CN215995326U - Range trimmer and treatment device for three-dimensional particle irradiation treatment - Google Patents

Abstract

The utility model relates to a range trimmer, which comprises a connecting plate and a plurality of sliding plate subunits fixedly arranged on the connecting plate; the sliding rail of each sliding plate subunit is fixedly arranged on the connecting plate, the energy reducing plate in a thin plate form is fixedly arranged on the sliding table, and the sliding table is supported on the sliding rail in a sliding manner and is connected with the driving mechanism; the energy reducing plates of the sliding plate subunits are arranged in parallel along the beam direction, and are driven to move in a translation manner along the slide rail through an independent driving mechanism so as to move in or out of the beam field to adjust the total thickness of the energy reducing plates penetrated by the beam to realize the energy reduction of the particle beam. The utility model also provides a treatment device for three-dimensional particle irradiation treatment, which comprises the range fine adjuster. The range trimmer can reduce the energy switching times of the accelerator, realize the rapid switching of particle energy, minimize the noise and vibration during working, save the arrangement space, expand more sub-modules for widening the energy regulation range, and finally realize more time-saving, comfortable and compact particle treatment performance.

Description

Range trimmer and treatment device for three-dimensional particle irradiation treatment

Technical Field

The present invention relates to particle radiation therapy, and more particularly to a range trimmer and a treatment apparatus for three-dimensional particle irradiation therapy.

Background

Particle radiotherapy is one of the most advanced cancer treatments in the world today. In contrast to conventional photon radiotherapy (X-ray radiotherapy), the particles, when irradiated into a patient, form a maximum dose Peak at the end of their range, a so-called Bragg Peak. By precisely controlling the particle beam energy and the particle beam irradiation position, high dose can be intensively irradiated into a target area of a target tumor, and meanwhile, the dose not required to be irradiated to surrounding normal tissues and normal organs is reduced to the minimum, so that more conformal dose distribution than X-ray radiotherapy is realized, the treatment effect of the tumor is improved, and the side effect is reduced.

Generally, a particle therapy device is composed of a particle accelerator and particle delivery system, a particle irradiation system, a patient positioning and verification system, and an irradiation control system, a treatment planning system. Particle beam generated by an accelerator usually has a beam spot size of less than 10mm, and when the particle beam is to be uniformly irradiated to a tumor target region with a diameter of 10 cm, for example, a particle irradiation system is needed to expand a pencil beam particle beam with a diameter of less than 1 cm to a range of 10 cm, and particle beams with different energies are needed to expand a Bragg peak originally with a width of only a few millimeters to a width of the tumor target region with a thickness corresponding to the irradiation direction, so that the irradiation dose of surrounding normal tissues and organs is reduced while uniform three-dimensional dose distribution is formed in the three-dimensional tumor target region.

There are generally two irradiation methods for achieving a three-dimensional conformal dose distribution, namely scatterer methods or two-dimensional irradiation methods and scanning irradiation methods or three-dimensional irradiation methods.

The two-dimensional irradiation method mainly uses a pair of dipolar electromagnets with orthogonal deflection directions, called rocking magnets, to scan the particle beam from the accelerator according to a planned trajectory to form a fixed trajectory, such as a circular trajectory or a ZigZag trajectory, or a trajectory given according to a treatment plan, and at the same time, a scatterer is installed in the irradiation head to expand the particle beam spot to a diameter of several centimeters, so that a uniform transverse (longitudinal or depth direction along the irradiation direction) dose distribution can be formed at the target region of the tumor, but the distribution is not limited to the region of the tumor, but a Collimator (Patient Collimator) or multi-leaf Collimator (MLC) made according to a two-dimensional shape given by the calculation of the treatment plan is used to remove unnecessary particle beams, and finally a two-dimensional distribution corresponding to the tumor is formed. In the two-dimensional irradiation method, a bragg peak broadening device called a Ridge Filter (Ridge Filter) is generally used for forming a dose distribution in the depth direction of a tumor, and is installed at a position behind a rocking magnet but far from a patient. The two-dimensional irradiation method also needs a device called a Range Compensator (Range Compensator) to adjust the Range of the particle beam irradiated to different lateral positions of the tumor target area to stop at the deepest position of the tumor target area corresponding to the irradiation position, i.e. the tumor bottom can be shaped. The basic principle of the method of using a rocking magnet to scan a fixed trajectory and a filter and collimator or multi-leaf grating to form the field of view is described in the utility model ZL200620164842.1 "three-dimensional conformal irradiation apparatus of heavy ion beam to the target area of a tumor". This is also described in detail in non-patent literature Review of Scientific Instruments 64(8) August 1993, page 2055-.

The three-dimensional irradiation method is also referred to as a pencil beam scanning irradiation method. The device mainly comprises a scanning magnet, a scanning power supply, a vacuum box, a vacuum window, an ionization chamber for monitoring beam position and dose, a signal processing circuit, a beam range fine-tuning device, an irradiation control system and the like. The three-dimensional irradiation method divides a tumor target area into a plurality of small areas, each small area irradiates a particle beam to the appointed position by controlling beam energy and current of a scanning electromagnet, each particle beam forms a three-dimensional sub-dose distribution, and a total three-dimensional dose distribution can be obtained by controlling the number of the irradiated particles of each irradiated area (irradiated point), so that the total three-dimensional dose distribution is in a shape suitable for the three-dimensional tumor target area, and the unnecessary dose to surrounding normal tissues is reduced. The three-dimensional irradiation method is described in detail in non-patent literature Review of Scientific Instruments 64(8) August 1993, page 2055-.

In the existing treatment irradiation technology, a three-dimensional pencil beam scanning irradiation method needs to control energy switching of a particle beam and position movement of an irradiation point to realize uniform distribution of dose in a tumor target area. There are three main ways in which the energy of the beam can be switched: firstly, the energy of an extracted beam is changed by using a synchrotron; secondly, an energy reducing device is arranged at the tail end of the irradiation head; thirdly, beam energy reducing and energy selecting devices are arranged between the accelerator and the treatment room.

The three particle energy switching methods are all insufficient:

first, the extraction beam energy is varied using a synchrotron. This approach has significant technical disadvantages: energy switching in this manner typically takes more than 1s to re-inject and accelerate to the required energy to change the accelerator extraction energy due to synchrotron characteristics. Especially for large tumors, more than 20 energy slices are needed, and the time consumed by beam energy switching can significantly reduce the overall treatment capacity of the device.

Second, an energy reducing device is installed at the end of the irradiation head. The device is arranged in a space between the tail end of an irradiation head and a patient, and at present, the energy reducing device mainly comprises a plurality of pluggable energy reducing plates and a plugging driving and controlling mechanism, wherein the energy reducing plates are usually made of plastic materials such as PMMA (polymethyl methacrylate) or PE (polyethylene). The energy reducing plate size is generally related to the desired field size and is larger than the field size, typically the field maximum size is 300 mm. The thickness of the energy reducing plate is determined according to the range of the required adjusting energy, and the sum of the thicknesses (all the energy reducing plates are inserted in a whole and are in an online state) is generally within 250 mm. This approach necessitates fast particle energy switching by means of an automated actuation structure. As described in patent document CN102763169A, "energy degrader and charged particle irradiation system having the energy degrader", two wedge blocks arranged along the beam direction are driven to make relative staggered motion perpendicular to the beam direction, so as to adjust the thickness of the energy-reducing material penetrated by the beam and adjust the particle range. The structure has the advantages of high adjusting speed and low movement noise, but larger spaces need to be reserved on the left side and the right side of the beam flow for accommodating the energy reducing material and arranging the driving structure when the two wedge blocks moving in a staggered mode are arranged. The design form occupies more space, and has improvement on the aspect of structural compactness.

Thirdly, beam energy reducing and selecting devices are arranged between the accelerator and the treatment room, and the beam is reduced through energy reducing plates arranged in the accelerator and the treatment room. The technical disadvantage of this approach is: after the energy reducing plate, beam transverse scattering and energy dispersion are large, after energy selection and transportation, the beam utilization rate is greatly reduced, lost particles cause difficulty to the maintenance of an accelerator, and the manufacturing and maintenance cost is increased. This energy reduction is typically applied in a cyclotron.

On the basis of the three energy reducing modes, a fourth mode is developed, namely a first mixed energy reducing mode and a second mixed energy reducing mode are adopted. The fourth mode can achieve the best overall performance.

As described in non-patent documents Takuji Furukawa, et al, Performance of the NIRS fast scanning system for the side-on radiotherapy, Med Phys.37,5672-5682(2010), the first way of changing energy of the accelerator has 11 energy (between 140 and 430 MeV/u) in total, and the second way of changing energy uses 10 energy reducing plates made of PMMA with thickness of 0.2mm-102.4mm and transverse dimension 240 x 240mm, and the switching of the energy reducing plates with different thicknesses is performed by a compression cylinder. In order to reduce the noise generated when the air cylinder works as much as possible, the switching time of the energy reducing plate needs at least 500 ms. The variable energy times of the device depending on the first variable energy mode are reduced compared with the case of singly using the first variable energy mode, and the injection times of the accelerator are reduced, so that the time can be saved. The technical scheme of switching the energy reducing plate based on the air compression cylinder has the following defects: because the air compression cylinder is adopted for driving, sharp noise and sudden mechanical vibration exist in the switching process of the energy reducing plate, the comfort of a patient in the treatment process can be influenced, even the panic mood of the patient can be triggered, and the requirement of the man-machine environment engineering on the 'pleasant' performance can not be met.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems of large occupied space, noise and the like in the prior art, the utility model provides a range fine adjuster and a treatment device for three-dimensional particle irradiation treatment.

The utility model provides a range trimmer, which comprises a connecting plate and a plurality of sliding plate subunits fixedly arranged on the connecting plate, wherein the connecting plate is fixedly provided with a plurality of sliding plate subunits; each sliding plate subunit comprises a driving mechanism, a sliding rail, an energy reducing plate and a sliding table, wherein the sliding rail is fixedly arranged on the connecting plate, the energy reducing plate in a thin plate form is fixedly arranged on the sliding table, and the sliding table is supported on the sliding rail in a sliding manner and is connected with the driving mechanism; the energy reducing plates of the sliding plate subunits are arranged in parallel along the beam direction, and are driven to move in a translation manner along the slide rail through an independent driving mechanism so as to move in or out of the beam field to adjust the total thickness of the energy reducing plates penetrated by the beam to realize the energy reduction of the particle beam.

Preferably, each of the slider sub-units further includes reinforcing bars provided at both sides of the energy reducing plate to prevent deformation of the energy reducing plate.

Preferably, each sliding plate subunit further comprises a connecting piece, and the energy reducing plate is connected with the sliding table through the connecting piece.

Preferably, each sliding plate subunit further comprises a fixed seat, and the sliding rail is fixed on the connecting plate through the fixed seat.

Preferably, the driving mechanism is a motor which drives the slide table through a speed reducer and a lead screw nut.

Preferably, the range trimmer comprises four sliding plate subunits, wherein the first sliding plate subunit and the second sliding plate subunit are fixedly mounted on one side of the connecting plate, and the third sliding plate subunit and the fourth sliding plate subunit are fixedly mounted on the other side of the connecting plate.

Preferably, the drive mechanism and the slide rail of a group of slide plate subunits on the same side are arranged in a symmetrical and reversed L-shaped installation.

Preferably, the energy reducing plates of the group of sliding plate subunits on the same side are designed to be staggered in height.

The utility model also provides a treatment device for three-dimensional particle irradiation treatment, which comprises the range fine adjuster.

Preferably, the irradiation controller determines the total thickness of the energy-reducing plate required by the range trimmer based on information given by the treatment planning system and the particle accelerator control system, and sends control instructions to the drive mechanism of the range trimmer to switch the movement of the energy-reducing plate.

Preferably, several range trimmers are used in superposition.

Preferably, the energy reducing plates in each range trimmer have different thicknesses, and/or the energy reducing plates of each sled subunit in the range trimmer have different thicknesses.

The range trimmer is used for rapidly switching the energy of the particle beam, has the technical characteristics of compact structure, reliable performance and strong expansibility, and can greatly shorten the time for switching the energy of the particle beam so as to improve the irradiation efficiency of particle radiation therapy. According to the treatment device for three-dimensional particle irradiation treatment, the specific design form of the range regulator of the irradiation device for cancer treatment for switching the energy of the particle beam is provided in the light of the application requirement of the fourth energy reduction mode, and compared with the prior art, the treatment device for three-dimensional particle irradiation treatment has the advantages of being fast, quiet and compact. In a word, based on the structural design of the range trimmer, the energy switching times of the accelerator can be reduced, the rapid switching of particle energy can be realized, the noise and vibration during working can be minimized, the arrangement space can be saved, more sub-modules can be expanded to widen the energy regulation range, and finally, the time-saving, comfortable and compact particle therapy performance can be realized.

Drawings

FIG. 1 is a schematic diagram of the structure of an irradiation system of a particle therapy device;

FIG. 2 is a schematic diagram of a range trimmer of FIG. 1;

FIG. 3 shows the assembled relationship of the four skateboard subunits and connection boards of FIG. 2;

FIG. 4 shows an exploded view of the first slider sub-unit and the connecting plate of FIG. 2;

fig. 5 is a schematic view of the assembled state of fig. 4.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1, a treatment apparatus for three-dimensional particle irradiation treatment according to a preferred embodiment of the present invention includes scanning magnets 4, 5, vacuum boxes 6, 7, a vacuum window 8, dose monitors 9, 10, a position monitor 11, a range fine-adjuster 12, and an irradiation controller 15. Specifically, with the aid of a particle accelerator control system 17, a particle beam 1 (here, particles refer to protons or carbon ions) extracted from a particle accelerator 18 is transported to a transport magnet 2 in front of a treatment room by a particle transport device 19, and then passes through a bellows 3 and enters a ceramic vacuum box 6. The first scanning magnet 4 and the second scanning magnet 5 deflect the particle beam 1 to a position of a tumor target 14 below the surface 13 of the patient's body as specified by the treatment planning system 16 in accordance with instructions from the irradiation controller 15. The deflected particle beam 1 enters a stainless steel vacuum box 7 and passes through a vacuum window 8, then enters a first beam dose monitor 9 and a second beam dose monitor 10, which are identically configured, and then enters a beam position monitor 11. The first beam dose monitor 9 and the second beam dose monitor 10 mainly monitor the number of the particle beams 1 passing therethrough, and the beam position monitor 11 mainly detects the positions of the particle beams after being deflected by the first scanning magnet 4 and the second scanning magnet 5. After the number of particles designated by the treatment planning system 16 is completed for each designated irradiation point, the first beam dose monitor 9 and the second beam dose monitor 10 send signals to the irradiation controller 15, and the irradiation controller 15 switches the position of the irradiation point to the next irradiation point by controlling the first scanning magnet 4 and the second scanning magnet 5. The above process is repeated until all the planned irradiation points have the planned irradiation particle beam. Here, each irradiation point has an energy parameter of the particle beam 1 to control a depth position of the irradiation point, in addition to the irradiation positions (x, y) controlled by the first scanning magnet 4 and the second scanning magnet 5. The energy parameter is set based on the calculation of the treatment plan, and is usually switched by adjusting the extraction energy of an accelerator or an energy adjuster provided in the particle transport line. Due to the mechanism of particle acceleration by some accelerators, the particle energy is not continuous, and after the beam passes through the first beam dose monitor 9, the second beam dose monitor 10 and the beam position monitor 11, the problem of discontinuous energy is compensated by installing a range trimmer 12. Particularly, the range trimmer 12 is a translational structure of an energy reducing plate, the energy of the particle beam is reduced by inserting the energy reducing plates with a series of thicknesses into the beam in different combination modes, the adjustment range of the range trimmer 12 on the energy of the particle beam is variable according to the fact that the tumor is located at different depth parts of the body, the maximum depth of the particle beam is just in the irradiation area of the tumor, and therefore the Bragg peak position of the particle beam 1 can be irradiated to the position in the target area designated by a treatment plan, and a conformal uniform dose distribution area is formed in the target area of the tumor.

The basic structure of the range trimmer 12 is explained in detail below.

As shown in fig. 2, the range fine adjuster 12 for radiation therapy according to a preferred embodiment of the present invention includes a first sliding plate subunit 121, a second sliding plate subunit 122, a third sliding plate subunit 123, a fourth sliding plate subunit 124, and an attachment plate 125, as shown in fig. 3, the first sliding plate subunit 121 and the second sliding plate subunit 122 are installed and fixed on the top of the attachment plate 125, and the third sliding plate subunit 123 and the fourth sliding plate subunit 124 are installed and fixed on the bottom of the attachment plate 125. It should be understood that the four sliding plate subunits 121, 122, 123, 124 are only used as examples and are not limited, and may be composed of a plurality of subunits, and the number of subunits may be increased or decreased according to the requirement, with scalability.

Since the basic structures of the first sled subunit 121, the second sled subunit 122, the third sled subunit 123 and the fourth sled subunit 124 are identical, the first sled subunit 121 is selected for further explanation below. As shown in fig. 4 and 5, the first slider subunit 121 includes a motor 1211, a fixing base 1212, a sliding rail 1213, a power reducing plate 1214, a sliding table 1215, a reinforcing bar 1216 and a connecting member 1217, wherein the sliding rail 1213 is fixed to the connecting plate 125 through the fixing base 1212, the power reducing plate 1214 is fixedly connected to the sliding table 1215 through the reinforcing bar 1216 and the connecting member 1217, the sliding table 1215 is slidably supported and mounted on the sliding rail 1213, and the motor 1211 drives the sliding table 1215 to move along the sliding rail 1213 through a speed reducer and a lead screw nut. The range trimmer 12 uses the silent motor 1211 and the slide rail 1213 as the driving devices, so that the noise and vibration during operation are reduced. It should be understood that the drive and transmission means are not limited to motor drive, screw drive, but may be replaced by any similar arrangement of wire, chain, linkage, etc.

The operation principle of the range trimmer 12 will be described in detail below.

The energy reducing plate 1214 is a thin plate made of plastic such as pmma (poly methacrylate) or pe (polyethylene) with variable thickness, and is connected to the sliding table 1215 through a connecting member 1217. To prevent deformation of the energy reducing plates 1214, reinforcing bars 1216 are provided on both sides of each energy reducing plate 1214. The motor 1211 drives the slide 1215 to reciprocate along the slide 1213 by remote control.

The four slider subunits 121, 122, 123, 124 are divided into two groups, and arranged on both sides of the connecting plate 125. The motors and slides of a set of slider sub-units 121, 122 or 123, 124 on the same side are arranged in a symmetrically inverted "L" shape, for example, the motor 1211 of the first slider sub-unit 121 and the motor of the second slider sub-unit 122 are located on opposite sides, respectively, and the slide 1213 of the first slider sub-unit 121 and the slide of the second slider sub-unit 122 are located on opposite sides, respectively. The connecting members of the group of sliding plate sub-units 121, 122 or 123, 124 on the same side are designed to be offset in height, for example, the connecting member 1217 of the first sliding plate sub-unit 121 is located at a high position, and the connecting member of the second sliding plate sub-unit 122 is located at a low position, so that collision interference during operation can be avoided. Of ski subunits 121, 122, 123, 124The double-L-shaped symmetrical arrangement design can realize the installation of two subunits in one height plane, thereby saving the valuable beam direction space, having flat and compact structure and saving the space. Thus, each of the sliding plate sub-units 121, 122, 123, 124 is driven by the respective motor 1211 to correspondingly drive the sliding table 1215 to drive the energy reducing plate 1214 to shield or open the field channel 125a on the connecting plate 125, so that each range trimmer 12 can generate 2⁴16 different states.

The method of using the range trimmer 12 is further described below.

During irradiation with the radioactive medical particles, the irradiation controller 15 determines the total thickness of the energy reducing plate 1214 required by the range trimmer 12 based on the information given by the treatment planning system 16 and the particle accelerator control system 17, and sends control commands to the motor 1211 of the range trimmer 12 to switch the movement of the energy reducing plate 1214.

There are three situations in the use of the range trimmer 12:

in the first case: when the energy of the particle beam 1 given by the treatment planning system 16 can be supplied directly by the accelerator, no range adjustment of the particle beam 1 is required. At this time, the irradiation controller 15 will issue an instruction to control the range trimmer 12 to switch to an empty state, through which the beam of the particle beam 1 directly passes to irradiate the patient;

in the second case: when the energy of the particle beam 1 given by the treatment planning system 16 cannot be directly supplied by the accelerator, the irradiation controller 15 requests the particle accelerator control system 17 to generate a higher energy adjacent thereto, while the irradiation controller 15 calculates the total thickness of the energy reduction plate 1214 of the range trimmer 12 and sends a corresponding control instruction. After the beam current of the particle beam 1 passes through the energy reducing plate 1214, the energy is reduced and the beam current is irradiated to the patient;

in the third case: when the irradiation of one equal energy layer is completed, the irradiation controller 15 acquires the number of remaining particle beams or the same information from the particle accelerator control system 17 and determines that the number is larger than the number of particles required for the next equal energy layer, and the irradiation controller 15 directly controls the range trimmer 12 to switch the total thickness of the energy reducing plate 1214 to adjust the energy of the particle beam 1. Under the condition of not changing the energy of the accelerator, the automatic and rapid switching of the particle range can be realized, the transduction times of the accelerator are reduced, and the irradiation dose rate is improved.

Thus, the range fine-tuning device 12 can automatically and rapidly switch the particle range through the controller according to the requirement of treatment irradiation (calculation result of treatment plan), reduce the transduction times of the accelerator and improve the irradiation efficiency.

The energy reducing plates in the plurality of range trimmers 12 have different thicknesses. The thickness of the energy reducing plate is different, the degree of beam energy reduction is different, and the adjustment of beam range is different.

The range trimmers 12 can be used alone or in combination. For example, the range trimmer 12 with the four energy reducing plates 1214 of 0.5mm, 1mm, 2mm, 4mm thickness can be used alone or in combination to form 16 different thicknesses in the range of 0mm-7.5 mm. But are not limited to these four thickness types and may be other dimensional thicknesses and form corresponding combined thicknesses. The utility model can be designed in multiple stacks where a greater range of energy modulation is desired. For example, two range fine-adjusters respectively comprising four energy reducing plates with the thicknesses of 0.5mm, 1mm, 2mm and 4mm can be used for forming an adjusting range with the adjusting precision of 0.5mm within 0-15mm singly or in combination for reducing beam energy. For another example, two range fine-adjusters respectively comprising three energy reducing plates with the thicknesses of 1mm, 2mm and 4mm can be used for forming the thickness types of 0mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm and 14mm singly or in combination for reducing the beam energy. It should be understood that the thickness of the energy reducing plate may vary and is not limited to the examples mentioned in the above description. Referring to fig. 2, 4 and 5, the range trimmer 12 further comprises a plurality of mounting supports 126 fixed on the connecting plate 125, each of the sliding plate sub-units 121, 122, 123, 124 is mounted against the inside of the mounting support 126, it being understood that the mounting supports 126 function to connect and fix a single or multiple sets of range trimmers 12, and the use of multiple sets of range trimmers 12 in a stacked manner can provide more power adjustment steps.

The functions that the utility model can realize are: 1) the automatic and rapid switching of the fine adjustment of the range in the particle irradiation treatment reduces the transduction times of the accelerator and improves the irradiation dose rate; 2) low noise, low vibration, and adjustable switching speed; 3) the structure is flat and compact, a larger space is reserved for the treatment device area, and the collision between the treatment device and the patient as well as the treatment bed is avoided; 4) and the expandability can realize the superposition of a plurality of subunits according to the requirement.

The above embodiments are merely preferred embodiments of the present invention, which are not intended to limit the scope of the present invention, and various changes may be made in the above embodiments of the present invention. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The utility model has not been described in detail in order to avoid obscuring the utility model.

Claims (12)

1. A range trimmer is characterized by comprising a connecting plate and a plurality of sliding plate subunits fixedly arranged on the connecting plate; each sliding plate subunit comprises a driving mechanism, a sliding rail, an energy reducing plate and a sliding table, wherein the sliding rail is fixedly arranged on the connecting plate, the energy reducing plate in a thin plate form is fixedly arranged on the sliding table, and the sliding table is supported on the sliding rail in a sliding manner and is connected with the driving mechanism; the energy reducing plates of the sliding plate subunits are arranged in parallel along the beam direction, and are driven to move in a translation manner along the slide rail through an independent driving mechanism so as to move in or out of the beam field to adjust the total thickness of the energy reducing plates penetrated by the beam to realize the energy reduction of the particle beam.

2. The range trimmer of claim 1, wherein each slider subunit further comprises reinforcing bars disposed on opposite sides of the energy reducing plate to prevent deformation of the energy reducing plate.

3. The range trimmer of claim 1, wherein each ramp subunit further comprises a connector, and the energy reducing plate is connected to the ramp by the connector.

4. The range trimmer of claim 1, wherein each slider subunit further comprises a holder by which the slider is secured to the connecting plate.

5. The range trimmer of claim 1, wherein the drive mechanism is a motor that drives the ramp through a speed reducer and a lead screw nut.

6. The range trimmer of claim 1, comprising four slider subunits, wherein the first and second slider subunits are mounted on one side of the connecting plate and the third and fourth slider subunits are mounted on the other side of the connecting plate.

7. The range trimmer of claim 6, wherein the drive mechanism and the slide rails of a set of slide sub-units on the same side are arranged in a symmetrical inverted "L" shape.

8. The range trimmer of claim 6, wherein the energy reducing plates of the sets of slide plate subunits on the same side are arranged in a staggered manner.

9. A treatment device for three-dimensional particle irradiation therapy comprising a range trimmer according to any of claims 1-8.

10. The treatment apparatus according to claim 9, wherein the irradiation controller determines a total thickness of the energy reduction plate required for the range trimmer based on information given by the treatment planning system and the particle accelerator control system, and sends control commands to the drive mechanism of the range trimmer to switch the movement of the energy reduction plate.

11. The treatment device of claim 9, wherein a plurality of range trimmers are used in a stacked arrangement.

12. The treatment device of claim 11, wherein the energy reducing plates in each range trimmer have different thicknesses and/or the energy reducing plates of each slide sub-unit in the range trimmer have different thicknesses.

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