Radiotherapy equipment alignment precision detection device and detection method

Abstract

The invention discloses a radiotherapy equipment alignment precision detection device which comprises a beam output component and a light limiting cylinder which is arranged below the beam output component and needs to be aligned, the beam output end face of the beam output component is provided with at least three laser ranging components, and the at least three laser ranging components are distributed on a circle coaxial with the beam output component; a laser detection part is arranged on the mounting disc at the top of the light limiting cylinder, and is used for detecting the irradiation position of a laser beam of the laser ranging part; the invention also discloses a radiotherapy equipment alignment precision detection method. The automatic high-precision alignment of the radiotherapy equipment can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of radiotherapy equipment, and in particular to a radiotherapy equipment alignment accuracy detection device and a detection method. Background Art

[0002] Intraoperative radiotherapy equipment refers to a type of equipment that performs radiotherapy on the resected tumor lesion after the tumor lesion tissue is removed during surgery. In order to ensure that the resected area has sufficient dose deposition and reduce the dose exposure of other normal tissues, the beam of the beam-emitting component needs to be accurately aligned with the resected area after passing through the light-limiting tube to ensure the irradiation effect. In order to achieve precise alignment, existing intraoperative radiotherapy equipment uses various automated alignment technologies, and the alignment accuracy between the beam and the resected area or target area is continuously improved, and the alignment process is also continuously shortened.

[0003] However, the alignment devices or alignment methods of these devices still need to be tested for their claimed alignment accuracy. At present, some products have adopted special alignment accuracy detection devices. The main idea is to set a film on the upper end of the light-limiting tube, and after actual irradiation of the film, perform image analysis on the dose deposition beam spot on the film to check whether the center of the beam spot coincides with the center of the upper end of the light-limiting tube. If the center of the beam spot coincides with the upper end of the light-limiting tube, the alignment accuracy is high; if the center of the beam spot does not coincide with the upper end of the light-limiting tube, an evaluation can be made based on the distance between the two.

[0004] However, this method still has the following shortcomings: Due to the dose difference at the edge of the beam, the beam spot image on the film is generally not a very regular image after identification and processing, and some errors will be introduced when determining the center of the image. If the film image is a regular elliptical image, its center is also located at the center of the field. The actual alignment considered at this time does not mean that the beam is also aligned at the lesion resection site. Because the film is located at the top of the light-limiting tube, there is still a distance of tens of centimeters between the film and the lesion resection site. The elliptical beam spot most likely represents a certain inclination angle of the beam. After being transmitted through the light-limiting tube for tens of centimeters, it is entirely possible that an offset has occurred, resulting in insufficient irradiation dose to the resected part. It can be seen that the evaluation accuracy of this method cannot be guaranteed, and the evaluation process is also more cumbersome.

[0005] Therefore, it is urgent to propose a more accurate alignment accuracy evaluation device and method, and apply this method to radiotherapy equipment to evaluate and correct the automatic alignment process to ensure alignment accuracy. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a radiotherapy equipment alignment accuracy detection device and detection method, and the present invention can realize automatic high-precision alignment of the radiotherapy equipment.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a radiotherapy equipment alignment accuracy detection device, comprising a beam-emitting component and a light-limiting cylinder arranged below the beam-emitting component and requiring alignment, the beam-emitting end face of the beam-emitting component is provided with at least three laser ranging components, and at least three of the laser ranging components are distributed on a circle coaxial with the beam-emitting component; a laser detection component is provided on the mounting plate on the top of the light-limiting cylinder, and the laser detection component is used to detect the position of the laser beam irradiated by the laser ranging component.

[0008] As a further improvement of the present invention, the laser detection component includes a plurality of circular reflective strips coaxially arranged with the light-limiting tube, and the reflective colors of the plurality of reflective strips are different.

[0009] As a further improvement of the present invention, the plurality of reflective tapes are arranged adjacent to each other or spaced apart.

[0010] As a further improvement of the present invention, the diameter of one of the plurality of reflective tapes is the same as the diameter of the circle where the laser ranging component is located.

[0011] As a further improvement of the present invention, an angle indication mark with 360° is provided on the edge of the mounting plate at the top of the light-limiting tube.

[0012] The present invention also provides a method for detecting alignment accuracy of radiotherapy equipment, which is implemented by using the above-mentioned radiotherapy equipment alignment accuracy detection device, and the detection method comprises:

[0013] When the automatic alignment between the beam-emitting component and the light-limiting cylinder of the radiotherapy device is completed, the laser distance-measuring component emits laser to measure the distance;

[0014] According to the distances measured by all the laser distance measuring components, it is judged whether there is an angle error between the beam-emitting component and the light-limiting cylinder. If the distances measured by all the laser distance measuring components are equal, there is no angle error. Otherwise, there is an angle error, and the angle error is corrected.

[0015] When there is no angular error between the beam-emitting component and the light-limiting cylinder, it is further determined whether there is a displacement error between the beam-emitting component and the light-limiting cylinder. The laser detection component detects the position of the laser beam irradiated by the laser ranging component. If the center of the circle where the laser projection point is located coincides with the center of the mounting disk of the light-limiting cylinder, there is no displacement error. Otherwise, there is a displacement error, and the displacement error is corrected.

[0016] As a further improvement of the present invention, the angle error is corrected as follows:

[0017] According to the coordinates of multiple laser projection points detected by the laser detection component in the beam-emitting component coordinate system, the normal vector of the surface formed by the multiple coordinates is calculated. The angular error of the automatic alignment of the radiotherapy equipment can be determined based on the angle between the calculated normal vector and the beam-emitting direction, thereby realizing the correction of the angular error.

[0018] As a further improvement of the present invention, the displacement error is corrected as follows:

[0019] According to the coordinates of the projection points of multiple laser projection points detected by the laser detection component in the disk coordinate system of the light limiting tube mounting disk, the center of the circle determined by the multiple coordinates is calculated. The displacement error of the automatic alignment of the radiotherapy equipment can be determined based on the distance between the calculated center of the circle and the origin of the disk coordinate system, thereby realizing the correction of the displacement error.

[0020] The beneficial effects of the present invention are:

[0021] The automatic alignment detection device of the present invention can visually see the approximate range of the error, and the automatic alignment detection method of the present invention can conveniently calculate the specific error size, and can also feed back to the control module for correction, and even realize automatic correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the detection device in an embodiment of the present invention;

[0023] Figure 2 In the embodiment of the present invention Figure 1 DD view in;

[0024] Figure 3 It is a schematic diagram of the structure of the light-limiting tube installation plate in an embodiment of the present invention, i.e., a measurement diagram;

[0025] Figure 4 When there is no error in the embodiment of the present invention Figure 1 EE view in;

[0026] Figure 5 In the embodiment of the present invention, when there is only displacement error Figure 1 EE view in . DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] Example

[0029] like Figure 1 As shown, a radiotherapy equipment alignment accuracy detection device comprises:

[0030] The laser distance measuring components 10 are arranged on the beam-out end face of the beam-out component 32 of the treatment head of the intraoperative radiotherapy device, and the number is three or more. The laser distance measuring components 10 are distributed on a circle coaxial with the treatment head beam-out component 32. The beam axes of the laser beams emitted by these laser distance measuring components 10 are perpendicular to the end face of the treatment head.

[0031] The reflective tape 20 is arranged on the mounting plate 33 for mounting the marker ball on the existing light-limiting tube 31. There are multiple circular reflective tapes 20, which are arranged adjacent to each other and coaxially with the light-limiting tube 31. After the laser beam emitted by the laser distance measuring component 10 irradiates the reflective tape 20, the reflective tape 20 can emit light to indicate the position of the laser beam irradiation. At the same time, the light of the reflective tape 20 can provide a very convenient visual display of the test results, which is intuitive and clear at a glance.

[0032] The angle indicator mark 30 is arranged at the edge of the mounting plate 33 of the light limiting tube 31 and is marked with 360° angle indicator marks, with each 5° being a grid.

[0033] This embodiment also provides a method for detecting alignment accuracy of radiotherapy equipment, including:

[0034] S100, when the radiotherapy equipment is automatically aligned, the laser distance measuring component 10 emits laser to measure the distance;

[0035] S200, when the distances measured by all the laser distance measuring components 10 are equal, go to S300; when the distances measured by all the laser distance measuring components 10 are not equal, calculate the normal vector on the plane where the surface of the mounting plate 33 is located and in the same direction as the beam direction according to the spatial coordinates of the projection point under the beam coordinate system {S}, and the normal vector is the angle error; input the angle error into the automatic alignment control module of the radiotherapy equipment to correct the angle error; after the angle error is corrected, the distances measured by all the laser distance measuring components 10 are equal;

[0036] S300, reading the coordinates of the laser beam in the disk coordinate system {P}, and calculating the center coordinates of the circle where the projection point is located in the disk coordinate system {P}, the center coordinates of which are the displacement error, and inputting the displacement error into the automatic alignment control module of the radiotherapy equipment to correct the displacement error;

[0037] S400, completing automatic alignment accuracy calibration.

[0038] After the calibration, the radiotherapy equipment can be automatically aligned again with high precision.

[0039] This embodiment uses three laser distance measuring components to demonstrate the detection device and detection method:

[0040] Depend on Figure 1 , 2It can be seen that the beam-emitting component coordinate system {S} is defined as: the central axis of the beam-emitting component 32 is the X-axis, and the direction is consistent with the beam-emitting direction; the YZ plane is the end surface of the beam-emitting component 32, that is, the installation surface of the laser ranging component 10. The origin of the coordinate is set at the intersection of the beam axis and the YZ plane, following the right-hand rule. Figure 1 , 3 It can be seen that the disk coordinate system {P} is defined as: the origin is located at the disk center of the light-limiting tube mounting disk, the X′Y′ plane coincides with the mounting disk, the X′ axis points to the direction of the disk center and the 0° mark line, and the Y′ axis points to the direction of the disk center and the 90° mark line, also following the right-hand rule. Figure 1 shown.

[0041] The first laser distance measuring component 11, the second laser distance measuring component 12, and the third laser distance measuring component 13 are installed on the beam-outgoing end face of the treatment head. The positions of the three laser distance measuring components 10 are located on a circle coaxial with the beam-outgoing component 32 (the beam-out port of the beam-outgoing component 32 is cylindrical here, and it is assumed that the beam emitted by the intraoperative radiotherapy device is coaxial with the beam-outgoing component 32). The beam axes of the laser beams emitted by the three laser distance measuring components 10 are perpendicular to the treatment end face, or parallel to the axis of the beam-outgoing component 32, or parallel to the beam axis. (1) Here, the first laser distance measuring component 11, the second laser distance measuring component 12, and the third laser distance measuring component 13 can be evenly distributed on the circle mentioned above. This embodiment adopts even distribution, such as Figure 2 As shown, in the beam-out component coordinate system {S}, the spatial coordinates of the first laser ranging component 11, the second laser ranging component 12, and the third laser ranging component 13 are respectively (0, 0, -r), (0, r·s in60°, r·cos60°), (0, -r·s in60°, r·cos60°), where r is the radius of the circle where the laser ranging component is located; of course, the first laser ranging component 11, the second laser ranging component 12, and the third laser ranging component 13 may not be evenly distributed on the circle mentioned above, that is, they may be arranged on this circle in a normal interval manner.

[0042] Figure 3The arrangement of multiple reflective tapes 20 on the mounting disk 33 of the light-limiting tube 31 and the disk surface coordinate system {P} are also shown. In addition to the original optical marker ball 331, multiple circles of reflective tapes 20 are coaxially and adjacently arranged with the axis of the mounting disk 33 of the light-limiting tube 31 (of course, they can also be arranged non-adjacently, such as arranged at intervals; this embodiment shows an adjacent arrangement). The reflective tapes 20 are flatly embedded in the mounting disk 33 of the light-limiting tube 31, that is, the reflective tapes 20 are flush with the disk surface of the mounting disk 33 of the light-limiting tube. In this embodiment, 5 circles of reflective tapes are shown: from the inside to the outside, they are the first reflective tape 21, the second reflective tape 22, the third reflective tape 23, the fourth reflective tape 24, and the fifth reflective tape 25. The width of each reflective tape is 0.5 mm, and of course the width of the reflective tape can be set thinner, such as 0.1 mm. Each reflective tape can produce light of different colors when irradiated by a laser beam. In this embodiment, the first reflective tape 21 is green-purple, the second reflective tape 22 is yellow, the third reflective tape 23 is green, the fourth reflective tape 24 is orange, and the fifth reflective tape 25 is red. In this embodiment, the diameter of the third reflective tape 23 is the same as the diameter of the circle where the laser distance measuring component 10 is located.

[0043] The specific detection process is as follows: After the automatic alignment process of the intraoperative equipment is completed, under ideal conditions, the laser beams emitted by the first laser ranging component 11, the second laser ranging component 12, and the third laser ranging component 13 should all and only irradiate the third reflective tape 21, emitting green light and aligning in place. In fact, when there is a deviation in the automatic alignment, the three laser ranging components will irradiate multiple reflective tapes 20, and there will be multiple colors of light bands. That is to say, when the surface of the light-limiting tube mounting plate 33 emits multiple lights, there will be errors in the automatic alignment.

[0044] In order to evaluate the specific error size, the first laser distance measuring component 11, the second laser distance measuring component 12, and the third laser distance measuring component 13 can measure the distance between each of them and the light limiting tube mounting plate 33, which are: h1, h2, and h3 respectively.

[0045] (1) When h1, h2, and h3 are equal, there is no angle error:

[0046] If all three laser beams fall on the green reflective tape, the green reflective tape will be lit up and emit green light, and there will be no displacement error. Figure 4 As shown. If the green reflective tape on the mounting plate 33 of the light-limiting tube 31 is lit in addition to other colors, the alignment error only has a displacement error. For example, if green, yellow, and orange are all lit or yellow and orange are lit, the corresponding displacement error is 0.5×3=1.5mm, which exceeds the required accuracy. Figure 5 shown.

[0047] pass Figure 5It is also possible to make a quick calculation by observing the projection position. By observing the position of the projection point of the laser beam on the mounting disk 33 of the light-limiting cylinder 31, it is easy to read the radius and angle of each projection point on the mounting disk 33 of the light-limiting cylinder. Assume that the radius of the projection point of the laser beam of the first laser distance measuring component 11, the second laser distance measuring component 12, and the third laser distance measuring component 13 are r1, r2, and r3, respectively, and the angles of each projection point are θ1, θ2, and θ3, respectively. Then, in the disk surface coordinate system of the mounting disk 33 of the light-limiting cylinder, the coordinates of the projection point are (r1·cosθ1, r1·s inθ1), (r2·cosθ2, r2·s inθ2), and (r3·cosθ3, r3·s inθ3). Because h1, h2, and h3 are equal, the coordinates C of the center of the circle determined by these three coordinates are easy to calculate. The distance between this coordinate and the origin of the disk surface coordinate system is the displacement error, and this coordinate is also the alignment error value, which can be used to evaluate the automatic alignment accuracy. The projection coordinates here can of course also be recorded and calculated in the form of plane polar coordinates.

[0048] (2) When h1, h2, and h3 are not equal, there are both angle errors and displacement errors:

[0049] The coordinates of the projection points of the first laser ranging component 11, the second laser ranging component 12, and the third laser ranging component 13 on the mounting disk 33 in the beam-emitting component coordinate system {S} are respectively (h1, 0, -r), (h2, r·s in60°, r·cos60°), and (h3, -r·s in60°, r·cos60°). The surface formed by these three coordinates is the disk surface of the light-limiting tube mounting disk 33. The normal vector of the surface can be calculated from the above three coordinates. By selecting the normal vector in the same direction as the X-axis of the beam-emitting component coordinate system {S}, the angular error of the automatic alignment of the radiotherapy equipment can be determined.

[0050] The calculated angle error is directly input into the treatment head control module, and the angle error is eliminated by rotating around the origin of the beam component coordinate system {S}. At this time, h1, h2, and h3 become equal, and the displacement error can be calculated according to the aforementioned situation of "when h1, h2, and h3 are equal".

[0051] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A radiotherapy equipment alignment accuracy detection device, comprising a beam-emitting component and a light-limiting cylinder arranged below the beam-emitting component and requiring alignment, characterized in that: The beam-out end surface of the beam-out component is provided with at least three laser ranging components, and the laser ranging components are distributed on a circle coaxial with the beam-out component; a laser detection component is provided on the mounting plate at the top of the light-limiting cylinder, and the laser detection component is used to detect the position irradiated by the laser beam of the laser ranging component.

2. The radiotherapy equipment alignment accuracy detection device according to claim 1, characterized in that: The laser detection component includes a plurality of circular reflective strips coaxially arranged with the light-limiting tube, and the plurality of reflective strips have different reflective colors.

3. The radiotherapy equipment alignment accuracy detection device according to claim 2, characterized in that: The plurality of reflective tapes are arranged adjacent to each other or spaced apart.

4. The radiotherapy equipment alignment accuracy detection device according to claim 2 or 3, characterized in that: The diameter of one of the plurality of reflective tapes is the same as the diameter of the circle where the laser distance measuring component is located.

5. The radiotherapy equipment alignment accuracy detection device according to claim 1, characterized in that: An angle indication mark with 360° is provided on the edge of the mounting plate at the top of the light-limiting cylinder.

6. A method for detecting alignment accuracy of radiotherapy equipment, characterized in that: The detection method is implemented by using the radiotherapy equipment alignment accuracy detection device as described in any one of claims 1 to 5, and the detection method comprises: When the automatic alignment between the beam-emitting component and the light-limiting cylinder of the radiotherapy device is completed, the laser distance-measuring component emits laser to measure the distance; According to the distances measured by all the laser distance measuring components, it is judged whether there is an angle error between the beam-emitting component and the light-limiting cylinder. If the distances measured by all the laser distance measuring components are equal, there is no angle error. Otherwise, there is an angle error, and the angle error is corrected. When there is no angular error between the beam-emitting component and the light-limiting cylinder, it is further determined whether there is a displacement error between the beam-emitting component and the light-limiting cylinder. The laser detection component detects the position of the laser beam irradiated by the laser ranging component. If the center of the circle where the laser projection point is located coincides with the center of the mounting disk of the light-limiting cylinder, there is no displacement error. Otherwise, there is a displacement error, and the displacement error is corrected.

7. The method for detecting alignment accuracy of radiotherapy equipment according to claim 6, characterized in that: The correction of the angle error is as follows: According to the coordinates of multiple laser projection points detected by the laser detection component in the beam-emitting component coordinate system, the normal vector of the surface formed by the multiple coordinates is calculated. The angular error of the automatic alignment of the radiotherapy equipment can be determined based on the angle between the calculated normal vector and the beam-emitting direction, thereby realizing the correction of the angular error.

8. The method for detecting alignment accuracy of radiotherapy equipment according to claim 7, characterized in that: The displacement error correction is as follows: According to the coordinates of the projection points of multiple laser projection points detected by the laser detection component in the disk coordinate system of the light limiting tube mounting disk, the center of the circle determined by the multiple coordinates is calculated. The displacement error of the automatic alignment of the radiotherapy equipment can be determined based on the distance between the calculated center of the circle and the origin of the disk coordinate system, thereby realizing the correction of the displacement error.

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