Ray beam collimation system

Abstract

The embodiment of the invention provides a ray beam collimation system, and relates to the technical field of medical equipment. The ray beam collimation system comprises a primary collimator and a multi-leaf collimator. The primary collimator is provided with a through hole with a fixed shape and size, and the through hole is matched with the multi-leaf collimator in shape and size. And the primary collimator is positioned below the ray source and above the multi-leaf collimator. The multi-blade collimator comprises at least two blade groups composed of a plurality of blades, the tail end of each blade is provided with a concave-convex part, the concave-convex part comprises a plurality of first protrusions arranged at intervals in the first direction, a first recess is formed between every two adjacent first protrusions, the at least two blade groups comprise two blades opposite in the second direction, and the first protrusions are arranged at intervals in the first direction. The first protrusion of one of the two opposite blades is used for being connected with the first recess of the other blade in an inserted mode. The ray beam collimation system provided by the embodiment of the invention has the benefits that leakage rays between the tail ends of the blades are shielded, and the irradiation space of a patient in radiotherapy is increased.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a beam collimation system. Background Technology

[0002] Radiotherapy equipment (such as medical linear accelerators and proton therapy systems) is a medical device that uses radiation to kill diseased cells and treat diseases. The beam collimation system is an important component of radiotherapy equipment, generally consisting of a primary collimator, a tungsten gate, and a multi-leaf collimator. Multi-leaf collimators are divided into two types: single-layer multi-leaf collimators and double-layer multi-leaf collimators.

[0003] A beam collimation system using a single-layer multi-leaf collimator consists of a primary collimator, tungsten gates, and a multi-leaf collimator. The beam emitted from the radiation source first undergoes preliminary conformation through a pre-collimation aperture on the primary collimator. The beam then passes through four tungsten gates (two gates per stage) for further conformation. The tungsten gates reduce beam leakage between the leaflets of the multi-leaf collimator. Finally, the movement of the leaflets on the multi-leaf collimator performs final conformation to define the beam's radiation range, thus adapting the final irradiation field to the shape of the patient's tumor. However, the tungsten gates, made of thick, high-density material, not only occupy a large space, compressing the patient's irradiation space, but also increase the accelerator load. Furthermore, some beam leakage between the relative leaflets cannot be blocked by the tungsten gates, resulting in additional radiation exposure to the patient. Summary of the Invention

[0004] This application provides a beam collimation system to address the problems in existing beam collimation systems where the tungsten gate occupies a large space in the accelerator head, compressing the patient's irradiation space, resulting in a heavy load and affecting the accelerator's mechanical performance. Furthermore, it also solves the problem of beam leakage between blades in existing collimation systems, which causes additional beam irradiation to the patient.

[0005] In a first aspect, embodiments of this application provide a beam collimation system, comprising:

[0006] A primary collimator having a through-hole for initial conformation of the ray;

[0007] A multi-leaf collimator, comprising at least two blade groups, each blade group comprising multiple blades, each blade being provided with a concave-convex portion, the concave-convex portion comprising multiple first protrusions spaced apart along a first direction, and a first depression being provided between two adjacent first protrusions;

[0008] At least two of the blade groups include two blades facing each other in a second direction, wherein a first protrusion of one of the two opposing blades is used to engage with a first recess of the other blade.

[0009] In one possible implementation, each blade is further provided with a blade body connected to the protrusion, the protrusion being located on one side of the blade body in the second direction, and in the first direction, the size of the protrusion being larger than the size of the blade body.

[0010] In one possible implementation, the protrusions and recesses extend beyond the blade body on both sides in the first direction.

[0011] In one possible implementation, the protrusion has an arc-shaped end face on the side opposite to the blade body in the second direction.

[0012] In one possible implementation, each blade has a first side and a second side in a third direction, the first side being provided with at least one second recess and the second side being provided with at least one second protrusion;

[0013] In the third direction, the second recess of one of the two adjacent blades is inserted into the second protrusion of the other blade.

[0014] In one possible implementation, the first side is provided with at least one third protrusion, and the second side is provided with at least one third recess;

[0015] In the third direction, the third protrusion of one of the two adjacent blades is inserted into the third recess of the other blade.

[0016] In one possible implementation, the field shape of the primary collimator and the maximum field shape of the multi-leaf collimator are both circular, and the multi-leaf collimator rotates relative to the primary collimator.

[0017] In one possible implementation, at least two of the blade groups are arranged in a single layer in the first direction; or, at least two of the blade groups are arranged in multiple layers in the first direction.

[0018] In one possible implementation, along a third direction, the blade located in the middle of the blade group has the largest size in the second direction, the blade located on the outermost side of the blade group has the smallest size in the second direction, and the size of each blade between the blade located in the middle of the blade group and the blade located on the outermost side of the blade group gradually decreases in the second direction.

[0019] In one possible implementation, the shape of the first protrusion includes, but is not limited to, a rectangle, a trapezoid, or an arc.

[0020] The shape of the first recess includes, but is not limited to, a rectangle, a trapezoid, or an arc.

[0021] In one possible implementation, the collimator further includes a housing in which the blade assembly is mounted, and a movable baffle is provided on the housing for blocking rays between two adjacent blades in a third-direction direction.

[0022] In one possible implementation, the primary collimator has a circular field shape, the multi-leaf collimator has a square maximum field shape, and the multi-leaf collimator rotates relative to the primary collimator.

[0023] In one possible implementation, the field shape of the primary collimator and the maximum field shape of the multi-leaf collimator are both square, and the multi-leaf collimator is fixed relative to the primary collimator.

[0024] This application provides a beam collimation system in which a first protrusion of one of two opposing blades of a multi-leaf collimator is used to connect with a first recess of the other blade. This prevents beam leakage between opposing blades, eliminating the need for a tungsten gate in the beam collimation system. This reduces the space occupied by the beam collimation system and, consequently, increases the irradiation space for the patient.

[0025] Furthermore, the elimination of the tungsten gate in the beam collimation system reduces its weight and the load on the radiotherapy equipment, simplifying the mechanical structure and thus lowering the failure rate. The absence of a tungsten gate also helps to shorten the source-skin distance, thereby increasing the dose rate of the radiotherapy equipment.

[0026] In addition, the first protrusion of one of the two opposing blades of the multi-leaf collimator is used to engage with the first recess of the other blade, which can prevent radiation leakage between the opposing blades. Thus, there is no radiation leakage between the opposing blades of the beam collimation system, and no additional radiation exposure to the patient. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the blades of a beam collimation system provided in Embodiment 1 of this application when they are in their initial state;

[0029] Figure 2 for Figure 1 A schematic diagram of the beam collimation system in the image when all the blades are closed;

[0030] Figure 3 for Figure 1 The diagram showing the length of the multi-leaf collimator blades when they are arranged is only shown in the beam collimation system.

[0031] Figure 4 This is a top view of the blade arrangement provided in Embodiment 1 of this application;

[0032] Figure 5 This is a schematic diagram of the structure of the first type of blade provided in Embodiment 1 of this application;

[0033] Figure 6 A schematic diagram of two opposing first-type blades when closed, as provided in Embodiment 1 of this application;

[0034] Figure 7 A schematic diagram of two opposing first-type blades when they are opened, as provided in Embodiment 1 of this application;

[0035] Figure 8 A cross-sectional schematic diagram of the second type of blade provided in Embodiment 1 of this application;

[0036] Figure 9 A schematic cross-sectional view of two adjacent second-type blades provided in Embodiment 1 of this application;

[0037] Figure 10 A schematic cross-sectional view of two adjacent third-type blades provided in Embodiment 1 of this application;

[0038] Figure 11 A cross-sectional schematic diagram of the fourth type of blade provided in Embodiment 1 of this application;

[0039] Figure 12 A schematic cross-sectional view of two adjacent fourth-type blades provided in Embodiment 1 of this application;

[0040] Figure 13 A schematic diagram of the blades of a beam collimation system in its initial state, provided as a variation of Embodiment 1 of this application;

[0041] Figure 14 for Figure 13 A schematic diagram of the beam collimation system in the image when all the blades are closed;

[0042] Figure 15 This is a schematic diagram of the structure of the shielding block provided in a modified example 1 of Embodiment 1 of this application;

[0043] Figure 16 A schematic diagram showing the two opposing blades when they are open, provided as a variation of Embodiment 1 of this application;

[0044] Figure 17A schematic diagram of two opposing blades when closed, provided as a variation of Embodiment 1 of this application;

[0045] Figure 18 A schematic diagram of two opposing blades when closed, provided as a variation of Embodiment 1 of this application;

[0046] Figure 19 This is a schematic diagram of the beam collimation system forming a radiation field according to Embodiment 2 of this application;

[0047] Figure 20 This is a schematic diagram showing the treatment head provided in Embodiment 3 of this application with all the blades fully open;

[0048] Figure 21 This is a front view of the treatment head provided in Embodiment 3 of this application when all the blades are fully open;

[0049] Figure 22 This is a cross-sectional schematic diagram of two adjacent blades provided in Embodiment 3 of this application;

[0050] Figure 23 This is a schematic diagram of the two opposing blades when they are open, as provided in Embodiment 3 of this application;

[0051] Figure 24 This is a schematic diagram of two opposing blades when they are closed, as provided in Embodiment 3 of this application.

[0052] Explanation of reference numerals in the attached figures:

[0053] 100 - Radiation source; 200 - Primary collimator; 201 - Through hole; 300 - Multi-leaf collimator; 30 - Blade assembly; 31 - Blade; 311 - Recessed / unconvex part; 3111 - First protrusion; 3112 - First recess; 3113 - Arc end face; 312 - Blade body; 313 - First side; 314 - Second side; 3131 - Second recess; 3141 - Second protrusion; 3132 - Third protrusion; 3142 - Third recess; 32 - Housing; 3114 - Recessed surface; 3115 - Side side; 33 - Shielding block;

[0054] 315-Fixed component; 316-Telescopic component; 317-Elastic component; 3152-Connecting protrusion; 3151-Fixed main body; 3153-Protrusion; 3154-First plane; 3155-First arc surface. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0056] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0058] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] In the above description, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0060] In related technologies, the tungsten gate in the X-ray beam collimation system is thick and heavy, occupying a lot of extra space. This results in a large space occupied by the X-ray beam collimation system, which compresses the patient's irradiation space, increases the load on the accelerator, complicates the mechanical structure, and increases the failure rate.

[0061] Furthermore, the tungsten gate in the beam collimation system cannot completely block radiation leakage between relative blades. In some cases, the gap between relative blades cannot be blocked in time by the tungsten gate, resulting in radiation leakage and causing additional radiation exposure to the patient.

[0062] It should be noted that, in order to prevent the opposing blades from colliding, there will be a gap between the two opposing blades when they are closed. This gap is the main source of ray leakage.

[0063] To address the aforementioned issues, this application employs two blade structures proposed in patents CN215995323U and CN217886816U to reduce radiation leakage (CN215995323U provides a static staggered blade structure, and CN217886816U provides a dynamic staggered blade structure), and redesigns a novel X-ray beam collimation system. This system includes a primary collimator and a multi-leaf collimator. The primary collimator has a through-hole of fixed shape and size, adapted to the multi-leaf collimator. The primary collimator is located below the X-ray source, and the multi-leaf collimator is located below the primary collimator. The through-hole in the primary collimator provides initial conformation to the X-ray beam, which is then precisely conformed by the multi-leaf collimator. The two opposing blades of the multi-leaf collimator can be interlocked, significantly reducing radiation leakage and eliminating the need for a tungsten gate in the collimation system. Consequently, the weight of the X-ray beam collimation system is reduced, allowing for greater patient irradiation space and a lower failure rate.

[0064] The beam collimation system provided in this application will be described in detail below with reference to specific embodiments.

[0065] Example 1

[0066] See Figures 1 to 3 As shown, this application provides a beam collimation system for use in a radiotherapy device. The radiotherapy device includes a radiation source 100 and a beam collimation system, wherein the radiation source 100 can emit a beam of radiation to the beam collimation system. The beam of radiation can be conical.

[0067] The beam collimation system includes a primary collimator 200. The primary collimator 200 is used to conform the beam emitted by the radiation source 100.

[0068] The primary collimator 200 is made of lead.

[0069] The outer side of the primary collimator 200 may be conical. In other embodiments, the outer side of the primary collimator 200 may also be cylindrical.

[0070] See Figure 1 As shown, the primary collimator 200 has a through-hole 201. The beam of radiation emitted from the radiation source 100 is projected onto the multi-leaf collimator 300 after passing through the through-hole 201.

[0071] See Figures 1 to 3 As shown, the beam collimation system also includes a multi-leaf collimator 300. The multi-leaf collimator 300 includes at least two sets of blades 30.

[0072] The number of blade groups 30 can be two, four, or six, etc. In this embodiment, the multi-leaf collimator 300 includes two blade groups 30.

[0073] See Figure 4 As shown, each blade group 30 includes multiple blades 31. The blades 31 are made of tungsten alloy.

[0074] The height direction of blade 31 is the Z-axis direction, that is, the first direction is the Z-axis direction. The length direction of blade 31 is the X-axis direction, that is, the second direction is the X-axis direction. The width direction of blade 31 is the Y-axis direction, that is, the third direction is the Y-axis direction. The X-axis, Y-axis and Z-axis are perpendicular to each other.

[0075] The two blade groups 30 are arranged opposite each other in the second direction, and the two blade groups 30 are located in the plane defined by the X-axis and Y-axis directions. That is, the two blade groups 30 are arranged in a single layer in the first direction, so that the multi-leaf collimator is a single-layer multi-leaf collimator.

[0076] In other embodiments, the multi-leaf collimator 300 has more than two blade groups 30, and each blade group 30 of the multi-leaf collimator 300 is arranged in multiple layers in a first direction. Specifically, the multi-leaf collimator 300 includes multiple blade group layers, and each blade group layer includes two blade groups 30. When the blade group layers are parallel, a co-directional multi-layer multi-leaf collimator is formed. When the blade group layers are orthogonal, an orthogonal multi-layer multi-leaf collimator is formed.

[0077] See Figure 5 As shown, each blade 31 is provided with a protrusion 311. The protrusion 311 includes a plurality of first protrusions 3111 spaced apart along a first direction, and a first recess 3112 is provided between two adjacent first protrusions 3111.

[0078] The number of the first protrusion 3111 and the first recess 3112 is not specifically set, but can be optimized according to the performance requirements of the beam collimation system.

[0079] In the second direction, the length of the first protrusion 3111 and the depth of the first recess 3112 are not specifically set, but the length of the first protrusion 3111 and the depth of the first recess 3112 can be modified according to the processing and manufacturing requirements.

[0080] The shape of the first protrusion 3111 and the shape of the first recess 3112 are not specifically set. As long as the shape of the first protrusion 3111 of one of the two opposing blades 31 matches the shape of the first recess 3112 of the other blade 31, the first protrusion 3111 of one of the two opposing blades 31 can be inserted into the first recess 3112 of the other blade 31.

[0081] The shape of the first protrusion 3111 includes, but is not limited to, a rectangle, a trapezoid, or an arc. The shape of the first recess 3112 includes, but is not limited to, a rectangle, a trapezoid, or an arc.

[0082] In this embodiment, the first recess 3112 has a recessed surface 3114 and two side surfaces 3115, which are disposed opposite to each other in a first direction. In this embodiment, both the recessed surface 3114 and the side surfaces 3115 are planar, and the side surfaces 3115 are perpendicular to the recessed surface 3114. The recessed surfaces 3114 of each of the first recesses 3112 of the protrusion 311 are located on the same plane.

[0083] See in some examples Figure 6 As shown, the two blade groups 30 include two blades 31 facing each other in a second direction. A first protrusion 3111 of one of the two opposing blades 31 is used to engage with a first recess 3112 of the other blade 31. Specifically, the multi-leaf collimator 300 includes a controller that can control the movement of the two opposing blades 31, such that the two opposing blades 31 close, that is, the first protrusion 3111 of one of the two opposing blades 31 engages with the first recess 3112 of the other blade 31, so that there is no gap between the two opposing blades 31, thereby preventing radiation leakage.

[0084] The X-ray beam collimation system provided in this application embodiment has a through hole 201 in the primary collimator 200, which can conform the X-ray beam. The first protrusion 3111 of one of the two opposing blades 31 of the multi-leaf collimator 300 is inserted into the first recess 3112 of the other blade, which can prevent the X-ray from leaking out of the two opposing blades 31. This eliminates the need for a tungsten gate in the X-ray beam collimation system, thereby reducing the space occupied by the X-ray beam collimation system and increasing the irradiation space for the patient.

[0085] Furthermore, the elimination of the tungsten gate in the beam collimation system reduces the load on the accelerator, simplifies the mechanical structure, and thus lowers the failure rate. The absence of a tungsten gate also helps to shorten the source-skin distance, enabling an increase in the dose rate of radiotherapy equipment.

[0086] In addition, the first protrusion 3111 of one of the two opposing blades 31 of the multi-leaf collimator 300 is used to engage with the first recess 3112 of the other blade 31, which can prevent radiation leakage between the opposing blades 31, so that there is no radiation leakage between the opposing blades of the beam collimation system and no additional radiation exposure to the patient.

[0087] In one possible implementation, see Figure 5 As shown, each blade 31 is also provided with a blade body 312 connected to the protrusion 311. The protrusion 311 is located on one side of the blade body 312 in the second direction. In the first direction, the size of the protrusion 311 is larger than the size of the blade body 312.

[0088] The blade 31 has a first recess 3112 in its concave-convex portion 311, which makes the thickness of the concave-convex portion 311 insufficient in the first direction. By making the size of the concave-convex portion 311 larger than the size of the blade body 312 in the first direction, the thickness of the concave-convex portion 311 in the first direction can be compensated, thereby preventing radiation penetration.

[0089] It should be noted that the thickness of the concave and convex portion 311 can be understood as the sum of the dimensions of each first protrusion 3111 in the first direction.

[0090] The concave and convex portion 311 may extend beyond the blade body 312 on one side in the first direction, or it may extend beyond the blade body 312 on both sides in the first direction.

[0091] In some examples, the protrusion 311 extends beyond the blade body 312 on both sides in the first direction. This arrangement allows the protrusion 311 to extend beyond the blade body 312 in the first direction to compensate for the thickness of the protrusion 311, preventing radiation penetration.

[0092] In one possible implementation, see Figure 5 As shown, the concave-convex portion 311 has an arc-shaped end face 3113 on the side opposite to the blade body 312 in the second direction.

[0093] Among them, the arc end face 3113 is arc-shaped.

[0094] See Figure 7 As shown, the beam collimation system has a center line L, which extends along the Z-axis and passes through the center of the radiation source 100.

[0095] When the two opposing blades 31 are open, the beam of radiation emitted by the radiation source 100 can pass between the blades 31 of the two opposing multi-leaf collimators 300. See also Figure 7 As shown, when the blade 31 moves in the second direction but has not yet passed the centerline L, the ray beam emitted by the radiation source 100 can be tangent to the arcuate end face 3113 of the blade 31. When the blade 31 moves in the second direction to the centerline L, the ray beam emitted by the radiation source 100 can be tangent to the arcuate end face 3113 of the blade 31. When the blade 31 moves in the second direction past the centerline L, the ray beam emitted by the radiation source 100 can be tangent to the arcuate end face 3113 of the blade 31. This configuration ensures that the arcuate end face 3113 of the blade 31 is tangent to the ray beam emitted by the radiation source 100 at any position in the second direction, reducing the penumbra of the rays.

[0096] In one possible implementation, each blade 31 has a first side 313 and a second side 314 in a third direction, the first side 313 being provided with at least one second recess 3131 and the second side 314 being provided with at least one second protrusion 3141.

[0097] In the third direction, the second recess 3131 of one of the two adjacent blades 31 is inserted into the second protrusion 3141 of the other blade 31. With this arrangement, when rays pass between adjacent blades 31, they can be blocked by the second protrusion 3141, thereby preventing leakage from the two adjacent blades 31.

[0098] See in some examples Figure 8 As shown, in the third direction, the size of the blade 31 is D1. In the third direction, the size of the second protrusion 3141 is D2. D2 can be one-tenth of D1.

[0099] The number of second depressions 3131 can be one or more. The number of second protrusions 3141 can be one or more.

[0100] The number of second depressions 3131 is equal to the number of second protrusions 3141.

[0101] See in some examples Figure 8 and Figure 9 As shown, the blade 31 has a second recess 3131 on the first side 313 and a second protrusion 3141 on the second side 314. In the third direction, the second recess 3131 of one of the two adjacent blades 31 is inserted into the second protrusion 3141 of the other blade 31.

[0102] See in some examples Figure 10 As shown, the blade 31 has two second recesses 3131 on the first side 313 and two second protrusions 3141 on the second side 314. In the third direction, the second recess 3131 of one of the two adjacent blades 31 is inserted into the second protrusion 3141 of the other blade 31.

[0103] In one possible implementation, see Figure 11 As shown, the first side 313 is provided with at least one third protrusion 3132, and the second side 314 is provided with at least one third recess 3142.

[0104] Among them, see Figure 12 As shown, in the third direction, the third protrusion 3132 of one of the two adjacent blades 31 is inserted into the third recess 3142 of the other blade 31. This arrangement allows the first side 313 to have the second recess 3131 and the third protrusion 3132, and the second side 314 to have the second protrusion 3141 and the third recess 3142. When rays pass between adjacent blades 31, they can be blocked by the second protrusion 3141 and the third protrusion 3132, thus preventing leakage from between the two adjacent blades 31.

[0105] The number of third depressions 3142 can be one or more. The number of third protrusions 3132 can be one or more.

[0106] The number of third depressions 3142 is equal to the number of third protrusions 3132.

[0107] In some examples, the blade 31 has a second recess 3131 and a third protrusion 3132 on the first side 313, and a second protrusion 3141 and a third recess 3142 on the second side 314.

[0108] In one possible implementation, the field shape of the primary collimator 200 and the maximum field shape of the multi-leaf collimator 300 are both circular, and the multi-leaf collimator 300 rotates relative to the primary collimator 200. This configuration allows adjustment of the orientation of the blades 31, enabling the field shape of the multi-leaf collimator 300 to adapt to the tumor shape, thereby meeting the needs of different treatment angles.

[0109] The primary collimator 200 is fixed in the radiotherapy equipment. The multi-leaf collimator 300 can rotate in the radiotherapy equipment.

[0110] The through hole 201 is circular in shape, which makes the primary collimator 200 form a circular firing field.

[0111] The multi-leaf collimator 300 includes two housings 32, each housing 32 having a semi-circular region 321 (see...). Figure 3 As shown), the two boxes 32 abut against each other in the X-axis direction, and the two semi-circular regions 321 form a full circular region, which forms the maximum field of the multi-leaf collimator 300.

[0112] Each housing 32 houses a blade assembly 30. The blades 31 of the blade assembly 30 are movable in the X-axis direction. Figure 1 The middle blade 31 is partially located within the semicircular region 321, and the blades 31 of the two blade groups 30 are not in contact. At this time, the blade 31 is in its initial state. Figure 2 The middle blade 31 is partially located within the semicircular region 321, and the two blades 31 of the two blade groups 30 are inserted into each other, at which point the blades 31 are in a closed state. When Figure 1 All the blades 31 in the box 32 move towards the inside of the box 32, so that both blade groups 30 are located inside the box 32. It can be understood that there are no blades 31 in the semi-circular area 321. At this time, the multi-blade collimator 300 forms the maximum field of fire. The area of ​​the maximum field of fire is the same as the two semi-circular areas 321. It can be understood that the shape of the maximum field of fire is circular.

[0113] In some examples, the blades 31 of the blade assembly 30 are arranged along a third direction, that is, along the Y-axis. Along this third direction, the blade 31 in the middle of the blade assembly 30 has the largest dimension in the second direction, and the blade 31 on the outermost side of the blade assembly 30 has the smallest dimension in the second direction. The dimensions of the blades 31 between the middle and outermost blades of the blade assembly 30 gradually decrease in the second direction. It can be understood that, along the third direction, the dimensions of the blades 31 on one side of the middle blade 31 gradually decrease in the second direction, and the dimensions of the blades 31 on the other side of the middle blade 31 gradually decrease in the second direction. This arrangement allows for space-saving installation when the blade assembly 30 is installed within the housing 32.

[0114] It should be noted that the blade assembly 30 includes a blade 31, which is the largest in size in the second direction, and the blade 31 is located in the middle of the blade assembly 30 in the third direction.

[0115] In some examples, the dimensions of each blade 31 in the second direction of the blade assembly 30 satisfy the following relationship:

[0116]

[0117] Among them, the dimension of the i-th blade in the blade group 30 along the -Y axis direction in the second direction is... .

[0118] The radius of the semicircular region 321 of the box 32 is R.

[0119] exist Figure 2 In the diagram, the central angle of the i-th blade in the two blade groups 30 along the -Y axis in the entire circular region is . ,in, Less than or equal to 180°.

[0120] exist Figure 2 When all blades 31 of the beam collimation system are closed, the portion of blade 31 located inside the housing 32 has a dimension of [missing value] in the second direction. .

[0121] A multi-leaf collimator 300 with the same dimensions as the individual blades 31 of the blade group 30 in the second direction (see [link]). Figure 13 and Figure 14 (As shown) In comparison, using the above-mentioned relationship to design the blade 31 can reduce the consumption of tungsten alloy materials by 15% to 25%, while saving 20% ​​to 30% of the space for the arrangement of the blade 31, making the overall structure of the multi-blade collimator more compact and reducing mechanical complexity.

[0122] In one possible implementation, the blade assembly 30 is installed in a housing 32, which is provided with a movable baffle (not shown in the figure) to block rays between two adjacent blades 31 in the third direction. With this configuration, when the blades 31 in the housing 32 extend, the baffle moves along with them, allowing it to block rays between two adjacent blades 31 and preventing ray leakage.

[0123] The baffle can be located on one side of the housing 32 in the +Z axis direction.

[0124] The baffle is equipped with a motor and a drive rod, allowing it to move in a second direction.

[0125] Both the shielding plate and the blade 31 are made of tungsten alloy. By shielding the blade 31 with the shielding plate, the thickness of the shielding material can be increased, reducing the possibility of radiation penetration.

[0126] This application provides a radiotherapy device, including a radiation source 100 and a beam collimation system, wherein the radiation source 100 is used to emit a beam to the beam collimation system.

[0127] The beam collimation system in this embodiment has the same structure as the beam collimation system provided in any of the above embodiments, and can bring the same or similar technical effects. It will not be described in detail here, but can be referred to the description of the above embodiments.

[0128] Variation 1 of Example 1

[0129] See Figures 13 to 15 As shown, the difference between the beam collimation system in Variation 1 of Embodiment 1 and the beam collimation system in Embodiment 1 is that the number of blades in the multi-leaf collimator 300 is insufficient to cover the circular field of the primary collimator 200.

[0130] The through hole 201 of the primary collimator 200 is circular, so that the primary collimator 200 forms a circular field of fire.

[0131] The structure of the multi-leaf collimator 300 is different. Specifically, the housing 32 of the multi-leaf collimator 300 does not have a semi-circular region. The individual blades 31 of the blade group 30 have the same dimensions in the second direction.

[0132] The multi-leaf collimator 300 also includes two blocking blocks 33, which are respectively disposed on both sides of the two blade groups 30 in a third direction. The two blocking blocks 33 are located between the two housings 32 and are fixedly connected to the two housings 32. It can be understood that the two blocking blocks 33 are fixed relative to the two housings 32.

[0133] Two blocking blocks 33 and two boxes 32 enclose a square area.

[0134] The shielding block 33 is made of tungsten alloy. The shielding block 33 is arc-shaped.

[0135] When all the blades 31 move toward the inside of the housing 32, so that both blade groups 30 are located inside the housing 32, the two blade groups 30 and the two blocking blocks 33 can block the edge of the circular field of the primary collimator 200. At this time, the multi-blade collimator 300 forms the maximum field of fire, and the shape of the maximum field of fire is square.

[0136] In this embodiment, the multi-leaf collimator 300 can rotate relative to the primary collimator 200.

[0137] The remaining parts of the modified Example 1 of Example 1 have the same structure and effect as Example 1.

[0138] Variation 2 of Example 1

[0139] See Figure 16 As shown, the difference between the beam collimation system in Variation 2 of Embodiment 1 and the beam collimation system in Embodiment 1 is that: in the first direction, the size of the concave-convex portion 311 is equal to the size of the blade body 312.

[0140] The structure and effects of the remaining parts in Variation 2 of Example 1 are the same as those in Example 1.

[0141] Variation 3 of Example 1

[0142] See Figure 17 As shown, the difference between the beam collimation system in Variation 3 of Embodiment 1 and the beam collimation system in Embodiment 1 is that: in the first direction, the size of the concave-convex portion 311 is equal to the size of the blade body 312.

[0143] The recessed surface 3114 is an arc surface. The recessed surfaces 3114 of each of the first recesses 3112 of the concave and convex portions 311 are located on the same arc surface. It can be understood that the shape of the first recess 3112 in this embodiment is different from the shape of the first recess 3112 in Embodiment 1.

[0144] The structure and effects of the remaining parts in Variation 3 of Example 1 are the same as those in Example 1.

[0145] Variation 4 of Example 1

[0146] See Figure 18 As shown, the difference between the beam collimation system in Variation 4 of Embodiment 1 and the beam collimation system in Embodiment 1 is that: in the first direction, the size of the concave-convex portion 311 is equal to the size of the blade body 312.

[0147] The recessed surface 3114 is a plane, and the side surface 3115 is a curved surface. It can be understood that the shape of the first recess 3112 in this embodiment is different from the shape of the first recess 3112 in Embodiment 1.

[0148] The structure and effects of the remaining parts in Variation 4 of Example 1 are the same as those in Example 1.

[0149] Example 2

[0150] See Figure 19 As shown, the difference between the beam collimation system in Embodiment 2 and the beam collimation system in Embodiment 2 is that the through hole 201 of the primary collimator 200 is square in shape, so that the primary collimator 200 forms a square beam field.

[0151] The multi-leaf collimator 300 has no obstruction block 33. When all the blades 31 of the multi-leaf collimator 300 move toward the inside of the housing 32, so that both blade groups 30 are located inside the housing 32, the multi-leaf collimator 300 forms the maximum field of view, and the shape of the maximum field of view is square.

[0152] In this embodiment, the multi-leaf collimator 300 cannot rotate relative to the primary collimator 200. That is, the primary collimator 200 and the multi-leaf collimator 300 are fixed in place in the radiotherapy device, and the multi-leaf collimator 300 is fixed relative to the primary collimator 200.

[0153] The structure and effects of the remaining parts in Example 2 are the same as those in Example 1.

[0154] Example 3

[0155] See Figures 20 to 24 As shown, the collimation system in Embodiment 3 differs from the collimation system in Embodiment 1 in that each blade 31 includes a fixing member 315, a telescopic member 316, and an elastic member 317. The fixing member 315 and the telescopic member 316 do not have protrusions or recesses 311. The blade 31 does not have a second recess 3131, a second protrusion 3141, a third recess 3142, or a third protrusion 3132.

[0156] The fixing member 315 and the telescopic member 316 are arranged sequentially in the first direction, and the fixing member 315 and the telescopic member 316 are slidably connected. Specifically, the fixing member 315 and the telescopic member 316 can slide using sliding protrusions and grooves.

[0157] The elastic member 317 is connected between the fixing member 315 and the telescopic member 316 in the second direction. Specifically, the fixing member 315 has a connecting protrusion 3152, and the elastic member 317 is connected between the connecting protrusion 3152 and the telescopic member 316 in the second direction.

[0158] The fastener 315 includes a fastening body 3151, a connecting protrusion 3152 and a protrusion 3153, with the connecting protrusion 3152 and the protrusion 3153 located on both sides of the fastening body 3151 in the first direction.

[0159] The end face of the fastener 315 includes a first plane 3154 and a first arc surface 3155 connected to each other. The first plane 3154 is located on the fastening body 3151, and a portion of the first arc surface 3155 is located on the fastening body 3151, while the other portion is located on the protrusion 3153.

[0160] The end face of the telescopic member 316 includes a second plane 3161 and a second arc surface 3162 connected to each other.

[0161] The first plane 3154 and the second plane 3161 are planar in shape.

[0162] The first arc surface 3155 and the second arc surface 3162 are circular arcs.

[0163] When the two opposing blades of the multi-leaf collimator 300 are opened, the first plane 3154 and the second plane 3161 of the blade 31 are located in the same plane, that is, the first plane 3154 and the second plane 3161 are aligned.

[0164] See Figure 23 and Figure 24 As shown, the fixing member 315 of one of the two opposing blades 31 is used to abut against the telescopic member 316 of the other blade 31. With this configuration, when the two opposing blades 31 of the multi-leaf collimator 300 are closed, the fixing member 315 of one of the opposing blades 31 abuts against the telescopic member 316 of the other blade 31. The fixing member 315 presses against the telescopic member 316, and the telescopic member 316 slides and compresses the elastic member 317. This causes the first plane 3154 and the second plane 3161 of the blade 31 to be misaligned, that is, the first plane 3154 and the second plane 3161 are located in different planes. Therefore, when the two opposing blades 31 are closed, there is no gap, which can prevent leakage from between the blades 31 of the two opposing multi-leaf collimators 300.

[0165] In one possible implementation, the fixing member 315 and the telescopic member 316 of each blade 31 are offset from each other in a third direction.

[0166] In some examples, see Figure 22 As shown, in the third direction, the dimensions of the fixing member 315 and the telescopic member 316 of the blade 31 are both D3, and the dimensions of the mutual misalignment between the fixing member 315 and the telescopic member 316 of the blade 31 are D4, which can be one-tenth of D3.

[0167] In the first direction, the fixing member 315 of one of the two adjacent blades 31 abuts against the telescopic member 316 of the other blade 31 in the first direction. With this arrangement, when a ray passes between the adjacent blades 31, it can be blocked by the fixing member 315 or the telescopic member 316 of the two adjacent blades 31, thereby preventing leakage from the two adjacent blades 31.

[0168] In the third direction, there is a gap between the fixing member 315 of one blade 31 and the fixing member 315 of the other blade 31, and there is a gap between the telescopic member 316 of one blade 31 and the telescopic member 316 of the other blade 31. This arrangement can reduce the friction between the two adjacent blades 31 during movement.

[0169] It should be pointed out that, Figure 20 and Figure 21 The shielding plate 34 in this embodiment has the same structure and effect as the shielding plate in embodiment one.

[0170] The structure and effects of the rest of the collimation system are the same as those in Implementation 1.

[0171] In other embodiments, the end faces of the fixing member 315 and the telescopic member 316 in Embodiment 3 are set as arc-shaped end faces. The fixing member 315 and the telescopic member 316 are provided with concave and convex portions 311. In this embodiment, the structure and effect of the concave and convex portions 311 are the same as those in Embodiment 1.

[0172] The technical features of the above-described embodiments can be combined in any way without conflicting with each other, and unless otherwise expressly limited, they all fall within the protection scope of this application.

[0173] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A beam collimation system, characterized in that, include: A primary collimator (200) having a through hole (201); A multi-leaf collimator (300) includes at least two blade groups (30), each blade group (30) includes multiple blades (31), each blade (31) is provided with a protrusion (311), the protrusion (311) includes multiple first protrusions (3111) spaced apart along a first direction, and a first recess (3112) is provided between two adjacent first protrusions (3111). At least two of the blade groups (30) include two blades (31) opposite each other in a second direction, wherein a first protrusion (3111) of one of the two opposite blades (31) is used to engage with a first recess (3112) of the other blade (31).

2. The beam collimation system according to claim 1, characterized in that, Each blade (31) is further provided with a blade body (312) connected to the protrusion (311), the protrusion (311) being located on one side of the blade body (312) in the second direction, and in the first direction, the size of the protrusion (311) being larger than the size of the blade body (312).

3. The beam collimation system according to claim 2, characterized in that, The concave and convex portions (311) extend beyond the blade body (312) on both sides in the first direction.

4. The beam collimation system according to claim 2, characterized in that, The concave-convex portion (311) has an arc-shaped end face (3113) on the side opposite to the blade body (312) in the second direction.

5. The beam collimation system according to claim 1, characterized in that, Each of the blades (31) has a first side (313) and a second side (314) in a third direction, the first side (313) being provided with at least one second recess (3131) and the second side (314) being provided with at least one second protrusion (3141). In the third direction, the second recess (3131) of one of the two adjacent blades (31) is inserted into the second protrusion (3141) of the other blade (31).

6. The beam collimation system according to claim 5, characterized in that, The first side (313) is provided with at least one third protrusion (3132), and the second side (314) is provided with at least one third recess (3142). In the third direction, the third protrusion (3132) of one of the two adjacent blades (31) is inserted into the third recess (3142) of the other blade (31).

7. The beam collimation system according to any one of claims 1-6, characterized in that, The field shape of the primary collimator (200) and the maximum field shape of the multi-leaf collimator (300) are both circular, and the multi-leaf collimator (300) rotates relative to the primary collimator (200).

8. The beam collimation system according to any one of claims 1-6, characterized in that, At least two of the blade groups (30) are arranged in a single layer in the first direction; or, at least two of the blade groups (30) are arranged in multiple layers in the first direction.

9. The beam collimation system according to claim 8, characterized in that, Along the third direction, the blade (31) located in the middle of the blade group (30) has the largest size in the second direction, the blade (31) located on the outermost side of the blade group (30) has the smallest size in the second direction, and the size of each blade (31) between the blade (31) located in the middle of the blade group (30) and the blade (31) located on the outermost side of the blade group (30) gradually decreases in the second direction.

10. The beam collimation system according to any one of claims 1-6, characterized in that, The shape of the first protrusion (3111) includes, but is not limited to, a rectangle, a trapezoid, or an arc. The shape of the first recess (3112) includes, but is not limited to, a rectangle, a trapezoid, or an arc.

11. The beam collimation system according to any one of claims 1-6, characterized in that, The collimator (300) also includes a housing (32), in which the blade assembly (30) is installed. A movable shield is provided on the housing (32) for shielding rays between two adjacent blades (31) in the third direction.

12. The beam collimation system according to any one of claims 1-6, characterized in that, The primary collimator (200) has a circular field shape, and the maximum field shape of the multi-leaf collimator (300) is square. The multi-leaf collimator (300) rotates relative to the primary collimator (200).

13. The beam collimation system according to any one of claims 1-6, characterized in that, The field shape of the primary collimator (200) and the maximum field shape of the multi-leaf collimator (300) are both square, and the multi-leaf collimator (300) is fixed relative to the primary collimator (200).

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