CN118203773B - Assembling method of adjustable space division radiotherapy collimator - Google Patents

Abstract

The present invention discloses an assembly method of an adjustable spatially segmented radiotherapy collimator, and relates to the technical field of radiotherapy. In step S2 of the present invention, a penetrating sheet capable of transmitting radiation is superimposed to form a penetrating portion, the number of penetrating sheets is calculated, and the thickness of each penetrating portion corresponds to the width of each radiation area. A shielding sheet capable of blocking radiation is superimposed to form a shielding portion, the number of shielding sheets is calculated, and the thickness of each shielding portion corresponds to the spacing of each radiation area; in S3, each penetrating portion and shielding portion are superimposed in sequence to form a collimation module, and the two sides of the collimation module are shielding portions respectively. The present invention assembles penetrating portions and shielding portions of different thicknesses according to the radiotherapy range and the spacing of the radiotherapy range, and then forms a collimation module by superimposing the penetrating portion and the shielding portion, and the collimation module is pressed to form a collimator. Since the thickness of the penetrating portion and the shielding portion can be assembled and adjusted as needed, it can be applied to spatially segmented radiotherapy with different requirements, thereby achieving the effect of reducing costs.

Description

An assembly method of an adjustable spatially segmented radiotherapy collimator

Technical Field

The invention relates to the technical field of radiotherapy, and specifically provides an assembling method of an adjustable space-fractionated radiotherapy collimator.

Background technique

Spatial fractionation radiation therapy (SFRT) is a radiotherapy technique that allows relatively high but varying radiation doses to be delivered to large tumors while sparing surrounding healthy organs. Lead plates with holes machined into them are usually used as collimators for spatial fractionation therapy.

However, since spatially fractionated radiotherapy requires frequent adjustment of the radiation range, the radiation range needs to be adjusted in different studies, and the protection range also needs to be adjusted. However, since the MBRT beam width is less than 1000μm, the production of the collimator requires precision processing instruments, and it is necessary to open several micron-level holes on the lead plate. The processing difficulty of micron-level holes is very high, resulting in a high production cost for the collimator. In addition, the spacing between the holes is also at the micron level, which further increases the processing difficulty, resulting in a further increase in the production cost of the collimator. Therefore, the existing spatially fractionated radiotherapy has a high cost problem due to the high processing difficulty of the collimator.

Summary of the invention

The present invention provides an assembling method of an adjustable spatial fractionation radiotherapy collimator, which is used to solve the problem of high cost due to high processing difficulty of the collimator in the existing spatial fractionation radiotherapy.

The technical solution of the present invention is as follows:

A method for assembling an adjustable spatially segmented radiotherapy collimator comprises the following steps:

S1. Count the width of each radiation area and the distance between each radiation area;

S2. Use penetrating sheets that can transmit radiation to form penetrating parts, calculate the number of penetrating sheets, and the thickness of each penetrating part corresponds to the width of each radiation area. Use shielding sheets that can block radiation to form shielding parts, calculate the number of shielding sheets, and the thickness of each shielding part corresponds to the spacing between each radiation area.

S3, stacking the penetration parts and the shielding parts in sequence to form a collimation module, with the shielding parts being located on both sides of the collimation module;

S4. Press the collimation module from both sides to eliminate the gaps between the penetration parts, so that the range of rays passing through the penetration parts is accurate and reliable, and the spacing between the radiation ranges is accurate and reliable.

In this solution, before each spatial fractionation radiotherapy, the penetration parts and shielding parts are assembled and stacked according to different radiation ranges and the spacing between the radiation ranges, so that the thickness of each penetration part is the same as the width of the corresponding radiation range, and the thickness of each shielding part is the same as the spacing between the corresponding reflection ranges. After the penetration parts and shielding parts are stacked to form each penetration part and shielding part, the penetration parts and shielding parts can be stacked in sequence to obtain a collimator that can be applied to different radiotherapy ranges, and there is no need to prepare a separate collimator for each spatial fractionation radiotherapy, thereby reducing the cost of spatial fractionation radiotherapy.

When the width of the radiotherapy range is large, in order to solve the problem that a large number of penetrating sheets need to be superimposed, the number error and large error are prone to occur during superposition, for this purpose, the penetrating part includes penetrating sheets with the same thickness and/or the penetrating part includes penetrating sheets with different thicknesses.

In this solution, the penetrating portion can be formed by stacking penetrating sheets of different thicknesses, or by stacking penetrating sheets of the same thickness. Therefore, when the width of the radiotherapy range is large, a penetrating sheet with a larger thickness can be stacked with a penetrating sheet with a smaller thickness, thereby reducing the number of penetrating sheets that need to be stacked and the probability of error. The fewer the number of penetrating sheets, the smaller the error generated when stacking, thus solving the problem of large errors caused by a large number of penetrating sheets.

When the spacing between radiotherapy areas is large, in order to solve the problem of a large number of shielding sheets that need to be stacked, errors in quantity and large errors may easily occur during stacking, so the shielding part includes shielding sheets with the same thickness and/or the shielding part includes shielding sheets with different thicknesses.

In this solution, the shielding part can be formed by stacking shielding sheets of different thicknesses, or by stacking shielding sheets of the same thickness. Therefore, when the width of the radiotherapy range is large, a shielding sheet with a larger thickness can be stacked with a shielding sheet with a smaller thickness, thereby reducing the number of shielding sheets that need to be stacked and the probability of error. The fewer the number of shielding sheets, the smaller the error generated when stacking, thus solving the problem of large errors caused by a large number of shielding sheets.

In order to solve the problem that the position of each penetrating piece or shielding piece is offset when superimposed, resulting in the irregular shape of the formed collimation module and being difficult to fix, in step S3, the collimation module is installed using a fixed structure provided with a positioning groove, and the width of the positioning groove is the same as the width of the penetrating piece, and the width of the penetrating piece is the same as the width of the shielding piece.

In this solution, the widths of each penetration piece and shielding piece are the same, and they can be positioned through a positioning groove to ensure that the penetration part and the shielding part can completely overlap when superimposed. When the collimation module is pressed from both sides, it is ensured that the force is evenly applied to all parts of the collimation module to avoid gaps in the collimation module due to uneven force, thereby ensuring the accuracy of the collimation module.

When the length of the radiotherapy range is different, penetrating plates and shielding plates of different lengths are needed to assemble the collimator. At this time, the fixed structure also needs to be suitable for penetrating plates and shielding plates of corresponding lengths. In order to solve the problem of high cost caused by the non-universality of the fixed structure, the fixed structure includes two fixed plates, and the two fixed plates are respectively provided with positioning grooves. The two fixed plates are respectively connected to the two sides of the collimation module through the positioning grooves.

In this solution, the fixing structure includes two fixing plates, which respectively fix two sides of the collimation module, and can be applicable to penetration sheets and shielding sheets of various lengths, thereby reducing costs.

Preferably, in step S3, a positioning structure is provided at one end of the positioning groove, an end face of a shielding part at the end of the collimation module abuts against the positioning structure, and then the penetration part and the shielding part are alternately stacked, and the shielding part is finally stacked in the positioning groove.

In this solution, the shielding part is supported from the bottom by the positioning structure, and the positioning structure can separate the workbench and the shielding part for easy access, and can provide support for the collimation module during the process of pressing the collimation module.

In order to solve the problem that the collimation module is easily damaged during the pressing process, in step S4, a pressing structure that is slidable with the fixed structure is used to press the collimation module, and the pressing structure and the fixed structure have an interference fit.

In this solution, the clamping structure and the fixed structure are in interference fit. When the clamping structure is used for clamping, the clamping structure is moved by gently tapping the clamping structure. The interference fit will create resistance to the movement of the clamping structure, reducing the pressure of the clamping structure on the alignment module when tapping, ensuring that the alignment module is clamped and avoiding damage to the alignment module. At the same time, the interference fit can also prevent the clamping structure from moving during use and from retreating during the clamping process, ensuring a stable clamping effect on the alignment module.

When the radiotherapy range is different, the thickness of the collimation module formed by superposition is also different. When the thickness of the superimposed collimation module is small, it is still necessary to move the penetrating sheet and the shielding sheet from one end of the positioning groove to the positioning structure. The moving distance of the penetrating sheet and the shielding sheet is long. When pressed and fixed, the distance that the pressing structure needs to move is also longer. Therefore, when the thickness of the collimation module is small, there is a problem that the operation is more time-consuming and inconvenient. For this reason, the positioning structure is slidably connected to the fixed structure, and the positioning structure and the fixed structure are interference fit.

In this solution, the position of the positioning structure is adjustable. Therefore, before the collimation module is superimposed, the position of the positioning structure can be adjusted first to shorten the moving distance of the penetration sheet and the shielding sheet. The moving distance of the clamping structure can also be reduced, making the assembly operation more convenient. In addition, the positioning structure can be moved before the collimation module is superimposed and assembled, so the positioning structure can be knocked hard to move it. At this time, the collimation module will not be damaged. Compared with gently knocking the clamping structure, knocking the positioning structure to move is easier. Therefore, although the total stroke of the positioning structure and the clamping structure remains unchanged, the difficulty of operation can be reduced, making the operation easier and more convenient. The interference fit between the positioning structure and the fixed structure also allows the positioning structure to move when subjected to a certain force, thereby preventing the collimation module from being damaged due to excessive pressure.

Preferably, the positioning structure and the clamping structure are both buckles, the buckle is provided with a slide groove, and the buckle is slidably connected to the fixed structure through the slide groove.

Preferably, the thickness of the penetrating sheet is in the range of 200-1000 μm; the thickness of the shielding sheet is in the range of 200-1000 μm; and the penetrating sheet is a polylactic acid sheet made by 3D printing.

In this scheme, 3D printing is used to prepare polylactic acid sheets, which can reduce costs while ensuring accuracy.

Beneficial effects of the present invention:

The present invention assembles penetration parts and shielding parts of different thicknesses according to the radiotherapy range and the spacing of the radiotherapy range, and then forms a collimation module by superimposing the penetration parts and the shielding parts, and compresses the collimation module to form a collimator. Since the thickness of the penetration parts and the shielding parts can be assembled and adjusted as needed, it can be applied to space-fractionated radiotherapy with different radiotherapy requirements, thereby achieving the effect of reducing costs.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solution of the present invention, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic structural diagram of a collimator in Embodiment 1;

FIG2 is a schematic diagram of the structure of the U-shaped plate in Example 1;

FIG3 is a schematic structural diagram of a collimation module in Embodiment 1;

FIG4 is a schematic structural diagram of another implementation of the collimator in Example 1;

FIG5 is a diagram showing the radiation beam irradiation effect in Example 1;

FIG6 is a schematic diagram of the structure of the middle buckle in the first embodiment;

FIG7 is a schematic diagram of the structure of a collimator in Embodiment 2;

FIG. 8 is a schematic diagram of the structure of the fixing plate in the second embodiment.

In the above drawings, the corresponding reference numerals are as follows:

1. Alignment module; 2. Fixing plate; 3. Buckle; 4. Positioning groove; 5. Positioning block; 6. Groove structure; 7. Slide groove; 8. U-shaped plate; 11. Penetration plate; 12. Shielding plate.

Detailed ways

In conjunction with the accompanying drawings, the technical solution of the present invention is clearly and completely described through specific implementation methods of the embodiments of the present invention.

Embodiment 1.

As shown in FIG3 , the first embodiment provides an assembly method of an adjustable spatially fractionated radiotherapy collimator, comprising the following steps:

S1. Count the width of each radiation area and the spacing between each radiation area; the width of each radiation area is used as the thickness of each penetration part, and the spacing between each radiation area is used as the thickness of each shielding part. Since the width and spacing of each radiation area in spatially fractionated radiotherapy may be different, it is necessary to separately count the width of each radiation area and the spacing between each radiation area, and count the order of each radiation area for easy assembly;

S2. Use penetrating sheets that can transmit radiation to form a penetrating portion, calculate the number of penetrating sheets, and the thickness of each penetrating portion corresponds to the width of each radiation area. Use shielding sheets that can block radiation to form a shielding portion, calculate the number of shielding sheets, and the thickness of each shielding portion corresponds to the spacing between each radiation area. For example, when the width of the first radiation area is 600 μm, the penetrating portion can be formed by superimposing three penetrating sheets of 200 μm, and when the width of the second radiation area is 700 μm, the penetrating portion can be formed by superimposing a penetrating sheet of 500 μm and a penetrating sheet of 200 μm.

S3, stacking the penetration parts and the shielding parts in sequence to form a collimation module, with the shielding parts being located on both sides of the collimation module;

S4. Compress the collimator module from both sides to eliminate the gaps between the penetration parts, so that the range of rays transmitted by the penetration parts is accurate and reliable, and the spacing between the radiation ranges is accurate and reliable. The operation of compressing the collimator module can improve the accuracy of the collimator and avoid inaccurate accuracy caused by gaps in the penetration pieces or shielding pieces in the collimator.

As shown in FIG5 , when the radiation beam irradiates the collimation module, the radiation beam can pass through the penetration portion, thereby forming spaced strip irradiation areas at the location where radiotherapy is required, achieving lateral heterogeneous dose distribution, that is, radiotherapy peak and valley areas.

As shown in Figure 1, the collimation module is fixed by a fixing structure, a positioning structure and a pressing structure, which are used to prevent the collimation module from loosening and ensure that the shielding part presses the penetration part, thereby ensuring that the size of the radiotherapy beam passing through the penetration part is accurate and reliable.

When the number of the penetrating parts is two or more, the thickness of the penetrating parts may be different to meet different radiotherapy requirements.

As shown in Figure 2, the fixed structure can be a U-shaped plate, and the two parallel inner sides of the U-shaped plate are provided with positioning grooves. The width of the positioning grooves is the same as the width of the penetration plate and the shielding plate, and the width of the shielding plate is the same as the width of the penetration plate, ensuring that the penetration plate and the shielding plate can completely overlap when superimposed.

The horizontal portion in the middle of the U-shaped plate can be used as a positioning structure to support the collimation module from the bottom.

As shown in Figure 4, a positioning structure may also be separately provided on the U-shaped plate to support the collimation module from the bottom. When a separate positioning structure is provided, the positioning structure and the clamping structure may adopt the same structure, so that the positioning structure and the clamping structure are common and the cost is reduced.

As shown in FIG6 , the positioning structure and the clamping structure can adopt a buckle, and the buckle is a rectangular parallelepiped structure, and a slide groove is provided on one side of the rectangular parallelepiped structure, and the width of the slide groove is the same as the thickness of the U-shaped plate. The fixing plate is inserted into the slide groove so that the buckle can slide along the length direction of the positioning groove. Four buckles are provided on each U-shaped plate, and the four buckles are respectively located on both sides of the collimation module, that is, two buckles are respectively provided on both sides of the collimation module. The end face of the collimation module is clamped by the buckle, so that the shielding part and the penetration part in the collimation module are kept in a close state, ensuring that there is no gap between the shielding part and the penetration part, thereby ensuring the dimensional accuracy of the radiation beam.

A positioning block is provided in the slide groove, and the width of the positioning block is the same as the width of the positioning groove. When the U-shaped plate is connected to the slide groove, the positioning block is also inserted into the positioning groove. Under the positioning effect of the positioning block, the buckle angle can be prevented from being deflected. After the positioning block is provided in the middle of the slide groove, the slide groove is divided into two separate groove structures.

The buckle and the U-shaped plate may be interference fit.

That is to say, the positioning structure and the pressing structure are slidably connected to the fixing structure, and the positioning structure and the pressing structure are interference fit with the fixing structure.

The shielding part can be made of tungsten, which has a higher density than lead and is not easily deformed. Tungsten does not react with particles and is non-toxic, which can better overcome the disadvantages of lead and eliminate the accompanying toxic hazards and mixed waste treatment costs. The shielding part can also be made of materials such as bismuth, rhenium, and thorium that can block radiation beams.

The material of the penetration part can be polylactic acid, and the radiation beam has good permeability on the penetration part made of polylactic acid, which can avoid the penetration part affecting the intensity of the radiation beam. The material of the penetration part can also be PETG polyethylene terephthalate, ABS acrylonitrile butadiene styrene copolymer, PC polycarbonate and other materials that allow radiation beam.

The shielding sheets stacked to form the shielding portion may include shielding sheets with the same thickness or shielding sheets with different thicknesses.

For example, the shielding sheets stacked to form the shielding portion may all have the same thickness.

For another example, the thicknesses of the shielding sheets stacked to form the shielding portion are all different.

For another example, some shielding sheets stacked to form the shielding portion have the same thickness, while the remaining shielding sheets have different thicknesses.

The penetration pieces stacked to form the penetration portion may include penetration pieces of the same thickness or may include penetration pieces of different thicknesses.

For example, the penetration sheets stacked to form the penetration portion may all have the same thickness.

For another example, the thicknesses of the penetration sheets stacked to form the penetration portion are all different.

For another example, some of the penetration sheets stacked to form the penetration portion have the same thickness, while the remaining penetration sheets have different thicknesses.

The thickness of the shielding sheet is in the range of 200-1000 μm. The thickness of the penetrating sheet 11 is in the range of 200-1000 μm.

In the above steps, the polylactic acid sheet can be produced by 3D printing.

For example, draw a rectangular PLA sheet model through design software, the thickness of the PLA sheet ranges from 200-1000μm. Export the STL format file and slice the PLA sheet model in Bambu Studio software. Select the nozzle model of the printer: 0.2mm.

Then set the 3D printing parameters, including: first layer speed: 40mm/s; first layer filling: 70mm/s; outer wall speed: 120mm/s; inner wall speed: 150mm/s; sparse filling: 100mm/s; internal solid filling: 150mm/s. Select polylactic acid as the printing filament, with a diameter of 1.75mm and a density of 1.26g/cm3. Set the nozzle temperature to 190-240℃ and the hot bed temperature to 35℃. Remove the printed polylactic acid sheet from the hot bed.

Embodiment 2:

The second embodiment provides an assembly method of an adjustable spatially fractionated radiotherapy collimator. The difference from the first embodiment is that the fixing structure in the second embodiment is different.

As shown in Figures 7 and 8, the fixing result includes two fixing plates, which are rectangular plates. A positioning groove is provided on one side of the rectangular plate, wherein the width of the positioning groove is the same as the width of the collimation module, and both sides of the collimation module can be inserted into the positioning groove. The shielding part is the same width as the penetration part, so that the positioning groove can constrain the shielding part and the penetration part at the same time. When two fixing components are respectively inserted on both sides of the collimation module, the collimation module is constrained by the positioning groove, so that the collimation module can only move along the length direction of the positioning groove. The shielding part and the penetration part are both plate-like structures, and the shielding part and the penetration part are perpendicular to the fixing plate.

The width of the slide groove is the same as the thickness of the fixed plate, and the fixed plate is inserted into the slide groove so that the buckle can slide along the length direction of the fixed plate. Two buckles are respectively arranged on each fixed plate, and the two buckles are respectively located on both sides of the collimation module, and the two buckles press the collimation module from both sides, so that the shielding part and the penetration part in the collimation module are kept in a close state, ensuring that there is no gap between the shielding part and the penetration part, thereby ensuring that the dimensional accuracy of the radiation beam meets the requirements.

When the length of the radiotherapy range is different, penetrating sheets of different lengths and shielding sheets of the same length as the head-penetrating sheet are stacked to form a collimation module. At this time, since the two fixing plates fix the collimation module from both sides, the technical solution of the second embodiment can be applied to penetrating sheets and shielding sheets of different lengths, thereby reducing the cost of the fixing structure.

Claims (8)

1. An assembly method of an adjustable space division radiotherapy collimator is characterized by comprising the following steps:

s1, counting the width of each radiation area and the interval between each radiation area;

S2, overlapping penetrating pieces capable of penetrating rays to form penetrating parts, calculating the number of the penetrating pieces, wherein the thickness of each penetrating part corresponds to the width of each radiation area, overlapping shielding pieces capable of blocking rays to form shielding parts, and calculating the number of the shielding pieces, wherein the thickness of each shielding part corresponds to the interval of each radiation area;

S3, sequentially superposing each penetrating part and the shielding part to form a collimation module, wherein shielding parts are respectively arranged at two sides of the collimation module;

s4, compacting the collimation module from two sides, eliminating gaps among the penetrating parts, enabling the ray range transmitted by the penetrating parts to be accurate and reliable, enabling the interval among the radiation ranges to be accurate and reliable,

In step S3, a collimation module is installed by adopting a fixed structure provided with a positioning groove, the width of the positioning groove is the same as the width of a penetrating piece, the width of the penetrating piece is the same as the width of a shielding piece,

In step S3, one end of the positioning slot is provided with a positioning structure, the end face of one shielding part at the end of the collimation module abuts against the positioning structure, then the penetrating part and the shielding part are alternately overlapped, and the shielding part is the last overlapped part in the positioning slot.

2. The method of assembling an adjustable spatial division radiotherapy collimator according to claim 1, wherein the penetration portions comprise penetration pieces of the same thickness and/or the penetration portions comprise penetration pieces of different thicknesses.

3. The method of assembling an adjustable spatial division radiotherapy collimator according to claim 1, wherein the shielding parts comprise shielding sheets of the same thickness and/or the shielding parts comprise shielding sheets of different thicknesses.

4. The method for assembling the space-adjustable split radiotherapy collimator according to claim 1, wherein the fixing structure comprises two fixing plates, the two fixing plates are respectively provided with a positioning groove, and the two fixing plates are respectively connected with two sides of the collimation module through the positioning grooves.

5. The method of assembling an adjustable spatial division radiotherapy collimator according to claim 1, wherein in step S4, a compression structure slidable with a fixing structure is used to compress the collimation module, and the compression structure is in interference fit with the fixing structure.

6. The method of claim 5, wherein the positioning structure is slidably coupled to the fixed structure, and wherein the positioning structure is in an interference fit with the fixed structure.

7. The method of claim 6, wherein the positioning structure and the pressing structure are both buckles, the buckles are provided with sliding grooves, and the buckles are slidably connected with the fixing structure through the sliding grooves.

8. The method of assembling an adjustable spatial division radiotherapy collimator of claim 1, wherein the thickness of the penetration piece is in the range of 200-1000 μm;

the thickness of the shielding sheet ranges from 200 mu m to 1000 mu m;

The penetrating sheet is a polylactic acid sheet formed by 3D printing.