CN110812718B

CN110812718B - Positioning device for radiotherapy and positioning method for radiotherapy

Info

Publication number: CN110812718B
Application number: CN201911286515.1A
Authority: CN
Inventors: 吴爱林; 吴爱东; 张洪波; 刘云琴; 杨益东; 朱磊; 钱立庭
Original assignee: Anhui Provincial Hospital
Current assignee: Anhui Provincial Hospital
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2022-02-15
Anticipated expiration: 2039-12-13
Also published as: CN110812718A

Abstract

The application relates to the technical field of tumor radiotherapy and discloses a positioning device and a positioning method for radiotherapy, wherein the positioning device for radiotherapy comprises: a memory device, a substrate, and a plurality of securing mechanisms arranged in an array; the substrate is provided with a plurality of through holes corresponding to the fixing mechanisms, and the fixing mechanisms are arranged on the first side of the substrate; the fixing mechanism includes: the driving part and the abutting part are connected with each other, the abutting part can extend out of the corresponding through hole to reach the second side of the substrate under the driving of the driving part, and a sensor is arranged on the abutting part and used for monitoring an obstacle on the first side of the substrate; the driving part drives the abutting part to move, the sensor sends a first signal to the driving part according to the monitored obstacle, the driving part reaches a first position close to the obstacle according to the first signal, and the memory device is used for recording and helping to reset the first position. The method and the device have better use convenience on the premise of realizing high-precision repeated positioning.

Description

Positioning device for radiotherapy and positioning method for radiotherapy

Technical Field

The invention relates to the technical field of tumor radiotherapy, in particular to a positioning device for radiotherapy and a positioning method for radiotherapy.

Background

The latest national cancer statistical data released by the national cancer center shows that as long as 2019, 1 month, more than 1 million people in China have confirmed diagnosis of cancer on average every day, and about 7.5 people have confirmed diagnosis of tumor every minute. The disease rate of malignant tumor in China keeps 3.9% increase every year in the last decade, and the death rate is 2.5% increase every year. It is seen that cancer has become one of the major public health threats.

Currently, the main methods for cancer treatment include surgery, radiotherapy, chemotherapy, and the like. According to the cancer report data in the world, about 70% of tumor patients need to receive radiation therapy according to the stage and type of tumor. The radiotherapy generally refers to external irradiation, that is, the X-ray or electron beam generated by a medical linear accelerator is used to accurately irradiate the tumor part with multiple doses, so that the irradiated dose of the tumor target area is ensured as much as possible on the basis of the tolerance of normal tissues around the tumor.

Postural fixation is required prior to radiation treatment. In the prior art, there are generally two modes of operation. One is scan positioning. In this positioning, some plastic material (usually facial net for head and body frame combined with vacuum pad or fixing net) is used to fix the position of the patient. The second is radiotherapy positioning, which means that before receiving precise radiotherapy each time, a radiotherapy technician uses a laser lamp and a marking line to restore the patient on a treatment couch to the coordinate position of the patient during scanning and positioning, and then moves the tumor center of the patient to the treatment center of an accelerator according to the planned bed moving value.

The conventional radiotherapy is generally performed for 20-35 times, five times a week, and in addition, many patients need to adjust rest in the radiotherapy process, so the radiotherapy period is long, and generally varies from 1-2 months. This requires that the positioning before each radiotherapy be maintained with a certain degree of accuracy during the treatment. If the posture is fixed by mistake, on one hand, the normal tissues are exposed to more than the expected dose, which can cause the occurrence of radiotherapy accidents, and on the other hand, the tumor is not fully irradiated, so that irradiation is missed, and the tumor can relapse.

The prior radiotherapy body position fixing technology has the following defects:

firstly, when the auxiliary positioning is performed by adopting the plastic material, because the radiotherapy period is relatively frequent, the mask, the fixing net or the vacuum cushion need to be kept in a stable state in the period, and the situations of deformation, air leakage and the like can not exist, otherwise, errors can occur in positioning.

Secondly, when the plastic material is used for assisting positioning, a large amount of medical waste is generated, and the environment is not environment-friendly.

Moreover, the positioning and positioning equipment special for radiotherapy currently used in China is single, and only limited equipment is configured with high-level online calibration equipment (such as CBCT). Furthermore, due to the technical level limitations, even the correct use and daily quality control of such devices has not been appreciated by some primary hospitals. In addition, such devices have poor image clarity, are complex to operate, and are harmful to radiation, and in general, the frequency and effect of their use are not ideal. Therefore, in clinical practice, it is difficult to timely detect and correct the positioning error of the patient.

Finally, due to the limited medical radiotherapy equipment in China, a plurality of tumor patients are treated, and the time for each positioning is generally not more than 5 minutes, and some patients can not even reach 2 minutes. In addition, the radiotherapy technicians have uneven levels and high working pressure, and the attention is difficult to keep high concentration for a long time, which can cause the generation of radiotherapy positioning errors of patients.

Disclosure of Invention

In order to solve or partially solve the above technical problems, an embodiment of the present application provides a positioning apparatus for radiotherapy and a positioning method for radiotherapy.

Wherein, radiotherapy includes with putting position device: a memory device, a substrate, and a plurality of securing mechanisms arranged in an array;

the substrate is provided with a plurality of through holes corresponding to the fixing mechanisms, and the fixing mechanisms are arranged on the first side of the substrate;

the fixing mechanism includes: the driving part and the abutting part are connected with each other, the abutting part can extend out of the corresponding through hole to reach the second side of the substrate under the driving of the driving part, and a sensor is arranged on the abutting part and used for monitoring an obstacle on the second side of the substrate;

the driving part drives the abutting part to move, the sensor sends a first signal to the driving part according to the monitored obstacle, the driving part reaches a first position close to the obstacle according to the first signal, and the memory device is used for recording and helping to reset the first position.

Another embodiment of the present application relates to a radiotherapy positioning method, which is applied to the positioning device for radiotherapy, and includes the following steps:

the driving piece drives the abutting piece to move from the first side of the substrate through the second side;

when the sensor monitors that the butting piece is close to an obstacle, a first signal is sent to the driving piece, so that the butting piece stops moving, and the butting piece is located at a first position;

the memory device records the position of the butting piece;

the abutting piece is restored to the initial position;

the memory device monitors a reset command and sends the recorded position information to the driving piece;

the driving piece drives the butting piece to reach the first position according to the received position information.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be clear that the drawings in the following description are only intended to illustrate some embodiments of the present application, and that for a person skilled in the art, it is possible to derive from these drawings, without inventive effort, technical features, connections or even method steps not mentioned in the other drawings.

Fig. 1 is a general schematic view of a positioning apparatus for radiotherapy according to an embodiment of the present application;

FIG. 2 is a schematic view of a securing mechanism of an embodiment of the present application;

FIG. 3 is a schematic view of a substrate according to an embodiment of the present application;

fig. 4 is a positioning flowchart of a radiotherapy positioning method according to an embodiment of the present application;

fig. 5 is a flow chart of the reduction of the radiotherapy positioning method according to the embodiment of the present application;

fig. 6 is a schematic plan view of a radiotherapy positioning apparatus according to an embodiment of the present invention.

Description of reference numerals:

1. a memory device; 2. a substrate; 21. a through hole; 22. a communication module; 3. a fixing mechanism; 31. a holding member; 32. a drive member; 33. a base; 34. a cavity; 35. an indicator light; 4. a sensor; 5. an obstacle.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings. The structure and the like of the extrusion mechanism of the liposome extruder are schematically simplified in the drawings.

Implementation mode one

The inventor of the present application finds that in the prior art with publication number CN107596580A, a radiotherapy positioning body frame plate and a radiotherapy positioning method are provided. Wherein, be provided with pressure sensor on the radiotherapy location body frame plate body, pressure sensor includes pressure sensing point array, pressure sensor is used for measuring the gravity distribution of human body when lying on the body frame plate body. Before CT positioning scanning, the radiotherapy positioning body frame plate is fixed on a bed body of a CT scanner, and a first human body weight distribution result is obtained simultaneously after CT scanning; before the radiotherapy, will radiotherapy location body frame plate is fixed in on the bed body of radiotherapy machine, through the second human body gravity distribution data with real-time measurement and existing first people's weight distribution result compare, if there is the error of deflecting, then with the state when patient's health reduction to CT scans, and then revised the error of deflecting.

That is, in the prior art, there is a method of correcting the positioning positions of two times of lying by comparing the pressure distributions of two times of human bodies on an array of devices before and after the automatic radiotherapy positioning device.

However, the human body is three-dimensional, and the pressure sensing data recorded on a two-dimensional device does not represent the three-dimensional state of the human body well due to the difference in height of each part of the body. In addition, the patient's weight is subject to significant changes from treatment to treatment over radiotherapy cycles up to the last month. Therefore, the high-precision resetting cannot be realized by scanning the weight distribution result of the human body twice.

In view of the above, a first embodiment of the present application provides a positioning device for radiotherapy, as shown in fig. 1, 2 and 3, comprising:

a memory device 1, a substrate 2, and a plurality of fixing mechanisms 3 arranged in an array;

a plurality of through holes 21 are formed in the substrate 2 corresponding to the fixing mechanisms 3, and the fixing mechanisms 3 are arranged on the first side of the substrate 2;

the fixing mechanism 3 includes: the driving part 32 and the abutting part 31 are connected with each other, the abutting part 31 can extend out from the corresponding through hole 21 to reach the second side of the substrate 2 under the driving of the driving part 32, a sensor 4 is arranged on the abutting part 31, and the sensor 4 is used for monitoring the obstacle 5 on the second side of the substrate 2;

the driving member 32 drives the holding member 31 to move, the sensor 4 sends a first signal to the driving member 32 according to the detected obstacle 5, the driving member 32 reaches a first position adjacent to the obstacle 5 according to the first signal, and the memory device 1 is used for recording and assisting in resetting the first position.

Further optionally, the holding member 31 has a rod-shaped structure disposed along the length direction of the cavity 34, and an end of the holding member 31 has an upwardly convex curved surface on which a rubber pad is disposed. The curved surface can make the tolerance ratio of the abutting piece 31 better, and the rubber pad can improve the comfort of the patient.

In an embodiment of the present application, the memory device 1 may be a computer memory, which may be used for memorizing data. In actual use, the memory device 1 can record the moving distance of each abutting member 31 by matching the number of the abutting member 31 in a plaintext or encrypted manner. The memory device 1 and the fixing mechanism 3 can be connected in a communication manner via a special communication module 22. This communication module 22 may be a wired or wireless network, and is not limited in the embodiments of the present application.

It will be appreciated that the functions of the memory device 1 may be implemented by means of a complete computer. This function may also be implemented by a separate chip with certain computing and execution capabilities. For example, the memory device 1 may include a memory chip, a processing chip, and various interfaces and the like. The communication of the driving member 32 can be more conveniently realized by means of a computer or a singlechip architecture, so that the issuing of control commands is facilitated. It is furthermore understood that the memory device 1 may be integrated in the fixing organ 3, in addition to being provided separately.

For the embodiments of the present application, the base plate 2 may be constructed as a bed as shown in fig. 1 and 3, and may also be vertically placed, that is, the base plate 2 may be disposed vertically or parallel to the ground. When the base plate 2 is arranged perpendicular to the ground, the patient can stand on the ground or sit on a stool for positioning, and the base plate has good convenience. When the patient is present on the second side of the base plate 2, this constitutes the "obstacle 5" mentioned in the embodiments of the present application.

For the purposes of this application, the plurality of fastening means 3 arranged in an array may have the same or slightly different structure. In each fastening mechanism 3, there can be a separate drive element 32 for driving the abutment 31.

Specifically, alternatively, the driver 32 may be: any one of an air pump, a motor and a hydraulic machine. Correspondingly, the fixing mechanism 3 may include a base 33 having a cavity 34, the abutting member 31 is disposed in the cavity 34, and an opening of the cavity 34 is disposed opposite to the through hole 21.

When an air pump is used as the driving member 32, the driving member 32 may only retain an air inlet in the cavity 34. The holding member 31 is pneumatically pushed to move. Similarly, when a hydraulic press is used as the driving member 32, the driving member 32 may only retain the liquid inlet in the cavity 34. The holding member 31 is moved by hydraulic pressure.

When a motor is used as the driving member 32, the rotational motion of the motor can be converted into the linear motion of the holding member 31 by various transmission members. In particular, the conversion of the movement can be performed by means of a worm gear, a rack and pinion, a screw slider or the like. How to convert rotational motion into linear motion is a huge number of technical solutions in the prior art, which are not the main points of the invention of the present application, and therefore, are not described herein again.

In the embodiment of the present application, the sensor 4 may be provided at an end of the abutting piece 31. Alternatively, the sensors 4 may include any one or a combination of the following sensors 4:

pressure sensor, distance sensor, trigger button.

That is, when the pressure sensor detects that the pressure of the obstacle 5 against the holding member 31 reaches a predetermined value, a first signal, i.e., a stop signal, may be sent to the driving member 32. The retainer 31 will stop moving accordingly.

When a distance sensor is used, the principle is similar, and when the distance sensor detects that the distance between the obstacle 5 and the abutting member 31 reaches a predetermined value, a first signal, i.e. a stop signal, can be sent to the driving member 32. The retainer 31 will stop moving accordingly.

When a trigger button is used, the principle is still similar, and when the obstacle 5 touches the trigger button, a first signal, i.e. a stop signal, can be sent to the drive member 32. The retainer 31 will stop moving accordingly.

Optionally, the sensor 4 comprises a pressure sensor, the memory device 1 being further adapted to record pressure data of the sensor 4;

alternatively, the sensor 4 comprises a distance sensor, and the memory means 1 is also arranged to record distance data of the sensor 4.

The recorded pressure data or distance data can be used as a reference when reproducing the position, thereby improving the accuracy of position reproduction.

Based on the positioning device for radiotherapy, a first embodiment of the present application further provides a positioning method for radiotherapy, in which the positioning device for radiotherapy is applied, as shown in fig. 4 and 5, the positioning method includes the following steps:

the driving member 32 drives the abutting member 31 to move from the first side of the substrate 2 through the second side;

when the sensor 4 detects that the abutting part 31 is close to the obstacle 5, a first signal is sent to the driving part 32, so that the abutting part 31 stops moving, and the abutting part 31 is located at a first position;

the memory device 1 records the position of the holding member 31;

the abutting piece 31 is restored to the initial position;

acquiring the position information recorded by the memory device 1;

the driving member 32 drives the abutting member 31 to the first position based on the acquired position information.

Accordingly, the embodiment of the present application further provides a workflow of radiotherapy positioning, which is specifically as follows:

1. as shown in fig. 4. When the patient is firstly treated by radiotherapy, the patient needs to be put in position. The patient may lie on the base plate 2 and be positioned by conventional positioning methods. After the positioning is completed, a command is sent to the driving member 32 to drive the abutting member 31 to move from the first side to the second side of the substrate 2.

2. Taking the sensor 4 as a pressure sensor, when the sensor 4 detects that the pressure of the body of the patient on the abutting member 31 is greater than a predetermined force, such as 5 newtons or 20g, the driving operation of the driving member 32 is stopped.

Referring to fig. 1, for the fixing mechanism 3 without detecting the patient's body, it will drive the holding member 31 to the maximum stroke position, and accordingly, the fixing mechanism 3 arranged in the array will surround the patient to form a 3D film-like structure, which fixes the position of the patient precisely.

3. With the memory device 1, it is possible to save and record the positional information of the abutting pieces 31 in the respective fixing mechanisms 3 one by one. This position information can be represented by information on the stroke of each holding member 31, pressure information of the air rod or hydraulic machine, and the like. After the information recording is completed, the patient can be subjected to radiotherapy. The patient returns to the ward or home after the radiotherapy is finished.

4. When the patient is required to perform a second radiotherapy treatment, the patient lies on the base plate 2. At this point, a reset command may be sent to the system. The memory device 1, monitoring the reset command, can send the recorded position information to the driver 32.

It is worth mentioning that this "send" action may also be initiated and retrieved by the system, rather than being actively issued by the memory device 1. In any way, it is sufficient if the position information can be transmitted to the drive element 32.

As shown in fig. 5, the driving member 32 can reset each of the holding members 31 to the previously recorded first position according to the acquired position information. The patient can fit the body well into the contour formed by each fixing mechanism 3 by fine-tuning the position of his body.

5. Therefore, the position of the patient can be coincided with the position of the patient in the last radiotherapy without further positioning and adjustment. Can realize quick accurate pendulum position.

In the prior art, the sensors 4 are arranged on a plane, so that only the pressure of the lowest point of the body to the plane can be effectively recorded, the position information of the sensors is incomplete, and the reproducibility is poor.

Compared with the prior art, the technical scheme provided by the embodiment of the application records three-dimensional position information, so that the reproducibility is better.

The technical scheme provided by the embodiment of the application does not need to be assisted by traditional positioning auxiliary tools, such as a mask, a fixing net, a vacuum cushion and the like. On one hand, treatment errors caused by various factors such as deformation and air leakage of the positioning and positioning auxiliary tool are avoided, errors caused by the change of the body type of the patient are also avoided, and the storage and operation difficulties are overcome; on the other hand, the medical treatment device is beneficial to saving medical cost, relieving the economic pressure of patients, reducing the generation of medical wastes and having positive significance for environmental sanitation and protection.

According to the technical scheme provided by the embodiment of the application, the fixing device can be driven to form the three-dimensional positioning outline of the patient according to the recorded position information before treatment, so that the positioning and adjustment of auxiliary tools do not need to be considered, the probability of the patient being repositioned is reduced, the flow is more simple, convenient and direct, the treatment efficiency is improved, and the discomfort of the patient is relieved.

Furthermore, the technical scheme provided by the embodiment of the application automatically records and recovers the individualized three-dimensional positioning information of the patient, so that radiotherapy technicians do not need to check the execution plan list repeatedly, the operation process is simplified, errors caused by human factors are reduced, and the operation difficulty is obviously reduced.

Finally, it is worth mentioning that the technical scheme provided by the embodiment of the present application does not affect the use of the conventional online calibration device in the using process, and simultaneously, can also design to record the whole body pressure distribution curve of the patient each time, thereby providing sufficient data information during the radiotherapy of the patient and providing a basis for the formulation of the patient adaptive radiotherapy plan.

Second embodiment

The second embodiment of the present application provides a positioning device for radiotherapy, which is a further improvement of the first embodiment, and the main improvement is that, referring to fig. 6, the positioning device further comprises: the same number of indicator lights 35 as the number of the fixing mechanisms 3, one to one, are connected in communication with the memory device 1 to reproduce the position of the obstacle 5.

By providing the indicator light 35, the general contour of the obstacle 5 can be indicated before the retainer 31 is lifted, and thus the convenience of use of the apparatus can be improved.

Further alternatively, the indicator light 35 may be provided at an end portion of the holding member 31; alternatively, the indicator light 35 may be disposed at the edge of the through hole 21, for example, a ring-shaped light may be formed around the through hole. When the indicator lamp 35 is disposed on the substrate 2, the structure of the holding member 31 can be simplified, and the cost can be reduced.

Therefore, the radiotherapy positioning method in this embodiment may further include, after the step of acquiring the position information recorded in the memory device 1 and before the step of driving the driving member 32 to drive the abutting member 31 to the first position according to the acquired position information, the steps of:

the indicator lamp 35 draws the outline of the obstacle 5 based on the acquired position information.

Accordingly, the embodiment of the present application also provides a workflow for radiotherapy positioning, which is as follows:

It is worth mentioning that in the memory device 1, the pieces 31 of the abutment member that do not touch the obstacle 5 can be marked.

4. When the patient needs to do the second radiotherapy treatment, the memory device 1 calls the marking information to turn on the indicator light 35 corresponding to the holding piece 31 touching the obstacle 5. Or the indicator lights 35 touching the obstacle 5 may be turned on in their entirety. In this way, each indicator light 35 will outline the patient's body generally on the base plate 2.

The patient can lie conveniently on the base plate 2 against the outline formed by the indicator lights 35. At this point, a reset command may be sent to the system. The memory device 1, monitoring the reset command, can send the recorded position information to the driver 32.

It is to be understood that the terminology used in the description of the embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of the present application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and "a" and "an" generally include at least two, but do not exclude at least one, unless the context clearly dictates otherwise.

It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present application to describe certain components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. For example, a first certain component may also be referred to as a second certain component, and similarly, a second certain component may also be referred to as a first certain component, without departing from the scope of the embodiments of the present application.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.

In the various embodiments described above, while, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated by those of ordinary skill in the art that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein or not shown and described herein, as may be understood by those of ordinary skill in the art.

Those of skill would further appreciate that the various illustrative logical blocks, modules, units, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, units, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

Finally, it should be noted that those skilled in the art will appreciate that embodiments of the present application present many technical details for the purpose of enabling the reader to better understand the present application. However, the technical solutions claimed in the claims of the present application can be basically implemented without these technical details and various changes and modifications based on the above-described embodiments. Accordingly, in actual practice, various changes in form and detail may be made to the above-described embodiments without departing from the spirit and scope of the present application.

Claims

1. A positioning device for radiotherapy, which is characterized by comprising:

a memory device (1), a substrate (2) and a plurality of fixing mechanisms (3) arranged in an array;

a plurality of through holes (21) are formed in the substrate (2) corresponding to the fixing mechanisms (3), and the fixing mechanisms (3) are arranged on the first side of the substrate (2);

the fixing mechanism (3) includes: the driving part (32) and the abutting part (31) are connected with each other, the abutting part (31) can extend out of the corresponding through hole (21) to reach the second side of the substrate (2) under the driving of the driving part (32), a sensor (4) is arranged on the abutting part (31), the sensor (4) is used for monitoring an obstacle (5) on the second side of the substrate (2), and the sensor (4) is a pressure sensor;

the driving part (32) of each fixing mechanism (3) drives the abutting part (31) to move, and for the fixing mechanism (3) without detecting the obstacle (5), the driving part drives the abutting part (31) to the maximum stroke position;

the driving piece (32) drives the abutting piece (31) to move, when the sensor (4) detects that the pressure of the obstacle (5) on the abutting piece is larger than a preset value, a first signal is sent to the driving piece (32), the abutting piece (31) stops moving according to the first signal, at the moment, the abutting piece (31) is located at a first position close to the obstacle (5), and the memory device (1) is used for recording and helping to reset the first position.

2. A pendulum device for radiotherapy according to claim 1, characterized in that said sensor (4) comprises a pressure sensor, said memory means (1) being further adapted to record pressure data of said sensor (4);

alternatively, the sensor (4) comprises a distance sensor, the memory device (1) being further adapted to record distance data of the sensor (4).

3. The positioning device for radiotherapy according to claim 1, characterized in that said driving member (32) is: any one of an air pump, a motor and a hydraulic machine.

4. The pendulum device for radiotherapy according to claim 1, characterized in that the base plate (2) is disposed vertically or parallel to the ground.

5. The pendulum device for radiotherapy according to claim 1, wherein the fixing mechanism (3) comprises a base (33) having a cavity (34), the abutting member (31) is disposed in the cavity (34), and an opening of the cavity (34) is disposed opposite to the through hole (21).

6. The pendulum device for radiotherapy according to claim 5, wherein the holding member (31) has a rod-shaped structure disposed along the length direction of the cavity (34), and the end of the holding member (31) has a curved surface protruding upward, and the curved surface is provided with a rubber pad.

7. The positioning device for radiotherapy according to claim 1, further comprising: the number of the indicator lights (35) is the same as that of the fixing mechanisms (3), and the indicator lights (35) are in one-to-one correspondence with the memory devices (1) to be in communication connection with the memory devices (1) so as to reproduce the positions of the obstacles (5).

8. The pendulum device for radiotherapy according to claim 7, characterized in that the indicator light (35) is arranged at the end of the holding member (31);

or the indicator light (35) is arranged at the edge of the through hole (21).

9. A radiotherapy positioning method applied to the positioning device for radiotherapy in any one of claims 1 to 8, comprising the following steps:

the driving piece (32) drives the abutting piece (31) to move from the first side to the second side of the substrate (2);

when the sensor (4) monitors that the abutting part (31) is close to the obstacle (5), a first signal is sent to the driving part (32) to stop the movement of the abutting part (31), and the abutting part (31) is located at a first position;

the memory device (1) records the position of the holding piece (31);

the abutting piece (31) returns to the initial position;

-acquiring position information recorded by the memory device (1);

the driving piece (32) drives the abutting piece (31) to the first position according to the acquired position information.