CALIBRATION METHOD, DEVICE AND STORAGE MEDIUM OF RADIOTHERAPY EQUIPMENT

• US 20200129785A1
• Filed: 06/02/2017
• Published: 04/30/2020
• Est. Priority Date: 06/02/2017
• Status: Active Grant

• Current Assignee: Our United Corporation
• Original Assignee: Our United Corporation
• Inventors: LI, Jinsheng, YAN, Hao
• Granted Patent: US 12,005,273 B2
• Time in Patent Office: Days
• CPC Class Codes: A61N 2005/1061 using an x-ray imaging system having a separate imaging source
• CPC Class Codes: A61N 2005/1076 using a dummy object placed in the radiation field, e.g. phantom
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1075 for testing, calibrating, or quality assurance of the radiation treatment apparatus

Abstract

Provided are a calibration method, device and storage medium of radiotherapy equipment. The calibration method of the radiotherapy equipment adopts an imaging body disposed within a preset distance range of an isocenter of radiotherapy equipment to perform error calibration on the radiotherapy equipment, and includes: imaging the imaging body through an imaging system to obtain an actual image of the imaging body; determining an image deviation between the actual image and a theoretical image of the imaging body, wherein the theoretical image is determined in advance based on a theoretical position of the imaging system and a spatial position of the imaging body in a rack; and determining a system error of imaging system based on the image deviation. Thus, the imaging system is calibrated without moving a treatment couch. The calibration accuracy of imaging system is not influenced by movement precision of treatment couch. The calibration accuracy is improved.

Claims

1. An error calibration method of radiotherapy equipment comprising an imaging system, wherein an imaging body disposed within a preset distance range of an isocenter of the radiotherapy equipment is adopted for error calibration of the radiotherapy equipment, and the error calibration method comprises:

imaging the imaging body through the imaging system to obtain an actual image of the imaging body;

determining an image deviation between the actual image and a theoretical image of the imaging body, the theoretical image being obtained in advance based on a theoretical position of the imaging system and a spatial position of the imaging body in the radiotherapy equipment; and

determining a system error of the imaging system based on the image deviation.

2. The error calibration method according to claim 1, wherein the radiotherapy equipment further comprises a positioning system, and the positioning system comprises a locating reference device and a treatment couch;

and

after determining a system error of the imaging system based on the image deviation, the error calibration method further comprises;

adjusting the imaging system based on the system error of the imaging system for error correction;

acquiring a scanned image of a model body placed on the treatment couch, the model body being provided with a reference point thereon;

positioning the model body on the treatment couch through the locating reference device and the treatment couch, to enable that the referent point on the model body overlaps a central point of the positioning system;

moving the treatment couch based on a position relationship between the central point of the positioning system and the isocenter of the radiotherapy equipment, to put the model body into the radiotherapy equipment;

imaging the model body that is put into the radiotherapy equipment through the imaging system subjected to the error correction to obtain an actual image of the model body; and

calibrating the positioning system based on the actual image and the scanned image of the model body to obtain a system error of the positioning system.

3. The error calibration method according to claim 1, wherein the radiotherapy equipment further comprises a positioning system, and the positioning system comprises a locating reference device and a treatment couch;

and

after determining a system error of the imaging system based on the image deviation, the error calibration method further comprises;

acquiring a scanned image of a model body placed on the treatment couch, the model body being provided with a reference point thereon;

positioning the model body on the treatment couch through the locating reference device and the treatment couch to enable that the referent point on the model body overlaps a central point of the positioning system;

moving the treatment couch based on a position relationship between the central point of the positioning system and the isocenter of the radiotherapy equipment, to put the model body into the radiotherapy equipment;

imaging the model body that is put into the radiotherapy equipment through the imaging system to obtain an initial image of the model body;

performing error compensation on the initial image of the model body based on the system error of the imaging system;

determining the initial image of which the error compensation is accomplished as an actual image of the model body; and

calibrating the positioning system based on the actual image and the scanned image of the model body to obtain a system error of the positioning system.

4. The error calibration system according to claim 2, wherein calibrating the positioning system based on the actual image and the scanned image of the model body comprises:

moving one of the actual image and the scanned image of the model body until a first area in the actual image of the model body overlaps a second area in the scanned image of the model body, wherein the first area and the second area are areas with the same content;

determining a first movement displacement and a first rotation angle, wherein the first movement displacement and the first rotation angle respectively refer to a moved displacement and a rotated angle of one of the actual image and the scanned image of the model body when the first area and the second area overlap with each other; and

determining the system error of the positioning system based on the first movement displacement and the first rotation angle.

5. The error calibration method according to claim 1, wherein the radiotherapy equipment further comprises a rack on which the imaging system is disposed;

the rack drives the imaging system to rotate around the isocenter of the radiotherapy equipment; and

the error calibration method further comprises;

driving the imaging system to rotate around the isocenter of the radiotherapy equipment through the rack;

imaging the imaging body at different rotation angles through the imaging system, when the rack drives the imaging system to rotate around the isocenter of the radiotherapy equipment, to obtain actual images of the imaging body at different rotation angles;

determining image deviations between the actual images and theoretical images of the imaging body at different rotation angles respectively; and

determining system errors of the imaging system at different rotation angles based on the image deviations at different rotation angles respectively.

6. A location method of a radiotherapy target, wherein radiotherapy equipment of which calibration is accomplished by the error calibration method according to claim 2 is adopted to locate the radiotherapy target;

and the location method comprises;

acquiring a scanned image of the radiotherapy target placed on a treatment couch, the radiotherapy target being provided with a reference point thereon;

positioning the radiotherapy target on the treatment couch through a positioning system to enable that the reference point on the radiotherapy target overlaps a central point of the positioning system;

moving the treatment couch based on a position relationship between the central point of the positioning system and an isocenter of the radiotherapy equipment, to put the radiotherapy target into the radiotherapy equipment;

imaging the radiotherapy target through an imaging system to obtain an actual image of the radiotherapy target; and

moving the radiotherapy target to a preset position based on the actual image and the scanned image of the radiotherapy target.

7. The location method according to claim 6, wherein positioning the radiotherapy target on the treatment couch through a positioning system comprises one of the following steps:

adjusting the positioning system based on a system error of the positioning system for error correction; and

positioning the radiotherapy target on the treatment couch through the positioning system subjected to error correction; and

positioning the radiotherapy target on the treatment couch through the positioning system, and performing error compensation based on the system error of the positioning system in the positioning process.

8. The location method according to claim 6, wherein imaging the radiotherapy target through the imaging system to obtain an actual image of the radiotherapy target comprises one of the following steps:

adjusting the imaging system based on a system error of the imaging system for error correction; and

imaging the radiotherapy target through the imaging system subjected to error correction to obtain the actual image of the radiotherapy target; and

imaging the radiotherapy target through the imaging system to obtain an initial image of the radiotherapy target;

performing error compensation on the initial image of the radiotherapy target based on the system error of the imaging system; and

determining the initial image of which the error compensation is accomplished as the actual image of the radiotherapy target.

10. An image calibration tooling, wherein the image calibration tooling comprises a support and at least one imaging body connected to an end of the support, and by connecting the image calibration tooling to radiotherapy equipment of which calibration is accomplished by the error calibration method according to claim 1, the at least one imaging body is located within a preset distance range of an isocenter of the radiotherapy equipment and error calibration is performed on the radiotherapy equipment.

11. The image calibration tooling according to claim 10, wherein one of the at least one imaging body is located in the isocenter of the radiotherapy equipment.

12. The image calibration tooling according to claim 11, wherein the imaging body is one of a sphere and a cube.

21. The error calibration system according to claim 3 wherein calibrating the positioning system based on the actual image and the scanned image of the model body comprises:

moving one of the actual image and the scanned image of the model body until a first area in the actual image of the model body overlaps a second area in the scanned image of the model body, wherein the first area and the second area are areas with the same content;

determining a first movement displacement and a first rotation angle, wherein the first movement displacement and the first rotation angle respectively refer to a moved displacement and a rotated angle of one of the actual image and the scanned image of the model body when the first area and the second area overlap with each other; and

determining the system error of the positioning system based on the first movement displacement and the first rotation angle.

22. A location method of a radiotherapy target, wherein radiotherapy equipment of which calibration is accomplished by the error calibration method according to claim 3 is adopted to locate the radiotherapy target;

and the location method comprises;

acquiring a scanned image of the radiotherapy target placed on a treatment couch, the radiotherapy target being provided with a reference point thereon;

positioning the radiotherapy target on the treatment couch through a positioning system to enable that the reference point on the radiotherapy target overlaps a central point of the positioning system;

moving the treatment couch based on a position relationship between the central point of the positioning system and an isocenter of the radiotherapy equipment, to put the radiotherapy target into the radiotherapy equipment;

imaging the radiotherapy target through an imaging system to obtain an actual image of the radiotherapy target; and

moving the radiotherapy target to a preset position based on the actual image and the scanned image of the radiotherapy target.

23. The location method according to claim 22, wherein positioning the radiotherapy target on the treatment couch through a positioning system comprises one of the following steps:

adjusting the positioning system based on a system error of the positioning system for error correction; and

positioning the radiotherapy target on the treatment couch through the positioning system subjected to error correction; and

positioning the radiotherapy target on the treatment couch through the positioning system, and performing error compensation based on the system error of the positioning system in the positioning process.

9. (canceled)

13. An error calibration device of radiotherapy equipment comprising an imaging system, wherein an imaging body disposed within a preset distance range of an isocenter of the radiotherapy equipment is adopted to calibrate the radiotherapy equipment, and the error calibration device comprises a first processor;

and

a first memory arranged to store an instruction executable by the first processor,

wherein the first processor is configured to;

image the imaging body through the imaging system to obtain an actual image of the imaging body;

determine an image deviation between the actual image and a theoretical image of the imaging body, the theoretical image being obtained in advance based on a theoretical position of the imaging system and a spatial position of the imaging body in the radiotherapy equipment; and

determine a system error of the imaging system based on the image deviation.

14. The error calibration device according to claim 13, wherein the radiotherapy equipment further comprises a positioning system, and the positioning system comprises a locating reference device and a treatment couch;

and

the first processor is further configured to;

adjust the imaging system based on the system error of the imaging system for error correction;

acquire a scanned image of a model body placed on the treatment couch, the model body being provided with a reference point thereon;

position the model body on the treatment couch through the locating reference device and the treatment couch to enable that the reference point on the model body overlaps a central point of the positioning system;

move the treatment couch based on a position relationship between the central point of the positioning system and the isocenter of the radiotherapy equipment, to put the model body into the radiotherapy equipment;

image the model body that is put into the radiotherapy equipment through the imaging system subjected to error correction to obtain an actual image of the model body; and

calibrate the positioning system based on the actual image and the scanned image of the model body to obtain a system error of the positioning system.

15. The error calibration device according to claim 13, wherein the radiotherapy equipment further comprises a positioning system and the positioning system comprises a locating reference device and a treatment couch;

and

the first processor is further configured to;

acquire a scanned image of a model body placed on the treatment couch, the model body being provided with a reference point thereon;

position the model body on the treatment couch through the locating reference device and the treatment couch, to enable that the reference point on the model body overlaps a central point of the positioning system;

move the treatment couch based on a position relationship between the central point of the positioning system and the isocenter of the radiotherapy equipment, to put the model body into the radiotherapy equipment;

image the model body that is put into the radiotherapy equipment through the imaging system to obtain an initial image of the model body;

perform error compensation on the initial image of the model body based on the system error of the imaging system;

determine the initial image of which the error compensation is accomplished as an actual image of the model body; and

calibrate the positioning system based on the actual image and the scanned image of the model body to obtain a system error of the positioning system.

17. The error calibration device according to claim 13, wherein the radiotherapy equipment further comprises a rack on which the imaging system is disposed;

the rack drives the imaging system to rotate around the isocenter of the radiotherapy equipment; and

the error calibration device further comprises;

a rotation module configured to drive the imaging system to rotate around the isocenter of the radiotherapy equipment through the rack;

a fourth imaging module configured to image the imaging body at different rotation angles through the imaging system, when the rack drives the imaging system to rotate around the isocenter of the radiotherapy equipment, to obtain actual images of the imaging body at different rotation angles;

a fourth determination module configured to determine image deviations between the actual images and theoretical images of the imaging body at different rotation angles respectively; and

a fifth determination module configured to determine system errors of the imaging system at different rotation angles based on the image deviations at different rotation angles respectively.

18. A locating device of a radiotherapy target, wherein radiotherapy equipment of which calibration is accomplished by the calibration method of claim 14 is adopted to locate the radiotherapy target;

and the locating device comprises a second processor; and

a second memory arranged to store an instruction executable by the second processor,

wherein the second processor is configured to;

acquire a scanned image of the radiotherapy target placed on a treatment couch, the radiotherapy target being provided with a reference point thereon;

position the radiotherapy target on the treatment couch through a positioning system to enable that the reference point on the radiotherapy target overlaps a central point of the positioning system;

move the treatment couch based on a position relationship between the central point of the positioning system and an isocenter of the radiotherapy equipment, to put the radiotherapy target into the radiotherapy equipment;

image the radiotherapy target through an imaging system to obtain an actual image of the radiotherapy target; and

move the radiotherapy target to a preset position based on the actual image and the scanned image of the radiotherapy target.

16. (canceled)

19. A computer readable storage medium, wherein an instruction is stored in the computer readable storage medium;

and when the computer readable storage medium runs on a computer, the computer executes an error calibration method of radiotherapy equipment comprising an imaging system, wherein an imaging body disposed within a preset distance range of an isocenter of the radiotherapy equipment is adopted for error calibration of the radiotherapy equipment, and the error calibration method comprises;

imaging the imaging body through the imaging system to obtain an actual image of the imaging body;

determining an image deviation between the actual image and a theoretical image of the imaging body, the theoretical image being obtained in advance based on a theoretical position of the imaging system and a spatial position of the imaging body in the radiotherapy equipment and

determining a system error of the imaging system based on the image deviation.

20. (canceled)