Device and method for realizing proton ultrahigh dose rate broadening irradiation

Abstract

The invention belongs to the technical field of medical radiotherapy, and particularly relates to a device and method for achieving proton ultrahigh dose rate broadening irradiation, the device comprises a range modulation wheel, a compensator and a sample to be irradiated which are sequentially arranged in the beam direction, and the beam is a pencil beam. The surface, perpendicular to the beam direction, of the to-be-irradiated sample is divided into a plurality of target areas, the range modulation wheel is composed of a plurality of concentric rings, the number of the concentric rings is equal to that of the target areas of the to-be-irradiated sample, each concentric ring corresponds to one target area of the to-be-irradiated sample, and each concentric ring is provided with a plurality of ridge-shaped filtering blocks. Under the condition that ultrahigh dose rate protons are subjected to Bragg peak broadening irradiation, point scanning without accelerator parameter change can be realized, the total time of the point scanning and the dose delivery time are in the same magnitude, the dead time of the point scanning method is reduced, and the Bragg peak broadening of different depths can be customized in a whole target region. And the overall dose uniformity is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical radiotherapy, and particularly relates to a device and method for realizing proton ultra-high dose rate broadened irradiation. Background Art

[0002] Ultra-high dose rate (FLASH) proton irradiation refers to a method of delivering proton radiation to a target area at a dose rate > 40 Gy / s, which can effectively kill cancer cells while having a certain protective effect on normal tissues, thus having excellent clinical application potential. However, the clinical application places extremely high requirements on this technology. On the time scale, since the dose rate of > 40 Gy / s can complete the established dose delivery in less than 1 s, the time scale of a single pulse is consistent with the generation and diffusion time scale of a single reactive oxygen radical. Therefore, in order to obtain a uniform biological effect, the irradiation time of the entire target area should be compressed as much as possible. On the other hand, on the spatial scale, since the target areas of clinical patients are mostly large and complex, different proton incident depths may be required at different positions in the same target area. If the method of Bragg peak broadening irradiation is used, different Bragg peak broadening ranges are required, and high requirements are placed on spatial uniformity and accuracy. Therefore, at present, ultra-high dose rate proton irradiation mainly uses the Bragg peak plateau area for penetrative irradiation, and less uses broadened Bragg peaks for irradiation, which severely limits the therapeutic potential of proton biological effects.

[0003] At present, it is still difficult to achieve Bragg peak broadening irradiation in clinical ultra-high dose rate proton irradiation, mainly because there are certain deficiencies in the two commonly used irradiation methods in the ultra-high dose rate broadening irradiation mode in a short time (<1 s): The first method is pencil beam scanning, that is, using a uniform small-area beam with a field size of about 1×1 cm 2 for intensity-modulated irradiation, changing the beam spot position through a scanning magnet, and changing the energy and range through an accelerator. The main problem of this method is that the displacement time required for point scanning and the accelerator adjustment time are much longer than the proton delivery time, resulting in different positions being irradiated successively when irradiating a large target area, and the non-uniformity on the time scale further affects the FLASH biological effect; the other method is passive scattering, that is, using a range modulation device to adjust the proton range in a certain pattern, so as to achieve changes in different incident depths at different positions. The advantage of this method is that it can simultaneously achieve large-area range adjustment, but the device activation, secondary particle yield, etc. at ultra-high dose rates will seriously affect the accuracy and uniformity of range adjustment. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a device and method for realizing ultra-high dose rate broadened irradiation of protons. By combining pencil beam scanning with passive scattering, the pencil beam is displaced to irradiate a customized range modulation wheel, so that it is not necessary to adjust the time of the accelerator on the time scale, and multi-point uniform combination is realized on the space scale, so as to meet the requirements of ultra-high dose rate protons for broadened irradiation of large clinical target areas.

[0005] In order to achieve the above-mentioned invention purpose, the technical solution of the present invention is as follows:

[0006] A device for realizing ultra-high dose rate broadened irradiation of protons includes a range modulation wheel, a compensator and a sample to be irradiated, which are arranged in sequence in the beam direction. The beam is a pencil beam. The surface of the sample to be irradiated perpendicular to the beam direction is divided into multiple target areas. The range modulation wheel consists of several concentric rings, and the number of concentric rings is equal to the number of target areas of the sample to be irradiated. Each concentric ring corresponds to a target area of the sample to be irradiated, and multiple ridge-shaped filter blocks are arranged on each concentric ring.

[0007] Furthermore, scanning magnets are arranged on the beam transport vacuum pipeline, and a uniform magnetic field is generated by a high-voltage power supply to make the beam displace rapidly in the horizontal direction.

[0008] Furthermore, the center of the range modulation wheel is a wheel axle, and several concentric rings are closely arranged around the wheel axle to form a disc-shaped structure.

[0009] Furthermore, the difference between the outer diameter and the inner diameter of the concentric ring is equal to the pencil beam spot width L.

[0010] Furthermore, the radial width of the ridge-shaped filter block is equal to the pencil beam spot width L, and the central circumferential length lr (the arc length between the midpoints on both sides of the bottom surface of the ridge-shaped filter block) is equal to the value obtained by equally dividing the central circumference of its corresponding concentric ring by an integer and is slightly greater than the pencil beam spot width L.

[0011] Furthermore, if the diameter of the wheel axle of the range modulation wheel is 2L, the central circumferential length lr of the ridge-shaped filter block on the nth concentric ring is equal to the value obtained by equally dividing the central circumference by 3(2n + 1).

[0012] Furthermore, if the radius of the wheel axle of the range modulation wheel is an integer multiple of the pencil beam spot width L, the central circumferential length lr of the ridge-shaped filter block on each concentric ring is equal to

[0013] Furthermore, different thicknesses of blocking materials are stacked along the beam direction on the ridge-shaped filter block. The thickness of the blocking material is determined by the broadening range of the corresponding target area. The thickness of the blocking material conforms to the energy of the mixed proton beam required for broadening the corresponding Bragg peak, and the area ratio conforms to the corresponding weight.

[0014] Further, the connecting line of the ridges of the ridge-type filter block is along the radial direction of the concentric ring.

[0015] Further, the blocking material is made of PMMA.

[0016] Further, the thickness of each point on the compensator along the beam direction is equal to the sum of the starting depth of the plateau region of the proton broadened Bragg peak, the broadening range of the range modulation wheel, and the difference between the maximum depth of the target area of the sample to be irradiated and the depth at the corresponding position due to the thickness non-uniformity of the target area of the sample to be irradiated.

[0017] Further, the compensator is fabricated by 3D printing, and the material is selected from PMMA or polyethylene.

[0018] A method for realizing proton ultra-high dose rate broadened irradiation by using the above device, comprising the following steps:

[0019] Step 1, generating a pencil beam spot in the scanning direction;

[0020] Step 2, dividing the sample to be irradiated into multiple target areas according to the pencil beam spot and numbering them;

[0021] Step 3, irradiating each target area of the sample to be irradiated by the beam passing through the range modulation wheel and the compensator in sequence.

[0022] Further, in Step 1, the pencil beam is generated by an accelerator, and the size of the pencil beam spot is adjusted to L×L by using an octupole lens or a double scattering target, and the beam intensity within this area is ensured to be uniform.

[0023] Further, in Step 2, according to the area of the pencil beam spot, the surface of the sample to be irradiated perpendicular to the beam direction is divided into different target areas in the order from left to right and from top to bottom, and the serial numbers of the corresponding target areas are marked with natural numbers n.

[0024] Further, in Step 2, the target areas are numbered. The horizontal direction number is denoted as i, and the vertical direction number is denoted as j. Then each target area has a corresponding number (i,j), and the maximum depth of each target area is denoted as d i,j 。

[0025] Further, in step 3, laser alignment is used to ensure that the center positions of the beam starting point, the starting point of the range modulation wheel, the starting point of the compensator, and the starting point of the sample to be irradiated are at the same central height. After the proton beam starts to be delivered, the relevant parameters remain unchanged. The scanning magnet works once every fixed time to shift the pencil beam to the next target area. The range modulation wheel keeps rotating at an angular velocity greater than 120° / s. During the irradiation of the same row of horizontal target areas numbered i in the horizontal direction of the target area, the sample to be irradiated and the compensator remain stationary. After the irradiation of the same row of horizontal target areas numbered i in the horizontal direction of the target area is completed, the sample to be irradiated and the compensator are jointly moved through the sample displacement platform, and the two remain relatively stationary, so that the center of the first target area in the same row numbered i + 1 in the horizontal direction of the target area is located at the next scanning point position of the pencil beam and continues to remain stationary, and the irradiation of the same row of target areas numbered i + 1 in the horizontal direction of the target area is completed. This process is repeated until all target areas are completely irradiated.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. The application of this method can achieve point scanning without changing the accelerator parameters under the condition of ultra-high dose rate proton Bragg peak broadening irradiation. Only the displacement time of the scanning magnet needs to be less than 100 ms. Taking the irradiation of a large target area of 6×6 cm with a pencil beam of 2×2 cm as an example, the total time of point scanning < 1 s, which is of the same order of magnitude as the dose delivery time, greatly reduces the dead time of the point scanning method, and the Bragg peak broadening with different depths can be customized for the entire target area, and the overall dose uniformity is greatly improved to be better than 90%; 2 the 2 of

[0028] 2. This method can be extended to the modulation of mixed proton beams with different dose rates and different energy spectra distributions. By adjusting the pencil beam spot, displacement path, microstructure of passive scattering devices, etc., the radiation field requirements in different scenarios can be met. Description of the Drawings

[0029] Figure 1 Schematic structural diagram of the device for realizing ultra-high dose rate broadening irradiation of protons;

[0030] Figure 2 Schematic structural diagram of the range modulation wheel;

[0031] Figure 3 Schematic diagram of the specific ring segmentation of the range modulation wheel;

[0032] Figure 4 Schematic structural diagram of the ridge filter block;

[0033] Figure 5 Schematic diagram of the spatial structure of the sample being irradiated;

[0034] Figure 6 Schematic diagram of the irradiation time structure of the sample. Detailed implementation manners

[0035] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0036] A device for realizing proton ultra-high dose rate broadened irradiation includes a range modulation wheel, a compensator, and a sample to be irradiated, which are sequentially arranged in the beam direction. The beam is a pencil beam. The surface of the sample to be irradiated perpendicular to the beam direction is divided into a plurality of target areas. The range modulation wheel is composed of a plurality of concentric rings. The number of concentric rings is equal to the number of target areas of the sample to be irradiated. Each concentric ring corresponds to a target area of the sample to be irradiated, and a plurality of ridge-shaped filter blocks are arranged on each concentric ring.

[0037] Aiming at the spatio-temporal non-uniformity problem in the large-area Bragg peak broadened irradiation of ultra-high dose rate proton beams, a method combining pencil beam scanning and passive scattering is designed. The specific technical solutions are as follows:

[0038] A device for realizing proton ultra-high dose rate broadened irradiation, as Figure 1 shown, includes a range modulation wheel, a compensator, and a sample to be irradiated, which are sequentially arranged in the beam direction. The beam is a pencil beam. The surface of the sample to be irradiated perpendicular to the beam direction is divided into a plurality of target areas. The range modulation wheel is composed of a plurality of concentric rings. The number of concentric rings is equal to the number of target areas of the sample to be irradiated. Each concentric ring corresponds to a target area of the sample to be irradiated, and a plurality of ridge-shaped filter blocks are arranged on each concentric ring.

[0039] 1. The pencil beam is generated by conventional accelerator means. The method of using octupole lenses or double scattering targets can be used to limit the pencil beam spot to a uniform field of 1×1 cm 2 or 2×2 cm 2 . The width of the pencil beam spot is denoted as L. By arranging scanning magnets for realizing the horizontal displacement of the beam on the beam transport vacuum pipeline, a uniform magnetic field is generated by a high-voltage power supply so that the beam is displaced rapidly and directionally in the horizontal direction.

[0040] 2. The sample to be irradiated is divided into target areas and numbered according to the area of the pencil beam spot. The surface of the sample to be irradiated perpendicular to the beam direction is sequentially divided into different target areas in the order from left to right and from top to bottom according to the area of the pencil beam spot. The natural number n is used to mark the serial number of the corresponding target area. The target areas are numbered. The horizontal direction number is denoted as i in the order from left to right, and the vertical direction number is denoted as j in the order from top to bottom. Then each target area has a corresponding number (i, j), and the maximum depth of this target area is denoted as d i,j .

[0041] 3. The center of the range modulation wheel is the axle, and multiple concentric acrylic rings are closely connected around the axle to form a disc-like structure, as Figure 2 shown. The difference between the outer and inner diameters of each concentric ring is consistent with the size of the pen beam spot width L. A total of n max (the maximum value of the natural numbers marking the target area numbers) concentric rings should be set, that is, the number of concentric rings to be set should be the same as the number of target areas of the sample to be irradiated, and each concentric ring corresponds to a target area of the sample to be irradiated. Each concentric ring is composed of multiple ridge-shaped filter blocks, as Figure 4 shown. The ridge-shaped filter blocks are equally cut from the center of the circle (the circumference of the concentric ring is equally divided), as Figure 3 shown. The radial width of the concentric ring is consistent with the size of the pen beam spot width L. The radial width of the ridge-shaped filter block is equal to the pen beam spot width L, and the central circumferential length lr (the arc length between the midpoints on both sides of the bottom surface of the ridge-shaped filter block) takes a value slightly larger than the pen beam spot width L suitable for equal cutting, that is, the central circumferential length lr is equal to the value obtained by equally dividing the center circumference of the corresponding concentric ring by an integer and is slightly larger than the pen beam spot width L. If the diameter of the axle of the range modulation wheel is 2L, the central circumferential length lr of the ridge-shaped filter block on the nth concentric ring is equal to the value obtained by dividing the center circumference by 3(2n + 1). If the radius of the axle of the range modulation wheel is an integer multiple of the pen beam spot width L, then the central circumferential length lr of the ridge-shaped filter block on each concentric ring is equal to Each ridge-shaped filter block stacks acrylic (PMMA) materials (blocking materials) with different thicknesses along the beam direction. The thickness of the blocking material is related to the broadening range of the corresponding target area, and the thickness conforms to the energy of the mixed proton beam required for the broadening of the corresponding Bragg peak, and the area ratio conforms to the corresponding weight. The connecting line of the ridges of the ridge-shaped filter block is along the radial direction of the concentric ring.

[0042] 4. The compensator is set between the range modulation wheel and the sample to be irradiated. The depth thickness of the compensator at the corresponding position is composed of the sum of three parts: one is the starting depth of the plateau region of the proton-broadened Bragg peak, the second is the difference between the broadening range of the range modulation wheel and the maximum depth of the target area of the sample to be irradiated, and the third is the maximum depth of the target area of the sample to be irradiated minus the depth along the beam direction of the sample to be irradiated at the corresponding position, as Figure 5 shown. The material of the compensator is PMMA.

[0043] 5. During irradiation applications, the central positions of the beam starting point, the starting point of the range modulation wheel, the starting point of the compensator, and the starting point of the sample to be irradiated are ensured to be at the same center height through laser alignment. After the proton beam starts to be delivered, the relevant parameters remain unchanged. The scanning magnet operates once every fixed time (single-dose delivery divided by the dose rate) to make the pencil beam position step once (shift to the next target area). The range modulation wheel rotates at an angular velocity greater than 120° / s. During the irradiation of the same row of horizontal target areas numbered i in the horizontal direction of the target area, the sample to be irradiated and the compensator remain stationary. After the irradiation of the same row of horizontal target areas numbered i in the horizontal direction of the target area is completed, the sample to be irradiated and the compensator move together through the sample displacement platform, and the two remain relatively stationary, so that the center of the first target area in the same row of horizontal target areas numbered i + 1 in the horizontal direction of the target area is located at the next scanning point position of the pencil beam and continues to remain stationary to complete the irradiation of the same row of horizontal target areas numbered i + 1 in the horizontal direction of the target area. This process is repeated until all target areas are completely irradiated.

[0044] Embodiment

[0045] The device layout of a device for realizing proton ultra-high dose rate spread irradiation according to the present invention is as Figure 1 shown

[0046] 1. Divide the target areas of the sample to be irradiated according to the pencil beam spot area and number them. The surface of the sample to be irradiated perpendicular to the beam direction is sequentially divided into different target areas from left to right and from top to bottom according to the pencil beam spot area, and the serial numbers of the corresponding target areas are marked with natural numbers. Number the target areas. The horizontal direction number is recorded as i in the order from left to right, and the vertical direction number is recorded as j in the order from top to bottom. Then each target area has a corresponding number (i, j), and the maximum depth of this target area is recorded as d i,j . Taking the 2×2 cm 2 pencil beam spot generated by the 100 MeV high-intensity proton cyclotron of the China Institute of Atomic Energy to uniformly irradiate a 6×6 cm 2 irregularly shaped and thick sample as an example, the biological sample can be divided into 9 different small target areas of 3×3. Taking the nth target area with the largest required depth as an example, assuming its maximum depth d i,j is 4.2 cm.

[0047] 2. Customize the corresponding passive scattering device range modulation wheel. According to the technical solution, for 9 different target areas, the range modulation wheel should have a 9-layer concentric ring structure. Then the overall range modulation wheel should be a disc-shaped with a radius of 20 cm, a wheel shaft with a diameter of Φ4 cm in the center, and 9 concentric rings with a width of 2 cm are arranged outward around the wheel shaft. Each concentric ring is customized with a ridge filter block according to the range depth of the corresponding target area. Taking the nth target area as an example:

[0048] 3. The inner diameter of the ring corresponding to the nth target area is 2n cm, and the outer diameter is 2n + 2 cm. Taking the center of the circle as the center point, the ring is equally divided into 3(2n + 1) pieces, then the central angle θ corresponding to each piece is 2π / (6n + 3), and the central circumferential length Acrylic blocks are stacked on each piece to form a ridge filter block. The design process of the ridge filter block is as follows:

[0049] 4. The range of 100 MeV protons in water is about 7.6 cm, and the width of the Bragg peak area that needs to be broadened is 4.2 cm. Considering the universality of the standardized module and the dose inhomogeneity at the front end of the Bragg peak, the ridge filter block is designed to make the range of protons in water broaden to 4.5 cm, that is, the Bragg peak is broadened at a depth of 3.1 cm - 7.6 cm, and the deviation part is compensated by the compensator.

[0050] The acrylic material PMMA is selected as the main body of the range modulator and the conformer (compensator) because its stopping power for protons is similar to that of biological tissues, it is easy to shape, has good stability and high temperature resistance.

[0051] To achieve Bragg peak broadening, proton beams of multiple energies need to be mixed, and different energies need to correspond to different proportion weights during mixing. According to Geiger's law, to make the range of protons incident on water through a PMMA material with a thickness of d be H, the following needs to be satisfied: In the formula, E(d) represents the remaining proton energy after passing through a thickness of d cm in the PMMA material. Then the thickness of the blocking material required for a 7.6 cm proton range in water is 0, and the thickness of the blocking material required for a 3.1 cm proton range in water is 3.92 cm. Then the maximum height of the ridge filter block is 3.92 cm, the minimum height is 0 cm, and the step size between them is 0.05 cm (the change in the height of the blocking material). Substitute the above formula to calculate the proton range R in water and the corresponding proton energy corresponding to different heights. Different proton energies are calculated for different weights according to the following formula:

[0052]

[0053] In the formula, d max is the maximum depth of SOBP, which is taken as 7.6 cm here, R is the range of the corresponding particle beam in water, Δ is the step size of R change, which is taken as 0.05 cm here, n is the number of calculations, taken as an integer, M, D 0 are correction factors, p is the Geiger's law coefficient of protons in water, generally taken as 1.77. After calculating the corresponding weights, the area occupied by the corresponding height is the weight multiplied by the total area of a single ridge filter block. After simulation verification and correction by the Monte Carlo program, a ridge filter block can be designed.

[0054] Then, 3(2n + 1) ridge-shaped filter blocks are arranged circumferentially along the central axis to form a complete concentric ring, which can ensure that the proton beam uniformly passes through the blocking materials with different thicknesses during rotation.

[0055] 5. After customizing the range modulation wheel, customize the compensator. The compensator can be fabricated by 3D printing, and the materials can be selected from polyethylene or acrylic. Taking the customization of the compensator for the corresponding area of the above-mentioned target area as an example, by evenly sampling points, in this embodiment, the starting depth of the plateau region of the proton broadened Bragg peak is 3.1 cm, the difference between the broadening range of the range modulation wheel and the maximum depth of the target area of the sample to be irradiated is 4.5 - 4.2 = 0.3 cm, and the difference between the depth at the corresponding position due to the uneven thickness of the target area of the sample to be irradiated and the maximum depth of the target area of the sample to be irradiated is d i,j -d 取点 (In this embodiment, d i,j = 4.2 cm), then the thickness of the compensator at each point is the sum of the three, that is, 3.1+(4.5 - 4.2)+(d i,j -d 取点 ), that is, the difference between the depth at the corresponding sampling point and the maximum depth of the target area plus 3.4 cm depth, so as to meet the irradiation requirements of the uneven and irregular target area.

[0056] 6. In practical applications, first use a laser for alignment to make the initial beam center position, the center position of the first range modulation ring, the center position of the first target area, and the center position of the first area of the compensator located on the same center height straight line. On the basis of calibrating the dose rate, start irradiation. The range modulation wheel continues to rotate at an angular velocity of >120° / s, and the irradiation time for each target area is recorded as T 0 .

[0057] The irradiation time of the sample is as shown in Figure 6 . Then, within the time range of 0 - T 0 , the beam irradiates the first target area, and the Bragg peak broadening proton FLASH irradiation of the first target area is realized through the first range modulation ring. After the time of T 0 arrives, the scanning magnet works for T 1 seconds to displace the pencil beam 2 cm in the horizontal direction, so that it falls on the second range modulation ring. The position of the sample to be irradiated and the compensator remains unchanged. Within the time of (T 0 +T 1 )-(2T 0 +T 1 ), the irradiation of the second target area is completed; similarly, after 2T 0 +T 1 arrives, the scanning magnet works for T 1 seconds, and then the irradiation of the third target area is carried out. After the irradiation of the third target area is completed, at T 1While the time-scanning magnet is operating, the sample to be irradiated and the compensator should move simultaneously, so that the beam center position, the fourth range modulation ring, the sample to be irradiated, and the position of the fourth region of the compensator remain on the same center-height straight line; then, only the scanning beam is horizontally moved in the fifth and sixth target areas; in the seventh target area, the scanning beam, the sample to be irradiated, and the compensator position are moved simultaneously; in the eighth and ninth target areas, only the scanning beam is moved until the irradiation is completed. The total time used is 9T 0 +8T 1 , meeting the requirements of ultra-high dose rate short-time irradiation.

[0058] 7. Verified by experiments, through the combination of pencil beam scanning and customized range modulation wheel, this method can meet the proton FLASH Bragg peak broadening irradiation requirements for biological samples with different depths. At the same time, without changing the accelerator parameters, the total time used is controlled in the s order of magnitude, and the time uniformity is good; the dose uniformity in the target area is good, basically better than 90%, and can meet the clinical application standard.

[0059] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A device for realizing ultra-high dose rate broadening of proton irradiation, characterized in that: It includes a range modulation wheel, a compensator and a sample to be irradiated which are sequentially arranged in the beam direction. The beam is a pencil beam. The surface of the sample to be irradiated perpendicular to the beam direction is divided into multiple target areas. The range modulation wheel is composed of a plurality of concentric rings. The number of the concentric rings is equal to the number of target areas of the sample to be irradiated. Each concentric ring corresponds to a target area of ​​the sample to be irradiated. A plurality of ridge filter blocks are arranged on each concentric ring.

2. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 1, characterized in that: A scanning magnet is arranged on the beam transport vacuum pipeline, and a high voltage power supply is used to generate a uniform magnetic field so that the beam can be rapidly displaced in a horizontal direction.

3. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 1, characterized in that: The center of the range modulation wheel is the wheel axle, and a plurality of concentric rings are closely arranged around the wheel axle to form a disc-shaped structure.

4. The device for realizing ultra-high dose rate broadening of proton irradiation according to claim 3, characterized in that: The difference between the inner and outer diameters of the concentric rings is equal to the pencil beam spot width L.

5. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 4, characterized in that: The radial width of the ridge filter block is equal to the pencil beam spot width L, and the central circumferential length lr is equal to the value of the central circumference of the concentric ring to which it belongs divided equally by an integer and is slightly larger than the pencil beam spot width L.

6. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 5, characterized in that: If the diameter of the wheel axle of the range modulation wheel is 2L, the central circumferential length lr of the ridge filter block on the nth concentric ring is equal to the value obtained by dividing the central circumference by 3(2n+1).

7. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 5, characterized in that: If the radius of the wheel axle of the range modulation wheel is an integer multiple of the pencil beam spot width L, then the central circumferential length lr of the ridge filter block on each concentric ring is equal to 8. The device for realizing ultra-high dose rate broadening of proton irradiation according to claim 5, characterized in that: The ridge filter block deposits blocking materials of different thicknesses along the beam direction. The thickness of the blocking material is determined by the corresponding target area broadening range. The thickness of the blocking material conforms to the mixed proton beam energy required for the corresponding Bragg peak broadening, and the area ratio conforms to the corresponding weight.

9. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 5, characterized in that: The ridge connection line of the ridge type filter block is along the radial direction of the concentric rings.

10. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 8, characterized in that: The barrier material is made of PMMA.

11. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 1, characterized in that: The thickness of each point on the compensator along the beam direction is equal to the sum of the starting depth of the plateau of the proton broadening Bragg peak, the difference between the broadening range of the range modulation wheel and the maximum vertical depth of the target area of ​​the sample to be irradiated, and the difference between the depth at the corresponding position caused by the uneven thickness of the target area of ​​the sample to be irradiated and the maximum vertical depth of the target area of ​​the sample to be irradiated.

12. The device for realizing proton ultra-high dose rate broadening irradiation according to claim 11, characterized in that: The compensator is made by 3D printing, and the material is PMMA or polyethylene.

13. A method for implementing proton ultra-high dose rate broadening irradiation using the device according to any one of claims 1 to 12, characterized in that: The steps include: Step 1, generating a pencil-shaped beam spot in a scanning direction; Step 2, dividing the sample to be irradiated into multiple target areas according to the pencil beam spot and numbering them; Step 3: The beam passes through the range modulation wheel and the compensator to irradiate each target area of ​​the sample to be irradiated in turn.

14. A method for realizing proton ultra-high dose rate broadening irradiation according to claim 13, characterized in that: In step 1, the pencil beam is generated by an accelerator, and the spot size of the pencil beam is adjusted to L×L using an octopole lens or a double scattering target, and the beam intensity within the area is ensured to be uniform.

15. The method for realizing proton ultra-high dose rate broadening irradiation according to claim 13, characterized in that: In step 2, the surface of the sample to be irradiated perpendicular to the beam direction is divided into different target areas in order from left to right and from top to bottom according to the pencil beam spot area, and the serial number of the corresponding target area is marked with a natural number n.

16. A method for realizing proton ultra-high dose rate broadening irradiation according to claim 13, characterized in that: In step 2, the target areas are numbered, with the horizontal number being i and the vertical number being j. Each target area has a corresponding number (i, j), and the maximum depth of each target area is d. i,j .

17. A method for realizing proton ultra-high dose rate broadening irradiation according to claim 13, characterized in that: In step 3, laser alignment is used to ensure that the center positions of the beam starting point, the range modulation wheel starting point, the compensator starting point and the sample to be irradiated are at the same center height. After the proton beam starts to be delivered, the relevant parameters remain unchanged. The scanning magnet works once at a fixed interval to move the pencil beam to the next target area. The range modulation wheel keeps rotating at an angular velocity greater than 120° / s. During the irradiation of the same row of horizontal target areas numbered i in the horizontal direction of the target area, the sample to be irradiated and the compensator remain stationary. After the irradiation of the same row of horizontal target areas numbered i in the horizontal direction of the target area is completed, the sample to be irradiated and the compensator move together through the sample displacement platform, and the two remain relatively still, so that the center of the first target area in the same row of target areas numbered i+1 is located at the next scanning point position of the pencil beam, and continues to remain stationary to complete the irradiation of the same row of target areas numbered i+1 in the horizontal direction of the target area, and this cycle is repeated until all target areas are irradiated.

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