Detection device and detection method for automatic quality assurance of cyber knife

Abstract

The invention relates to the technical field of radiotherapy, in particular to a cyber knife automatic quality assurance detection device and method, and the device comprises a Cherenkov light emission model, a detection mechanism, and a computer processing unit. Weak Cherenkov light generated in the interaction process of rays and substances is utilized to excite quantum dots to emit light, automatic quality guarantee radial error measurement of a cyber knife can be achieved without additional media, the method has the advantages of being rapid, accurate, simple and the like, the problem that film post-processing time is long can be effectively solved, and the method is suitable for large-scale popularization and application. The method is helpful for guaranteeing the positive implementation of related automatic quality assurance detection under the condition that the treatment time of the cyber knife in most hospitals in China is short, has the characteristic of being capable of being repeatedly used through one-time calibration, and can greatly reduce the cost of carrying out the automatic quality assurance detection of the cyber knife in the hospitals; the problem of high cost caused by the fact that a die body and a film used for automatic quality assurance detection of a wave cutter at the present stage are provided for foreign manufacturers can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of radiotherapy, in particular to a CyberKnife automatic quality assurance detection device and detection method. Background Art

[0002] As one of the three major methods of treating tumors, radiotherapy aims to kill tumor cells to the maximum extent and effectively protect surrounding normal tissues and important organs. Large medical radiotherapy equipment, such as linear accelerators and treatment planning systems, must have strict quality control to ensure that the correct radiotherapy is implemented on patients.

[0003] The CyberKnife Auto Quality Assurance (AQA) test is similar to the Winston-Lutz test of the stereotactic system. It is a quick and simple system irradiation accuracy test. It uses the gold standard tracking method to analyze and compare the difference between the center of mass of the horizontal and orthogonal radiation fields in the phantom projected on the film and the center of mass of the tungsten ball in the phantom, so as to detect the accuracy of the image center and the robotic arm. According to WS667-2019 "Quality Control Test Specification for Robotic Arm Radiotherapy Devices" and AAPM TG-135 recommendations, AQA testing should be performed daily as one of the items for acceptance testing and stability testing. Although the film can obtain various information required for CyberKnife AQA, it still has the disadvantages of long post-processing time and the fact that the film is a disposable consumable and cannot be reused. In most domestic hospitals, it is difficult to ensure that relevant AQA tests can be actively implemented under the condition of tight CyberKnife treatment time. At the same time, the phantoms and films used in CyberKnife AQA testing are currently provided by foreign manufacturers, and the cost of carrying out CyberKnife AQA testing is relatively expensive. Therefore, it is necessary to develop a real-time CyberKnife AQA device with good linearity, simple measurement, high resolution, low cost and reusability.

[0004] Cherenkov light is generated in the energy loss process of charged particles whose speed exceeds the phase velocity of light propagating in the dielectric. It is one of the forms of energy loss of charged particles, and its energy loss is approximately proportional to the energy deposition of charged particles. Therefore, the optical properties of Cherenkov light (number of photons, etc.) can be used as an "intermediary parameter" to determine the corresponding charged particle dose deposition in the medium (the beam field of the ray can also be reflected by detecting the light field of Cherenkov photons). Cherenkov optical imaging has many advantages of optical imaging, such as fast imaging speed, low price, and wide application range. In particular, it can be used to obtain information on the high-energy radiation field of radiotherapy in homogeneous models. Summary of the invention

[0005] In view of the above problems in the prior art, the present invention is proposed.

[0006] Therefore, an object of the present invention is to provide a CyberKnife automatic quality assurance test device.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a CyberKnife automatic quality assurance detection device, comprising:

[0008] Cherenkov light emission model, detection mechanism and computer processing unit;

[0009] The Cherenkov light emission model is used to make the X-ray A and X-ray B emitted by the CyberKnife generate Cherenkov light, so that the Cherenkov light excites the quantum dots to emit fluorescence. After the detection mechanism detects and collects the fluorescence intensity data, the computer processing unit processes and analyzes the fluorescence intensity data.

[0010] As a preferred solution of the CyberKnife automatic quality assurance detection device of the present invention, wherein: the Cherenkov light emission model includes a rectangular body, a tungsten ball arranged at the center of the rectangular body, and a box arranged outside the rectangular body;

[0011] The rectangular body has a density of 1 g / cm 3 The box body is made of synthetic resin or acrylic material, and the box body is made of light-transmitting acrylic material.

[0012] As a preferred solution of the CyberKnife automatic quality assurance detection device of the present invention, the interior of the box is filled with a solution with a concentration of 1g / L, the solute material of the solution is quantum dots with stable luminescence, the absorption spectrum band of the quantum dots is 300-400nm, and the emission peak is greater than 450nm.

[0013] As a preferred solution of the CyberKnife automatic quality assurance detection device of the present invention, wherein: the Cherenkov light emission model further includes a frame arranged outside the box body, and a reflector fixedly connected to the inside of the frame;

[0014] There are two reflectors, and the two groups of reflectors are at an angle of 45° to the exit surfaces of the two beams of X-ray A and X-ray B respectively.

[0015] As a preferred solution of the CyberKnife automatic quality assurance detection device of the present invention, the detection mechanism includes a bracket arranged outside the Cherenkov light emission model, a remote trigger time gating module adapted to be installed outside the bracket, and a detector adapted to be installed outside the remote trigger time gating module.

[0016] As a preferred solution of the CyberKnife automatic quality assurance detection device of the present invention, wherein: the detection mechanism also includes a filter adapted to be installed on the outside of the detector, an imaging lens adapted to be installed on the outside of the filter, and a tungsten alloy stray radiation shielding layer mounted on the outside of the remote trigger time gating module, the detector, the filter and the imaging lens;

[0017] Wherein, the transmission band of the filter is greater than 450nm.

[0018] As a preferred solution of the CyberKnife automatic quality assurance detection device of the present invention, wherein: the computer processing unit includes a signal transmission system, a processor, a memory and a non-transient computer storage medium;

[0019] The signal transmission system is used to wirelessly transmit the optical signal acquired by the detector to the processor;

[0020] The processor is used to implement the CyberKnife automatic quality assurance detection method according to the optical signal to obtain a corrected optical signal image;

[0021] The memory stores computer instructions which, when executed by the processor, cause the processor to perform the CyberKnife automatic quality assurance testing method;

[0022] The non-transitory computer storage medium stores a computer program, which, when executed by one or more processors, causes the processors to perform the CyberKnife automatic quality assurance detection method.

[0023] The present invention also provides a detection method.

[0024] In order to solve the above technical problems, the present invention also provides the following technical solutions: a detection method for implementing the CyberKnife automatic quality assurance detection device, and,

[0025] The detector was mounted on the outside of the bracket to obtain two sets of light field images during the CyberKnife automatic quality assurance inspection process. Temporal and spatial median filtering was applied to the detector's field programmable gate array.

[0026] As a preferred solution of the detection method of the present invention, wherein: a stack of flat and dark field images with the same number of frames is collected, a flat field correction factor is obtained pixel by pixel, and a flat field correction is performed on the original light field image.

[0027] As a preferred solution of the detection method of the present invention, the corrected light field image is binarized, and the deviation in the head-foot direction, left-right direction, and ventral-dorsal direction of the field is calculated respectively, so as to obtain the total radial deviation of the CyberKnife automatic quality assurance detection.

[0028] The beneficial effects of the present invention are as follows: the weak Cherenkov light generated in the process of interaction between rays and matter is used to excite quantum dots to emit light, and the radial error measurement of the CyberKnife automatic quality assurance can be achieved without additional media.

[0029] The present invention has the characteristics of being fast, accurate, and simple, and can effectively solve the problem of long film post-processing time. It is helpful to ensure the active implementation of relevant automatic quality assurance testing under the condition of tight CyberKnife treatment time in most domestic hospitals, thereby effectively ensuring the efficacy of radiotherapy and protecting the radiation safety of patients.

[0030] The present invention has the characteristic of being reusable after one calibration, which can significantly reduce the cost of hospitals carrying out automatic quality assurance testing of CyberKnife, and can solve the high cost problem caused by the fact that the phantoms and films used in the automatic quality assurance testing of CyberKnife are currently provided by foreign manufacturers. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0032] Figure 1 It is an overall schematic diagram of the present invention.

[0033] Figure 2 It is a schematic diagram of the detection mechanism of the present invention.

[0034] Figure 3 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0038] Example 1

[0039] Reference Figure 1 and Figure 2 , which is the first embodiment of the present invention, provides a CyberKnife automatic quality assurance detection device, comprising:

[0040] Cherenkov light emission model 100, detection mechanism 200 and computer processing unit;

[0041] The Cherenkov light emission model 100 is used to make the X-ray A and X-ray B emitted by the CyberKnife generate Cherenkov light, so that the Cherenkov light excites the quantum dots to emit fluorescence. After the detection mechanism 200 detects and collects the light intensity data of the fluorescence, the computer processing unit processes and analyzes the light intensity data of the fluorescence.

[0042] Specifically, the Cherenkov light emission model 100 includes a rectangular body 101, a tungsten ball 102 disposed at the center of the rectangular body 101, and a box 103 disposed outside the rectangular body 101;

[0043] The rectangular body 101 has a density of 1 g / cm 3 The box body 103 is made of a synthetic resin or acrylic material, and the box body 103 is made of a light-transmitting acrylic material.

[0044] Furthermore, the box 103 is filled with a solution with a concentration of 1 g / L, the solute material of the solution is quantum dots with stable luminescence, the absorption spectrum of the quantum dots is in the range of 300-400 nm, and the emission peak is greater than 450 nm.

[0045] The Cherenkov light emission model 100 further includes a frame 104 disposed outside the box 103 and a reflector 105 fixedly connected to the inside of the frame 104;

[0046] There are two reflectors 105, and the two sets of reflectors 105 are at an angle of 45° to the exit planes of the two beams of X-ray A and X-ray B, respectively.

[0047] It should be further explained that the size of the rectangular body 101 is set to 5×5×5 cm 3 The overall dimensions of the rectangular body 101 and the box 103 are 6.35×5×6.35cm 3 , the size of the tungsten ball 102 is a sphere with a diameter of 1.9 cm;

[0048] The rectangular body 101 is embedded with 4 non-coplanar circular gold labels with a diameter of 2 mm. The distance between each gold label is greater than 20 mm. The angle of the triangle formed by each 3 gold labels is greater than 15°, and there is no overlap in the 45° field of view on both sides, so as to accurately obtain the position information of the rectangular body 101.

[0049] The wall thickness of the box 103 is 3 mm, and the liquid inlet and outlet cannot be set on the ray path;

[0050] The solutes of the solution inside the box 103 include quantum dots with stable light emission, such as carbon quantum dots, cadmium quantum dots, indium quantum dots, and perovskite quantum dots.

[0051] The CyberKnife emits two X-rays A and X-ray B in horizontal and orthogonal directions. X-ray A and X-ray B generate Cherenkov light in the box 103 through the rectangular body 101. The Cherenkov light excites the quantum dots in the box 103 to emit opticemission a and opticemission b, which are reflected by two reflectors 105 for detection and collection by the detection mechanism 200.

[0052] It is worth noting that the wavelength band of Cherenkov light is concentrated between 300 and 400 nm. In order to make Cherenkov light excite quantum dots to emit light, the wavelength band of Cherenkov light needs to match the wavelength band of quantum dots. Therefore, the absorption spectrum band of quantum dots needs to be set to 300 to 400 nm.

[0053] Example 2

[0054] Reference Figure 1 and Figure 2 , which is the second embodiment of the present invention. Different from the previous embodiment, this embodiment provides that the detection mechanism 200 includes a bracket 201 arranged on the outside of the Cherenkov light emission model 100, a remote trigger time gating module 202 adapted to be installed on the outside of the bracket 201, and a detector 203 adapted to be installed on the outside of the remote trigger time gating module 202.

[0055] Specifically, the detection mechanism 200 also includes a filter 204 adapted to be installed on the outside of the detector 203, an imaging lens 205 adapted to be installed on the outside of the filter 204, and a tungsten alloy stray radiation shielding layer 206 mounted on the outside of the remote trigger time gating module 202, the detector 203, the filter 204 and the imaging lens 205;

[0056] The transmission band of the filter 204 is greater than 450 nm, thereby matching the emission band of the quantum dots.

[0057] Further, the computer processing unit includes a signal transmission system, a processor, a memory, and a non-transitory computer storage medium;

[0058] The signal transmission system is used to wirelessly transmit the optical signal acquired by the detector 203 to the processor;

[0059] The processor is used to implement the CyberKnife automatic quality assurance detection method according to the optical signal to obtain a corrected optical signal image;

[0060] The memory stores computer instructions which, when executed by the processor, cause the processor to perform the CyberKnife automatic quality assurance testing method;

[0061] The non-transitory computer storage medium stores a computer program, which, when executed by one or more processors, causes the processors to perform the CyberKnife automatic quality assurance detection method.

[0062] It should be further explained that the detector 203 adopts an ICCD (Intensified Charge-coupled Device) detector, and the remote trigger time gating module 202 adopts a scintillator-coupled SiPM (Silicon photomultiplier) module.

[0063] The imaging lens 205 uses a high dynamic range and high transmittance imaging lens to ensure a large amount of light input and improve the detection performance of quantum dot fluorescence emission.

[0064] The remote trigger time gating module 202 can synchronize the shutter of the detector 203 with the beam pulse to reduce the influence of ambient light on optical imaging.

[0065] The thickness of the tungsten alloy stray radiation shielding layer 206 is not less than 3 cm to prevent stray radiation from penetrating the detector 203 .

[0066] When in use, the detector 203 acquires the light intensity distribution and the ambient light background frame in two ray perpendicular directions respectively, and the computer processing unit processes the light field image and acquires the corresponding CyberKnife automatic quality assurance radial deviation.

[0067] Example 3

[0068] Reference Figure 1 to Figure 3 , which is the third embodiment of the present invention, is different from the previous embodiment in that this embodiment provides a detection method for implementing the CyberKnife automatic quality assurance detection device, and,

[0069] The detector is mounted on the outside of the bracket to obtain two sets of light field images during the CyberKnife automatic quality assurance inspection process. Temporal and spatial median filtering is applied to the detector's field programmable gate array (FPGA).

[0070] Specifically, a flat-field and dark-field image stack with the same number of frames is collected, a flat-field correction factor is obtained pixel by pixel, and a flat-field correction is performed on the original light field image.

[0071] Furthermore, the corrected light field image was binarized, and the deviations in the head-foot direction, left-right direction, and ventral-dorsal direction of the field were calculated, respectively, and the total radial deviation of the CyberKnife automatic quality assurance test was obtained.

[0072] The specific process of this detection method is:

[0073] Step 1: Determine the geometric positions of the Cherenkov light emission model 100 and the detection mechanism 200 in the isocenter plane according to the CyberKnife automatic quality assurance beam field;

[0074] Step 2, based on the light intensity data of optical emission b and optical emission a emitted by the quantum dots excited by the Cherenkov light generated by the horizontal ray X-ray B and the orthogonal ray X-ray A in the Cherenkov light emission model 100 in the CyberKnife automatic quality assurance test, detection is performed in combination with the detector 203 encapsulating the corresponding band filter 204;

[0075] Step 3, using 5 frames and 5×5 pixel motion windows to perform temporal and spatial median filtering on the field programmable gate array of the detector 203, respectively, eliminating additional denoising or smoothing in post-processing, collecting flat-field and dark-field image stacks of the same number of frames, obtaining pixel-by-pixel flat-field correction factors, and performing flat-field correction on the original light field image;

[0076] Step 4: Binarize the corrected light field image, calculate the deviation in the head-foot direction, left-right direction, and ventral-dorsal direction of the field, and then obtain the total radial deviation of the CyberKnife automatic quality assurance test.

[0077] In summary, the weak Cherenkov light generated during the interaction between rays and matter is used to excite quantum dots to emit light, and the CyberKnife automatic quality assurance radial error measurement can be achieved without additional media.

[0078] The present invention has the characteristics of being fast, accurate, and simple, and can effectively solve the problem of long film post-processing time. It is helpful to ensure the active implementation of relevant automatic quality assurance testing under the condition of tight CyberKnife treatment time in most domestic hospitals, thereby effectively ensuring the efficacy of radiotherapy and protecting the radiation safety of patients.

[0079] The present invention has the characteristic of being reusable after one calibration, which can significantly reduce the cost of hospitals carrying out automatic quality assurance testing of CyberKnife, and can solve the high cost problem caused by the fact that the phantoms and films used in the automatic quality assurance testing of CyberKnife are currently provided by foreign manufacturers.

Claims

1. A CyberKnife automatic quality assurance test device, characterized by: include, A Cherenkov light emission model (100), a detection mechanism (200), and a computer processing unit; The Cherenkov light emission model (100) is used to make the X-ray (A) and X-ray (B) emitted by the CyberKnife generate Cherenkov light, so that the Cherenkov light excites the quantum dots to emit fluorescence. After the detection mechanism (200) detects and collects the light intensity data of the fluorescence, the computer processing unit processes and analyzes the light intensity data of the fluorescence.

2. The CyberKnife automatic quality assurance testing device according to claim 1, characterized in that: The Cherenkov light emission model (100) comprises a rectangular body (101), a tungsten ball (102) arranged at the center of the rectangular body (101), and a box (103) arranged outside the rectangular body (101); The rectangular body (101) has a density of 1 g / cm 3 The box body (103) is made of a light-transmitting acrylic material.

3. The CyberKnife automatic quality assurance testing device according to claim 2, characterized in that: The box (103) is filled with a solution with a concentration of 1 g / L, the solute material of the solution is quantum dots with stable luminescence, the absorption spectrum of the quantum dots is in the range of 300 to 400 nm, and the emission peak is greater than 450 nm.

4. The CyberKnife automatic quality assurance testing device according to claim 3, characterized in that: The Cherenkov light emission model (100) further comprises a frame (104) arranged outside the box (103), and a reflector (105) fixedly connected to the inside of the frame (104); There are two reflectors (105), and the two groups of reflectors (105) form an angle of 45° with the exit surfaces of the two beams of X-ray (A) and X-ray (B), respectively.

5. The CyberKnife automatic quality assurance testing device according to claim 4, characterized in that: The detection mechanism (200) comprises a bracket (201) arranged outside the Cherenkov light emission model (100), a remote trigger time gating module (202) adapted to be installed outside the bracket (201), and a detector (203) adapted to be installed outside the remote trigger time gating module (202).

6. The CyberKnife automatic quality assurance testing device according to claim 5, characterized in that: The detection mechanism (200) further comprises a filter (204) adapted to be installed on the outside of the detector (203), an imaging lens (205) adapted to be installed on the outside of the filter (204), and a tungsten alloy stray radiation shielding layer (206) sleeved on the outside of the remote trigger time gating module (202), the detector (203), the filter (204) and the imaging lens (205); Wherein, the transmission band of the filter (204) is greater than 450 nm.

7. The CyberKnife automatic quality assurance testing device according to claim 6, characterized in that: The computer processing unit includes a signal transmission system, a processor, a memory, and a non-transitory computer storage medium; The signal transmission system is used to wirelessly transmit the optical signal acquired by the detector (203) to the processor; The processor is used to implement the CyberKnife automatic quality assurance detection method according to the optical signal to obtain a corrected optical signal image; The memory stores computer instructions which, when executed by the processor, cause the processor to perform the CyberKnife automatic quality assurance testing method; The non-transitory computer storage medium stores a computer program, which, when executed by one or more processors, causes the processors to perform the CyberKnife automatic quality assurance detection method.

8. A detection method, characterized in that: A CyberKnife automatic quality assurance detection device for implementing any one of claims 1 to 7, and The detector was mounted on the outside of the bracket to obtain two sets of light field images during the CyberKnife automatic quality assurance inspection process. Temporal and spatial median filtering was applied to the detector's field programmable gate array.

9. The detection method according to claim 8, characterized in that: The flat-field and dark-field image stacks with the same number of frames were collected to obtain the flat-field correction factor pixel by pixel, and the flat-field correction was performed on the original light-field image.

10. The detection method according to claim 9, characterized in that: The corrected light field image was binarized, and the deviations in the head-foot direction, left-right direction, and ventral-dorsal direction of the field were calculated respectively, and then the total radial deviation of the CyberKnife automatic quality assurance test was obtained.

Images