Primary collimator suitable for electron linear accelerator
By using a primary collimator in the electronic linear accelerator to replace the traditional primary and secondary collimators, the transformation of the illumination shape is achieved, which solves the problems of insufficient treatment space and radiation leakage, and improves the therapeutic space and radiation protection effect.
Patent Information
- Application Number
- CN202422264515.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-13
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-09-13
AI Technical Summary
The three-stage collimator design of existing medical electronic linear accelerators results in less than 50 cm of treatment space, poor patient experience, and increases the chance of radiation leakage.
The target unit, the primary collimator upper unit, the primary collimator lower unit, the equalizer and the ionization chamber are adopted, and a primary collimator is used to replace the traditional primary and secondary collimators, so as to realize the field of light from circular to square, and cool and shield through the heat dissipation cover and shield cover to reduce radiation leakage.
Effectively increase the treatment space by 10 cm or more, reduce the radiation leakage rate to less than 1‰, simplify the design and reduce costs.
Smart Images
Figure CN223053160U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of medical electron linear accelerators, and specifically relates to a primary collimator applicable to an electron linear accelerator. Background Art
[0002] A medical electron linear accelerator generally uses a primary collimator in the shape of a flared opening to constrain and collimate the beam. The field shape coming out of the primary collimator is circular, and then it is converted into a square through a secondary collimator. The secondary collimator (Jaw) is generally divided into upper and lower layers. Each layer is a pair of parallel tungsten alloy beam blockers that can move in an opening and closing manner. The upper and lower layers of blockers are perpendicular to each other, and the field can be limited within the required square area through the opening and closing movement. Modern accelerators are also equipped with single-layer or double-layer multi-leaf collimators (MLC), which are placed under the secondary collimator to perform the final conformal shaping of the tumor area. There are generally also devices such as transmission ionization chambers and flattening filters between the layers of collimators to monitor and shape the beam.
[0003] In the case where the source axis distance (SAD) is 1 meter, the axial space occupied by the above three-level collimators and other accessories reaches 50 cm or more, and the actual space left for patient treatment is less than 50 cm.
[0004] The existing three-level collimator design results in an actual treatment space of less than 50 cm, a narrow space, and a poor patient experience; moreover, the beam is converted from circular to square using two-level three-layer (the secondary collimator has upper and lower layers) collimators, wasting the space height and increasing the probability of radiation leakage. Content of the Utility Model
[0005] The purpose of the utility model is to provide a primary collimator applicable to an electron linear accelerator, so as to solve the problems of the narrow treatment space of the existing three-level collimator, poor patient experience, and easy increase in the probability of radiation leakage mentioned in the above background art.
[0006] To achieve the above purpose, the utility model provides the following technical solution: A primary collimator applicable to an electron linear accelerator, comprising a target unit, an upper unit of the primary collimator, a lower unit of the primary collimator, a flattening filter, and an ionization chamber arranged in sequence from top to bottom along the central axis. A radiation target is installed inside the target unit.
[0007] Preferably, a heat dissipation sleeve is sleeved on the outer surface of the target unit, and the outer side of the heat dissipation sleeve is attached to the inner wall of the upper unit of the primary collimator. The heat dissipation sleeve is used for the circulating cooling work of the constant temperature water system.
[0008] Preferably, a shielding cover is sleeved on the outer sides of the upper unit of the primary collimator and the lower unit of the primary collimator. The shielding cover is used for ray shielding work.
[0009] Preferably, a plurality of groups of upper screw holes are formed at the top of the upper unit of the primary collimator. When the upper unit of the primary collimator is installed with the shielding cover, bolts are passed through the upper screw holes and threadedly fixed to the surface of the shielding cover.
[0010] Preferably, a plurality of groups of lower screw holes are formed at the bottom of the lower unit of the primary collimator. When the lower unit of the primary collimator is installed with the shielding cover, bolts are passed through the lower screw holes and threadedly fixed to the surface of the shielding cover.
[0011] Preferably, the central axes of the ray target coincide with the central axes of the target unit, the upper unit of the primary collimator, the lower unit of the primary collimator, the flattening filter, and the ionization chamber respectively.
[0012] Preferably, the upper end surface inside the upper unit of the primary collimator coincides with the bottom of the target unit, and the cross-sectional shape of the top of the upper unit of the primary collimator is circular; the lower end surface of the upper unit of the primary collimator coincides with the upper end surface of the lower unit of the primary collimator, and the cross-sectional shape of the bottom of the upper unit of the primary collimator is square.
[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows: The primary collimator applicable to the electron linear accelerator is, from top to bottom along the central axis, a target unit, an upper unit of the primary collimator, a lower unit of the primary collimator, a flattening filter, and an ionization chamber; a heat dissipation sleeve is surrounded around the target unit for circulating cooling of the collimation system by a constant temperature water system. The present utility model adopts a primary collimator to replace the original primary and secondary collimators, realizes the function of converting the irradiation field from circular to square, saves the head space, reduces the radiation leakage probability and the difficulty of the shielding design caused by the cascade, and overcomes the problems such as insufficient treatment space and increased radiation leakage caused by the two-stage and three-layer structure of the primary and secondary collimators; In summary, the primary collimator with a circular-to-square design adopted by the present utility model can effectively replace the two-stage and three-layer structure of the traditional primary and secondary collimators, simplifies the design, improves the stability while saving costs; saves the head space, effectively increases the treatment space by 10 cm or more; reduces the radiation leakage caused by the cascade, and can reduce the head leakage rate to less than 1‰. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 is a three-dimensional external structure schematic diagram of the present utility model;
[0015] Figure 2 is a transverse cross-sectional structure schematic diagram of the present utility model;
[0016] Figure 3 is a longitudinal cross-sectional structure schematic diagram of the present utility model;
[0017] Figure 4 is a front view sectional structure schematic diagram of the present utility model;
[0018] Figure 5 This is the schematic diagram of the explosion structure of the present utility model.
[0019] In the figure: 1. Target unit; 11. Ray target; 2. Upper unit of primary collimator; 21. Upper screw hole; 3. Lower unit of primary collimator; 31. Lower screw hole; 4. Flattening filter; 5. Ionization chamber; 6. Shielding cover; 7. Heat dissipation sleeve cover. Specific embodiments
[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. In addition, the terms "first", "second", "third", "upper, lower, left, right", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. At the same time, in the description of the present utility model, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.
[0021] The structure of a primary collimator applicable to an electron linear accelerator provided by the present utility model is as Figure 1 , Figure 3 and Figure 4 shown, including a target unit 1, an upper unit 2 of the primary collimator, a lower unit 3 of the primary collimator, a flattening filter 4, and an ionization chamber 5 arranged in sequence from top to bottom along the central axis. A ray target 11 is installed inside the target unit 1. A heat dissipation sleeve cover 7 is sleeved on the outer surface of the target unit 1, and the outer side of the heat dissipation sleeve cover 7 is attached to the inner wall of the upper unit 2 of the primary collimator. The heat dissipation sleeve cover 7 is used for the circulating cooling work of the constant temperature water system. A shielding cover 6 is sleeved on the outer sides of the upper unit 2 of the primary collimator and the lower unit 3 of the primary collimator. The shielding cover 6 is used for ray shielding work.
[0022] From top to bottom along the central axis of the present utility model, there are a target unit 1, an upper unit 2 of the primary collimator, a lower unit 3 of the primary collimator, a flattening filter 4, and an ionization chamber 5; a heat dissipation sleeve cover 7 is surrounded around the target unit 1 for the circulating cooling of the collimation system by the constant temperature water system. The present utility model uses a primary collimator to replace the original primary and secondary collimators, realizing the function of converting the irradiation field from circular to square, saving the head space, and reducing the radiation leakage probability and the difficulty of the shielding design caused by the cascade.
[0023] Furthermore, as Figure 2 and Figure 5As shown in the figure, several groups of upper screw holes 21 are provided at the top of the upper unit 2 of the primary collimator. When the upper unit 2 of the primary collimator is installed with the shielding cover 6, bolts are passed through the upper screw holes 21 and threadedly fixed to the surface of the shielding cover 6. Several groups of lower screw holes 31 are provided at the bottom of the lower unit 3 of the primary collimator. When the lower unit 3 of the primary collimator is installed with the shielding cover 6, bolts are passed through the lower screw holes 31 and threadedly fixed to the surface of the shielding cover 6. The central axis of the ray target 11 coincides with the central axes of the target unit 1, the upper unit 2 of the primary collimator, the lower unit 3 of the primary collimator, the flattening filter 4, and the ionization chamber 5. The upper end surface inside the upper unit 2 of the primary collimator coincides with the bottom of the target unit 1, and the cross-sectional shape of the top of the upper unit 2 of the primary collimator is circular; the lower end surface of the upper unit 2 of the primary collimator coincides with the upper end surface of the lower unit 3 of the primary collimator, and the cross-sectional shape of the bottom of the upper unit 2 of the primary collimator is square.
[0024] During implementation, the function of the upper unit 2 of the primary collimator is to convert the radiation field of the beam from circular to square. The upper end surface inside the upper unit 2 of the primary collimator coincides with the bottom of the target unit 1, and the cross-sectional shape of the top of the upper unit 2 of the primary collimator is circular; the lower end surface of the upper unit 2 of the primary collimator coincides with the upper end surface of the lower unit 3 of the primary collimator, and the cross-sectional shape of the bottom of the upper unit 2 of the primary collimator is square; both the upper and lower units of this primary collimator are made of tungsten alloy material, and the manufacturing difficulty is not great after disassembly.
[0025] Working principle: When in use, from top to bottom along the central axis of the present utility model, there are the target unit 1, the upper unit 2 of the primary collimator, the lower unit 3 of the primary collimator, the flattening filter 4, and the ionization chamber 5 in sequence; a heat dissipation sleeve 7 is surrounded around the target unit 1 for circulating cooling of the collimation system by a constant temperature water system. The present utility model uses a primary collimator to replace the original primary and secondary collimators, realizing the function of converting the radiation field from circular to square, saving the head space, and reducing the radiation leakage probability and the difficulty of the shielding design caused by cascading.
[0026] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-mentioned exemplary embodiments, and without departing from the spirit or basic characteristics of the present utility model, the present utility model can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present utility model. Any reference signs in the claims should not be regarded as limiting the claimed rights.
Claims
1. A primary collimator suitable for an electron linear accelerator, comprising a target unit (1), a primary collimator upper unit (2), a primary collimator lower unit (3), a flattener (4) and an ionization chamber (5) arranged in sequence from top to bottom along a central axis, characterized in that: A ray target (11) is installed inside the target unit (1).
2. A primary collimator suitable for an electron linear accelerator according to claim 1, characterized in that: The outer surface of the target unit (1) is covered with a heat dissipation sleeve (7), and the outer side of the heat dissipation sleeve (7) is in contact with the inner wall of the primary collimator upper unit (2). The heat dissipation sleeve (7) is used for circulating cooling of a constant temperature water system.
3. The primary collimator for an electron linear accelerator according to claim 1, characterized in that: A shielding cover (6) is sleeved on the outer sides of the primary collimator upper unit (2) and the primary collimator lower unit (3), and the shielding cover (6) is used for radiation shielding.
4. The primary collimator for an electron linear accelerator according to claim 1, characterized in that: A plurality of groups of upper screw holes (21) are provided at the top of the primary collimator upper unit (2), and when the primary collimator upper unit (2) and the shielding cover (6) are installed, bolts are used to penetrate the upper screw holes (21) and are threadedly fixed to the surface of the shielding cover (6).
5. The primary collimator for an electron linear accelerator according to claim 1, characterized in that: A plurality of groups of lower screw holes (31) are provided at the bottom end of the primary collimator lower unit (3), and when the primary collimator lower unit (3) and the shielding cover (6) are installed, bolts are used to penetrate the lower screw holes (31) and are threadedly fixed to the surface of the shielding cover (6).
6. The primary collimator for an electron linear accelerator according to claim 1, characterized in that: The central axis of the ray target (11) coincides with the central axes of the target unit (1), the primary collimator upper unit (2), the primary collimator lower unit (3), the homogenizer (4) and the ionization chamber (5).
7. The primary collimator for an electron linear accelerator according to claim 1, characterized in that: The upper end surface inside the primary collimator upper unit (2) coincides with the bottom of the target unit (1), and the cross-sectional shape of the top of the primary collimator upper unit (2) is circular; the lower end surface of the primary collimator upper unit (2) coincides with the upper end surface of the primary collimator lower unit (3), and the cross-sectional shape of the bottom of the primary collimator upper unit (2) is square.