Isocenter correction method and system for radiotherapy equipment, and storage medium

Abstract

The present application discloses a method and system for correcting the isocenter of a radiotherapy device, and a storage medium, and belongs to the field of medical device technology. The method comprises: obtaining at least one image group taken by an imaging unit of the radiotherapy device; determining the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction based on the correspondence between the at least one image group and at least one coordinate axis direction; and correcting the isocenter of the radiotherapy device based on the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction. There is no need to correct the isocenter of the radiotherapy device by manually analyzing the film, which effectively improves the correction efficiency of the isocenter of the radiotherapy device.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to an isocenter correction method and system, and a storage medium for radiotherapy equipment. Background Art

[0002] Radiotherapy is an important means of treating cancer, and radiotherapy equipment (abbreviated as radiotherapy equipment) is the key medical equipment for carrying out radiotherapy.

[0003] Radiotherapy equipment usually includes: a rotating frame, and a treatment head located on the rotating frame. Usually, after the treatment head of the radiotherapy equipment is assembled, or after the treatment head in the radiotherapy equipment is repaired, the isocenter of the radiotherapy equipment needs to be calibrated so that the offset between the corrected isocenter and the treatment isocenter (that is, the focus point of the radiation beam emitted by the treatment head) is less than a preset value. Otherwise, the radiation beam emitted by the treatment head may not irradiate the target area of ​​the patient, resulting in the radiotherapy equipment being unable to accurately treat the target area of ​​the patient.

[0004] In the related art, when the isocenter of the radiotherapy device needs to be corrected, the radiation beam of the treatment head needs to be irradiated on the film to form a focal spot on the film, and the center of the focal spot is the treatment isocenter. It is also necessary to manually analyze the offset between the center of the focal spot and the preset point (the preset point is the isocenter of the radiotherapy device), and then the isocenter of the radiotherapy device can be corrected by the offset. However, the efficiency of verifying the isocenter of the radiotherapy device through film is currently low. Summary of the invention

[0005] The embodiment of the present application provides a method and system for isocenter correction of radiotherapy equipment, and a storage medium. The problem of low efficiency in verifying the isocenter of radiotherapy equipment by film in the prior art can be solved. The technical solution is as follows:

[0006] In one aspect, a method for isocenter correction of a radiotherapy device is provided, the method comprising:

[0007] Acquire at least one image group taken by an imaging unit of a radiotherapy device, each of the image groups comprising two images taken when the imaging unit is located at two relative positions, the two images being images containing the same blocking body;

[0008] Based on the correspondence between the at least one image group and the at least one coordinate axis direction, determining the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction;

[0009] Based on the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction, the isocenter of the radiotherapy device is corrected.

[0010] Optionally, based on the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction, correcting the isocenter of the radiotherapy device includes:

[0011] Determine the offset of the isocenter of the radiotherapy device in the direction of the corresponding coordinate axis based on the deviation between the two blocking bodies in the image group in the direction of the corresponding coordinate axis;

[0012] The isocenter is corrected based on the offset.

[0013] Optionally, determining the offset of the isocenter of the radiotherapy device in the direction of the corresponding coordinate axis based on the deviation between the two blocking bodies in the image group in the direction of the corresponding coordinate axis includes:

[0014] Based on the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction, an offset calculation formula is used to determine the offset of the isocenter in the corresponding coordinate axis direction;

[0015] The offset calculation formula is:

[0016]

[0017] Among them, d is the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction; D is the offset of the isocenter in the corresponding coordinate axis direction; S1 is the distance between the ray source in the imaging part and the isocenter; S2 is the distance from the ray emitted by the ray source in the imaging part to the detector after passing through the isocenter.

[0018] Optionally, correcting the isocenter based on the offset includes:

[0019] Correcting the isocenter using a correction formula based on the offset;

[0020] Wherein, the correction formula is:

[0021] O1=O2-D;

[0022] Among them, O1 is the corrected coordinate value of the isocenter in the direction of the corresponding coordinate axis; O2 is the coordinate value of the isocenter in the direction of the corresponding coordinate axis before correction.

[0023] Optionally, determining the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction based on the correspondence between the at least one image group and the at least one coordinate axis direction includes:

[0024] Based on the correspondence between the at least one image group and the at least one coordinate axis direction, determining the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction;

[0025] Based on the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction, the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction is determined.

[0026] Optionally, the number of the at least one image group is two, and the two image groups correspond to the X-axis direction and the Z-axis direction in the coordinate system of the radiotherapy device respectively;

[0027] Among them, the two images in the image group corresponding to the Z-axis direction are images taken by the imaging unit in the X-axis direction; the two images in the image group corresponding to the X-axis direction are images taken by the imaging unit in the Z-axis direction.

[0028] On the other hand, an isocenter correction system for a radiotherapy device is provided, the system comprising: a radiotherapy device, a blocking body and a processing device, wherein:

[0029] The radiotherapy device comprises: an imaging unit, the imaging unit being used to photograph the blocking body;

[0030] The blocking body is detachably mounted at the isocenter of the radiotherapy device, and the center of the blocking body coincides with the isocenter of the radiotherapy device;

[0031] The processing device is connected to the imaging part, and the processing device is used to execute any of the above-mentioned isocenter correction methods for radiotherapy equipment.

[0032] Optionally, the imaging unit includes: a ray source and a detector arranged relatively to each other.

[0033] Optionally, the system further includes: a detection phantom, the blocking body is installed at a central position of the detection phantom, and the blocking body is detachably installed at the isocenter of the radiotherapy device through the detection phantom.

[0034] On the other hand, a computer-readable storage medium is provided, wherein at least one instruction is stored in the storage medium, and the instruction is loaded and executed by a processor to implement the isocenter correction method of the radiotherapy equipment as described in any one of the above.

[0035] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0036] By acquiring at least one image group containing the same blocking body through the imaging unit, and then analyzing the deviation of the two blocking bodies in each image group in the corresponding coordinate axis direction, the isocenter of the radiotherapy equipment can be corrected. There is no need to correct the isocenter of the radiotherapy equipment by manually analyzing the film, which effectively improves the correction efficiency of the isocenter of the radiotherapy equipment. In addition, in the process of correcting the isocenter of the radiotherapy equipment, only the imaging unit of the radiotherapy equipment is required to work, and the treatment head of the radiotherapy equipment is not required to work. The radiation generated by the treatment head when working is much greater than the radiation generated by the imaging unit when working. Therefore, in the process of correcting the isocenter of the radiotherapy equipment provided by the present application, the radiation amount can also be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 It is a structural schematic diagram of an isocenter correction system of a radiotherapy device provided in an embodiment of the present application;

[0039] Figure 2 is a schematic diagram of the structure of a detection phantom provided in an embodiment of the present application;

[0040] Figure 3 It is an isocenter correction method for radiotherapy equipment provided in an embodiment of the present application;

[0041] Figure 4 It is another isocenter correction method for radiotherapy equipment provided in an embodiment of the present application;

[0042] Figure 5 This is a schematic diagram of an imaging unit acquiring an image group corresponding to the Z-axis direction provided by an embodiment of the present application;

[0043] Figure 6 This is a schematic diagram of an imaging unit acquiring an image group corresponding to the X-axis direction provided by an embodiment of the present application;

[0044] Figure 7 is a schematic diagram of an image group corresponding to the Z-axis direction provided by an embodiment of the present application;

[0045] Figure 8 is a schematic diagram of another image group corresponding to the Z-axis direction provided by an embodiment of the present application;

[0046] Fig. 9is a schematic diagram of an image group corresponding to the X-axis direction provided by an embodiment of the present application;

[0047] Fig.10 is a schematic diagram of another image group corresponding to the X-axis direction provided by an embodiment of the present application;

[0048] Fig.11 It is a schematic diagram of an image group corresponding to the Z-axis direction when the isocenter of the radiotherapy device is offset downward in the Z-axis direction, provided by an embodiment of the present application;

[0049] Fig.12 This is a relationship diagram between deviation and offset on the Z axis provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0051] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of the structure of an isocenter correction system of a radiotherapy device provided in an embodiment of the present application. The isocenter verification system 100 of the radiotherapy device may include: a radiotherapy device 101 , a blocking body 102 and a processing device 103 .

[0052] The radiotherapy device 101 may include: an imaging unit 1012. It should be noted that the radiotherapy device 101 may also generally include: a rotating frame 1013 and a treatment head 1011. The treatment head 1011 and the imaging unit 1012 both need to be mounted on the mounting surface of the rotating frame 1013, and the rotating frame 1013 can simultaneously drive the treatment head 1011 and the imaging unit 1012 to rotate. Optionally, the imaging unit 1012 may include: a ray source 1012a and a detector 1012b that are relatively arranged. Among them, the ray emission direction of the ray source 1012a may be perpendicular to the ray emission direction of the treatment head 1011.

[0053] The blocking body 102 is detachably mounted at the isocenter of the radiotherapy device 101, and the center of the blocking body 102 may coincide with the isocenter of the radiotherapy device 101. For example, the blocking body 102 may be a metal ball, such as a tungsten ball.

[0054] The processing device 103 may be connected to the imaging unit 1012 in the radiotherapy device 101. The processing device 103 may control the imaging unit 1012 in the radiotherapy device 101 to image the barrier 102 located at the isocenter of the radiotherapy device 101. After the imaging unit 1012 images the barrier 102, the imaging unit 1012 may send the acquired image of the barrier 102 to the processing device 103.

[0055] In the process of the imaging unit 1012 imaging the blocking body 102, the ray source 1012a in the imaging unit 1012 can emit a ray beam toward the blocking body 102, and the detector 1012b in the imaging unit 1012 can capture the projection data generated after passing through the blocking body 102, and generate a two-dimensional image (also called an image) corresponding to the blocking body 102 based on the projection data.

[0056] For example, the ray source 1012a in the imaging unit 1012 may be a tube that can emit X-rays, the X-rays are KV level, and the X-rays may be cone beam rays. The detector 1012b in the imaging unit 1012 may be a flat panel detector.

[0057] Optionally, the isocenter verification system 100 of the radiotherapy device may further include: a detection phantom 104. The blocking body 103 may be installed at the center of the detection phantom 104. The blocking body 103 may be detachably installed at the isocenter of the radiotherapy device through the detection phantom 104.

[0058] For examples, please refer to Figure 2 , Figure 2 104 is a schematic diagram of a structure of a detection phantom provided in an embodiment of the present application. The detection phantom 104 may be in the shape of a cube, and the center of the detection phantom 104 has an inner cavity for accommodating the blocking body 102 .

[0059] In the embodiment of the present application, the radiotherapy device 101 may further include: a treatment bed 1014. The detection phantom 104 may be mounted on the treatment bed 1014. When the isocenter of the radiotherapy device 101 needs to be corrected, the radiotherapy device 101 may control the treatment bed 1014 to move a specified distance so that the center of the blocking body in the detection phantom 104 on the treatment bed 1014 coincides with the isocenter of the radiotherapy device.

[0060] It should be noted that the radiotherapy device 101 has a three-dimensional coordinate system, and the three-dimensional coordinate system can be an IEC coordinate system. Among them, the Z-axis direction in the three-dimensional coordinate system of the radiotherapy device 101 is the height direction of the radiotherapy device 101; the Y-axis direction of the radiotherapy device 101 is the direction of the axis of the rotating frame 1013, that is, the radiotherapy device 101 can rotate around the Y-axis; the X-axis direction of the radiotherapy device 101 is perpendicular to the Z-axis direction, and perpendicular to the Y-axis direction.

[0061] Please refer to Figure 3 , Figure 3 The isocenter correction method of a radiotherapy device provided in an embodiment of the present application is applied to Figure 1 The processing device 103 in the isocenter correction system of the radiotherapy device shown. The isocenter correction method of the radiotherapy device may include:

[0062] Step 201: Acquire at least one image group taken by an imaging unit of a radiotherapy device, wherein each image group includes two images taken when the imaging unit is located at two relative positions, and the two images are images containing the same blocking body.

[0063] Step 202: Based on the correspondence between at least one image group and at least one coordinate axis direction, determine the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction.

[0064] Step 203: Correct the isocenter of the radiotherapy device based on the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction.

[0065] In summary, the isocenter correction method for the radiotherapy equipment provided in the embodiment of the present application can correct the isocenter of the radiotherapy equipment by acquiring at least one image group containing the same blocking body through the imaging part, and then analyzing the deviation of the two blocking bodies in each image group in the corresponding coordinate axis direction. There is no need to correct the isocenter of the radiotherapy equipment by manually analyzing the film, which effectively improves the correction efficiency of the isocenter of the radiotherapy equipment. Moreover, in the process of correcting the isocenter of the radiotherapy equipment, only the imaging part of the radiotherapy equipment is required to work, and the treatment head of the radiotherapy equipment is not required to work. The radiation generated by the treatment head when working is much greater than the radiation generated by the imaging part when working. Therefore, in the process of correcting the isocenter of the radiotherapy equipment provided by the present application, the radiation amount can also be effectively reduced.

[0066] Please refer to Figure 4 , Figure 4 Another isocenter correction method for radiotherapy equipment provided in an embodiment of the present application is provided. The isocenter correction method for radiotherapy equipment is applied to Figure 1 The processing device 103 in the isocenter correction system of the radiotherapy device shown. The isocenter correction method of the radiotherapy device may include:

[0067] Step 301: Acquire at least one image group taken by an imaging unit of a radiotherapy device.

[0068] Each image group includes two images taken when the imaging unit is located at two relative positions, and the two images are images containing the same blocking body.

[0069] In the embodiment of the present application, after the barrier is installed at the isocenter of the radiotherapy device, the processing device can control the imaging unit in the radiotherapy device to image the barrier. The imaging unit of the radiotherapy device can obtain at least one image group after photographing the barrier at different positions, and the imaging unit of the radiotherapy device can send the at least one image group it photographed to the processing device, so that the processing device can obtain at least one image group.

[0070] For example, the number of at least one image component in the radiotherapy device is two, and the two image groups can correspond to the X-axis direction and the Z-axis direction in the coordinate system of the radiotherapy device, respectively.

[0071] Among them, when the imaging part of the radiotherapy equipment needs to obtain two images in the image group corresponding to the X-axis direction, the imaging part of the radiotherapy equipment needs to shoot the blocking body in the Z-axis direction, that is, the two images in the image group corresponding to the X-axis direction are the images shot by the imaging part in the Z-axis direction; when the imaging part of the radiotherapy equipment needs to obtain two images in the image group corresponding to the Z-axis direction, the imaging part of the radiotherapy equipment needs to shoot the blocking body in the X-axis direction, that is, the two images in the image group corresponding to the Z-axis direction are the images shot by the imaging part in the X-axis direction.

[0072] For example, see Figure 5 , Figure 5 1 is a schematic diagram of an imaging unit obtaining an image group corresponding to the Z-axis direction provided by an embodiment of the present application. When the ray source 1012a in the imaging unit rotates to the 0° position under the drive of the rotating frame, the detector 1012b in the imaging unit is located at the 180° position, and the image obtained by the imaging unit photographing the blocking body 102 in the X-axis direction (positive or negative) is an image in the image group corresponding to the Z-axis direction. When the ray source 1012a in the imaging unit rotates to the 180° position under the drive of the rotating frame, the detector 1012b in the imaging unit is located at the 0° position, and the image obtained by the imaging unit photographing the blocking body 102 in the X-axis direction (positive or negative) is another image in the image group corresponding to the Z-axis direction. It should be noted that, for the convenience of the following description, when the ray source 1012a in the imaging unit is located at the 0° position and the detector 1012b is located at the 180° position, the image captured by the imaging unit on the blocking body 102 is referred to as a 0° image; when the ray source 1012a in the imaging unit is located at the 180° position and the detector 1012b is located at the 0° position, the image captured by the imaging unit on the blocking body 102 is referred to as a 180° image. That is, the image group corresponding to the Z-axis direction includes: a 0° image and a 180° image.

[0073] Please refer to Figure 6 , Figure 61 is a schematic diagram of an imaging unit obtaining an image group corresponding to the X-axis direction provided by an embodiment of the present application. When the ray source 1012a in the imaging unit rotates to a 90° position under the drive of the rotating frame, the detector 1012b in the imaging unit is located at a 270° position, and the image obtained by the imaging unit photographing the blocking body 102 in the Z-axis direction (positive or negative) is an image in the image group corresponding to the X-axis direction. When the ray source 1012a in the imaging unit rotates to a 270° position under the drive of the rotating frame, the detector 1012b in the imaging unit is located at a 90° position, and the image obtained by the imaging unit photographing the blocking body 102 in the Z-axis direction (positive or negative) is another image in the image group corresponding to the X-axis direction. It should be noted that, for the convenience of the following description, when the ray source 1012a in the imaging unit is located at the 90° position and the detector 1012b is located at the 270° position, the image captured by the imaging unit on the blocking body 102 is referred to as a 90° image; when the ray source 1012a in the imaging unit is located at the 270° position and the detector 1012b is located at the 90° position, the image captured by the imaging unit on the blocking body 102 is referred to as a 270° image. That is, the image group corresponding to the Z-axis direction includes: a 90° image and a 270° image.

[0074] Step 302: Based on the correspondence between at least one image group and at least one coordinate axis direction, determine the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction.

[0075] In an embodiment of the present application, after acquiring at least one image group, the processing device can determine the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction based on the correspondence between the at least one image group and at least one coordinate axis direction.

[0076] For example, if the processing device simultaneously obtains an image group corresponding to the Z-axis direction and an image group corresponding to the X-axis direction, the processing device needs to separately determine the deviation between the two blocking bodies in the image group corresponding to the Z-axis direction in the Z-axis direction, and the deviation between the two blocking bodies in the image group corresponding to the X-axis direction in the X-axis direction.

[0077] In the present application, if the isocenter of the radiotherapy device coincides with the treatment isocenter, then after the imaging unit of the radiotherapy device photographs the blocking body at the isocenter at two relative positions, the two blocking bodies in the two images obtained by photographing coincide with each other in the same coordinate system, or, even if the two blocking bodies do not coincide with each other in the same coordinate system, the deviation between the two is small, for example, the deviation between the two is less than 0.1 mm. If the isocenter of the radiotherapy device does not coincide with the treatment isocenter, then after the imaging unit of the radiotherapy device photographs the blocking body at the isocenter at two relative positions, the two blocking bodies in the two images obtained by photographing do not coincide with each other in the same coordinate system, and the deviation between the two is large.

[0078] The embodiment of the present application will explain the deviation existing in the image group corresponding to the Z-axis direction and the deviation existing in the image group corresponding to the X-axis direction in the following two aspects.

[0079] First, for the image group corresponding to the Z-axis direction, when the isocenter of the radiotherapy device coincides with the treatment isocenter, such as Figure 7 As shown, Figure 7 is a schematic diagram of an image group corresponding to the Z-axis direction provided by an embodiment of the present application. The positions of the two blocking bodies in the 0° image and the 180° image in the image group corresponding to the Z-axis direction in the same coordinate system are basically coincident. When the isocenter of the radiotherapy device does not coincide with the treatment isocenter, such as Figure 8 As shown, Figure 8 It is a schematic diagram of another image group corresponding to the Z-axis direction provided in an embodiment of the present application. The positions of the two blocking bodies in the 0° image and the 180° image in the image group corresponding to the Z-axis direction in the same coordinate system do not overlap, and the deviation between the two is large.

[0080] It should be noted that in the image group corresponding to the Z-axis direction, the 0° image and the 180° image are both images in the YZ plane in the three-dimensional coordinate system of the radiotherapy device. For this reason, the two blocking bodies in the 0° image and the 180° image can be compared in the YZ coordinate system. Among them, the vertical direction in the 0° image and the 180° image can be the Y-axis direction, and the horizontal direction can be the Z-axis direction.

[0081] Secondly, for the image group corresponding to the Z-axis direction, when the isocenter of the radiotherapy device coincides with the treatment isocenter, such as Fig. 9 As shown, Fig. 9 is a schematic diagram of an image group corresponding to the X-axis direction provided by an embodiment of the present application. The positions of the two blocking bodies in the 90° image and the 270° image in the image group corresponding to the X-axis direction in the same coordinate system are basically coincident. When the isocenter of the radiotherapy device does not coincide with the treatment isocenter, such as Fig.10 As shown, Fig.10This is a schematic diagram of another image group corresponding to the X-axis direction provided in an embodiment of the present application. The positions of the two blocking bodies in the 90° image and the 270° image in the image group corresponding to the X-axis direction in the same coordinate system do not overlap, and the deviation between the two is large.

[0082] It should be noted that in the image group corresponding to the X-axis direction, the 90° image and the 270° image are both images in the XY plane in the three-dimensional coordinate system of the radiotherapy device. For this reason, the two blocking bodies in the 90° image and the 270° image can be compared in the XY coordinate system. Among them, the vertical direction in the 90° image and the 270° image can be the Y-axis direction, and the horizontal direction can be the X-axis direction.

[0083] To this end, if the isocenter of the radiotherapy equipment does not coincide with the treatment isocenter, and after the processing device acquires at least one image group, the processing device can determine the distance between the centers of the two blocking bodies in the image group in the corresponding coordinate axis direction as the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction.

[0084] For example, the processing device determines the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction based on the correspondence between at least one image group and at least one coordinate axis direction, which may include the following steps:

[0085] Step A1: Based on the correspondence between at least one image group and at least one coordinate axis direction, determine the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction.

[0086] In an embodiment of the present application, after acquiring at least one image group, the processing device can determine the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction based on the correspondence between the at least one image group and at least one coordinate axis direction.

[0087] For example, for the image group corresponding to the Z-axis direction, since both images in the image group are images in the YZ plane in the coordinate system of the radiotherapy device, the radiotherapy device can determine the coordinate values ​​of each contour point of the blocking body in the two images in the YZ coordinate system, and determine the coordinates of the center point of each blocking body based on the coordinates of each contour point, and then obtain the coordinate value of the center point of each blocking body in the image group corresponding to the Z-axis direction in the Z-axis direction.

[0088] Similarly, the processing device can obtain the coordinate value of the center point of each blocking body in the image group corresponding to the X-axis direction in the X-axis direction.

[0089] Step B1: Based on the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction, determine the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction.

[0090] In an embodiment of the present application, after the processing device determines the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction, the processing device can determine the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction based on the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction.

[0091] For example, the processing device may determine the difference between the coordinate values ​​of the center points of the two blocking bodies in the image group in the corresponding coordinate axis direction as the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction.

[0092] It should be noted that when the isocenter of the radiotherapy equipment is offset upward in the Z-axis direction relative to the treatment isocenter, the isocenter of the radiotherapy equipment needs to be corrected downward in the Z-axis direction; when the isocenter of the radiotherapy equipment is offset downward in the Z-axis direction relative to the treatment isocenter, the isocenter of the radiotherapy equipment needs to be corrected upward in the Z-axis direction.

[0093] In order to facilitate subsequent correction, it can be stipulated that when the isocenter of the radiotherapy device is offset upward in the Z-axis direction, the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction is positive, and when the isocenter of the radiotherapy device is offset downward in the Z-axis direction, the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction is negative. In this way, the offset of the isocenter of the radiotherapy device in the Z-axis direction calculated later through this deviation with positive and negative signs is also with positive and negative signs. For example, the offset when the isocenter of the radiotherapy device is offset upward in the Z-axis direction is positive, or the offset when the isocenter of the radiotherapy device is offset upward in the Z-axis direction is negative. In this way, when the isocenter of the radiotherapy device is subsequently corrected, regardless of whether the isocenter of the radiotherapy device is offset upward or downward in the Z-axis direction, the current coordinate value of the isocenter of the radiotherapy device in the Z-axis direction can be subtracted from this offset with positive and negative signs, so that the isocenter of the radiotherapy device can be corrected in the Z-axis direction.

[0094] For example, Figure 8 As shown, when the isocenter of the radiotherapy device is offset upward in the Z-axis direction, the blocking body in the 0° image is biased to the left, and the blocking body in the 180° image is biased to the right. At this time, the processing device can use the difference between the coordinate value of the center point of the blocking body in the 0° image in the Z-axis direction and the coordinate value of the center point of the blocking body in the 180° image in the Z-axis direction as: the deviation between the two blocking bodies in the image group in the Z-axis direction, and the deviation is positive.

[0095] like Fig.11 As shown, Fig.11 This is a schematic diagram of an image group corresponding to the Z-axis direction when the isocenter of the radiotherapy device is offset downward in the Z-axis direction, provided by an embodiment of the present application. When the isocenter of the radiotherapy device is offset downward in the Z-axis direction, the blocking body in the 0° image is biased to the right, and the blocking body in the 180° image is biased to the left. At this time, the processing device can use the difference between the coordinate value of the center point of the blocking body in the 0° image in the Z-axis direction and the coordinate value of the center point of the blocking body in the 180° image in the Z-axis direction as: the deviation between the two blocking bodies in the image group in the Z-axis direction, and the deviation is negative.

[0096] To this end, regardless of whether the isocenter of the radiotherapy equipment is offset upward or downward in the Z-axis direction, for the image group corresponding to the Z-axis direction, the difference between the coordinate value of the center point of the blocking body in the 0° image in the image group in the Z-axis direction and the coordinate value of the center point of the blocking body in the 180° image in the Z-axis direction can be used as the deviation between the two blocking bodies in the Z-axis direction.

[0097] Similarly, no matter whether the isocenter of the radiotherapy equipment is offset to the left or to the right in the X-axis direction, for the image group corresponding to the X-axis direction, the difference between the coordinate value of the center point of the blocking body in the 90° image in the image group in the X-axis direction and the coordinate value of the center point of the blocking body in the 270° image in the X-axis direction can be used as the deviation between the two blocking bodies in the X-axis direction.

[0098] Step 303: Based on the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction, determine the offset of the isocenter of the radiotherapy device in the corresponding coordinate axis direction.

[0099] In an embodiment of the present application, after the processing device determines the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction, the processing device can determine the offset of the isocenter of the radiotherapy device in the corresponding coordinate axis direction based on the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction.

[0100] In this application, please refer to Fig.12 , Fig.12: is a relationship diagram between a deviation and an offset on the Z axis provided in an embodiment of the present application. When the ray source in the imaging unit is located at the 0° position and the detector in the imaging unit is located at the 180° position, the position of the center point of the blocking body in the 0° image obtained by the imaging unit photographing the blocking body is position 1; when the ray source in the imaging unit is located at the 180° position and the detector in the imaging unit is located at the 0° position, the position of the center point of the blocking body in the 180° image obtained by the imaging unit photographing the blocking body is position 2. After unifying the coordinate system of the 0° image and the coordinate system of the 180° image, the position of the center point of the blocking body in the 180° image is position 2', and the difference between the coordinate value of position 1 in the Z axis direction and the coordinate value of position 2' in the Z axis direction is the deviation d between the two blocking bodies in the coordinate system of the 0° image and the 180° image. Z .

[0101] exist Fig.12 In the figure, O is the treatment isocenter; O' is the isocenter of the radiotherapy equipment; D Z It is the offset of the isocenter of the radiotherapy device in the Z-axis direction.

[0102] In this way, according to the triangle similarity principle, we can get the following formula:

[0103]

[0104] Wherein, S1 is the distance between the ray source and the isocenter O' of the radiotherapy equipment; S2 is the distance from the ray emitted by the ray source to the detector after passing through the isocenter of the radiotherapy equipment.

[0105] Similarly, according to a similar principle, the deviation d between the two blocking bodies in the image group corresponding to the X-axis in the X-axis direction can be obtained: x , and the offset D of the isocenter of the radiotherapy device in the X-axis direction X , satisfying the following formula:

[0106]

[0107] In this way, the processing device obtains the deviation d between the two blocking bodies on the Z axis in the image group corresponding to the Z axis. Z After that, the offset D of the isocenter of the radiotherapy device in the Z-axis direction can be calculated by the above formula (1): Z The processing device obtains the deviation d of the two blocking bodies on the X axis in the image group corresponding to the X axis. X After that, the offset D of the isocenter of the radiotherapy device in the X-axis direction can be calculated by the above formula (2): X It should be noted that, since the d determined in step 302 above Z and d XBoth contain positive and negative signs, so the D calculated by the above formula (1) Z and D calculated by the above formula (2) X Both contain positive and negative signs.

[0108] Combining the above formula (1) and formula (2), we can get the offset calculation formula, which is:

[0109]

[0110] Wherein, d is the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction; D is the offset of the isocenter in the corresponding coordinate axis direction.

[0111] To this end, after the processing device obtains the deviation of the two blocking bodies in any image group in the corresponding coordinate axis direction, the processing device can obtain the deviation of the isocenter of the radiotherapy device in the corresponding coordinate axis direction through the above offset calculation formula.

[0112] Step 304: Correct the isocenter of the radiotherapy device based on the offset.

[0113] In the embodiment of the present application, after the processing device obtains the offset of the radiotherapy device in the direction of the coordinate axis, the processing device can correct the isocenter of the radiotherapy device based on the offset.

[0114] For example, the processing device may use a correction formula based on the offset to correct the isocenter of the radiotherapy device. The correction formula is:

[0115] O1=O2-D;

[0116] Among them, O2 is the coordinate value of the isocenter of the radiotherapy equipment in the direction of a certain coordinate axis before correction; O1 is the coordinate value of the isocenter of the radiotherapy equipment in the direction of the coordinate axis after correction.

[0117] For example, assuming that the isocenter of the radiotherapy device is offset upward in the Z-axis direction, then, according to step 303, it can be calculated that the offset of the isocenter of the radiotherapy device in the Z-axis direction is positive. At this time, the processing device needs to subtract this offset from the current coordinate value of the isocenter of the radiotherapy device in the Z-axis direction, which is equivalent to moving the isocenter of the radiotherapy device downward, and the new coordinate value obtained in the Z-axis direction is only the coordinate value after the isocenter of the radiotherapy device is corrected. Assuming again that the isocenter of the radiotherapy device is offset downward in the Z-axis direction, then, according to step 303, it can be calculated that the offset of the isocenter of the radiotherapy device in the Z-axis direction is negative. At this time, the processing device needs to subtract this offset from the current coordinate value of the isocenter of the radiotherapy device in the Z-axis direction, which is equivalent to moving the isocenter of the radiotherapy device upward, and the new coordinate value obtained in the Z-axis direction is only the coordinate value after the isocenter of the radiotherapy device is corrected. In this way, the correction of the isocenter of the radiotherapy device in the Z-axis direction can be achieved.

[0118] Similarly, the isocenter of the radiotherapy equipment can be corrected in the X-axis direction.

[0119] It should be noted that, since the offset of the isocenter of the radiotherapy equipment in the Y-axis direction is usually small, the embodiment of the present application does not need to correct the isocenter of the radiotherapy equipment in the Y-axis direction.

[0120] In an embodiment of the present application, after the processing device calibrates the isocenter of the radiotherapy device, the radiotherapy device subsequently needs to compensate for the movement of the treatment bed based on the corrected isocenter to ensure that the isocenter of the radiotherapy device can coincide with the treatment isocenter as much as possible.

[0121] It should be noted that the order of the steps of the isocenter correction method for radiotherapy equipment provided in the embodiment of the present application can be appropriately adjusted, and the steps can be increased or decreased accordingly according to the circumstances. Any technician familiar with the technical field can easily think of the changes within the technical scope disclosed in the present application, and they should be covered within the scope of protection of the present application, so they will not be repeated here.

[0122] In summary, the isocenter correction method for the radiotherapy equipment provided in the embodiment of the present application can correct the isocenter of the radiotherapy equipment by acquiring at least one image group containing the same blocking body through the imaging part, and then analyzing the deviation of the two blocking bodies in each image group in the corresponding coordinate axis direction. There is no need to correct the isocenter of the radiotherapy equipment by manually analyzing the film, which effectively improves the correction efficiency of the isocenter of the radiotherapy equipment. Moreover, in the process of correcting the isocenter of the radiotherapy equipment, only the imaging part of the radiotherapy equipment is required to work, and the treatment head of the radiotherapy equipment is not required to work. The radiation generated by the treatment head when working is much greater than the radiation generated by the imaging part when working. Therefore, in the process of correcting the isocenter of the radiotherapy equipment provided by the present application, the radiation amount can also be effectively reduced.

[0123] The present application also provides an isocenter correction system for a radiotherapy device, such as Figure 1 As shown, the system 100 may include: a radiotherapy device 101 , a blocking body 102 and a treatment device 103 .

[0124] The radiotherapy device 101 includes an imaging unit 1012 for photographing the blocking body 102. The blocking body 102 is detachably mounted at the isocenter of the radiotherapy device 101, and the center of the blocking body coincides with the isocenter of the radiotherapy device 101.

[0125] The processing device 103 is connected to the imaging unit 1012 and is used to Figure 2 or Figure 3 An isocenter correction method for a radiotherapy device is shown.

[0126] Optionally, the imaging unit 1012 includes: a ray source 1012a and a detector 1012b that are arranged opposite to each other.

[0127] Optionally, the isocenter correction system 100 of the radiotherapy device may further include: a detection phantom 104 , a blocking body 102 installed at the center of the detection phantom 104 , and the blocking body 102 is detachably installed at the isocenter of the radiotherapy device 101 through the detection phantom 104 .

[0128] It should be noted that the working principle of the isocenter correction system of the radiotherapy equipment can refer to the corresponding content in the embodiment of the isocenter verification method of the radiotherapy equipment mentioned above, and the embodiments of the present application will not be repeated here.

[0129] The present application also provides a correction device for the isocenter of a radiotherapy device, which can be the processing device in the above embodiment. The verification device can include: a processor and a memory, wherein the memory stores at least one instruction, which is loaded and executed by the processor to implement Figure 2 or Figure 3 An isocenter correction method for a radiotherapy device is shown.

[0130] The present application also provides a computer-readable storage medium. The computer-readable storage medium stores instructions, which, when executed on a processing component, cause the processing component to execute a command to implement Figure 2 or Figure 3 An isocenter correction method for a radiotherapy device is shown.

[0131] In the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0132] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0133] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for isocenter correction of radiotherapy equipment, characterized in that: The method comprises: Acquire at least one image group taken by an imaging part of a radiotherapy device, each of the image groups comprising two images taken when the imaging part is located at two relative positions, the two images are images containing the same blocking body, and the blocking body is detachably mounted at the isocenter of the radiotherapy device, and the center of the blocking body coincides with the isocenter of the radiotherapy device; Based on the correspondence between the at least one image group and the at least one coordinate axis direction, determining the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction; Based on the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction, an offset calculation formula is used to determine the offset of the isocenter in the corresponding coordinate axis direction; Correcting the isocenter based on the offset; The offset calculation formula is: Among them, d is the deviation between the two blocking bodies in the image group in the corresponding coordinate axis direction; D is the offset of the isocenter in the corresponding coordinate axis direction; S1 is the distance between the ray source in the imaging part and the isocenter; S2 is the distance from the ray emitted by the ray source in the imaging part to the detector after passing through the isocenter.

2. The method according to claim 1, characterized in that Correcting the isocenter based on the offset includes: Correcting the isocenter using a correction formula based on the offset; Wherein, the correction formula is: O1=O2-D; Among them, O1 is the corrected coordinate value of the isocenter in the direction of the corresponding coordinate axis; O2 is the coordinate value of the isocenter in the direction of the corresponding coordinate axis before correction.

3. The method according to claim 1, characterized in that Based on the correspondence between the at least one image group and the at least one coordinate axis direction, determining the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction includes: Based on the correspondence between the at least one image group and the at least one coordinate axis direction, determining the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction; Based on the coordinate value of the center point of each blocking body in the image group in the corresponding coordinate axis direction, the deviation between two blocking bodies in the image group in the corresponding coordinate axis direction is determined.

4. The method according to claim 1, characterized in that: The number of the at least one image group is two, and the two image groups correspond to the X-axis direction and the Z-axis direction in the coordinate system of the radiotherapy device respectively; Among them, the two images in the image group corresponding to the Z-axis direction are images taken by the imaging unit in the X-axis direction; the two images in the image group corresponding to the X-axis direction are images taken by the imaging unit in the Z-axis direction.

5. An isocenter correction system for radiotherapy equipment, characterized in that: The system comprises: a radiotherapy device, a blocking body and a processing device, wherein: The radiotherapy device comprises: an imaging unit, the imaging unit being used to photograph the blocking body; The blocking body is detachably mounted at the isocenter of the radiotherapy device, and the center of the blocking body coincides with the isocenter of the radiotherapy device; The processing device is connected to the imaging unit, and is used to execute the isocenter correction method of the radiotherapy device as described in any one of claims 1 to 4.

6. The system according to claim 5, characterized in that The imaging unit comprises a ray source and a detector which are arranged opposite to each other.

7. The system according to claim 5, characterized in that The system further comprises: a detection phantom, the blocking body is installed at the center of the detection phantom, and the blocking body is detachably installed at the isocenter of the radiotherapy device through the detection phantom.

8. A computer-readable storage medium, characterized in that: The storage medium stores at least one instruction, which is loaded and executed by the processor to implement the isocenter correction method of the radiotherapy equipment as described in any one of claims 1 to 4.

Images