A radiotherapy plan verification phantom

Abstract

The present invention relates to a radiotherapy plan verification phantom, comprising a first phantom hemisphere and a second phantom hemisphere, wherein the first phantom hemisphere and the second phantom hemisphere are connected to form a spherical phantom, wherein the spherical phantom is provided with phantom end shafts extending at both ends, wherein the spherical phantom is installed on a phantom frame, wherein the phantom frame is provided with two end shaft support grooves arranged in the horizontal direction, wherein the phantom end shafts are inserted into the end shaft support grooves in a rotational fit. The beneficial effects of the present invention are as follows: a spherical phantom that can rotate in the vertical direction and a phantom frame that can rotate in the horizontal direction are adopted to realize arbitrary adjustment and setting of the plane position of the inspection film in the spherical phantom in the three-dimensional space, the spherical phantom is convenient to assemble and can be conveniently installed on the phantom frame, a semicircular shaft is adopted to combine the first phantom hemisphere and the second phantom hemisphere, thereby avoiding the setting of a connector in the spherical phantom to affect the inspection data, and a vertical rotation drive device and a horizontal rotation drive device are adopted to realize dynamic verification of the three-dimensional radiotherapy dose.

Description

Technical Field

[0001] The invention belongs to a radiotherapy detection and verification device, and in particular relates to a radiotherapy plan verification phantom. Background Art

[0002] Three-dimensional conformal intensity modulated radiotherapy uses beams generated by multiple radiation sources to accurately focus the beams on the lesion location, achieve the effect of eliminating the lesion, and maximize the protection of healthy tissues to achieve the treatment of diseases such as tumors. In three-dimensional conformal intensity modulated radiotherapy, it is necessary to formulate a radiotherapy plan for the rays generated by the radiotherapy equipment. Before using it to treat patients, the dose needs to be measured and verified to ensure that the designed radiotherapy plan is consistent with the actual irradiation, thereby ensuring the safety and accuracy of the irradiation. However, the radiotherapy plan is a three-dimensional model calculated and generated by the control system of the radiotherapy equipment. At present, there are few three-dimensional radiation measurement detection devices. The most practical method is to use test films for verification. In order to facilitate data processing, the test film is usually placed in a rectangular phantom. The test film verifies the actual dose of a plane in the three-dimensional radiotherapy. Through data processing, it is compared with the dose of the corresponding plane in the radiotherapy plan to determine whether the radiotherapy effect is consistent with the radiotherapy plan. However, for different patients, there will be different lesions, and the targets and areas of radiotherapy will be different. Therefore, it is necessary to use test films to actually verify the three-dimensional radiotherapy plan at various plane positions in space. Three-dimensional intensity modulated radiotherapy plans usually have multiple radiation fields, and each radiation field has a different irradiation angle. During the verification of different radiation field fluxes, it is necessary to enter the treatment room to adjust the phantom angle so that the film or ionization chamber is perpendicular to the radiation field. For a special form of three-dimensional intensity modulated radiotherapy, rotational intensity modulated radiotherapy, during its implementation, the accelerator gantry angle will continue to change as the treatment progresses. In order to measure the dose flux of each radiation field, it is necessary to verify that the film or ionization chamber angle moves continuously to ensure that the film or ionization chamber is always at a perpendicular angle to the gantry. Summary of the invention

[0003] The purpose of the present invention is to provide a technical solution for a radiotherapy plan verification phantom, to achieve position adjustment of a test film in a spherical phantom in three-dimensional space, and to realize dynamic testing.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is: a radiotherapy plan verification phantom, comprising a first phantom hemisphere and a second phantom hemisphere, the first phantom hemisphere is provided with a first hemisphere plane, the second phantom hemisphere is provided with a second hemisphere plane, the first hemisphere plane and the second hemisphere plane are connected to form a spherical phantom, the spherical phantom is provided with phantom end shafts extending at both ends, the axis of the phantom end shaft passes through the center of the spherical phantom, the first hemisphere plane and the second hemisphere plane pass through the axis of the phantom end shaft, the spherical phantom is installed on a phantom frame, the phantom frame is provided with two end shaft support grooves arranged in the horizontal direction, and the phantom end shaft is embedded in the end shaft support groove in a rotational fit.

[0005] Furthermore, in order to form a complete spherical mold body, the first mold body hemisphere is provided with a docking edge, and the docking edge protrudes from the first hemisphere plane at the periphery of the first mold body hemisphere, and the second mold body hemisphere is provided with a docking groove corresponding to the docking edge, and the docking edge is embedded in the docking groove, so that the first mold body hemisphere and the second mold body hemisphere form a complete spherical mold body; a first inspection medium groove is provided on the first hemisphere plane, and a second inspection medium groove is provided on the second hemisphere plane.

[0006] Furthermore, a preferred docking edge structure is that the first mold body hemisphere is provided with four docking edges equally divided by the circumference, the distance from the inner side surface of the docking edge to the center of the spherical mold body is 0.8 times the spherical radius, and the height of the docking edge is equal to the radius of the mold body end axis.

[0007] Furthermore, a combination structure of a first mold body hemisphere and a second mold body hemisphere is that the mold body end shaft is arranged on the first mold body hemisphere, the first mold body hemisphere is provided with a first docking screw hole, the second mold body hemisphere is provided with a second docking hole corresponding to the first docking screw hole, the second docking hole is a step hole, the second docking hole is provided with a docking screw screwed into the first docking screw hole, and the mold body end shaft is arranged on the first mold body hemisphere.

[0008] Furthermore, another combination structure of the first mold body hemisphere and the second mold body hemisphere is that the first mold body hemisphere is provided with a first semicircular shaft, and the second mold body hemisphere is provided with a second semicircular shaft, the first semicircular shaft and the second semicircular shaft are inserted into the end shaft sleeve to form the mold body end shaft, and the end shaft sleeve is embedded in the end shaft support groove in a rotatable fit.

[0009] Furthermore, in order to control and observe the rotation angle of the spherical mold in the vertical plane, a vertical rotation dial and a vertical rotation pointer are provided at one end of the mold frame, the vertical rotation dial is sleeved on the end shaft of the mold, the vertical rotation dial is provided with a positioning protrusion embedded in the end shaft support groove, and the vertical rotation pointer is installed on the end shaft of the mold and rotates with the end shaft of the mold.

[0010] Furthermore, in order to realize the rotation angle of the spherical mold body in the horizontal plane, the mold body frame is provided with an arc-shaped arm, the two end shaft support grooves are arranged at both ends of the arc-shaped arm, and the mold body frame is installed on the mold body base and rotates on the mold body base.

[0011] Furthermore, in order to realize the dynamic rotation of the spherical mold body, the mold body frame is provided with a vertical rotation driving device for driving the spherical mold body to rotate, and the mold body base is provided with a horizontal rotation driving device for driving the mold body frame to rotate.

[0012] Furthermore, a dynamic rotation drive device for a spherical mold body is provided, wherein the vertical rotation drive device comprises a vertical rotation drive frame installed at one of the end shaft support grooves, the vertical rotation drive frame is provided with a first motor, the output shaft of the first motor is provided with a first driving gear, the mold body end shaft is provided with a mold body gear, and the mold body gear is meshed with the first driving gear; the horizontal rotation drive device comprises a second motor arranged on the mold body base, the output shaft of the second motor is provided with a second driving gear, the lower end of the mold body frame is provided with a mold body frame gear, and the mold body frame gear is meshed with the second driving gear.

[0013] Furthermore, in order to achieve stable and accurate driving, the mold body gear is mounted on the mold body end shaft through a sliding key, the first motor and the second motor are servo motors, the number of teeth of the mold body gear is greater than the number of teeth of the first drive gear, and the number of teeth of the mold body frame gear is greater than the number of teeth of the second drive gear; and a shaft hole cover is provided at the upper end of the end shaft support groove.

[0014] The beneficial effects of the present invention are as follows: a spherical phantom that can rotate in the vertical direction and a phantom frame that can rotate in the horizontal direction are adopted to realize arbitrary adjustment and setting of the plane position of the inspection film in the spherical phantom in the three-dimensional space; the spherical phantom is easy to assemble and can be conveniently installed on the phantom frame; a semicircular axis is adopted to combine the first phantom hemisphere and the second phantom hemisphere, thereby avoiding the setting of connecting parts in the spherical phantom to affect the inspection data; a vertical rotation drive device and a horizontal rotation drive device are adopted to realize dynamic verification of the three-dimensional radiotherapy dose.

[0015] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the main structure diagram of the present invention;

[0017] Figure 2 It is an exploded view of the main structure of the present invention;

[0018] Figure 3 It is an exploded view of the spherical phantom structure of the present invention;

[0019] Figure 4 It is an assembly diagram of the present invention;

[0020] Figure 5 It is a schematic diagram of the rotation adjustment of the present invention;

[0021] Figure 6 It is a schematic diagram of disassembling the vertical rotating dial of the present invention;

[0022] Figure 7 It is a structural diagram of the spherical mold body of the present invention using a first semicircular axis and a second semicircular axis combination;

[0023] Figure 8 Is adopted Figure 7 Exploded view of the spherical phantom and phantom frame structure of the structure;

[0024] Fig. 9 Is adopted Figure 7 Exploded view of the spherical phantom structure of the structure;

[0025] Fig.10 It is a structural diagram of the present invention provided with a vertical rotation drive device and a horizontal rotation drive device;

[0026] Fig.11 yes Fig.10 The structure is viewed from the bottom of the phantom base;

[0027] Fig.12 yes Fig.10 An exploded view of the structure of the spherical phantom, phantom frame and vertical rotation drive device;

[0028] Fig.13 yes Fig.10 A schematic diagram of the installation of the vertical rotation drive device of the structure, the vertical rotation drive frame 51 is installed on the mold frame, and the mold gear is installed on the mold end shaft;

[0029] Fig.14 yes Fig.10 Schematic diagram of the installation of the vertical rotation drive device of the structure, the mold end shafts at both ends of the spherical mold body are embedded in the end shaft support grooves. DETAILED DESCRIPTION

[0030] like Figures 1 to 8A radiotherapy plan verification phantom includes a first phantom hemisphere 11 and a second phantom hemisphere 12, wherein the first phantom hemisphere is provided with a first hemispherical plane 11b, and the second phantom hemisphere is provided with a second hemispherical plane 12b, the first hemispherical plane and the second hemispherical plane are connected to form a spherical phantom 10, the spherical phantom is provided with a phantom end shaft 13 extending at both ends, the axis of the phantom end shaft passes through the center C of the spherical phantom, the first hemispherical plane and the second hemispherical plane pass through the axis of the phantom end shaft, the spherical phantom is installed on a phantom frame 20, the phantom frame is provided with two end shaft support grooves 21 arranged in the horizontal direction, and the phantom end shaft is embedded in the end shaft support groove in a rotational fit.

[0031] The first mold body hemisphere is provided with a docking edge 14, and the docking edge protrudes from the first hemisphere plane 11b around the first mold body hemisphere. The second mold body hemisphere is provided with a docking groove 15 corresponding to the docking edge, and the docking edge is embedded in the docking groove, so that the first mold body hemisphere and the second mold body hemisphere constitute a complete spherical mold body 10; a first test medium groove 11c is provided on the first hemisphere plane, and a second test medium groove 12c is provided on the second hemisphere plane.

[0032] The first mold body hemisphere is provided with four abutting edges 14 equally divided on the circumference, the distance E from the inner side of the abutting edge to the center of the spherical mold body is 0.8 times the spherical radius R, and the height H of the abutting edge is equal to the radius of the mold body end axis.

[0033] like Figures 1 to 5 As shown, a combination structure of a first mold body hemisphere and a second mold body hemisphere is that the mold body end shaft 13 is arranged on the first mold body hemisphere 11, the first mold body hemisphere is provided with a first docking screw hole 11s, the second mold body hemisphere is provided with a second docking hole 12s corresponding to the first docking screw hole, the second docking hole is a step hole, the second docking hole is provided with a docking screw 16 screwed into the first docking screw hole, and the mold body end shaft is arranged on the first mold body hemisphere.

[0034] like Figures 6 to 8 As shown, another combination structure of a first mold body hemisphere and a second mold body hemisphere is that the first mold body hemisphere is provided with a first semicircular shaft 11a, and the second mold body hemisphere is provided with a second semicircular shaft 12a, and the first semicircular shaft and the second semicircular shaft are inserted into the end shaft sleeve 17 to form the mold body end shaft, and the end shaft sleeve is embedded in the end shaft support groove 21 with a rotational fit.

[0035] A vertical rotating dial 30 and a vertical rotating pointer 31 are provided at one end of the mold frame. The vertical rotating dial is sleeved on the mold end shaft 13. The vertical rotating dial is provided with a positioning protrusion 32 embedded in the end shaft support groove. The vertical rotating pointer is installed on the mold end shaft and rotates with the mold end shaft.

[0036] The mold frame is provided with an arc-shaped arm 22, and two end shaft support grooves 21 are arranged at both ends of the arc-shaped arm. The mold frame is installed on the mold base 40 and rotates on the mold base.

[0037] The mold frame 20 is provided with a vertical rotation driving device for driving the spherical mold to rotate, and the mold base is provided with a horizontal rotation driving device for driving the mold frame to rotate.

[0038] The vertical rotation drive device includes a vertical rotation drive frame 51 installed at one of the end shaft support grooves 21, and the vertical rotation drive frame is provided with a first motor 52, and the output shaft of the first motor is provided with a first driving gear 53, and the mold body end shaft is provided with a mold body gear 54, and the mold body gear is meshed with the first driving gear; the horizontal rotation drive device includes a second motor 61 arranged on the mold body base, and the output shaft of the second motor is provided with a second driving gear 62, and the lower end of the mold body frame is provided with a mold body frame gear 63, and the mold body frame gear 63 is meshed with the second driving gear 62.

[0039] The mold body gear is sleeved on the mold body end shaft through a sliding key 33, the first motor and the second motor are servo motors, the number of teeth of the mold body gear is greater than the number of teeth of the first driving gear, and the number of teeth of the mold body frame gear is greater than the number of teeth of the second driving gear; an axis hole cover 55 is provided at the upper end of the end shaft support groove.

[0040] Embodiment 1:

[0041] like Figures 1 to 4 A radiotherapy plan verification phantom includes a spherical phantom 10 composed of a first phantom hemisphere 11 and a second phantom hemisphere 12.

[0042] The first mold body hemisphere 11 is a hemisphere, and the first mold body hemisphere is provided with a first hemisphere plane 11b, and the first hemisphere plane 11b passes through the center C of the hemisphere (also the center of the spherical mold body 10), and the first hemisphere plane 11b is the docking surface with the second mold body hemisphere 12. The first mold body hemisphere is provided with a mold body end shaft 13, and two coaxial mold body end shafts 13 extend from the two ends of the first mold body hemisphere, and the axis of the mold body end shaft 13 passes through the center C of the first mold body hemisphere (that is, the center of the spherical mold body). The first mold body hemisphere is provided with a docking edge 14, and the docking edge protrudes from the first hemisphere plane 11b at the periphery of the hemisphere. In this embodiment, the docking edge is symmetrically arranged with the sphere center C as the center, and the distance E from the inner side of the docking edge to the sphere center of the spherical mold body is 0.8 times the spherical radius R, so that the first mold body hemisphere forms four docking edges 14 arranged in equal parts of the circumference, and the four docking edges are separated at the edge of the hemisphere. Such a structural design makes the processing of the docking edge more convenient and obtains good processing quality. The height H of the docking edge is equal to the radius of the mold body end shaft 13, so that the mold body end shaft can be completely connected with the first mold body hemisphere, and the mold body end shaft is arranged in the center of two symmetrical docking edges. The first mold body hemisphere is provided with a first docking screw hole 11s, and the docking screw hole 11s is arranged on the first hemisphere plane 11b. There are four first docking screw holes 11s arranged at the separation of the docking edge, close to the edge of the first mold body hemisphere. A first test medium slot 11c is provided on the first hemisphere plane for accommodating a test medium, such as a two-dimensional ionization chamber or a test film.

[0043] The second mold body hemisphere 12 is a hemisphere, and the second mold body hemisphere is provided with a second hemisphere plane 12b, and the second hemisphere plane 12b passes through the center C of the hemisphere (which is also the center of the spherical mold body 10), and the second hemisphere plane 12b is the docking surface with the first mold body hemisphere 11. The second mold body hemisphere is provided with a docking groove 15 corresponding to the docking edge 14 of the first mold body hemisphere, and the second mold body hemisphere is provided with a second docking hole 12s corresponding to the first docking screw hole 11s, and the second docking hole is a stepped hole. A second test medium slot 12c is provided on the second hemisphere plane for accommodating a test medium, such as a two-dimensional ionization chamber or a test film.

[0044] The first model hemisphere and the second model hemisphere are made of polystyrene (also known as "equivalent solid water").

[0045] When the first mold body hemisphere 11 and the second mold body hemisphere 12 are docked, the docking edge 14 of the first mold body hemisphere is embedded in the docking groove 15 of the second mold body hemisphere, and the second docking hole 12s is provided with a docking screw 16 screwed into the first docking screw hole 11s, so that the first mold body hemisphere and the second mold body hemisphere are connected and fixed to form a complete spherical mold body 10. The docking edge and the docking groove can be matched to accurately dock the first mold body hemisphere and the second mold body hemisphere to stably form a complete sphere. In order to make the spherical mold body 10 form a complete and homogeneous entity, a filling column 18 is filled in the second docking hole 12s, and the upper surface of the filling column coincides with the spherical surface of the second mold body hemisphere. The filling column 18 is made of the same material as the second mold body hemisphere.

[0046] The spherical mold body is installed on the mold body frame 20, and the mold body frame is provided with an arc-shaped arm 22. Two end shaft support grooves 21 are arranged at both ends of the arc-shaped arm. The bottom end of the arc-shaped groove is a semicircular arc corresponding to the mold body end shaft 13, and the two end shaft support grooves 21 are arranged in the horizontal direction. The mold body end shaft 13 is embedded in the end shaft support groove 21 and can rotate in the end shaft support groove 21. The bottom surface of the mold body frame is provided with a mold body frame rotating shaft 23, and the mold body frame rotating shaft 23 corresponds to the center of the arc-shaped arm 22. The mold body frame is installed on the mold body base 40, and the mold body base is provided with a guide hole 41. The mold body frame rotating shaft 23 and the guide hole 41 are rotatably matched, so that the mold body frame can rotate horizontally on the mold body base. A scale line 42 indicating the rotation position of the mold body frame is provided on the mold body base.

[0047] A vertical rotating dial 30 and a vertical rotating pointer 31 are provided at one end of the mold body frame 20. The vertical rotating dial is provided with a center hole 34, and the center hole 34 of the vertical rotating dial is sleeved on the mold body end shaft 13. The vertical rotating dial is provided with a positioning protrusion 32 embedded in the end shaft support groove, so that the vertical rotating dial is fixed to the position between the mold body frame 20, and the mold body end shaft 13 is rotatably matched with the center hole 34 of the vertical rotating dial. The vertical rotating pointer 31 is also installed on the mold body end shaft 13, and the mold body end shaft 13 is provided with a flat key 33. The vertical rotating pointer is provided with a keyway 35 matched with the flat key 33, so that the vertical rotating pointer 31 rotates synchronously with the spherical mold body 10. The vertical rotating pointer 31 is kept on the mold body end shaft 13 through the shaft end cover 36.

[0048] The present invention designs the phantom to be spherical. When the rays pass through the spherical phantom from different angles, a specific three-dimensional dose distribution will be formed in the spherical phantom. Compared with a cubic phantom, when the cubic phantom rotates, the path of the rays passing through the phantom will change, and the corresponding three-dimensional dose distribution will also change. The present invention adopts a spherical phantom. When the phantom rotates, the path of the rays remains unchanged, and the spatial distribution of the dose will not change.

[0049] When the radiotherapy plan verification phantom is used, the test medium is first placed in the first test medium slot 11c and the second test medium slot 12c. The test medium can be a plate-shaped two-dimensional ionization chamber 70, which is embedded in the first test medium slot 11c and the second test medium slot 12c. The test medium can also be a test film 71. When the test film is used, the first test medium slot and the second test medium slot are filled with a filling plate (not shown in the figure) so that the test film is located in the center plane of the spherical phantom 10. The specific method can be that the first phantom hemisphere 11 is placed on the phantom frame 20, the phantom end shaft 13 is embedded in the two end shaft support grooves 21 of the phantom frame, and the test medium is placed in the first test medium slot 11c, such as Figure 4 Then the second mold body hemisphere 12 is butted with the first mold body hemisphere 11 and fixed with butt screws 16 to form a complete spherical mold body 10 with the inspection film disposed therein.

[0050] Then, the vertical rotating dial 30 is mounted on the mold frame 20, and the vertical rotating pointer 31 is mounted on the mold end shaft 13. Then, the spherical mold 10 is rotated to adjust the rotation angle position of the test film 71 in the vertical plane (i.e., the angle with the horizontal plane); the mold frame 20 is rotated to adjust the rotation angle position of the test film 71 in the horizontal plane, so that the test film 71 reaches the desired spatial position, such as Figure 5 To reduce the impact on the radiation and facilitate observation, the vertical rotating dial 30 and the vertical rotating pointer 31 can be removed. Figure 6 As shown. So far, the setting of the radiotherapy plan verification phantom has been completed.

[0051] Embodiment 2:

[0052] like Figures 7 to 9 , a radiotherapy plan verification phantom. This embodiment is an improvement of the first embodiment.

[0053] This embodiment adopts another combined structure of the first mold body hemisphere 11 and the second mold body hemisphere 12. The first mold body hemisphere is provided with a first semicircular shaft 11a, and the second mold body hemisphere is provided with a second semicircular shaft 12a. The first semicircular shaft and the second semicircular shaft are inserted into the end shaft sleeve 17 to form the mold body end shaft, and the end shaft sleeve is inserted into the end shaft support groove 21 in a rotational fit.

[0054] A step ring 17a is provided at one end of the end shaft sleeve 17, and the step ring 17a is embedded between the spherical mold body 10 and the mold body frame 20 (ie, the end shaft support groove 21), so that the end shaft sleeve 17 will not move axially or fall off during use.

[0055] The flat key 33 for positioning the vertical rotating pointer 31 is arranged on the first semicircular shaft 11a, and the flat key 33 is movably matched with the first semicircular shaft 11a (i.e., movable match that can be installed and removed). When assembling the first mold body hemisphere 11 and the second mold body hemisphere 12, the flat key 33 is first removed, and after the end shaft sleeve 17 is inserted into the first semicircular shaft 11a and the second semicircular shaft 12a, the flat key 33 is installed on the first semicircular shaft 11a. Similarly, the flat key 33 can also be arranged on the second semicircular shaft 12a.

[0056] The spherical mold structure of this embodiment uses the docking edge 14 of the first mold hemisphere and the docking groove 15 of the second mold hemisphere to achieve precise matching of the spherical mold, and uses the first semicircular shaft 11a and the second semicircular shaft 12a to cooperate with the end shaft sleeve 17 to achieve connection and fixation.

[0057] Compared with the spherical phantom assembly structure of the first embodiment, the first embodiment needs to set a docking screw hole 11s in the first phantom hemisphere and a second docking hole 12s in the second phantom hemisphere, and fix it with a docking screw 16. The spherical phantom 10 is not a completely continuous and homogeneous entity, which has a certain impact on the information obtained by the inspection film 71, reduces the accuracy of the data, and usually requires correction during the data processing process.

[0058] The combined structure of this embodiment avoids the use of butt screws to fix the first mold body hemisphere and the second mold body hemisphere. The first mold body hemisphere and the second mold body hemisphere are both a continuous and homogeneous entity, which can completely avoid the defects caused by screw connection and fixation, and the assembly process is also more convenient.

[0059] Embodiment three:

[0060] like Figures 10 to 14 , a radiotherapy plan verification phantom. This embodiment is an improvement of the first embodiment or the second embodiment (the structure of the first embodiment or the second embodiment is taken as an example in the figure).

[0061] This embodiment uses a driving and control device to drive the rotation of the spherical mold body 10 and the mold body frame 20. The mold body frame 20 is provided with a vertical rotation driving device for driving the spherical mold body 10 to rotate, and the mold body base is provided with a horizontal rotation driving device for driving the mold body frame 20 to rotate.

[0062] The vertical rotation driving device includes a vertical rotation driving frame 51, which is installed at an end shaft support groove 21 of the mold frame 20. The vertical rotation driving frame 51 is a U-shaped frame, and one side of the U-shaped frame is fixed to the outer side of the end shaft support groove 21 by screws 56. A first motor 52 is installed on the other side of the U-shaped frame, and the output shaft of the first motor is provided with a first driving gear 53, and the first driving gear 53 is located in the U-shaped groove of the U-shaped frame.

[0063] The mold body end shaft is provided with a mold body gear 54, which can be sleeved on the mold body end shaft 13 by a sliding key 33 (the vertical rotation dial 30 and the vertical rotation pointer 31 are no longer installed at this time), and the mold body gear 54 is meshed with the first driving gear 53, so that the first motor 52 drives the spherical mold body 10 to rotate. The first motor is a servo motor, which can control the rotation position of the spherical mold body in real time. The number of teeth of the mold body gear is greater than the number of teeth of the first driving gear, that is, the first motor 52 drives the spherical mold body 10 to rotate with a reduction ratio, which can improve the driving stability and control accuracy, and can also improve the driving torque.

[0064] The U-shaped frame of the vertical rotation driving frame 51 can limit the axial movement of the mold body gear 54 .

[0065] In order to prevent the mold body gear 54 from moving upward and disengaging from the first driving gear 53 during transmission, a shaft hole cover 55 is provided at the upper end of the end shaft support groove.

[0066] The bottom surface of the mold base 40 is provided with a supporting foot 43, so that a lower cavity is formed at the bottom of the mold base. The horizontal rotation drive device includes a second motor 61 arranged on the mold base 40, and the output shaft of the second motor 61 penetrates downward into the lower cavity of the mold base. The output shaft of the second motor is provided with a second driving gear 62. The mold frame rotating shaft 23 at the lower end of the mold frame also penetrates into the lower cavity of the mold base, and the mold frame rotating shaft is provided with a mold frame gear 63, which is fixedly connected with the mold frame rotating shaft and rotates synchronously. The mold frame gear 63 is meshed with the second driving gear 62, so that the second motor 61 drives the mold frame 20 to rotate. The second motor is a servo motor, which can control the rotation position of the mold frame 20 in real time. The number of teeth of the mold frame gear is more than the number of teeth of the second driving gear, that is, the second motor 61 drives the mold frame 20 to rotate at a reduction ratio, which can improve the driving stability and control accuracy, and can also improve the driving torque.

[0067] The vertical rotation driving device of this embodiment is installed in the mold frame 20 in an assembly mode. Fig.12 As shown in FIG. 1 , the vertical rotation drive frame 51 equipped with the first motor 52 and the first drive gear 53, the mold body gear 54 and the shaft hole cover 55 are all independently disassembled components. When in use, Fig.13 As shown, the vertical rotation drive frame 51 is mounted on the mold frame 20 (with the first motor 52 and the first drive gear 53 also mounted therewith) by means of screws 56, and the mold gear 54 is mounted on the mold end shaft 13. Then, as shown in FIG. Fig.14 As shown, the die end shafts at both ends of the spherical die 10 are embedded into the two end shaft support grooves 21, the die gear 54 is meshed with the first drive gear 53, and then the shaft hole cover 55 is installed to the upper end of the end shaft support groove 21, and the assembly work is completed.

[0068] After the vertical rotation driving frame 51, the mold body gear 54 and the shaft hole cover 55 are disassembled, the structure of the first or second embodiment can be restored.

[0069] This embodiment uses a vertical rotation drive device and a horizontal rotation drive device, which can perform real-time automatic position movement and control of the inspection medium, dynamically adapt the inspection medium to the radiation source, and realize one-time automatic verification of multiple different angle fields of the three-dimensional radiotherapy plan. For a special form of three-dimensional intensity modulated radiotherapy - rotational intensity modulated radiotherapy, during the implementation of this example, the angle of the verification film or ionization chamber will move continuously with the change of the angle of the radiation source, ensuring that the film or ionization chamber is always at a vertical angle to the frame, thereby realizing the verification of the rotational intensity modulated radiotherapy flux. A two-dimensional ionization chamber that can automatically control the rotation angle in real time can realize dose detection of multiple planes in the radiotherapy area during a single operation, which helps to realize spatial detection and analysis of the radiotherapy plan.

Claims

1. A radiotherapy plan verification phantom, characterized in that: It comprises a first mold body hemisphere and a second mold body hemisphere, the first mold body hemisphere is provided with a first hemispherical plane, the second mold body hemisphere is provided with a second hemispherical plane, the first hemispherical plane and the second hemispherical plane are connected to form a spherical mold body, the first mold body hemisphere is provided with a first semicircular shaft, the second mold body hemisphere is provided with a second semicircular shaft, the first semicircular shaft and the second semicircular shaft are inserted into the end shaft sleeve to form a mold body end shaft, the axis of the mold body end shaft passes through the center of the spherical mold body, the first hemispherical plane and the second hemispherical plane pass through the axis of the mold body end shaft, the spherical mold body is installed on a mold body frame, the mold body frame is provided with two end shaft support grooves arranged in the horizontal direction, and the mold body end shaft is embedded in the end shaft support groove in a rotational fit; A vertical rotating dial and a vertical rotating pointer are provided at one end of the mold body frame, the vertical rotating dial is sleeved on the mold body end shaft, the vertical rotating dial is provided with a positioning convex block embedded in the end shaft support groove, and the vertical rotating pointer is installed on the mold body end shaft and rotates with the mold body end shaft; The mold frame is provided with an arc-shaped arm, and the two end shaft supporting grooves are arranged at the two ends of the arc-shaped arm. The mold frame is installed on the mold base and rotates on the mold base.

2. A radiotherapy plan verification phantom according to claim 1, characterized in that: The first mold body hemisphere is provided with a docking edge, the docking edge protrudes from the first hemisphere plane at the periphery of the first mold body hemisphere, the second mold body hemisphere is provided with a docking groove corresponding to the docking edge, the docking edge is embedded in the docking groove, so that the first mold body hemisphere and the second mold body hemisphere constitute a complete spherical mold body; A first test medium groove is arranged on the first hemispherical plane, and a second test medium groove is arranged on the second hemispherical plane.

3. A radiotherapy plan verification phantom according to claim 2, characterized in that: The first mold body hemisphere is provided with four docking edges equally divided by the circumference, the distance from the inner side of the docking edge to the center of the spherical mold body is 0.8 times the spherical radius, and the height of the docking edge is equal to the radius of the mold body end axis.

4. A radiotherapy plan verification phantom according to claim 2, characterized in that: The mold body end shaft is arranged on the first mold body hemisphere, the first mold body hemisphere is provided with a first docking screw hole, the second mold body hemisphere is provided with a second docking hole corresponding to the first docking screw hole, the second docking hole is a step hole, and the second docking hole is provided with a docking screw screwed into the first docking screw hole.

5. A radiotherapy plan verification phantom according to claim 1, characterized in that: The mold body frame is provided with a vertical rotation driving device for driving the spherical mold body to rotate, and the mold body base is provided with a horizontal rotation driving device for driving the mold body frame to rotate.

6. A radiotherapy plan verification phantom according to claim 5, characterized in that: The vertical rotation drive device includes a vertical rotation drive frame installed at one of the end shaft support grooves, the vertical rotation drive frame is provided with a first motor, the output shaft of the first motor is provided with a first driving gear, the mold body end shaft is provided with a mold body gear, and the mold body gear is meshed with the first driving gear; the horizontal rotation drive device includes a second motor arranged on the mold body base, the output shaft of the second motor is provided with a second driving gear, the lower end of the mold body frame is provided with a mold body frame gear, and the mold body frame gear is meshed with the second driving gear.

7. A radiotherapy plan verification phantom according to claim 6, characterized in that: The mold body gear is mounted on the mold body end shaft through a sliding key, the first motor and the second motor are servo motors, the number of teeth of the mold body gear is greater than that of the first driving gear, and the number of teeth of the mold body frame gear is greater than that of the second driving gear; a shaft hole cover is provided at the upper end of the end shaft support groove.

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