Radiotherapy quality control method for detecting and positioning laser sag and twist

Abstract

The invention relates to the technical field of radiotherapy, and particularly discloses a radiotherapy quality control method for detecting and positioning laser sag and twist, which is mainly completed through cooperation of a measuring device, the measuring device comprises a bottom plate, and four vertex angle positions of the lower end surface of the bottom plate are respectively provided with an adjusting base capable of finely adjusting height. The two vertex angle positions of one side of the upper end face of the bottom plate are each provided with a supporting rod in an inclined state. The device can be used for measuring and positioning laser sag and torsion, and has the following specific effects: 1, the top laser sag arranged on a cross section can be detected, namely whether rotation around the X axis exists or not; 2, the laser sag of the top arranged on the sagittal plane can be detected, namely, whether rotation around the Y axis exists or not can be detected; 3, the laser twist of the left wall arranged on the cross section can be detected, namely whether the left wall rotates around the X axis or not; 4, the laser twist of the right wall arranged on the cross section can be detected, namely whether the right wall rotates around the X axis or not; and 5, the laser twist of the bed tail arranged on the sagittal plane can be detected, namely whether the bed tail rotates around the Y axis or not.

Description

Technical Field

[0001] The present invention relates to the field of radiotherapy technology, and more specifically, it relates to a radiotherapy quality control method for detecting the verticality and torsion of positioning lasers. Background Art

[0002] Radiotherapy quality control devices are used to measure the verticality and torsion of positioning lasers in a medical linear accelerator room. With the advent of the era of precision radiotherapy, the quality control of radiotherapy-related equipment has become more stringent. The accuracy of positioning lasers directly affects the accuracy of radiotherapy positioning and resetting of patients, and is closely related to the treatment effect.

[0003] Currently, it is difficult to measure the perpendicularity of the top laser of an accelerator and a CT simulation locator. The existing method is to use the principle of water surface reflection and confirm the verticality of the top laser by observing the coincidence degree of the incident light and the reflected light. However, this method has the following disadvantages: 1. The reflected light is very weak, and the detection result can only be observed by the naked eye, and the measurement result is very subjective. 2. The measurement result can only qualitatively judge whether the top laser is vertically irradiated, and cannot quantitatively measure the deviation angle.

[0004] Therefore, there is an urgent need for a new radiotherapy quality control technology that can accurately measure the verticality of lasers. Summary of the Invention

[0005] The present invention provides a radiotherapy quality control method for detecting the verticality and torsion of positioning lasers to solve the above technical problems.

[0006] A radiotherapy quality control method for detecting the verticality and torsion of positioning lasers is mainly completed in cooperation with a measuring device. The measuring device includes a bottom plate. At each of the four corner positions on the lower end surface of the bottom plate, an adjusting base capable of fine-tuning the height is installed. At each of the two corner positions on one side of the upper end surface of the bottom plate, an inclined support rod is provided. The two support rods are symmetrically arranged. A high-precision scale is provided between the tops of the two support rods. The middle of the top of the high-precision scale is denoted as point A. In the middle of the side surface of the bottom plate close to the support rod, a bubble level is provided. The middle of the upper end surface of the bottom plate where the bubble level is located is denoted as point O. On the middle of one side surface of the bottom plate perpendicular to the side surface of the bottom plate where point O is located, a bubble level is provided. The middle of the upper end of the other side surface of the bottom plate opposite to the side surface of the bottom plate where point O is located is recorded as O 1 point, and points O and O 1 form an alignment line of OO 1 ; The angle formed between the upper end surface of the bottom plate and the lower inclined surfaces of the two support rods is 60 degrees;

[0007] The radiotherapy quality control method for detecting the verticality and torsion of positioning lasers specifically includes the following steps:

[0008] Step S1: Turn the side of the measuring device with the scale towards the laser position to be measured;

[0009] Step S2: Place the measuring device flat on the treatment bed and level the adjustment base according to the indication of the bubble level.

[0010] Step S3: Align the cross-sectional laser on the right wall with the bottom plate OO 1 alignment line for positioning.

[0011] Step S4: The emitted laser intersects the high-precision scale at point B. If point B coincides with point A, it is determined that the laser twist is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end surface of the bottom plate are A 1 point and B 1 point respectively, then it is determined that the laser twist deviates, and the deviation angle is ∠A 1 BB 1 ;

[0012] Step S5: Since point A 1 , point B 1 are the projections of point A and point B on the high-precision scale on the bottom plate respectively, the distance between points A and B on the high-precision scale is equal to the distance between A 1 , B 1 points. Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, from which the deviation angle ∠A 1 BB 1 = arctan(A 1 B 1 / B 1 B).

[0013] Preferably, the upper surface of the high-precision scale is in the same plane as the upper inclined surfaces of the two support rods.

[0014] Preferably, when measuring the verticality of the top laser set for the cross-section, the radiotherapy quality control method for detecting the verticality and twist of the laser specifically includes the following steps:

[0015] Step S1: Place the measuring device flat on the treatment bed and level the adjustment base according to the indication of the bubble level.

[0016] Step S2: Align the top laser set for the cross-section with the bottom plate OO 1 alignment line for positioning.

[0017] Step S3: The emitted top laser intersects the high-precision scale at point B. If point B coincides with point A, it is determined that the laser verticality is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end surface of the bottom plate are A 1 point and B1 If the point is reached, it is determined that the laser verticality deviates, and the deviation angle is ∠A 1 BB 1 ;

[0018] Step S4. Since point A 1 point and point B 1 are respectively the projections of point A and point B on the high-precision scale on the bottom plate, the distance between points A and B on the high-precision scale is equal to the distance between points A 1 and B 1 . Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, the deviation angle ∠A 1 BB 1 = arctan(A 1 B 1 / B 1 B).

[0019] Preferably, when measuring the top laser verticality set for the sagittal plane, the radiotherapy quality control method for detecting and positioning laser verticality and torsion specifically includes the following steps:

[0020] Step S1. Place the measuring device flat on the treatment bed and level the adjustment base according to the indication of the bubble level;

[0021] Step S2. Align the top laser set for the sagittal plane with the alignment line of the bottom plate OO 1 for positioning;

[0022] Step S3. The emitted top laser intersects the high-precision scale at point B. If point B coincides with point A, it is determined that the laser verticality is good; if point B does not coincide with point A, and the corresponding projections of points A and B on the upper end face of the bottom plate are points A 1 point and B 1 point respectively, then it is determined that the laser verticality deviates, and the deviation angle is ∠A 1 BB 1 ;

[0023] Step S4. Since point A 1 point and point B 1 are respectively the projections of point A and point B on the high-precision scale on the bottom plate, the distance between points A and B on the high-precision scale is equal to the distance between points A 1 and B 1 . Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, the deviation angle ∠A 1 BB 1 = arctan(A1 B 1 / B 1 B).

[0024] Preferably, when measuring the laser twist of the left wall set in the cross-section, the radiotherapy quality control method for detecting the laser verticality and twist specifically includes the following steps:

[0025] Step S1: Turn the side with scale of the measuring device towards the left wall;

[0026] Step S2: Place the measuring device flat on the treatment bed and level the adjusting base according to the indication of the bubble level;

[0027] Step S3: Align the left wall laser set in the cross-section with the bottom plate OO 1 alignment line for positioning;

[0028] Step S4: The emitted left wall laser intersects the high-precision scale at point B. If point B coincides with point A, it is determined that the laser twist is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end surface of the bottom plate are A 1 point and B 1 point respectively, then it is determined that the laser twist deviates, and the deviation angle is ∠A 1 BB 1 ;

[0029] Step S5: Since point A 1 point, B 1 point are the projections of point A and point B on the high-precision scale on the bottom plate respectively, the distance between points A and B on the high-precision scale is equal to the distance between A 1 , B 1 points. Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, the deviation angle ∠A 1 BB 1 = arctan(A 1 B 1 / B 1 B).

[0030] Preferably, when measuring the laser twist of the right wall set in the cross-section, the radiotherapy quality control method for detecting the laser verticality and twist specifically includes the following steps:

[0031] Step S1: Turn the side with scale of the measuring device towards the right wall;

[0032] Step S2: Place the measuring device flat on the treatment bed and level the adjusting base according to the indication of the bubble level;

[0033] Step S3: Align the right-wall laser set on the cross-section with the bottom plate OO 1 and perform the positioning according to the alignment line;

[0034] Step S4: The emitted right-wall laser intersects the high-precision scale at point B. If point B coincides with point A, it is determined that the laser twist is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end face of the bottom plate are A 1 point and B 1 point respectively, then it is determined that the laser twist deviates, and the deviation angle is ∠A 1 BB 1 ;

[0035] Step S5: Since point A 1 and point B 1 are the projections of point A and point B on the high-precision scale on the bottom plate respectively, the distance between points A and B on the high-precision scale is equal to the distance between A 1 and B 1 points. Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, the deviation angle ∠A 1 BB 1 can be calculated as arctan(A 1 B 1 / B 1 B).

[0036] Preferably, when measuring the laser twist of the foot of the bed set on the sagittal plane, the radiotherapy quality control method for detecting the verticality and twist of the positioning laser specifically includes the following steps:

[0037] Step S1: Turn the side with scale of the measuring device towards the foot of the bed;

[0038] Step S2: Place the measuring device flat on the treatment bed and level the adjustment base according to the indication of the bubble level;

[0039] Step S3: Align the foot-of-the-bed laser set on the sagittal plane with the bottom plate OO 1 and perform the positioning according to the alignment line;

[0040] Step S4: The emitted foot-of-the-bed laser intersects the high-precision scale at point B. If point B coincides with point A, it is determined that the laser twist is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end face of the bottom plate are A 1 point and B 1 point respectively, then it is determined that the laser twist deviates, and the deviation angle is ∠A 1 BB 1 ;

[0041] Step S5: Since A1 Points A and B 1 The points are the projections of points A and B on the high-precision scale ruler onto the bottom plate. Therefore, the distance between points A and B on the high-precision scale ruler is equal to the distance between points A and B. Given that OA = OO 1 and B 1 are equal, and AA 1 = BB 1 = OAcos60°. From this, the deviation angle ∠A 1 BB 1 can be calculated as arctan(A 1 B 1 / B 1 / B 1 ).

[0042] The beneficial effects of the present invention are as follows. The present invention can be used to measure and locate the laser verticality and torsion, and the specific functions are as follows: 1. It can detect the top laser verticality set in the cross-section, that is, whether there is rotation around the X-axis; 2. It can detect the top laser verticality set in the sagittal plane, that is, whether there is rotation around the Y-axis; 3. It can detect the left wall laser torsion set in the cross-section, that is, whether there is rotation around the X-axis; 4. It can detect the right wall laser torsion set in the cross-section, that is, whether there is rotation around the X-axis; 5. It can detect the bed tail laser torsion set in the sagittal plane, that is, whether there is rotation around the Y-axis. Description of the Drawings

[0043] Figure 1 is a measurement schematic diagram of a radiotherapy quality control method for detecting and locating the laser verticality and torsion of the present invention.

[0044] Figure 2 is a three-dimensional structural diagram of the measurement device of the present invention.

[0045] Figure 3 is a placement position diagram of the measurement device of the present invention.

[0046] Figure 4 is a top view of the measurement device of the present invention.

[0047] Figure 5 is a left view of the measurement of the present invention.

[0048] In the figure: 1. High-precision scale ruler; 2. Alignment line; 3. Bottom plate; 4. Adjusting base; 5. Bubble level; 6. Support rod. Detailed Embodiments

[0049] Reference will now be made to example embodiments to discuss the subject matter described herein. It should be understood that these embodiments are discussed so that those skilled in the art can better understand and thus implement the subject matter described herein. Changes can be made to the functions and arrangements of the elements discussed without departing from the scope of protection of the content of this specification. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described relative to some examples can also be combined in other examples.

[0050] Example 1

[0051] A radiotherapy quality control method for detecting and positioning laser sag and torsion is mainly completed in cooperation with a measuring device. The measuring device includes a bottom plate 3. At each of the four corner positions on the lower end surface of the bottom plate 3, an adjusting base 4 capable of fine-tuning the height is installed. At each of the two corner positions on one side of the upper end surface of the bottom plate 3, an inclined support rod 6 is provided. The two support rods 6 are symmetrically arranged. A high-precision scale 1 is provided between the tops of the two support rods 6. The upper surface of the high-precision scale 1 is in the same plane as the upper inclined surfaces of the two support rods 6. The middle of the top of the high-precision scale 1 is denoted as point A. A bubble level 5 is provided in the middle of the side surface of the bottom plate 3 close to the support rod 6. The middle of the upper end surface of the bottom plate 3 where the bubble level 5 is located is denoted as point O. A bubble level 5 is provided in the middle of one side surface of the bottom plate 3 perpendicular to the side surface where the O point of the bottom plate is located. The middle of the upper end of the other side surface of the bottom plate 3 opposite to the side surface where the O point of the bottom plate 3 is located is recorded as O 1 point, and O point and O 1 point form the alignment line 2 of OO 1 ; The angle formed between the upper end surface of the bottom plate 3 and the lower inclined surfaces of the two support rods 6 is 60 degrees.

[0052] When measuring the top laser sag of the cross-section, the radiotherapy quality control method for detecting and positioning laser sag and torsion specifically includes the following steps:

[0053] Step S1: Place the measuring device flat on the treatment bed and level the adjusting base 4 according to the indication of the bubble level 5;

[0054] Step S2: Align the top laser of the cross-section with the alignment line 2 of OO 1 of the bottom plate 3 for positioning;

[0055] Step S3: The emitted top laser intersects the high-precision scale 1 at point B. If point B coincides with point A, it is determined that the laser sag is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end surface of the bottom plate 3 are A 1 point and B 1 point respectively, then it is determined that the laser sag deviates, and the deviation angle is ∠A 1 BB 1 ;

[0056] Step S4. Since point A 1 and point B 1 are the projections of point A and point B on the high-precision scale 1 onto the bottom plate 3 respectively, the distance between points A and B on the high-precision scale 1 is equal to the distance between points A 1 and B 1 . Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, the deviation angle ∠A 1 BB 1 = arctan(A 1 B 1 / B 1 ).

[0057] Embodiment 2

[0058] Based on the measuring device in Embodiment 1, when measuring the top laser sagittal plane, the radiotherapy quality control method for detecting and positioning laser sagittal plane and torsion specifically includes the following steps:

[0059] Step S1. Place the measuring device flat on the treatment bed and level the adjusting base 4 according to the indication of the bubble level 5;

[0060] Step S2. Align the top laser set in the sagittal plane with the alignment line 2 of the bottom plate 3 for positioning; 1

[0061] Step S3. The emitted top laser intersects the high-precision scale 1 at point B. If point B coincides with point A, it is determined that the laser sagittal plane is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end face of the bottom plate 3 are point A 1 and point B 1 respectively, then it is determined that the laser sagittal plane deviates, and the deviation angle is ∠A 1 BB 1 ;

[0062] Step S4. Since point A 1 and point B 1 are the projections of point A and point B on the high-precision scale 1 onto the bottom plate 3 respectively, the distance between points A and B on the high-precision scale 1 is equal to the distance between points A 1 and B 1 . Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, the deviation angle ∠A 1 BB 1 = arctan(A​1 B 1 / B 1 B).

[0063] Example 3

[0064] Based on the measuring device in Example 1, when measuring the laser torsion of the left wall set in the cross-section, the radiotherapy quality control method for detecting the laser verticality and torsion specifically includes the following steps:

[0065] Step S1: Turn the side with scale of the measuring device towards the left wall;

[0066] Step S2: Place the measuring device flat on the treatment bed and level the adjusting base 4 according to the indication of the bubble level 5;

[0067] Step S3: Align the left wall laser set in the cross-section with the OO 1 alignment line 2 of the bottom plate 3 for positioning;

[0068] Step S4: The emitted left wall laser intersects the high-precision scale 1 at point B. If point B coincides with point A, it is determined that the laser torsion is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end surface of the bottom plate 3 are A 1 point and B 1 point respectively, then it is determined that the laser torsion deviates, and the deviation angle is ∠A 1 BB 1 ;

[0069] Step S5: Since point A 1 , point B 1 are the projections of point A and point B on the high-precision scale 1 on the bottom plate 3 respectively, the distance between points A and B on the high-precision scale 1 is equal to the distance between A 1 , B 1 points. Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, from which the deviation angle ∠A 1 BB 1 = arctan(A 1 B 1 / B 1 B).

[0070] Example 4

[0071] When measuring the laser torsion of the right wall set in the cross-section, the radiotherapy quality control method for detecting the laser verticality and torsion specifically includes the following steps:

[0072] Step S1: Turn the side with scale of the measuring device towards the right wall;

[0073] Step S2: Place the measuring device flat on the treatment bed and level the adjusting base 4 according to the indication of the bubble level 5;

[0074] Step S3: Align the right-wall laser set in the cross-section with the OO 1 alignment line 2 of the bottom plate 3 for positioning;

[0075] Step S4: The emitted right-wall laser intersects the high-precision scale 1 at point B. If point B coincides with point A, it is determined that the laser twist is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end face of the bottom plate 3 are A 1 point and B 1 point respectively, then it is determined that the laser twist deviates, and the deviation angle is ∠A 1 BB 1 ;

[0076] Step S5: Since point A 1 point, point B 1 point are respectively the projections of point A and point B on the high-precision scale 1 on the bottom plate 3, the distance between points A and B on the high-precision scale 1 is equal to the distance between A 1 , B 1 points. Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, from which the deviation angle ∠A 1 BB 1 = arctan(A 1 B 1 / B 1 B).

[0077] Example 5

[0078] Based on the measuring device in Example 1, when measuring the twist of the laser at the foot of the bed set in the sagittal plane, the radiotherapy quality control method for detecting the verticality and twist of the positioning laser specifically includes the following steps:

[0079] Step S1: Turn the side with scale of the measuring device towards the foot of the bed;

[0080] Step S2: Place the measuring device flat on the treatment bed and level the adjusting base 4 according to the indication of the bubble level 5;

[0081] Step S3: Align the laser at the foot of the bed set in the sagittal plane with the OO 1 alignment line 2 of the bottom plate 3 for positioning;

[0082] Step S4: The laser emitted at the foot of the bed intersects the high-precision scale 1 at point B. If point B coincides with point A, it is determined that the laser twist is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the upper end surface of the bottom plate 3 are point A 1 point and B 1 point, then it is determined that the laser twist deviates, and the deviation angle is ∠A 1 BB 1 ;

[0083] Step S5: Since point A 1 point, B 1 point are the projections of point A and point B on the high-precision scale 1 on the bottom plate 3 respectively, the distance between points A and B on the high-precision scale 1 is equal to the distance between point A 1 and B 1 points. Given that OA = OO 1 , AA 1 = BB 1 = OAcos60°, the deviation angle ∠A 1 BB 1 = arctan(A 1 B 1 / B 1 B).

[0084] Based on the above embodiments, the present invention can be used to measure and locate the laser verticality and twist, and the specific functions are as follows: 1. It can detect the verticality of the top laser set in the cross-section, that is, whether it rotates around the X-axis; 2. It can detect the verticality of the top laser set in the sagittal plane, that is, whether it rotates around the Y-axis; 3. It can detect the twist of the left wall laser set in the cross-section, that is, whether it rotates around the X-axis; 4. It can detect the twist of the right wall laser set in the cross-section, that is, whether it rotates around the X-axis; 5. It can detect the twist of the laser at the foot of the bed set in the sagittal plane, that is, whether it rotates around the Y-axis.

[0085] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, rather than limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A radiotherapy quality control method for detecting the sag and torsion of a positioning laser, mainly performed by a measuring device, characterized in that: The measuring device comprises a base plate, and an adjustment base capable of fine-tuning the height is respectively installed at the four top corner positions of the lower end surface of the base plate, and an inclined support rod is respectively arranged at the two top corner positions on one side of the upper end surface of the base plate, and the two support rods are symmetrically arranged, and a high-precision ruler is arranged for quality inspection at the top end of the two support rods, and the middle part of the top of the high-precision ruler is recorded as point A, and a bubble level is arranged in the middle part of one side of the base plate close to the support rod, and the middle part of the upper end surface of the base plate where the bubble level is located is recorded as point O, and a bubble level is arranged in the middle part of a side surface of the base plate perpendicular to the side where point O of the base plate is located, and the middle part of the upper end of the other side surface of the base plate opposite to the side where point O of the base plate is located is recorded as point O1, and point O and point O1 form an alignment line OO1; the angle formed between the upper end surface of the base plate and the lower inclined surfaces of the two support rods is 60 degrees; The radiotherapy quality control method for detecting the sag and torsion of the positioning laser specifically comprises the following steps: Step S1, facing the scaled side of the measuring device toward the laser position to be measured; Step S2, placing the measuring device flat on the treatment bed, and leveling the adjustment base according to the indication of the bubble level; Step S3, align the right wall cross section laser with the bottom plate OO1 alignment line for positioning; Step S4, the emitted laser intersects with the high-precision scale at point B. If point B coincides with point A, it is determined that the laser torsion is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the end surface of the bottom plate are point A1 and point B1 respectively, it is determined that the laser torsion deviates, and the deviation angle is ∠A1BB1; Step S5. Since point A1 and point B1 are projections of point A and point B on the high-precision ruler on the base plate, respectively, the distance between point AB on the high-precision ruler is equal to the distance between points A1 and B1. It is known that OA=OO1, AA1=BB1=OAcos60°, and the deviation angle ∠A1BB1=arctan(A1B1 / B1B) can be calculated.

2. A radiotherapy quality control method for detecting the sag and torsion of a positioning laser according to claim 1, characterized in that: The upper surface of the high-precision scale is in the same plane as the upper inclined surfaces of the two support rods.

3. A radiotherapy quality control method for detecting the sag and torsion of a positioning laser according to claim 1, characterized in that: When measuring the top laser sag of a cross section, the following steps are included: Step S1, placing the measuring device flat on the treatment bed, and leveling the adjustment base according to the indication of the bubble level; Step S2, aligning the top laser set on the cross section with the alignment line OO1 of the bottom plate for positioning; Step S3, the emitted top laser intersects with the high-precision scale at point B. If point B coincides with point A, it is determined that the laser verticality is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the end surface of the bottom plate are point A1 and point B1 respectively, it is determined that the laser verticality deviates, and the deviation angle is ∠A1BB1; Step S4, since point A1 and point B1 are the projections of point A and point B on the high-precision ruler on the base plate respectively, the distance between point AB on the high-precision ruler is equal to the distance between points A1 and B1. It is known that OA=OO1, AA1=BB1=OAcos60°, and the deviation angle ∠A1BB1=arctan(A1B1 / B1B) can be calculated.

4. A radiotherapy quality control method for detecting the sag and torsion of a positioning laser according to claim 1, characterized in that: When measuring the top laser sag of the sagittal plane, the following steps are included: Step S1, placing the measuring device flat on the treatment bed, and leveling the adjustment base according to the indication of the bubble level; Step S2, aligning the top laser set on the sagittal plane with the bottom plate OO1 alignment line for positioning; Step S3, the emitted top laser intersects with the high-precision scale at point B. If point B coincides with point A, it is determined that the laser verticality is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the end surface of the bottom plate are point A1 and point B1 respectively, it is determined that the laser verticality deviates, and the deviation angle is ∠A1BB1; Step S4, since point A1 and point B1 are the projections of point A and point B on the high-precision ruler on the base plate respectively, the distance between point AB on the high-precision ruler is equal to the distance between points A1 and B1. It is known that OA=OO1, AA1=BB1=OAcos60°, and the deviation angle ∠A1BB1=arctan(A1B1 / B1B) can be calculated.

5. A radiotherapy quality control method for detecting the sag and torsion of a positioning laser according to claim 1, characterized in that: When the left wall laser torsion measurement of the cross section is performed, the following steps are specifically included: Step S1, facing the scaled side of the measuring device toward the left wall; Step S2, placing the measuring device flat on the treatment bed, and leveling the adjustment base according to the indication of the bubble level; Step S3, align the left wall laser set in the cross section with the bottom plate OO1 alignment line for positioning; Step S4, the emitted left wall laser intersects with the high-precision scale at point B. If point B coincides with point A, it is determined that the laser torsion is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the end surface of the bottom plate are point A1 and point B1 respectively, it is determined that the laser torsion deviates, and the deviation angle is ∠A1BB1; Step S5. Since point A1 and point B1 are projections of point A and point B on the high-precision ruler on the base plate, respectively, the distance between point AB on the high-precision ruler is equal to the distance between points A1 and B1. It is known that OA=OO1, AA1=BB1=OAcos60°, and the deviation angle ∠A1BB1=arctan(A1B1 / B1B) can be calculated.

6. A radiotherapy quality control method for detecting the sag and torsion of a positioning laser according to claim 1, characterized in that: When measuring the right wall laser torsion of the cross section, the following steps are specifically included: Step S1, facing the scaled side of the measuring device toward the right wall; Step S2, placing the measuring device flat on the treatment bed, and leveling the adjustment base according to the indication of the bubble level; Step S3, align the right wall laser set in the cross section with the bottom plate OO1 alignment line for positioning; Step S4, the emitted right wall laser intersects with the high-precision scale at point B. If point B coincides with point A, it is determined that the laser torsion is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the end surface of the bottom plate are point A1 and point B1 respectively, it is determined that the laser torsion deviates, and the deviation angle is ∠A1BB1; Step S5, since point A1 and point B1 are the projections of point A and point B on the high-precision ruler on the base plate respectively, the distance between point AB on the high-precision ruler is equal to the distance between points A1 and B1. It is known that OA=OO1, AA1=BB1=OAcos60°, and the deviation angle ∠A1BB1=arctan(A1B1 / B1B) can be calculated.

7. A radiotherapy quality control method for detecting the sag and torsion of a positioning laser according to claim 1, characterized in that: When measuring the laser torsion of the foot of the bed in the sagittal plane, the following steps are included: Step S1, facing the scaled side of the measuring device toward the end of the bed; Step S2, placing the measuring device flat on the treatment bed, and leveling the adjustment base according to the indication of the bubble level; Step S3, aligning the bed end laser set in the sagittal plane with the bottom plate OO1 alignment line for positioning; Step S4, the emitted bedside laser intersects with the high-precision scale at point B. If point B coincides with point A, it is determined that the laser torsion is good; if point B does not coincide with point A, and the corresponding projections of point A and point B on the end surface of the bottom plate are point A1 and point B1 respectively, it is determined that the laser torsion deviates, and the deviation angle is ∠A1BB1; Step S5, since point A1 and point B1 are the projections of point A and point B on the high-precision ruler on the base plate respectively, the distance between point AB on the high-precision ruler is equal to the distance between points A1 and B1. It is known that OA=OO1, AA1=BB1=OAcos60°, and the deviation angle ∠A1BB1=arctan(A1B1 / B1B) can be calculated.

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