Double-layer multi-leaf collimator

Abstract

The utility model discloses a double-layer multi-leaf collimator, and relates to the technical field of radiotherapy, the double-layer multi-leaf collimator comprises an upper layer collimator and a lower layer collimator, each layer collimator comprises two oppositely arranged box bodies and a leaf group installed in the box bodies, and the leaf group is driven by a motor to reciprocate along a first direction; a sliding mechanism and a driving mechanism are installed on one side of the outer portion of the box body, and the sliding mechanism and the driving mechanism are matched with each other, so that the box body reciprocates in the second direction. Wherein the second direction and the first direction are perpendicular to each other on the same plane. According to the utility model, the problems of low conformal precision and high leakage rate caused by the width of the blades of the multi-blade collimator in the prior art are solved, the double-side adjustable multi-blade collimator is provided, the leakage rate of the collimator is reduced, and the dose adjusting precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of radiotherapy, in particular to a double-layer multi-leaf collimator. Background Art

[0002] The medical electron linear accelerator is an important medical device commonly used in tumor treatment. It can generate high-energy electron beams or photon beams to irradiate tumor tissue to destroy cancer cells and control tumor growth. However, to ensure the accuracy and effectiveness of treatment, the shape and energy distribution of the beam must be accurately controlled to ensure that the tumor tissue receives an adequate dose while the surrounding normal tissue is minimally damaged. The multi-leaf collimator is one of the beam adjustment devices commonly used in linear accelerators. It consists of a series of movable metal leaves that are used to adjust the shape and size of the beam to match the shape and size of the tumor. However, existing multi-leaf collimators have some problems in practical applications:

[0003] 1. Leaf width limitation: In existing multi-leaf collimators, the width of the leaves is limited to a certain extent, which will limit the accuracy and conformality of the beam, resulting in a loss of treatment accuracy.

[0004] 2. High leakage rate: Gaps between blades or edge effects may cause beam leakage, making part of the dose unable to be accurately delivered to the tumor tissue, thereby reducing the treatment effect.

[0005] 3. Limitations of leaf side dose distribution: Affected by the inherent structure of the leaf side, the dose distribution on the leaf side is basically fixed. Utility Model Content

[0006] The purpose of this utility model is to solve the problem of low conformal accuracy and high leakage rate of multi-leaf collimators in the prior art due to the width of the leaves, and provide the following technical solutions:

[0007] A double-layer multi-leaf collimator comprises an upper and lower collimator layer, each layer comprising two opposing housings and a blade assembly mounted within the housings. The blade assembly is driven by a motor to reciprocate in a first direction. A sliding mechanism and a driving mechanism are mounted on one side of the housing exterior. The sliding mechanism and the driving mechanism cooperate to cause the housing to reciprocate in a second direction. The second direction is perpendicular to the first direction and lies in the same plane.

[0008] The sliding mechanism includes several slide rails arranged side by side along the second direction, the slide rails extend in the second direction, and several sliders adapted to the slide rails are provided on the slide rails. The sliders slide relative to the slide rails, and one side of the sliders is fixedly connected to the frame so that the sliders are fixed to the frame.

[0009] The driving mechanism includes a linear motor, a stator of the linear motor is installed on the outside of the box, and a mover of the linear motor is installed on the frame.

[0010] Preferably, the slide rails are provided in two groups.

[0011] Preferably, two sliders are provided.

[0012] Each of the blade groups includes a plurality of blades arranged side by side along the second direction, one end of the blade is installed in the box body, and the other end extends to the outside of the box body. Each of the blades performs reciprocating motion along the first direction under the drive of the motor.

[0013] Preferably, the box is in the shape of a rectangular parallelepiped.

[0014] The utility model has the following advantages:

[0015] Due to the irregular shape of the treatment area, when the multi-leaf collimator is conforming to the treatment area, there is a gap problem between two adjacent leaves, which leads to leakage problems in the gap formed between the two adjacent leaves when the upper collimator is conforming to the treatment area. At the same time, due to the limitation of the width of the leaves, when the leaves of the upper collimator are conforming to the treatment area, there is leakage of electron beam at the edge of the leaves close to the treatment area and the use of inaccurate dose during the process of matching the leaves with the treatment area. The design provided by the present invention solves the above problems. The specific principle of the solution is that the leaves of the upper collimator first pass through the treatment area according to the treatment area. The movement in the first direction and the second direction achieves conformity to the treatment area; the leaves of the lower collimator are then moved in the second direction so that the positions of the leaves of the lower collimator are not only staggered with the leaves of the upper collimator, so as to achieve the purpose of blocking the electron beam leaking from the gap between the two adjacent leaves of the upper collimator, but also, the leaves of the lower collimator, by moving in the first direction, will also conform to the treatment area according to the edge shape of the treatment area, which makes the leaves of the upper collimator and the lower collimator preferably have the smallest upper and lower layer deviation, so as to achieve the purpose of minimizing the leakage rate and improving the dose adjustment accuracy.

[0016] The multi-leaf collimator provided by the present invention is a double-layer design. The leaves of each layer of the collimator can not only move in the first direction, but also can move in the second direction at the same time by controlling the movement of the box in the second direction. This design not only blocks the light beams emitted between the gaps of the upper leaves by the lower leaves, thereby reducing the leakage rate, but also makes the misalignment deviation of the upper and lower leaves adjustable, getting rid of the design of fixed width of the leaves. The minimum deviation can be appropriately selected according to the shape of the treatment area. This misalignment deviation further reduces the leakage rate between the leaves, and can also modulate the width of the leaves to improve the conformity of the leaves, thereby improving the dosage accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the utility model;

[0018] Figure 2 Schematic diagram of the top view of the structure of the leaves of the upper collimator and the leaves of the lower collimator when the leaves of the multi-leaf collimator conform to the shape.

[0019] Among them: 1. collimator, 2. blade assembly, 3. housing, 4. stator, 5. mover, 6. slider, 7. slide rail, 8. drive mechanism, 9. slide machine, 10. blade. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein can be combined with each other.

[0023] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In the description of this utility model, it should be noted that the terms "upper" and "lower" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the utility model product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art. Such terms are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first" and "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0024] See Figure 1A double-layer multi-leaf collimator includes two layers of collimators 8, one above the other. Each layer of collimator 8 includes two oppositely arranged boxes 3 and a blade group 2 installed inside the boxes 3. The blade group 2 reciprocates along a first direction driven by a motor. A sliding mechanism 9 and a driving mechanism 8 are installed on one side of the outside of the boxes 3. The sliding mechanism 9 and the driving mechanism 8 cooperate with each other to make the boxes 3 reciprocate in a second direction. The driving mechanism 8 is used to drive the boxes to reciprocate in the second direction. The sliding mechanism makes the boxes slide relative to the mounting frame of the double-layer multi-leaf collimator. The movement of the boxes 3 in the second direction drives the blade group 2 to move in the second direction. The second direction and the first direction are perpendicular to each other on the same plane.

[0025] Each blade assembly 2 includes a plurality of blades 10 arranged side by side along the second direction. One end of each blade is mounted within the housing 3, and the other end extends outside the housing. Each blade 10 is driven by a motor to reciprocate along the first direction. The end of each blade 10 extending outside the housing is configured to conform to the treatment area with the opposing blade 10.

[0026] See Figure 2 (The dotted line portion in the figure shows the blades of the lower collimator, and the straight line portion shows the blades of the upper collimator). Due to the irregular shape of the treatment area, when the collimator is conforming to the treatment area, due to the gap problem between the two adjacent blades 10, when the blades of the upper collimator are conforming to the treatment area, there is a leakage problem in the gap formed between the two adjacent leaves 10. At the same time, due to the limitation of the width of the leaves, when the blades of the upper collimator are conforming to the treatment area, there is leakage of electron beams at the edge of the treatment area where the leaves 10 are close to the edge of the treatment area and the treatment area is matched. The design provided in this embodiment solves the above problems. The specific solution is originally The principle is that the blades of the upper collimator first conform to the treatment area by moving in the first direction and the second direction according to the treatment area; the blades of the lower collimator then move in the second direction, so that the positions of the blades of the lower collimator are not only staggered with the blades of the upper collimator, so as to achieve the purpose of blocking the electron beam leaking from the gap between the two adjacent blades of the upper collimator, but also, the blades of the lower collimator, by moving in the first direction, will also conform to the treatment area according to the edge shape of the treatment area, which makes the blades of the upper collimator and the lower collimator preferably have the smallest upper and lower layer deviation, so as to achieve the purpose of minimizing the leakage rate and improving the dose adjustment accuracy.

[0027] The sliding mechanism 9 includes several slide rails 7 arranged side by side along the second direction, and the slide rails 7 extend in the second direction. Several sliders 6 adapted to the slide rails 7 are provided on the slide rails 7. The sliders 6 slide relative to the slide rails 7, and one side of the slider 6 is fixedly connected to the frame so that the slider 6 is fixed to the frame.

[0028] In this embodiment, the slide rails 7 are provided in two groups. The reason for providing two groups is that at least two groups of slide rails 7 can fix the box body 3 more firmly.

[0029] In this embodiment, two sliders 6 are provided, and two sliders 6 are provided on each slide rail 7, which is also in consideration of the firmness of the box body 3 when it is fixed.

[0030] The driving mechanism 8 includes a linear motor, the stator 4 of the linear motor is installed outside the box 3, and the mover 5 of the linear motor is installed on the frame.

[0031] In this embodiment, when the linear motor is started, its mover 5 and stator 4 move relative to each other. Because the mover 5 is fixed to the frame, it drives the housing 3 to move in the second direction. Because the housing 3 and the frame are connected by a sliding connection between the slider 6 and the slide rail 7, the sliding connection drives the housing 3.

[0032] In this embodiment, the box body 3 is in the shape of a rectangular parallelepiped.

[0033] The working principle of this utility model is:

[0034] During use, the control system calculates the optimal movement distance of the blades in the first direction and the second direction according to the shape of the area to be treated, and then the control system controls the operation of the motor. The motor controls the blades on the two blade groups 2 of the upper collimator to move relative to each other in the first direction, and at the same time, the linear motor controls the box 3 to move in the second direction. After moving to the optimal position, the blades of the two blade groups 2 located on the upper collimator are arranged around to form a pattern similar to the treatment area; then the control system controls the two blade groups 2 of the lower collimator to move relative to each other in the first direction, and also controls the box 3 of the lower collimator to move in the second direction. The blades of the lower collimator will form a staggered distribution with the blades of the upper collimator according to needs. The blades of the upper collimator and the lower leaves of the lower collimator together obtain the optimal conformal area for the treatment area, thereby achieving the purpose of reducing the leakage rate. At the same time, because the leaves of the upper and lower layers are staggered, and the range of the staggered setting can be adjusted optimally according to the irregular shape of the edge of the treatment area after calculation, the error of the edge is minimized, and the leakage rate is lowest and the edge dose is most accurate.

[0035] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A double-layer multi-leaf collimator, characterized in that: The collimator comprises an upper and lower layer (1), each layer (1) comprising two boxes (3) arranged opposite to each other and a blade group (2) installed inside the boxes (3), wherein the blade group (2) performs reciprocating motion in a first direction under the drive of a motor; a sliding mechanism (9) and a driving mechanism (8) are installed on one side of the outside of the boxes (3), and the sliding mechanism (9) and the driving mechanism (8) cooperate with each other to enable the boxes (3) to perform reciprocating motion in a second direction; The second direction and the first direction are perpendicular to each other on the same plane.

2. A double-layer multi-leaf collimator according to claim 1, characterized in that: The sliding mechanism (9) comprises a plurality of slide rails (7) arranged side by side along a second direction, the slide rails (7) extending in the second direction, a plurality of sliders (6) adapted to the slide rails (7) being provided on the slide rails (7), the sliders (6) sliding relative to the slide rails (7), and one side of the sliders (6) being fixedly connected to the frame.

3. The double-layer multi-leaf collimator according to claim 1, characterized in that: The driving mechanism (8) comprises a linear motor, a stator (4) of the linear motor is mounted on the outside of the box (3), and a mover (5) of the linear motor is mounted on a frame.

4. The double-layer multi-leaf collimator according to claim 2, characterized in that: The slide rails (7) are provided in two groups.

5. The double-layer multi-leaf collimator according to claim 2, characterized in that: There are two sliders (6).

6. The double-layer multi-leaf collimator according to claim 1, characterized in that: Each of the blade groups (2) comprises a plurality of blades (10) arranged side by side along the second direction, one end of each of the blades (10) is mounted in the box (3), and each of the blades (10) performs reciprocating motion along the first direction under the drive of a motor.

7. The double-layer multi-leaf collimator according to claim 1, characterized in that: The box body (3) is arranged in a rectangular parallelepiped.

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