Flattening device of tumor radiotherapy apparatus and design method thereof

Abstract

The invention discloses a method for designing a flattening device of a tumor radiotherapy apparatus. The method comprises the following steps: obtaining an initial contour size and an initial contour curve of the flattening device according to theoretical calculation; dose simulation analysis is carried out based on the initial contour curve of the flattening device, and a contour curve segment influencing dose distribution in the initial contour curve of the flattening device is intercepted; reading a profile curve segment, sampling from continuous data, and drawing an XY coordinate graph of an initial discrete point; preparing a flattening device based on the initial profile curve, carrying out an actual dose distribution test on the flattening device to obtain an actual dose distribution diagram of the flattening device, reading a dose distribution position Xi which does not meet the flattening requirement from the actual dose distribution diagram of the flattening device, and analyzing and calculating the height Yi of the flattening device when the dose distribution position Xi meets the flattening requirement. Discrete point modification coordinates (Xi, Yi) are obtained; and correspondingly marking the modified coordinates (Xi, Yi) of the discrete points in the XY coordinate graph, and performing curve fitting on initial discrete point data in the XY coordinate graph.

Description

Technical Field

[0001] The present invention relates to the technical field of radiotherapy equipment, and in particular to a uniformizer of a tumor radiotherapy apparatus and a design method thereof. Background Art

[0002] Conventional medical linear accelerator smoothing device design involves preliminary theoretical calculations to determine the smoothing device's external dimensions. This is then simulated in a Monte Carlo dose analysis program. The analysis results are compared with the beam dose smoothing requirements specified in the standard. If these requirements are not met, the smoothing device dimensions are adjusted and the simulation is repeated until the results meet these requirements. During the design simulation process, the smoothing device height must be repeatedly corrected. To achieve higher calculation accuracy and minimize the impact of simulation errors, the program's computational workload increases. When multiple corrections are required, the entire simulation analysis process is time-consuming and inefficient. Furthermore, while the simulation analysis is based on theoretical foundations, subtle variations in manufacturing material composition, uniformity, and smoothing device installation can cause the simulation results to not fully match the measured results, necessitating multiple corrections to the smoothing device. This repeated iteration of simulation, machining, resimulation, and remachining is both costly and time-consuming.

[0003] In addition, conventional homogenizers are mostly made of a single high atomic number material. The beam attenuates greatly when passing through the homogenizer, and the radiation dose utilization rate is relatively low.

[0004] In view of this, the present invention patent is proposed. Summary of the Invention

[0005] To address the above technical issues, the present invention provides a uniformizer for a tumor radiotherapy device and a design method thereof. By employing a precise contour correction method, the uniformizer is conveniently, quickly, and accurately designed, reducing the time and cost associated with multiple iterations of uniformizer structural dimensions. Specifically, the following technical solutions are employed:

[0006] A method for designing a uniformizer for a tumor radiotherapy device, comprising:

[0007] The initial contour size and initial contour curve of the leveler are obtained according to theoretical calculations;

[0008] Perform dose simulation analysis based on the initial contour curve of the uniformizer, and intercept the contour curve segment that affects the dose distribution in the initial contour curve of the uniformizer;

[0009] Read the contour curve segment, sample from the continuous data, and draw the XY coordinate graph of the initial discrete points, where X represents the radial size of the leveler and Y represents the height of the leveler;

[0010] A uniformizer is prepared based on the initial profile curve, and an actual dose distribution test of the uniformizer is performed to obtain an actual dose distribution map of the uniformizer. The dose distribution position X that does not meet the uniformity requirement is read from the actual dose distribution map of the uniformizer. i , by analyzing and calculating the dose distribution position X i Leveler height Y when leveling requirements are met i , get the modified coordinates of discrete points (X i , Y i );

[0011] Modify the coordinates (X i , Y i ) are marked in the XY coordinate graph, and curve fitting is performed on the initial discrete point data in the XY coordinate graph to generate a high-order polynomial equation for the contour curve of the smoother.

[0012] As an optional embodiment of the present invention, in a method for designing a uniformizer for a tumor radiotherapy apparatus according to the present invention, obtaining the initial contour size and initial contour curve of the uniformizer according to theoretical calculation includes:

[0013] The radiation source S passes through the homogenizer to obtain a uniformly distributed radiation beam;

[0014] The dose at a radius R from the beam center is: Where α is the attenuation coefficient, T represents the height of the flattener, h is the vertical distance between the radiation source S and the flattener, H is the vertical distance between the radiation source S and the water phantom, D(R) is the dose distribution after flattening, and Do is the dose distribution in the field without the flattener.

[0015] At a radius R from the beam center max When the uniformity requirement is met, D(R)=const, 0≤R≤R max , where const is a constant, then

[0016] From this we get T(r) is the height of the leveler at a radius of r from the center axis of the leveler;

[0017] The height of the leveler within the radius range of -r to r from the center axis of the leveler is calculated and connected into a line to obtain the initial contour curve of the leveler.

[0018] As an optional embodiment of the present invention, in a method for designing a uniformizer for a tumor radiotherapy apparatus according to the present invention, performing a dose simulation analysis based on an initial contour curve of the uniformizer and extracting a contour curve segment that affects the dose distribution from the initial contour curve of the uniformizer includes:

[0019] Based on the initial contour curve of the homogenizer, Monte Carlo simulation analysis was used to simulate the dose distribution of particles passing through the homogenizer in the medical accelerator treatment head, and a simulated dose distribution map was obtained;

[0020] By analyzing the flatness and symmetry of the simulated dose distribution map, the areas in the simulated dose distribution map that do not meet the requirements are determined;

[0021] The initial contour curve of the uniformizer corresponding to the area that does not meet the requirements in the simulated dose distribution diagram is intercepted, which is the contour curve segment that affects the dose distribution.

[0022] As an optional embodiment of the present invention, in a method for designing a uniformizer for a tumor radiotherapy device of the present invention, the reading of the contour curve segments, sampling from continuous data, and drawing an XY coordinate graph of the initial discrete points, where X represents the radial dimension of the uniformizer and Y represents the height of the uniformizer, includes:

[0023] Read the contour curve segment, use the uniform sampling method to read the initial discrete points with equal radial spacing from the continuous data, and draw the XY coordinate graph of the initial discrete points;

[0024] Alternatively, the contour curve segment is read, and a partition sampling method is used, whereby the number of initial discrete points selected for the key focus area is greater than the number of initial discrete points affecting the non-key focus area.

[0025] As an optional embodiment of the present invention, in a method for designing a uniformizer for a tumor radiotherapy apparatus of the present invention, the coordinates of the discrete points are modified (X i , Y i ) are marked in the XY coordinate graph, and curve fitting is performed on the initial discrete point data in the XY coordinate graph to generate the high-order polynomial equation of the flattener profile curve, including:

[0026] Modify the coordinates (X i , Y i ) is marked in the XY coordinate graph, and the least squares method is used to perform curve fitting on the initial discrete point data in the XY coordinate graph to generate a high-order polynomial equation Y=AX for the contour curve of the equalizer. 6 +BX 5 +CX 4 +DX 3 +EX 2 +FX+G;

[0027] The high-order polynomial equation Y=AX 6 +BX 5 +CX 4 +DX 3 +EX 2 +FX+G is imported into the drawing software to generate the contour curve of the leveler and draw the three-dimensional model of the leveler.

[0028] The present invention also provides a homogenizer structure manufactured using the homogenizer design method for tumor radiotherapy equipment, comprising:

[0029] The base is made of high atomic number metal material, and the overall outline is cone-shaped;

[0030] The surface layer is made of a metal material with a low atomic number. The surface layer is covered on the base and is combined with the base to form a cone shape.

[0031] As an optional embodiment of the present invention, in a leveler structure of the present invention, the substrate is made of high atomic number metal lead, and the surface layer is made of low atomic number metal material copper.

[0032] As an optional embodiment of the present invention, in a leveler structure of the present invention, the substrate is made of tungsten, a metal with a high atomic number, and the surface layer is made of aluminum, a metal with a low atomic number.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a method for designing a uniformizer for a tumor radiotherapy device. This method combines theoretical analysis and calculation with actual dose distribution measurements. Using an XY coordinate diagram of discrete points, the uniformizer's radial dimensions are mapped to its height. The more precisely the discrete points are collected within a set range, the more accurate the uniformizer height design. A single correction can achieve satisfactory results. Compared to traditional methods, this method eliminates the need for multiple corrections and simulations, saving significant simulation time. Furthermore, due to discrepancies between the actual object and the simulation analysis, multiple simulations require multiple physical object processing. This method can significantly reduce processing costs and time.

[0035] Therefore, the method for designing a uniformizer for a tumor radiotherapy device of the present invention requires fewer repeated corrections, takes less time for simulation analysis, does not require multiple iterative processing, has a high correction success rate, and saves a lot of time and cost.

[0036] The equalizer structure of the present invention is composed of two or more parts. The base is made of conical high atomic number metal material to equalize the higher dose area near the central axis of the radiation field. The surface is made of low atomic number metal material, and the passing rays are less attenuated, which is beneficial to the utilization rate of the radiation dose. At the same time, the surface is relatively easy to process, which is more convenient when modifying the equalizer structure.

[0037] Therefore, the uniformizer structure of the present invention adopts a combined structure to obtain a more excellent dose distribution, which not only ensures that the dose distribution flatness near the center of the field meets the requirements, but also can more fully utilize the radiation dose, reduce the accelerator operating power, and increase the accelerator service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A flow chart of a method for designing a uniformizer for a tumor radiotherapy device according to an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of an experimental model structure for obtaining the initial contour size and initial contour curve of a uniformizer according to theoretical calculations in a method for designing a uniformizer for a tumor radiotherapy apparatus according to an embodiment of the present invention;

[0040] Figure 3 An example of a dose distribution diagram in a method for designing a uniformizer for a tumor radiotherapy device according to an embodiment of the present invention;

[0041] Figure 4 In a method for designing a uniformizer for a tumor radiotherapy apparatus according to an embodiment of the present invention, the coordinates (X i , Y i ) corresponds to a diagram marked in the XY coordinate graph, which is a schematic diagram of curve fitting for the initial discrete point data in the XY coordinate graph;

[0042] Figure 5 A schematic structural diagram of a homogenizer structure of a tumor radiotherapy apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0044] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0045] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein may be combined with each other.

[0046] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0047] In the description of the present invention, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art. Such terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0048] See also Figure 1 As shown, a method for designing a uniformizer for a tumor radiotherapy device according to this embodiment includes:

[0049] The initial contour size and initial contour curve of the leveler are obtained according to theoretical calculations;

[0050] Perform dose simulation analysis based on the initial contour curve of the uniformizer, and intercept the contour curve segment that affects the dose distribution in the initial contour curve of the uniformizer;

[0051] Read the contour curve segment, sample from the continuous data, and draw the XY coordinate graph of the initial discrete points, where X represents the radial size of the leveler and Y represents the height of the leveler;

[0052] Based on the initial contour curve, a uniformizer is prepared, and an actual dose distribution experiment of the uniformizer is performed to obtain an actual dose distribution map of the uniformizer. The dose distribution position X that does not meet the uniformity requirement is read from the actual dose distribution map of the uniformizer. i , by analyzing and calculating the dose distribution position X i Leveler height Y when leveling requirements are met i , get the modified coordinates of discrete points (X i , Y i );

[0053] Modify the coordinates (X i , Y i ) are marked in the XY coordinate graph, and curve fitting is performed on the initial discrete point data in the XY coordinate graph to generate a high-order polynomial equation for the contour curve of the smoother.

[0054] This embodiment of a method for designing a uniformizer for a tumor radiotherapy device combines theoretical analysis and calculations with actual dose distribution measurements. Using an XY coordinate plot of discrete points, the uniformizer's radial dimensions are mapped to its height. The more precisely the discrete points are collected within a set range, the more accurate the uniformizer height design. A single correction can achieve satisfactory results. Compared to traditional methods, this method eliminates the need for multiple corrections and simulations, saving significant simulation time. Furthermore, due to discrepancies between the actual device and the simulation analysis, multiple simulations require multiple physical processing steps. This method for designing a uniformizer for a tumor radiotherapy device significantly reduces processing costs and time.

[0055] In summary, the method for designing a uniformizer for a tumor radiotherapy device in this embodiment requires fewer repeated corrections, takes less time for simulation analysis, does not require multiple iterative processing, has a high correction success rate, and saves a lot of time and cost.

[0056] In this embodiment, a Python program is compiled to read the contour curve segment and a visualization tool is used to draw an XY coordinate graph, where X represents the radial size of the leveler and Y represents the height of the leveler.

[0057] See also Figure 2 As shown, in the design method of a uniformizer for a tumor radiotherapy device according to this embodiment, the initial contour size and initial contour curve of the uniformizer 3 obtained according to theoretical calculation include:

[0058] The radiation source S passes through the homogenizer 3 to obtain a uniformly distributed radiation beam;

[0059] The dose at a radius R from the beam center is: Where α is the attenuation coefficient, T represents the height of the flattener, h is the vertical distance between the radiation source S and the flattener, H is the vertical distance between the radiation source S and the water phantom, D(R) is the dose distribution after flattening, and Do is the dose distribution in the field without the flattener.

[0060] At a radius R of 4 from the beam center max When the uniformity requirement is met, D(R)=const, 0≤R≤R max , where const is a constant, then

[0061] From this we get T(r) is the height of the leveler at a radius of r from the center axis of the leveler;

[0062] The height of the leveler within the radius range of -r to r from the center axis of the leveler is calculated and connected into a line to obtain the initial contour curve of the leveler.

[0063] Furthermore, in a method for designing a uniformizer for a tumor radiotherapy device according to this embodiment, the dose simulation analysis is performed based on the initial contour curve of the uniformizer, and extracting the contour curve segment that affects the dose distribution from the initial contour curve of the uniformizer includes:

[0064] Based on the initial contour curve of the homogenizer, Monte Carlo simulation analysis was used to simulate the dose distribution of particles passing through the homogenizer in the medical accelerator treatment head, and a simulated dose distribution map was obtained;

[0065] By analyzing the flatness and symmetry of the simulated dose distribution map, the areas in the simulated dose distribution map that do not meet the requirements are determined;

[0066] The initial contour curve of the uniformizer corresponding to the area that does not meet the requirements in the simulated dose distribution diagram is intercepted, which is the contour curve segment that affects the dose distribution.

[0067] Monte Carlo simulation analysis, such as Geant4, BEAMnrc, etc., simulates the particle transport process in the medical accelerator treatment head.

[0068] By simulating the dose of particles passing through the homogenizer, it is possible to analyze whether the structure of the homogenizer meets relevant performance requirements, such as the flatness and symmetry of the dose distribution.

[0069] The function of the homogenizer is to make the radiation dose distribution uniform. Figure 3 The figure shows the radiation dose distribution after being leveled by the leveler. There is a depression in the middle area of ​​the curve in the figure. The dose distribution does not meet the standard requirements and needs to be corrected.

[0070] In the method for designing a uniformizer for a tumor radiotherapy device according to this embodiment, the steps of reading the contour curve segments, sampling from continuous data, and drawing an XY coordinate graph of initial discrete points, where X represents the radial dimension of the uniformizer and Y represents the height of the uniformizer, include:

[0071] Read the contour curve segment, use the uniform sampling method to read the initial discrete points with equal radial spacing from the continuous data, and draw the XY coordinate graph of the initial discrete points;

[0072] Alternatively, read the contour curve segment and use the partition sampling method. The number of initial discrete points selected for the key focus area is greater than the number of initial discrete points affecting the non-key focus area. A non-uniform sampling strategy is adopted to comprehensively consider the fitting accuracy and calculation amount to select the appropriate number of sampling points.

[0073] As an optional implementation of this embodiment, in the method for designing a uniformizer for a tumor radiotherapy device of this embodiment, the coordinates of the discrete points are modified (X i , Y i) are marked in the XY coordinate graph, and curve fitting is performed on the initial discrete point data in the XY coordinate graph to generate the high-order polynomial equation of the flattener profile curve, including:

[0074] Modify the coordinates (X i , Y i ) is marked in the XY coordinate graph, and the least squares method is used to perform curve fitting on the initial discrete point data in the XY coordinate graph to generate a high-order polynomial equation Y=AX for the contour curve of the equalizer. 6 +BX 5 +CX 4 +DX 3 +EX 2 +FX+G;

[0075] The high-order polynomial equation Y=AX 6 +BX 5 +CX 4 +DX 3 +EX 2 +FX+G is imported into the drawing software to generate the contour curve of the leveler and draw the three-dimensional model of the leveler.

[0076] The high-order polynomial equation described in this embodiment is a sixth-order polynomial. Other high-order polynomials may also be used. The order should be selected according to actual needs. Too high an order will lead to overfitting.

[0077] The method for fitting a contour curve with discrete points in this embodiment can be used to compile a program to fit the discrete points into a curve, convert the curve into a format recognizable by drawing software, and import the curve into the drawing software to draw a three-dimensional model of the leveler.

[0078] In a method for designing a uniformizer for a tumor radiotherapy apparatus according to this embodiment, a uniformizer is prepared based on the initial contour curve, an actual dose distribution experiment of the uniformizer is conducted, and an actual dose distribution map of the uniformizer is obtained. From the actual dose distribution map of the uniformizer, the dose distribution position X that does not meet the uniformity requirement is read. i , by analyzing and calculating the dose distribution position X i Leveler height Y when leveling requirements are met i , get the modified coordinates of discrete points (X i , Y i ).

[0079] This embodiment conducts a test on the actual dose distribution of the homogenizer based on Figure 2 The structure shown is realized by placing a measuring instrument in the water phantom 5 to read the dose distribution under a certain range of radiation. The relevant data and the final curve are obtained by the dose analysis software. i The dose is read from the actual dose distribution diagram and the judgment is based on the relevant national standards.

[0080] In this embodiment, at the position point that does not meet the requirements, the uniformity profile curve (such as Figure 4 The height of this position can be determined by software, and the dosage here can be determined by comparing with the standard requirements. To meet the standard requirements, the height of the leveler at this position should be corrected, and the corrected data can be organized into new discrete points, such as Figure 4 The Y-axis value is then fitted into a new uniformizer profile curve.

[0081] See also Figure 5 As shown, this embodiment also provides a homogenizer structure manufactured using the homogenizer design method of the tumor radiotherapy device, including:

[0082] The base 1 is made of a high atomic number metal material and has a cone-shaped overall outline;

[0083] The surface layer 2 is made of a metal material with a low atomic number. The surface layer is covered on the base 1 and is combined with the base 1 to form a cone shape.

[0084] The equalizer structure of this embodiment consists of two or more parts. The base 1 adopts a conical high atomic number metal material to equalize the higher dose area near the central axis of the radiation field. The surface layer 2 adopts a low atomic number metal material, and the passing rays are less attenuated, which is beneficial to the utilization rate of the radiation dose. At the same time, the surface layer 2 is relatively easy to process, which is more convenient when modifying the equalizer structure.

[0085] Therefore, the uniformizer structure of this embodiment adopts a combined structure to obtain a better dose distribution, which not only ensures that the dose distribution flatness near the center of the field meets the requirements, but also can make more effective use of the radiation dose, reduce the accelerator operating power, and increase the accelerator service life.

[0086] As an optional implementation of this embodiment, in a leveler structure of this embodiment, the base 1 is made of high atomic number metal lead, and the surface layer 2 is made of low atomic number metal material copper.

[0087] Lead and copper are a relatively good combination, and lead and aluminum can also be used. The substrate 1 is made of a material with a large attenuation coefficient, and the coating is made of a material with a small attenuation coefficient.

[0088] Tungsten has a high attenuation, but through appropriate combination, such as minimizing the height of this highly attenuating material, uniformity is improved and dose attenuation is minimized. Using tungsten instead of lead as a substrate provides a feasible solution.

[0089] As an optional implementation of this embodiment, a leveler structure of this embodiment utilizes tungsten, a high-atomic-number metal, as the base 1, and aluminum, a low-atomic-number metal, as the surface layer 2. Tungsten and aluminum are another suggested alternative to the materials of this patent. Actual usage needs to be determined through calculations, actual testing, and usage scenarios.

[0090] This embodiment also provides a computer-readable storage medium storing a computer-executable program. When the computer-executable program is executed, the method for designing a uniformizer structure using the tumor radiotherapy device is implemented.

[0091] The computer-readable storage medium described in this embodiment may include a data signal propagated in baseband or as part of a carrier wave, which carries a readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable storage medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, device, or component. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above.

[0092] This embodiment also provides an electronic device, including a processor and a memory, wherein the memory is used to store a computer executable program. When the computer program is executed by the processor, the processor executes the equalizer and the design method thereof using the tumor radiotherapy device.

[0093] The electronic device is implemented as a general-purpose computing device. The processor may be one or multiple processors operating in concert. The present invention also does not exclude distributed processing, meaning the processors may be dispersed across different physical devices. The electronic device of the present invention is not limited to a single entity but may also be the sum of multiple physical devices.

[0094] The memory stores a computer executable program, typically a machine-readable code, which can be executed by the processor to enable the electronic device to perform the method of the present invention, or at least some of the steps in the method.

[0095] The memory includes a volatile memory, such as a random access memory unit (RAM) and / or a cache memory unit, and may also be a non-volatile memory, such as a read-only memory unit (ROM).

[0096] It should be understood that the electronic devices of the present invention may also include elements or components not shown in the above examples. For example, some electronic devices also include display units such as screens, and some electronic devices also include human-computer interaction elements such as buttons and keyboards. As long as the electronic device can execute a computer-readable program stored in its memory to implement the method of the present invention or at least some of the steps of the method, it can be considered an electronic device covered by the present invention.

[0097] Through the above description of the implementation mode, it is easy for those skilled in the art to understand that the present invention can be implemented by hardware capable of executing a specific computer program, such as the system of the present invention, and the electronic processing unit, server, client, mobile phone, control unit, processor, etc. contained in the system. The present invention can also be implemented by computer software that executes the method of the present invention, such as control software executed by a microprocessor, an electronic control unit, a client, a server, etc. However, it should be noted that the computer software that executes the method of the present invention is not limited to being executed by one or a specific hardware entity, and it can also be implemented in a distributed manner by unspecified specific hardware. For computer software, the software product can be stored in a computer-readable storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), or it can be distributed and stored on a network, as long as it enables an electronic device to execute the method according to the present invention.

[0098] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A method for designing a homogenizer for a tumor radiotherapy device, characterized in that: include: The initial contour size and initial contour curve of the leveler are obtained according to theoretical calculation; Perform dose simulation analysis based on the initial contour curve of the equalizer, and extract the contour curve segment that affects the dose distribution in the initial contour curve of the equalizer; Read the contour curve segment, sample from the continuous data, and draw the XY coordinate graph of the initial discrete points, where X represents the radial dimension of the leveler and Y represents the height of the leveler; Based on the initial contour curve, a uniformizer is prepared, and an actual dose distribution experiment of the uniformizer is performed to obtain an actual dose distribution map of the uniformizer. The dose distribution position X that does not meet the uniformity requirement is read from the actual dose distribution map of the uniformizer. i , by analyzing and calculating the dose distribution position X i The height Y of the leveler when the leveling requirements are met i , get the modified coordinates of discrete points (X i , Y i ); Modify the coordinates (X i , Y i ) are marked in the XY coordinate diagram, and curve fitting is performed on the initial discrete point data in the XY coordinate diagram to generate a high-order polynomial equation for the equalizer profile curve.

2. The method for designing a uniformizer for a tumor radiotherapy device according to claim 1, characterized in that: The initial contour size and initial contour curve of the leveler obtained according to theoretical calculation include: The radiation source S passes through the homogenizer to obtain a uniformly distributed radiation beam; The dose at a radius R from the beam center is: Where α is the attenuation coefficient, T represents the height of the homogenizer, h is the vertical distance between the radiation source S and the homogenizer, H is the vertical distance between the radiation source S and the water phantom, D(R) is the dose distribution after homogenization, and Do is the dose distribution in the field without the homogenizer; At a radius R from the beam center max When the uniformity requirement is met, D(R)=const, 0≤R≤R max , where const is a constant, then From this we get T(r) is the height of the leveler at a radius of r from the center axis of the leveler; The height of the leveler within the radius range of -r to r from the center axis of the leveler is calculated and connected into a line to obtain the initial contour curve of the leveler.

3. The method for designing a uniformizer for a tumor radiotherapy device according to claim 1, characterized in that: The dose simulation analysis is performed based on the initial contour curve of the equalizer, and the contour curve segment affecting the dose distribution in the initial contour curve of the equalizer is intercepted, which comprises: Based on the initial contour curve of the homogenizer, Monte Carlo simulation analysis is used to simulate the dose distribution of particles passing through the homogenizer in the medical accelerator treatment head, and a simulated dose distribution diagram is obtained; By analyzing the flatness and symmetry of the simulated dose distribution map, the areas in the simulated dose distribution map that do not meet the requirements are determined; The initial contour curve of the uniformizer corresponding to the area in the simulated dose distribution diagram that does not meet the requirements is intercepted, that is, the contour curve segment that affects the dose distribution.

4. The method for designing a uniformizer for a tumor radiotherapy device according to claim 1, characterized in that: The reading of the profile curve segment, sampling from the continuous data, and drawing the XY coordinate diagram of the initial discrete points, where X represents the radial dimension of the leveler and Y represents the height of the leveler, includes: Read the contour curve segment, use the uniform sampling method to read the initial discrete points with equal radial spacing from the continuous data, and draw the XY coordinate graph of the initial discrete points; Alternatively, the contour curve segment is read, and a partition sampling method is used, where the number of initial discrete points selected for the key focus area is greater than the number of initial discrete points selected for the non-key focus area.

5. The method for designing a uniformizer for a tumor radiotherapy device according to claim 1, characterized in that: The discrete point modification coordinates (X i , Y i ) are marked in the XY coordinate diagram, and the initial discrete point data in the XY coordinate diagram are curve fitted to generate the high-order polynomial equation of the uniformizer profile curve, including: Modify the coordinates (X i , Y i ) is marked in the XY coordinate diagram, and the initial discrete point data in the XY coordinate diagram is fitted by the least square method to generate a high-order polynomial equation Y=AX of the contour curve of the equalizer 6 +BX 5 +CX 4 +DX 3 +EX 2 +FX+G; The high-order polynomial equation Y = AX 6 +BX 5 +CX 4 +DX 3 +EX 2 +FX+G is imported into the drawing software to generate the contour curve of the leveler and draw the three-dimensional model of the leveler.

6. A homogenizer structure manufactured by the homogenizer design method of tumor radiotherapy equipment according to any one of claims 1 to 5, characterized in that: include: The base is made of high atomic number metal material, and the overall outline is cone-shaped; The surface layer is made of a metal material with a low atomic number. The surface layer is covered on the base and is combined with the base to form a cone shape.

7. A homogenizer structure according to claim 6, characterized in that: The substrate is made of lead, a metal with a high atomic number, and the surface layer is made of copper, a metal material with a low atomic number.

8. A homogenizer structure according to claim 6, characterized in that: The substrate is made of tungsten, a metal with a high atomic number, and the surface layer is made of aluminum, a metal material with a low atomic number.

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