neutron irradiation positioning parameter determination method described in any one of the technical solutions of the above-mentioned neutron irradiation positioning parameter determination method.

[0044] In a third aspect, the present invention provides a computer-readable storage medium storing a plurality of program codes, wherein the program codes are suitable for being loaded and run by a processor to execute the neutron irradiation positioning parameter determination method described in any one of the technical solutions of the above-mentioned neutron irradiation positioning parameter determination method.

[0045] The above one or more technical solutions of the present invention have at least one or more of the following beneficial effects:

[0046] In the technical solution of the present invention, the initial irradiation angle and the initial source-skin distance are first automatically optimized based on the patient structure difference, anti-collision interference, and irradiation angle limitation, and then the irradiation parameter set is determined based on the initial irradiation angle, the initial source-skin distance, and the interference relationship, and all irradiation angles in the irradiation parameter set are traversed. The ideal dose of the tumor target area at each irradiation angle is obtained by performing a preset operation to form an ideal dose set of the tumor target area, and the irradiation angle and source-skin distance corresponding to the maximum dose value in the ideal dose set of the tumor target area are taken as the final neutron irradiation positioning parameters. The preset operation includes determining the simulated dose per unit time based on the CT image, the source-skin distance, and the pre-constructed different tissue dose depth curve library, determining the shortest simulated irradiation time based on the simulated dose per unit time and the preset prescription dose threshold, and calculating the ideal dose of the tumor target area at each irradiation angle based on the shortest simulated irradiation time and the simulated dose per unit time. The present invention comprehensively considers factors such as patient structure differences, anti-collision interference, and irradiation angle limitations, automatically and quickly iteratively optimizes the initial irradiation angle and source-skin distance that can be implemented for neutron therapy, establishes a dose-depth curve library based on the reaction characteristics of neutrons and matter, and constructs a personalized composite dose-depth curve model based on source-skin distance, boron concentration, and CT images. It simultaneously considers the urgent needs of reducing the irradiation dose to endangered organs as much as possible and increasing the irradiation dose to tumor tissue as much as possible, and obtains the optimal irradiation positioning plan through iterative calculation and evaluation at different irradiation angles, which can save the time for the first formulation of the neutron irradiation plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The disclosure of the present invention will become more easily understood with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In addition, similar numbers in the figures are used to represent similar components, among which:

[0048] Figure 1 is a schematic flow chart of main steps of a method for determining neutron irradiation positioning parameters according to an embodiment of the present invention;

[0049] Figure 2 It is a schematic flow chart of main implementation steps for determining an initial irradiation angle and an initial source-skin distance according to an embodiment of the present invention;

[0050] Figure 3 It is a schematic flow chart of main implementation steps of determining an irradiation parameter set according to an embodiment of the present invention;

[0051] Figure 4 It is a flowchart of the main implementation steps of obtaining an ideal dose of a tumor target area under an irradiation angle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] Some embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0053] In the description of the present invention, "module" and "processor" may include hardware, software or a combination of the two. A module may include hardware circuits, various suitable sensors, communication ports, and memories, and may also include software parts, such as program codes, or a combination of software and hardware. The processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor, or any other suitable processor. The processor has data and / or signal processing functions. The processor may be implemented in software, hardware, or a combination of the two. Non-temporary computer-readable storage media include any suitable medium that can store program codes, such as a magnetic disk, a hard disk, an optical disk, a flash memory, a read-only memory, a random access memory, and the like. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The term "at least one A or B" or "at least one of A and B" has a similar meaning to "A and / or B", and may include only A, only B, or A and B. The singular terms "one" and "the" may also include plural forms.

[0054] Here we first explain some terms involved in the present invention.

[0055] CT (Computed Tomography) is a medical imaging technology that uses precise X-ray beams and highly sensitive detectors to scan the human body layer by layer. The scanned data is processed by a computer to generate high-resolution images of the body's internal cross-section, coronal or sagittal planes. CT images reflect the degree of X-ray absorption by organs and tissues in different grayscales. They have high-density resolution and can clearly display soft tissue and bone structures. The CT value is an indicator of the density of a substance, and the CT values ​​of different tissues are different. The "layer" in CT refers to the ability of the CT data acquisition system to obtain images synchronously. Simply put, the "layer" is the number of images that can be obtained synchronously in a CT scan, reflecting the functional parameters of the CT scan.

[0056] Source Skin Distance (SSD): The distance from the center of the radiation source to the irradiation center of the skin.

[0057] CBE (Combined Biological Effectiveness): Combined biological effect.

[0058] RBE (Relative Biological Effectiveness): Relative biological effect.

[0059] ROI (region of interest): region of interest.

[0060] The current neutron therapy planning system software is mainly composed of functional modules such as data import, patient management, registration and fusion, contouring, plan formulation, evaluation and comparison, among which plan formulation is the core of the neutron therapy planning system software. Most of the time of radiation therapy physicists is spent in the plan formulation process. Based on the neutron therapy planning system software, the present invention designs an automatic optimization method for neutron therapy plan schemes in the plan formulation module, which realizes one-key automatic optimization generation of patient irradiation path and automatic optimization evaluation of irradiation time through source information, material information, location information, target area and endangered organ limit, etc., which can improve the efficiency of users in formulating neutron therapy plans and lower the threshold for users.

[0061] The method for determining neutron irradiation positioning parameters proposed by the present invention is an automatic optimization method for neutron irradiation positioning parameters, which overcomes the shortcomings of traditional manual experience, and can directly provide a better irradiation positioning scheme (irradiation angle and source-skin distance) based on the personalized differences of various parts of the patient, the collision interference between the patient and the treatment head, and the reaction characteristics of neutrons and materials, greatly saving the time for the first formulation of the neutron irradiation plan. The method for determining neutron irradiation positioning parameters provided by the present invention is applied to the neutron irradiation plan formulation stage, and specifically improves and innovates the neutron treatment plan formulation process based on the geometric characteristics, physical characteristics and tumor / organ limit index requirements of the neutron treatment model, considers the relative biological effects of different particles and the composite biological effects of different boron drugs, can calculate the influence of boron drug concentration changes on dose results, and can calculate the equivalent dose of each human tissue in the irradiation area with high fidelity; the optimal irradiation plan can be quickly given in the plan optimization algorithm, and the equivalent dose of other normal tissues can be reduced as much as possible under the premise of ensuring the target area dose requirements, and avoids the vital organs of the human body, thereby developing an efficient automatic optimization function of the neutron treatment plan.

[0062] See attached Figure 1 , Figure 1 FIG. 1 is a flow chart showing the main steps of a method for determining neutron irradiation positioning parameters according to an embodiment of the present invention. Figure 1 As shown, the method for determining neutron irradiation positioning parameters in the embodiment of the present invention mainly includes the following steps S1 to S3.

[0063] Step S1: determining the initial irradiation angle and the initial source-skin distance based on the positional relationship between the organ tissue and the tumor target area in the CT image and the interference relationship between the skin outer contour and the treatment head;

[0064] In this embodiment, the interference relationship between the outer contour of the skin and the treatment head can be specifically determined by an interference relationship judgment model. It should be understood that the interference relationship judgment model can judge whether the outer contour of the skin and the treatment head interfere with each other under the input parameters and output the judgment result. The interference relationship judgment model can be a model or module in the prior art that can realize anti-collision interference judgment.

[0065] Step S2: determining an irradiation parameter set based on the initial irradiation angle, the initial source-skin distance and the interference relationship, wherein the irradiation parameter set includes a plurality of sets of one-to-one corresponding irradiation angles and source-skin distances;

[0066] In this embodiment, based on the initial irradiation angle, multiple irradiation angles are continuously updated according to the preset angle increments, and each irradiation angle obtained needs to meet the condition that no interference occurs. Specifically, each time an irradiation angle is updated according to the preset angle increment, whether interference occurs to the irradiation angle is judged based on the interference relationship. When it is judged that interference occurs, the source-skin distance can be adjusted to make the irradiation angle meet the condition that no interference occurs, thereby obtaining an irradiation parameter set formed by all irradiation angles and source-skin distances that correspond to each other and meet the conditions.

[0067] Step S3: traverse all the irradiation angles in the irradiation parameter set, obtain the ideal dose of the tumor target area at each irradiation angle by executing the preset operation to form an ideal dose set of the tumor target area, and take the irradiation angle and source-skin distance corresponding to the maximum dose value in the ideal dose set of the tumor target area to determine as the final neutron irradiation positioning parameters;

[0068] In this embodiment, the preset operation includes: selecting a set of one-to-one corresponding irradiation angles and source-skin distances from the irradiation parameter set as the current irradiation angle and the current source-skin distance, determining the simulated dose per unit time based on the CT image, the current source-skin distance and a pre-constructed library of dose depth curves for different tissues, determining the shortest simulated irradiation time based on the simulated dose per unit time and a preset prescription dose threshold, and calculating the ideal dose of the tumor target area at the current irradiation angle based on the shortest simulated irradiation time and the simulated dose per unit time.

[0069] In an embodiment of the present application, the method further includes: constructing a different tissue dose depth curve library based on the neutron-matter reaction characteristics, wherein the different tissue dose depth curve library includes a U-segment hydrogen dose depth curve associated with the source-skin distance (e.g., recorded as Sh), a U-segment nitrogen dose depth curve (e.g., recorded as Sn), a U-segment gamma dose depth curve (e.g., recorded as Sr), and a U-segment boron dose depth curve associated with the source-skin distance and the boron concentration (e.g., recorded as Sb), wherein U is a positive integer obtained by dividing according to the CT value. For example, U can be set to a positive integer in the range of 1 to 100.

[0070] Based on the above step S1, Figure 2 FIG. 1 is a flow chart of a specific implementation method of determining an initial irradiation angle and an initial source-skin distance provided in an embodiment of the present application. Figure 2 The steps shown mainly include the following steps 11 to 14.

[0071] Step 11: extracting the coordinates of the contour points of the tumor and each organ at risk on each CT layer of the CT image;

[0072] Step 12: determining the center of gravity of the tumor based on the coordinates of the contour points, and traversing all points of the skin outer contour on each layer of CT layer layer by layer based on the center of gravity of the tumor to determine the nearest incident point;

[0073] Step 13: determining an initial value of the irradiation angle based on the tumor center of gravity and the incident point, and calculating the distance from the beam port center to the skin based on the interference relationship between the skin outer contour and the treatment head and the safe distance between the treatment head and the patient, and recording it as the initial value of the source-skin distance;

[0074] In this embodiment, the safety distance between the treatment head and the patient can be customized according to actual needs, for example, the safety distance can be set to 5 cm.

[0075] Step 14: Determine an initial illumination angle and an initial source-skin distance based on the initial value of the illumination angle, the initial value of the source-skin distance, and the interference relationship.

[0076] In a specific implementation manner, the above step 14 may specifically include the following steps a1 to a6:

[0077] Step a1: judging whether interference occurs when the irradiation angle is taken as the initial value based on the interference relationship between the skin outer contour and the treatment head, if yes, updating the irradiation angle according to the preset angle step and executing step a2, otherwise determining the initial irradiation angle and the initial source-skin distance according to the initial value of the irradiation angle and the initial value of the source-skin distance;

[0078] Exemplarily, the preset angle step may be set to 1 degree.

[0079] Step a2: determine whether the updated illumination angle interferes, if yes, execute step a3, otherwise determine the initial illumination angle and the initial source-skin distance according to the updated illumination angle and the initial value of the source-skin distance;

[0080] Step a3: determine whether the updated illumination angle reaches the limit, if yes, execute step a4, otherwise update the illumination angle according to the preset angle step and execute step a2;

[0081] In this embodiment, whether the limit is reached can be determined by determining whether the cumulative updated angle step reaches 360 degrees.

[0082] Step a4: adjusting the illumination angle to the initial value of the illumination angle, and updating the source-skin distance according to a preset distance step length based on the initial value of the source-skin distance;

[0083] Exemplarily, the preset distance step may be set to 1 cm.

[0084] Step a5: judging whether interference occurs based on the updated source-skin distance, if yes, executing step a6, otherwise determining the initial illumination angle and the initial source-skin distance according to the initial value of the illumination angle and the updated source-skin distance;

[0085] Step a6: Determine whether the updated source-skin distance reaches the preset source-skin distance threshold. If yes, prompt positioning failure. Otherwise, update the source-skin distance according to the preset distance step and execute step a5.

[0086] Exemplarily, the preset source-skin distance threshold may be 20 cm.

[0087] Based on the above step S2, Figure 3 FIG. 1 is a flow chart of a specific implementation method of determining an irradiation parameter set provided in an embodiment of the present application. Figure 3 The steps shown mainly include the following steps 21 to 23.

[0088] Step 21: using the initial irradiation angle as the current irradiation angle, and using the initial source-skin distance as the current source-skin distance;

[0089] Step 22: judging whether interference occurs at the current illumination angle based on the interference relationship, if interference occurs, executing step 23, otherwise executing step 25;

[0090] Step 23: Update the current source-skin distance based on the preset length increment, and determine whether interference occurs. If interference occurs, execute step 24; if no interference occurs, execute step 25;

[0091] Step 24: determine whether the updated source-skin distance reaches the source-skin distance threshold, if yes, the current irradiation angle and the current source-skin distance are not included in the irradiation parameter set, and execute step 26, otherwise continue to execute step 23;

[0092] Step 25: taking the current irradiation angle and the current source-skin distance as a set of parameters in one-to-one correspondence and counting them into the irradiation parameter set;

[0093] Step 26: Update the current illumination angle based on the preset angle increment, and determine whether the illumination angle has reached the limit. If yes, end the process; otherwise, return to step 22.

[0094] In this embodiment, the preset angle increment may specifically include a yaw angle of ±X degrees, a roll angle of ±Y degrees, and a pitch angle of ±Z degrees, wherein the values ​​of X, Y, and Z may be customized, and the number of illumination angles in the illumination parameter set finally obtained is related to the preset angle increment. For example, 1≤X≤45, 1≤Y≤10, 1≤Z≤10, and the corresponding number of illumination angles in the illumination parameter set that can be obtained is G, and 1≤G≤40131. Among them, the maximum value of G is determined according to (2*X+1)*(2*Y+1)*(2*Z+1), that is, the maximum value of G in this embodiment = (2*45+1)*(2*10+1)*(2*10+1)=91*21*21=40131.

[0095] It can be understood that determining whether the illumination angle has reached the limit in step 26 can specifically be determining whether an angle update within a range of 360 degrees is completed based on a preset angle increment.

[0096] Based on the above step S3, Figure 4 The figure shows a specific implementation process of the preset operation provided in an embodiment of the present application, which specifically includes the following steps 31 to 36. The preset operation specifically includes the following steps: Figure 4 Steps 31 to 34 shown in the figure, wherein the specific implementation of determining the shortest simulated irradiation time based on the simulated dose within the unit time and the preset prescription dose threshold in the preset operation is as follows Figure 4 Step 35 is shown.

[0097] Step 31: Based on the CT image, all pixels on the central axis of the neutron beam from the skin entrance point to the skin exit point at the current irradiation angle are counted to obtain the CT value, ROI attribute and different component equivalent factors corresponding to each pixel, wherein the different component equivalent factors include boron CBE, hydrogen RBE, nitrogen RBE and gamma RBE;

[0098] It is understandable that each pixel has a unique ROI attribute. For example, the ROI attribute may be used to characterize that the location of the pixel is an organ at risk region, or to characterize that the location of the pixel is a tumor target region.

[0099] Exemplarily, the boron CBE can be recorded as Bj(CBE), the hydrogen RBE can be recorded as Hj(RBE), the nitrogen RBE can be recorded as Nj(RBE), and the gamma RBE can be recorded as Rj(RBE), where j represents the jth pixel, 1≤j≤P, where P represents the number of pixels on the central axis of the neutron beam from the skin incident point to the skin exit point.

[0100] Step 32: extracting a U-segment hydrogen dose depth curve, a U-segment nitrogen dose depth curve, and a U-segment gamma dose depth curve corresponding to the current source-skin distance from a pre-built different tissue dose depth curve library based on the current source-skin distance, and extracting a U-segment boron dose depth curve corresponding to the current source-skin distance and boron concentration;

[0101] Step 33: Based on the CT value of each pixel and the extracted U-segment hydrogen dose depth curve, the U-segment nitrogen dose depth curve, the U-segment gamma dose depth curve, and the U-segment boron dose depth curve, the boron dose, hydrogen dose, nitrogen dose, and gamma dose of each pixel are counted;

[0102] Exemplarily, the statistical boron dose, hydrogen dose, nitrogen dose and gamma dose of each pixel can be recorded as B(j), H(j), N(j) and R(j), respectively, where j represents the jth pixel.

[0103] Step 34: Determine the simulated dose of the ROI per unit time based on the ROI attributes of each pixel, the different component equivalent factors, and the corresponding boron dose, hydrogen dose, nitrogen dose, and gamma dose.

[0104] In this embodiment, the step 34 may specifically include the following steps b1 and b2:

[0105] Step b1: counting the number of ROIs on the central axis of the neutron beam based on the ROI attribute of each pixel, wherein the ROI includes a ROI for characterizing an organ at risk and a ROI for characterizing a tumor target area;

[0106] In this embodiment, the number of ROIs refers to the number of specific endangered organs and target areas. All pixels on a line from the skin incident point to the exit point on the central axis of the neutron beam, each pixel belongs to a certain organ, but multiple pixels may belong to the same organ, that is, one pixel corresponds to one organ, but one organ generally corresponds to multiple pixels. For example, the number of pixels on the central axis of the neutron beam is 3n, n≥1, where the ROI attribute of n pixels indicates that the pixel corresponds to the endangered organ brain, where the ROI attribute of n pixels indicates that the pixel corresponds to the endangered organ eye, where the ROI attribute of n pixels indicates that the pixel corresponds to the tumor target area, then the number of ROIs on the central axis of the neutron beam obtained by statistics is 3.

[0107] Step b2: Calculate the simulated dose per unit time for each ROI based on the equivalent factors of the different components and the boron dose, hydrogen dose, nitrogen dose and gamma dose.

[0108] Specifically, in this embodiment, the equivalent factors of different components are Bj(CBE), Hj(RBE), Nj(RBE) and Rj(RBE), and the boron dose, hydrogen dose, nitrogen dose and gamma dose are B(j), H(j), N(j) and R(j), respectively. The simulated dose value of each pixel can be calculated according to Bj(CBE)*B(j)+Hj(RBE)*H(j)+Nj(RBE)*N(j)+Rj(RBE)*R(j). It can be understood that each ROI is composed of multiple pixels, and then the simulated dose of each ROI per unit time can be obtained based on the simulated dose value of each pixel.

[0109] In this embodiment, the simulated dose of the ROI calculated for the target area per unit time is the minimum simulated dose of the target area ROI, and the simulated dose of the ROI calculated for the organ at risk per unit time is the maximum simulated dose of the organ at risk ROI.

[0110] Step 35: Obtain the prescription dose threshold corresponding to each ROI, calculate multiple simulated irradiation times based on the prescription dose threshold of each ROI and the simulated dose of the ROI per unit time, and select the minimum value as the shortest simulated irradiation time.

[0111] Exemplarily, the prescription dose threshold of each ROI is Vi, then 1≤i≤M, where i represents the i-th ROI, and M is the total number of ROIs on the central axis of the neutron beam counted in the above step b1.

[0112] In this embodiment, the ratio of the prescription dose threshold of each ROI to the simulated dose per unit time is calculated, and the minimum value of the ratio is taken as the shortest simulated irradiation time.

[0113] Step 36: Calculate the ideal dose of the tumor target area at the current irradiation angle based on the shortest simulated irradiation time and the simulated dose of the target area per unit time.

[0114] In this embodiment, the ROI is a specific organ at risk or target area. Therefore, based on the simulated dose of the ROI per unit time, the simulated dose of the target area per unit time can be obtained, and then the ideal dose of the tumor target area under the current irradiation angle can be obtained by multiplying the shortest simulated irradiation time with the simulated dose of the target area per unit time.

[0115] This application comprehensively considers factors such as patient structure differences, anti-collision interference, and irradiation angle limitations to automatically and quickly iterate and optimize the initial irradiation angle and source-skin distance that can be implemented for neutron therapy. Then, a personalized composite dose depth curve model is constructed based on the depth dose curve library, ROI structure, and equivalent factors to obtain the doses of each component that vary with pixels, namely B(j), H(j), N(j), and R(j). At the same time, the urgent needs of reducing the irradiation dose to endangered organs as much as possible and increasing the irradiation dose to tumor tissue as much as possible are considered. The optimal irradiation positioning plan is obtained through iterative calculation and evaluation at different irradiation angles, which saves the time for the first formulation of the neutron irradiation plan.

[0116] It should be pointed out that although the various steps in the above embodiments are described in a specific order, those skilled in the art can understand that in order to achieve the effects of the present invention, different steps do not have to be performed in such an order. They can be performed simultaneously (in parallel) or in other orders. These changes are within the scope of protection of the present invention.

[0117] It is understood by those skilled in the art that the present invention implements all or part of the processes in the method of the above embodiment, and can also be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable storage medium may include: any entity or device, medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory, random access memory, electric carrier signal, telecommunication signal and software distribution medium, etc. that can carry the computer program code.

[0118] Furthermore, the present invention also provides an electronic device. In an electronic device embodiment according to the present invention, the electronic device includes at least one processor and at least one memory, the memory can be configured to store a program for executing the neutron irradiation positioning parameter determination method of the above method embodiment, and the processor can be configured to execute the program in the storage device, which includes but is not limited to the program for executing the neutron irradiation positioning parameter determination method of the above method embodiment. For ease of explanation, only the parts related to the embodiment of the present invention are shown. For specific technical details not disclosed, please refer to the method part of the embodiment of the present invention.

[0119] In the embodiment of the present application, the electronic device may be a control device device formed by various devices. In some possible implementations, the electronic device may include multiple memories and multiple processors. The program for executing the neutron irradiation positioning parameter determination method of the above method embodiment may be divided into multiple subprograms, and each subprogram may be loaded and run by a processor to execute different steps of the neutron irradiation positioning parameter determination method of the above method embodiment. Specifically, each subprogram may be stored in different memories, and each processor may be configured to execute programs in one or more memories to jointly implement the neutron irradiation positioning parameter determination method of the above method embodiment, that is, each processor executes different steps of the neutron irradiation positioning parameter determination method of the above method embodiment, to jointly implement the neutron irradiation positioning parameter determination method of the above method embodiment.

[0120] The above-mentioned multiple processors may be processors deployed on the same device. For example, the above-mentioned electronic device may be a high-performance device composed of multiple processors, and the above-mentioned multiple processors may be processors configured on the high-performance device. In addition, the above-mentioned multiple processors may also be processors deployed on different devices. For example, the above-mentioned electronic device may be a server cluster, and the above-mentioned multiple processors may be processors on different servers in the server cluster.

[0121] Furthermore, the present invention also provides a computer-readable storage medium. In a computer-readable storage medium embodiment according to the present invention, the computer-readable storage medium can be configured to store a program for executing the neutron irradiation positioning parameter determination method of the above method embodiment, and the program can be loaded and run by the processor to implement the above neutron irradiation positioning parameter determination method. For ease of explanation, only the parts related to the embodiment of the present invention are shown. For specific technical details not disclosed, please refer to the method part of the embodiment of the present invention. The computer-readable storage medium can be a storage device formed by various electronic devices. Optionally, the computer-readable storage medium in the embodiment of the present invention is a non-temporary computer-readable storage medium.

[0122] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for determining neutron irradiation positioning parameters, characterized in that: The method comprises: Step S1: determining the initial irradiation angle and the initial source-skin distance based on the positional relationship between the organ tissue and the tumor target area in the CT image and the interference relationship between the skin outer contour and the treatment head; Step S2: determining an irradiation parameter set based on the initial irradiation angle, the initial source-skin distance and the interference relationship, wherein the irradiation parameter set includes a plurality of sets of one-to-one corresponding irradiation angles and source-skin distances; Step S3: traverse all the irradiation angles in the irradiation parameter set, obtain the ideal dose of the tumor target area at each irradiation angle by executing the preset operation to form an ideal dose set of the tumor target area, and take the irradiation angle and source-skin distance corresponding to the maximum dose value in the ideal dose set of the tumor target area to determine as the final neutron irradiation positioning parameters; The preset operation includes: selecting a set of one-to-one corresponding irradiation angles and source-skin distances from the irradiation parameter set as the current irradiation angle and the current source-skin distance, determining a simulated dose per unit time based on the CT image, the current source-skin distance and a pre-constructed library of dose depth curves for different tissues, determining the shortest simulated irradiation time based on the simulated dose per unit time and a preset prescription dose threshold, and calculating the ideal dose of the tumor target area at the current irradiation angle based on the shortest simulated irradiation time and the simulated dose per unit time.

2. The method according to claim 1, characterized in that In step S1, determining the initial irradiation angle and the initial source-skin distance based on the positional relationship between the organ tissue and the tumor target area in the CT image and the interference relationship between the skin outer contour and the treatment head includes: Step 11: extracting the coordinates of the contour points of the tumor and each organ at risk on each CT layer of the CT image; Step 12: determining the tumor center of gravity based on the coordinates of the contour points, and traversing all points of the skin outer contour on each layer of CT layer layer by layer based on the tumor center of gravity to determine the nearest incident point; Step 13: determining an initial value of the irradiation angle based on the tumor center of gravity and the incident point, and calculating the distance from the beam port center to the skin based on the interference relationship between the skin outer contour and the treatment head and the safe distance between the treatment head and the patient, and recording it as the initial value of the source-skin distance; Step 14: Determine an initial illumination angle and an initial source-skin distance based on the initial value of the illumination angle, the initial value of the source-skin distance, and the interference relationship.

3. The method according to claim 2, characterized in that Determining the initial irradiation angle and the initial source-skin distance based on the initial value of the irradiation angle, the initial value of the source-skin distance and the interference relationship in step 14 includes: Step a1: judging whether interference occurs when the irradiation angle is taken as the initial value based on the interference relationship between the skin outer contour and the treatment head, if yes, updating the irradiation angle according to the preset angle step and executing step a2, otherwise determining the initial irradiation angle and the initial source-skin distance according to the initial value of the irradiation angle and the initial value of the source-skin distance; Step a2: determine whether the updated illumination angle interferes, if yes, execute step a3, otherwise determine the initial illumination angle and the initial source-skin distance according to the updated illumination angle and the initial value of the source-skin distance; Step a3: determine whether the updated illumination angle reaches the limit, if yes, execute step a4, otherwise update the illumination angle according to the preset angle step and execute step a2; Step a4: adjusting the illumination angle to the initial value of the illumination angle, and updating the source-skin distance according to a preset distance step length based on the initial value of the source-skin distance; Step a5: judging whether interference occurs based on the updated source-skin distance, if yes, executing step a6, otherwise determining the initial illumination angle and the initial source-skin distance according to the initial value of the illumination angle and the updated source-skin distance; Step a6: Determine whether the updated source-skin distance reaches the preset source-skin distance threshold. If yes, prompt positioning failure. Otherwise, update the source-skin distance according to the preset distance step and execute step a5.

4. The method according to claim 1, characterized in that: Determining the irradiation parameter set based on the initial irradiation angle, the initial source-skin distance and the interference relationship in step S2 includes: Step 21: using the initial irradiation angle as the current irradiation angle, and using the initial source-skin distance as the current source-skin distance; Step 22: judging whether interference occurs at the current illumination angle based on the interference relationship, if interference occurs, executing step 23, otherwise executing step 25; Step 23: Update the current source-skin distance based on the preset length increment, and determine whether interference occurs. If interference occurs, execute step 24; if no interference occurs, execute step 25; Step 24: determine whether the updated source-skin distance reaches the source-skin distance threshold, if yes, the current irradiation angle and the current source-skin distance are not included in the irradiation parameter set, and execute step 25, otherwise continue to execute step 23; Step 25: taking the current irradiation angle and the current source-skin distance as a set of parameters in one-to-one correspondence and counting them into the irradiation parameter set; Step 26: Update the current illumination angle based on the preset angle increment, and return to step 22.

5. The method according to claim 1, characterized in that The method also includes: constructing a different tissue dose depth curve library based on the neutron-matter reaction characteristics, wherein the different tissue dose depth curve library includes a U-segment hydrogen dose depth curve, a U-segment nitrogen dose depth curve, a U-segment gamma dose depth curve associated with the source-skin distance, and a U-segment boron dose depth curve associated with the source-skin distance and boron concentration, wherein U is a positive integer obtained by dividing according to the CT value.

6. The method according to claim 5, characterized in that Determining the simulated dose per unit time based on the CT image, the current source-skin distance and the pre-built different tissue dose depth curve library in step S3 includes: Based on the CT image, all pixels on the central axis of the neutron beam from the skin entrance point to the skin exit point at the current irradiation angle are counted to obtain the CT value, ROI attribute and different component equivalent factors corresponding to each pixel, wherein the different component equivalent factors include boron CBE, hydrogen RBE, nitrogen RBE and gamma RBE; Based on the current source-skin distance, a U-segment hydrogen dose depth curve, a U-segment nitrogen dose depth curve, and a U-segment gamma dose depth curve corresponding to the current source-skin distance are extracted from a pre-built different tissue dose depth curve library, and a U-segment boron dose depth curve corresponding to the current source-skin distance and boron concentration is extracted; Based on the CT value of each pixel and the extracted U-segment hydrogen dose depth curve, the U-segment nitrogen dose depth curve, the U-segment gamma dose depth curve, and the U-segment boron dose depth curve, the boron dose, hydrogen dose, nitrogen dose, and gamma dose of each pixel are counted; The simulated dose per unit time is determined based on the ROI attribute of each pixel, the different component equivalent factors, and the corresponding boron dose, hydrogen dose, nitrogen dose, and gamma dose.

7. The method according to claim 6, characterized in that The determining of the simulated dose per unit time based on the ROI attribute of each pixel, the equivalent factors of different components and the corresponding boron dose, hydrogen dose, nitrogen dose and gamma dose includes: Counting the number of ROIs on the central axis of the neutron beam based on the ROI attribute of each pixel, wherein the ROI includes a ROI for characterizing an organ at risk and a ROI for characterizing a tumor target area; The simulated dose per unit time of each ROI is calculated based on the different component equivalent factors and the boron dose, hydrogen dose, nitrogen dose and gamma dose.

8. The method according to claim 1, characterized in that: Determining the shortest simulated irradiation time based on the simulated dose within the unit time and the preset prescription dose threshold in step S3 includes: Obtain the prescription dose threshold corresponding to each ROI; A plurality of simulated irradiation times are calculated based on the prescription dose threshold of each ROI and the simulated dose within the unit time, and the minimum value is selected as the shortest simulated irradiation time.

9. An electronic device comprising at least one processor and at least one memory, wherein the memory is suitable for storing a plurality of program codes, wherein: The program code is suitable for being loaded and run by the processor to execute the method for determining neutron irradiation positioning parameters according to any one of claims 1 to 8.

10. A computer-readable storage medium storing a plurality of program codes, characterized in that: The program code is suitable for being loaded and run by a processor to execute the method for determining neutron irradiation positioning parameters according to any one of claims 1 to 8.

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