Accelerator-based online adaptive radiotherapy planning quality control method and device

Abstract

This invention discloses an accelerator-based online adaptive radiotherapy planning quality control method and apparatus. The main design concept involves configuring a verification system and detecting the status of the accelerator and optical surface system before creating the online adaptive radiotherapy plan; acquiring the latest CT images and registering them with historical CT images to generate the current online adaptive radiotherapy plan; performing a first-stage verification of the current online adaptive radiotherapy plan before radiotherapy; calibrating the positioning error using the optical surface tracking system after determining the plan's usability; initiating radiotherapy after positioning error calibration and performing a second-stage verification of the online adaptive radiotherapy plan during radiotherapy; and performing a third-stage verification of the online adaptive radiotherapy plan after radiotherapy. This invention not only helps improve the reliability of adaptive plans but also provides a solid foundation for promoting the standardized clinical application of radiotherapy technology on a wider scale.

Description

Technical Field

[0001] This invention relates to the field of radiotherapy system technology, and in particular to an online adaptive radiotherapy planning quality control method and apparatus based on an accelerator. Background Technology

[0002] The main challenge of radiotherapy is "variability" (such as changes caused by target displacement, patient anatomy, and disease progression), which can easily lead to deviations in dosage and target area. Therefore, online adaptive radiotherapy (oART) combined with optical surface tracking systems is gradually being applied clinically, effectively optimizing treatment plans and achieving individualized and precise control of radiotherapy parameters.

[0003] However, the process of combining optical surface tracking systems with online adaptive radiotherapy technology is highly complex, encompassing multiple sub-steps such as optical tracking, image guidance, automatic delineation, planning re-optimization, and radiation field adjustment. In actual clinical applications, even a small error in any sub-step can accumulate into dose deviation, affecting efficacy or increasing the risk of side effects.

[0004] Based on the above analysis, the applicant believes that there is an urgent need to combine CT-integrated linear accelerator technology to build a comprehensive quality control system for oART, which is crucial for the safety, accuracy and sustainable implementation of oART. Summary of the Invention

[0005] In view of the above, the present invention aims to provide an online adaptive radiotherapy planning quality control method and apparatus based on accelerators to solve the specific problems mentioned above.

[0006] The technical solution adopted in this invention is as follows:

[0007] In a first aspect, the present invention provides an accelerator-based online adaptive radiotherapy planning quality control method, comprising:

[0008] Before creating an online adaptive radiotherapy plan, configure the verification system and check the status of the accelerator and optical surface system;

[0009] The system acquires the latest CT images and registers them with historical CT images to generate the current online adaptive radiotherapy plan.

[0010] Before radiotherapy is administered, the current online adaptive radiotherapy plan is validated in the first phase, which includes at least: simulating dose delivery in a real accelerator treatment environment and deciding whether the generated plan is allowed to be used for treatment.

[0011] After determining that the current plan is available, the optical body surface tracking system performs positioning error calibration;

[0012] Radiotherapy was initiated after the setup error was calibrated, and the current online adaptive radiotherapy plan was validated in the second phase during radiotherapy, including at least: in vivo dose validation of the electronic field imager;

[0013] After the radiotherapy is completed, the current online adaptive radiotherapy plan will be validated in the third phase, which includes at least the following: comparing and calculating the difference in dose through three-dimensional dose reconstruction.

[0014] In at least one possible implementation, the first stage verification specifically includes:

[0015] Export the online adaptive radiotherapy planning dataset;

[0016] Automatically capture and import online adaptive radiotherapy planning datasets to complete image, structure, and plan registration;

[0017] The three-dimensional dose distribution of the current online adaptive radiotherapy plan is reconstructed based on the real beam model and CT density information to simulate dose delivery in the real accelerator head treatment environment;

[0018] The three-dimensional dose distribution was compared and validated with the original planned dose in multiple dimensions.

[0019] After multidimensional comparison and verification, it was determined that the current online adaptive radiotherapy plan can be approved for actual radiotherapy implementation;

[0020] After the plan is approved, the flux distribution map of the electronic field imager is calculated based on the planned dose distribution and the physical density of the CT.

[0021] In at least one possible implementation, the positioning error calibration by the optical body surface tracking system includes:

[0022] Import the patient's planned external contour and positioning coordinates into the optical body surface tracking system;

[0023] Delineate the region of interest for optical surface tracking;

[0024] Automatically compare the real-time outer contour of the body surface with the planned region of interest, and obtain the six-dimensional positioning error;

[0025] The position of the accelerator treatment bed is adjusted based on the six-dimensional positioning error until the preset standard is reached, thus completing the error correction.

[0026] In at least one possible implementation, the second-stage verification specifically includes:

[0027] The in vivo dose verification module of the electron field imager is automatically activated by the accelerator, and the field flux map and electron field imager verification parameters for in vivo verification are set and adjusted.

[0028] During the current execution of the plan, the accelerator continuously emits beams. The dose output from each planned field is received by the electron field imager detector plate in the form of photon flux, and the comparison results of the flux distribution measured by the electron field imager and the flux distribution calculated in the plan are output simultaneously.

[0029] After the project is completed, save the flux map and throughput analysis results measured by the electronic field imager.

[0030] In at least one possible implementation, the third-stage verification specifically includes:

[0031] The flux information acquired by the electronic field imager is reconstructed in three dimensions onto the patient's anatomical structure, and the actual radiation dose of each voxel of the patient is recovered through the back projection reconstruction algorithm.

[0032] Comparing dose-volume histogram parameters is used to assess the execution of the current online adaptive radiotherapy plan during treatment;

[0033] If the evaluation results show significant differences, the online adaptive radiotherapy plan will be adjusted again.

[0034] In at least one possible implementation, the registration with historical CT images specifically includes:

[0035] Rigid registration is performed based on bony landmarks, which is used as the initial alignment of CT images;

[0036] The historical CT images are deformed until they match the tissue anatomy information in the latest CT images;

[0037] Copy the target area outlined in the historical CT image onto the latest CT image;

[0038] If the deformed target area is found to differ from the latest CT image, or if the automatically delineated organs at risk show structural abnormalities, modifications and adjustments will be made until the problem is determined to be resolved. Then, the online adaptive radiotherapy plan will proceed to automatic optimization and calculation.

[0039] In a second aspect, the present invention provides an accelerator-based online adaptive radiotherapy planning quality control device, comprising:

[0040] The preparation module is used to configure the verification system and detect the status of the accelerator and optical surface system before creating an online adaptive radiotherapy plan;

[0041] The CT registration module is used to acquire the latest CT images and register them with historical CT images to generate the current online adaptive radiotherapy plan.

[0042] The first verification module is used to perform a first-stage verification of the current online adaptive radiotherapy plan before radiotherapy is implemented, which includes at least: simulating dose delivery in a real accelerator treatment environment and deciding whether the generated plan can be used for treatment;

[0043] The positioning calibration module is used by the optical body surface tracking system to calibrate positioning errors after determining that the current plan is available;

[0044] The second verification module is used to begin radiotherapy after the setup error is calibrated and to perform a second-stage verification of the current online adaptive radiotherapy plan during radiotherapy, which includes at least: in vivo dose verification of the electronic field imager;

[0045] The third verification module is used to perform a third-stage verification of the current online adaptive radiotherapy plan after the radiotherapy is performed, which includes at least: measuring and calculating the difference in dose by comparing the three-dimensional dose reconstruction.

[0046] Thirdly, the present invention provides an electronic device comprising: one or more processors, a memory, and one or more computer programs, the memory being a non-volatile storage medium, wherein the one or more computer programs are stored in the memory, the one or more computer programs including instructions that, when executed by the device, cause the electronic device to perform the method as described in the first aspect or any possible implementation thereof.

[0047] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when run on a computer, causes the computer to perform the method as described in the first aspect or any possible implementation thereof.

[0048] Fifthly, the present invention also provides a computer program product, which, when executed by a computer, performs the method described in the first aspect or any possible implementation thereof. In one possible design of the fifth aspect, the relevant program involved in the product may be stored wholly or partially on a memory packaged with a processor, or may be stored wholly or partially on a storage medium not packaged with a processor.

[0049] It should be understood that the second to fifth aspects of the embodiments of this application are consistent with the technical solutions of the first aspect of the embodiments of this application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation are similar, and will not be described again.

[0050] The main design concept of this invention lies in establishing a systematic, standardized, and quantifiable quality control system for the entire treatment planning process, from generation to execution, to ensure the accuracy and safety of oART plans. Specifically, before creating an online adaptive radiotherapy (oART) plan, a verification system is configured and the status of the accelerator and optical surface system is checked; the latest CT images are acquired and registered with historical CT images to generate the current online adaptive radiotherapy plan; before radiotherapy, the current online adaptive radiotherapy plan undergoes a first-stage verification; after determining the plan's usability, the optical surface tracking system calibrates the positioning error; after positioning error calibration, radiotherapy begins, and the online adaptive radiotherapy plan undergoes a second-stage verification during radiotherapy; after radiotherapy, the online adaptive radiotherapy plan undergoes a third-stage verification. This invention not only helps improve the reliability of adaptive plans but also provides a solid foundation for promoting the standardized clinical application of radiotherapy technology on a wider scale.

[0051] In summary, the advantages of this invention are at least as follows:

[0052] 1. Key aspects of clinical safety assurance

[0053] The biggest advantage of online adaptive radiotherapy (oART) lies in "individualized dose adjustment," but it also brings high-risk "procedural complexity." This invention significantly improves the safety and controllability of oART by constructing a multi-stage quality control system, performing closed-loop verification from treatment plan generation to treatment execution.

[0054] 2. Filling the gaps in quality control standards

[0055] Currently, there are no mature quality control standards for oART in the industry. The solution proposed in this invention covers a multi-level dose verification strategy before, during, and after treatment, providing a realistic and feasible blueprint for the development of industry quality control standards.

[0056] 3. Promote clinical application and standardization

[0057] By implementing a more standardized quality control process, the difficulties faced by oART due to its complex operation and limited promotion can be alleviated, laying the foundation for the large-scale application of this technology in the industry. Attached Figure Description

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0059] Figure 1 A flowchart illustrating the accelerator-based online adaptive radiotherapy planning quality control method provided in this embodiment of the invention;

[0060] Figure 2This is a schematic diagram of an accelerator-based online adaptive radiotherapy planning quality control device provided in an embodiment of the present invention. Detailed Implementation

[0061] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0062] This invention proposes an embodiment of an online adaptive radiotherapy planning quality control method based on accelerators, specifically, as follows: Figure 1 As shown, it includes:

[0063] Step S1: Before creating an online adaptive radiotherapy plan, configure the verification system and check the status of the accelerator and optical surface system;

[0064] Traditional radiotherapy planning involves patient positioning on a simulated CT scanner to acquire planning images, followed by plan design based on these images. Once the plan is validated, the patient can begin treatment. This traditional plan validation method can also be implemented on a CT-integrated accelerator. However, in practice, online adaptive radiotherapy (oART) requires the patient to wait on the accelerator treatment table from positioning to treatment. If the patient leaves the treatment table, the change in position can render the oART plan unsuitable for the current treatment. Furthermore, due to the rapid and compact nature of online adaptive radiotherapy, real-time dynamic adjustments based on the patient's imaging data (such as CT, X-ray, MRI, etc.) are necessary to minimize patient waiting time. Therefore, changes in tumor location, target boundary, and morphological alterations of normal tissues during treatment must be adapted and validated in real-time at each treatment cycle.

[0065] Therefore, conventional pre-treatment validation methods on accelerators, such as validation using conventional physical devices, have proven unsuitable for the aforementioned oART combined with accelerator treatment plans. However, validation of radiotherapy plans is crucial for ensuring their effectiveness, accuracy, and real-time adaptability during treatment. Therefore, in view of this problem, the present invention proposes the remedial measures mentioned in step S1 above, prior to the creation of an online adaptive radiotherapy plan.

[0066] To elaborate, this step includes three sub-steps:

[0067] Step 1, configuring the verification system, specifically includes:

[0068] 1) Accelerator model establishment and parameter tuning;

[0069] In actual operation, parameters of the target accelerator head, beam parameters (percent depth dose, off-axis ratio, output factor, etc.), and CT-density curves in the planning system can be loaded into a third-party independent verification system (i.e., a software system配套 with the accelerator, such as but not limited to the United Imaging uAssure 3D QA system). After the target accelerator model in the third-party independent verification system is constructed, it is necessary to compare with the dose calculation results of the original treatment planning system (TPS) and optimize the parameters to make them consistent at the clinical dose level. If the dose deviation between the two is > 2%, then fine-tuning of parameters such as CT-density curves, calculation grids, and beam currents needs to be carried out until the dose deviation between the TPS system and the third-party independent verification system is controlled within ±2%.

[0070] 2) Define the consistency of the coordinate system;

[0071] The purpose of this step is to ensure that the positioning CT images, dose calculations, and plan verifications are "aligned" in the same physical coordinate system. Therefore, the DICM standard image orientation, the coordinates of the plan management system, and the image registration coordinates of the third-party independent verification system can be defined according to the IEC 61217 standard to make the coordinates of the three consistent.

[0072] 3) Set up the adaptive plan verification interface;

[0073] Since oART is not pre-determined but generated online, before using the third-party independent verification system, the setting of data interfaces should be added to establish an adaptive plan data file, including CT images, plan files (RT Structure, RTPlan, RT Dose), etc., and send the exported interfaces and nodes to the third-party independent verification system in an automatic or semi-automatic manner.

[0074] 4) Conduct simulation tests;

[0075] Based on the patient plan verification phantom, simulate the process of the adaptive radiotherapy plan through the third-party independent verification system, and refer to the clinical treatment process to import the adaptive radiotherapy plan data into the third-party independent verification system for trial calculation to ensure that there are no problems such as loss, misalignment, and large calculation deviations in the plan files.

[0076] Link 2: Detect the status of the accelerator equipment (which can be but not limited to daily inspection. After the following inspection items pass the daily inspection, it can be used for subsequent online adaptive radiotherapy). Specifically, it includes:

[0077] 1) Fix the first phantom (BB phantom) on the accelerator treatment couch using the phantom fixture;

[0078] 2) Move the treatment couch to align the laser lamp with the crosshair on the surface of the BB phantom;

[0079] 3) Access the EPD QA module through a third-party independent verification system, select the automatic quality control option, and perform the test after confirming the phantom placement;

[0080] 4) After the test is completed, the third-party independent verification system compares the baseline data created after the linear accelerator is debugged and accepted, and evaluates and analyzes the consistency of the mechanical and dose parameters of MLC, EPID, collimator, treatment bed, gantry, laser, isocenter and beam. Understandably, if the deviation of each parameter is less than the corresponding preset tolerance range, the test can be considered passed.

[0081] 5) After removing the BB phantom, place the second phantom (2D QA phantom) on the treatment bed. Similarly, the cross lines on the phantom surface must be aligned with the laser light.

[0082] 6) Re-enter the EPD QA module, select the EPD imaging quality control module, and perform imaging quality detection after confirming the phantom placement;

[0083] 7) After the image quality detection is completed, the third-party independent verification system analyzes the image spatial resolution, contrast, signal-to-noise ratio and other parameters. Similarly, if the result is less than the tolerance, the detection is indicated as passed.

[0084] It can be added here that the BB phantom is a verification phantom provided with the accelerator. This phantom is a hollow cylinder with a diameter of 13 cm and a length of 30.9 cm, made of polymethyl methacrylate (PMMA), and has 18 steel balls with a diameter of 4 mm embedded in its surface. During daily inspections, the spatial coordinates of the steel balls within the BB phantom relative to the beam center are determined. Standard phantoms with defined structures are mainly used for testing the mechanical precision of the accelerator. Regarding the 2D QA phantom, it is also a verification phantom provided with the accelerator. This phantom is a cuboid with a diameter of 25 cm × 25 cm × 10 cm, also made of PMMA, and contains quality control components (such as metal wire pairs, simulated tissue density modules, water modules, etc.). It is mainly used to test the geometric accuracy and image quality of kVCT images.

[0085] Step 3: Inspect the condition of the optical surface system (this can also be done daily). This includes:

[0086] 1) Turn on the camera of the optical body surface tracking system and start the accompanying software after the camera has warmed up;

[0087] 2) After confirming that the light environment is consistent with the acceptance test of the supporting software, place the accelerator rack at 0°, the small head at 0°, and the radiation field at 40cm x 40cm.

[0088] 3) Place the calibration plate with a 1m x 1m grid on the accelerator treatment bed, point the arrow on the calibration plate toward the accelerator gantry, align the crosshair mark with the light field, and place the calibration plate at a source-skin distance (SSD) of 100cm.

[0089] 4) Enter the daily inspection module of the supporting software, collect images, and then execute the preset detection process of the optical body surface tracking system;

[0090] 5) If the test results show that the overall deviation is less than 0.6mm, the test is considered to have passed. If it is greater than 0.6mm, troubleshooting is required. The test can be used for subsequent plan generation only after the test is passed.

[0091] After completing the above preparations, we can continue with the subsequent core solution creation process of oART. Continuing from the previous text, step S2 is to obtain the latest CT images and register them with historical CT images to generate the current online adaptive radiotherapy plan.

[0092] For the day's schedule, the following procedure can be used as a reference for acquiring CT images:

[0093] (1) Positioning fixation: The patient lies on the accelerator treatment bed and is positioned according to the requirements of the patient's first treatment; with reference to the laser line positioning, the laser line is aligned with the positioning line marked on the fixation device during the patient's first treatment.

[0094] (2) CT topology scan: Based on different lesion locations, set the FOV range of the fixed CT topology image for conventional radiotherapy.

[0095] (3) CT image scanning: For CT localization scanning of patients, head-first and spiral scanning is generally selected; the slice thickness of conventional radiotherapy is generally 3mm, tube voltage is 120KV, and tube current is 200 or 250mA; for infant patients, the scanning conditions can be appropriately reduced to reduce the radiation dose.

[0096] (4) CT image quality assessment: After the scan is completed, it is necessary to review the image quality, whether the scanning range meets the clinical requirements, and observe whether the patient's outer contour and the fixation device fit well.

[0097] Specifically, the registration with historical CT images mentioned here can include:

[0098] When registering the original CT image acquired earlier with the new CT image acquired on the same day, rigid registration can be performed based on bony landmarks (such as the lumbar spine or pelvis) as a preliminary alignment of the CT images.

[0099] Then, the historical CT images are deformed until they match the tissue anatomy information in the latest CT images.

[0100] Next, the target area outlined in the historical CT image is copied onto the latest CT image;

[0101] If a difference is detected between the deformed target area and the latest CT image, or if the automatically delineated organs at risk show structural abnormalities, modifications and adjustments are made until no problems are determined. Then, the process proceeds to the online adaptive radiotherapy plan automatic optimization and calculation stage, specifically generating the current online adaptive radiotherapy plan, which includes:

[0102] Automatically load the constraints of the original radiotherapy plan (from TPS), including: CT density table, beam information, prescribed dose, and dose target parameters for the target area and organs at risk;

[0103] Based on changes in the physiological location of the tissue, the leaf sequence and dose target parameter weights of the multi-leaf grating system are automatically optimized, and the priority of dose limits for the target area and organs at risk is adjusted to ensure that the dose distribution of the online adaptive radiotherapy plan meets clinical requirements and completes the final dose calculation.

[0104] Once the dose distribution calculated by expert knowledge meets clinical requirements, subsequent multi-stage program validation steps can be implemented.

[0105] Step S3: Before radiotherapy is administered, the current online adaptive radiotherapy plan is validated in the first phase, which includes at least: simulating dose delivery in a real accelerator treatment environment and deciding whether the generated plan can be used for treatment.

[0106] This can be elaborated upon:

[0107] First, export the online adaptive radiotherapy planning dataset from the planning management system (PACS / ARIA). The dataset mainly includes the CT images, RT structure, RT plan, and RT dose mentioned above.

[0108] The system automatically captures and imports online adaptive radiotherapy planning datasets through a third-party independent verification system, and automatically completes the registration of images, structures and plans. In actual operation, after completing the registration involved in this step, it is also necessary to pay attention to whether the image orientation is correct, whether the system can recognize ISO points, and check whether the plan structure is completely imported.

[0109] Next, a third-party independent verification system calls the Monte Carlo or quasi-Monte Carlo algorithm to reconstruct the three-dimensional dose distribution of the newly generated plan based on the real beam model and CT density information, simulating dose delivery in the real accelerator head treatment environment, and using this as the "gold standard" for the effectiveness of the plan.

[0110] The three-dimensional dose distribution is compared and validated with the dose in the original TPS plan, and an automatic visualization analysis report is generated. Examples of indicators and standards for multidimensional comparison and validation are as follows: 1) Point dose comparison: the deviation between the planned dose and the validated dose should be ≤ ±2%; 2) Planar dose comparison: based on the Gamma analysis method, according to the evaluation criteria of a threshold of 10% and 3%2mm, the pass rate should be ≥ 95%; 3) Machine jump count (MU) comparison: the difference between the planned dose and the validated plan should be ≤ 5 MU.

[0111] If, after multidimensional comparative verification, the independent third-party calculation results are determined to meet the established clinical evaluation requirements, then the currently generated online adaptive radiotherapy plan can be approved for actual radiotherapy. Further, after the generated plan is approved, the TPS backend server can calculate the flux distribution map of the Electronic Portal Imaging Device (EPID) based on the planned dose distribution and the physical density of the CT scan for the next stage of plan verification. Prior to this, a patient positioning error calibration is required, as follows:

[0112] Step S4: After determining that the current plan is available, the optical body surface tracking system performs positioning error calibration.

[0113] Specifically, the patient's planned outer contour and positioning coordinates can be imported from the treatment planning management system into the optical surface tracking system. Next, the region of interest (ROI) for optical surface tracking is delineated: relatively stable areas with curves or obvious bony structures are selected, and the ROI is preferably delineated in the target area not covered by the open thermoplastic mesh. Then, the position of the real-time outer contour of the body surface is automatically compared with the position of the ROI in the plan, and the six-dimensional (6D) positioning error is obtained. Finally, the position of the accelerator treatment bed is adjusted according to the six-dimensional positioning error displayed by the system until the preset standard is reached. If the error translation is less than 1mm and the rotation error is less than 1°, the error correction is confirmed to be correct, and then the next stage of verification of the online adaptive radiotherapy plan can be performed.

[0114] Step S5: After the setup error is calibrated, radiotherapy is started and the current online adaptive radiotherapy plan is validated in the second phase during radiotherapy, including at least: in vivo dose validation of the electronic field imager;

[0115] This stage mainly refers to EPD 2D in vivo dose verification: As mentioned earlier, the two-dimensional photon transmission flux distribution map detected by the patient's actual EPD is compared in real time with the EPD flux distribution map calculated by TPS to determine whether the current radiotherapy plan is being executed accurately. The specific process is as follows:

[0116] (1) The EPID in vivo dose verification module is automatically activated via the accelerator, and the in vivo verification field flux map and EPID verification parameters are set and adjusted. The EPID verification parameters mentioned here include the distance to the imaging plate (SID), the planned Gamma pass rate threshold, the treatment interruption threshold, and the detection points. Specifically, for IMRT / CRT plans, each field corresponds to one monitoring point; for ARC plans, one detection point is set every 30° by default; furthermore, the SID is set to 100cm by default; the Gamma pass rate follows the planning verification standard of the first stage before treatment (threshold 10%, 3% 2mm evaluation standard), with a pass rate ≥95%. In practice, the pass rate threshold can be set to 90% without limitation.

[0117] (2) Subsequently, during the execution of the current plan, the accelerator continuously emits beams. The dose output by each field in the plan is received by the EPD detector in the form of photon flux, and the comparison results of the flux distribution measured by EPD and the flux distribution calculated in the plan are output synchronously. If the comparison result indicates that the pass rate of the detection point is higher than the predetermined threshold, it will indicate that the test is passed; otherwise, it will indicate that the test is not passed. When the pass rate is lower than the preset treatment interruption threshold, the device will be triggered to stop emitting beams, indicating that there is a large difference between the current patient position or anatomical structure and the current plan design. Therefore, the treatment needs to be interrupted and the plan or patient position needs to be adjusted.

[0118] (3) Finally, after the plan is completed, the flux map measured by EPD and the Gamma pass rate analysis results are uploaded to the background plan management server for storage, so as to facilitate subsequent access, especially the dose three-dimensional reconstruction process during the next stage of verification.

[0119] Step S6: After the radiotherapy is completed, perform a third-stage validation of the current online adaptive radiotherapy plan, which includes at least: measuring and calculating the difference in dose by comparing the three-dimensional dose reconstruction.

[0120] This invention argues that even following the above steps, the comparison of 2D EPID flux distribution can indicate whether there is a significant difference between the current actual treatment dose distribution and the plan. However, it still has certain limitations in more accurately capturing the specific locations and dose magnitudes of dose distribution differences caused by positioning errors, changes in body position, and anatomical deformation.

[0121] Therefore, in order to accurately grasp the actual target coverage and promptly identify treatment risks, this invention proposes to reconstruct the flux information acquired by EPID in three dimensions onto the patient's anatomical structure, i.e., on CT images, after treatment. Specifically, the actual radiation dose to each voxel of the patient is recovered using a back-projection reconstruction algorithm. The dose-volume histogram (DVH) parameters are compared to assess the execution of the new treatment plan. If the difference is significant, the plan needs to be adjusted again to ensure that the positioning error and the degree of physiological changes are as consistent as possible with the original plan design. The specific process is as follows:

[0122] (1) Load the treatment plan and import the planned CT images, structural delineation and planned dose distribution.

[0123] (2) Preprocess the treatment transmission flux map, convert the 2D transmission dose image measured by EPD into the dose in the water body model, and apply the deconvolution algorithm to remove the inherent scattering effect of EPD.

[0124] (3) The preprocessed flux map is back-projected using the Monte Carlo algorithm to achieve three-dimensional dose reconstruction. The cumulative dose of each voxel is calculated using the CT-density map and a VHD map is drawn.

[0125] (4) Comparison of planned dose and treatment reconstructive dose: First, compare the three-dimensional dose distribution and use the Gamma method to analyze the dose deviation in the transverse, sagittal and coronal planes. The pass rate should be ≥95% according to the preset threshold such as 10% and 3mm / 2% evaluation criteria. Second, compare the DVH parameters. One is the target dose comparison index, which includes D98%, D95%, D90% and D2%. The other is the organ at risk dose comparison index, which includes the average dose, D1% and maximum dose.

[0126] In summary, the main design concept of this invention lies in establishing a systematic, standardized, and quantifiable quality control system for the entire treatment planning process, from generation to execution, to ensure the accuracy and safety of oART plans. Specifically, before creating an online adaptive radiotherapy plan, a verification system is configured and the status of the accelerator and optical surface system is checked; the latest CT images are acquired and registered with historical CT images to generate the current online adaptive radiotherapy plan; before radiotherapy, the current online adaptive radiotherapy plan undergoes a first-stage verification; after determining that the current plan is usable, the optical surface tracking system calibrates the positioning error; after positioning error calibration, radiotherapy begins, and the online adaptive radiotherapy plan undergoes a second-stage verification during radiotherapy; after radiotherapy is completed, the online adaptive radiotherapy plan undergoes a third-stage verification. This invention not only helps improve the reliability of adaptive plans but also provides a solid foundation for promoting the standardized clinical application of radiotherapy technology on a larger scale.

[0127] As can be seen from the above embodiments, the contributions of this invention to the industry include at least the following:

[0128] 1. Improve treatment accuracy and safety

[0129] By standardizing quality control processes (such as optical tracking calibration, image registration verification, automatic delineation review, and plan re-optimization logic verification), the accumulation of random and systematic errors in each stage is reduced, avoiding under-dose in the target area or over-dose that endangers organs due to dose deviation; at the same time, abnormal data during treatment (such as excessive body surface displacement and equipment response delay) are monitored in real time to trigger interruption or correction mechanisms and reduce the risk of clinical accidents.

[0130] 2. Ensure time efficiency and process coordination

[0131] Standardizing processes can clarify the operational specifications and time nodes for each step (such as the time limit from image acquisition to plan re-optimization), avoid redundancy or delays in team collaboration, and meet oART's high requirements for timeliness.

[0132] 3. Support the promotion and standardized application of technology.

[0133] Establish unified quality control indicators (such as surface tracking accuracy ≤1mm, plan optimization convergence threshold, etc.) to provide quantifiable standards for widespread clinical application and promote the popularization of oART technology.

[0134] 4. Achieve end-to-end traceability and continuous improvement

[0135] Record all parameters before, during, and after treatment (such as tracking data, dosage differences, and execution logs) to facilitate backtracking and analysis of error root causes, optimize quality control nodes, and improve closed-loop data management; and form an adaptive improvement mechanism for iterative updates to the quality control protocol.

[0136] 5. Economic and resource optimization significance

[0137] Early detection of errors can prevent invalid irradiation or planned resets, reduce repetitive work, and reduce time and resource waste; regular quality control and maintenance (such as optical camera calibration and accelerator output stability testing) ensure long-term stable operation of equipment and extend equipment life.

[0138] Corresponding to the above embodiments and preferred solutions, the present invention also provides an embodiment of an accelerator-based online adaptive radiotherapy planning quality control device, such as... Figure 2 As shown, it may specifically include the following components:

[0139] Preparation module 201 is used to configure the verification system and detect the status of the accelerator and optical surface system before creating an online adaptive radiotherapy plan;

[0140] The CT registration module 202 is used to acquire the latest CT image and register it with historical CT images to generate the current online adaptive radiotherapy plan;

[0141] The first verification module 203 is used to perform a first-stage verification of the current online adaptive radiotherapy plan before radiotherapy is implemented, which includes at least: simulating dose delivery in a real accelerator treatment environment and deciding whether the generated plan is allowed to be used for treatment;

[0142] The positioning calibration module 204 is used to perform positioning error calibration by the optical body surface tracking system after determining that the current plan is available;

[0143] The second verification module 205 is used to begin radiotherapy after the setup error is calibrated and to perform a second-stage verification of the current online adaptive radiotherapy plan during radiotherapy, which includes at least: in vivo dose verification of the electronic field imager.

[0144] The third verification module 206 is used to perform a third-stage verification of the current online adaptive radiotherapy plan after the radiotherapy is performed, which includes at least: measuring and calculating the difference in dose by comparing the three-dimensional dose reconstruction.

[0145] The above should be understood Figure 2 The division of components in the accelerator-based online adaptive radiotherapy planning and quality control device shown is merely a logical functional division. In actual implementation, all or part of these components can be integrated into a single physical entity, or they can be physically separated. Furthermore, all of these components can be implemented entirely through software calls via processing elements; alternatively, some components can be implemented through software calls via processing elements, while others can be implemented in hardware. For example, a particular module can be a separate processing element or integrated into a chip in an electronic device. The implementation of other components is similar. Moreover, these components can be integrated together or implemented independently. During implementation, each step of the above method or each of the above components can be completed through integrated logic circuits in the hardware of the processor element or through software instructions.

[0146] For example, these components can be one or more integrated circuits configured to implement the above methods, such as one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs). Alternatively, these components can be integrated together to form a system-on-a-chip (SOC).

[0147] Based on the above embodiments and preferred solutions, those skilled in the art will understand that, in actual operation, the technical concept involved in this invention can be applied to various implementation methods. The following embodiments are used as illustrative examples:

[0148] (1) An electronic device. The device may specifically include: one or more processors, a memory, and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the steps / functions of the foregoing embodiments or equivalent embodiments.

[0149] Specifically, the electronic device can be a computer-related electronic device, such as, but not limited to, various computing terminals and electronic products.

[0150] Specifically, the processor, communication interface, and memory can all communicate with each other via a communication bus. The processor may be a central processing unit (CPU), DSP, microcontroller, or digital signal processor, and may also include a GPU, an embedded neural network processing unit (NPU), and an image signal processor (ISP). The processor may also include a specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. Furthermore, the processor may have the function of operating one or more software programs, which can be stored in a storage medium such as memory. The aforementioned memory / storage medium may include: non-volatile memory, such as a non-removable disk, USB flash drive, portable hard drive, optical disc, etc., as well as read-only memory (ROM), random access memory (RAM), etc.

[0151] (2) A computer data storage medium storing a computer program or the above-described device, which, when executed, causes a computer to perform the steps / functions of the foregoing embodiments or equivalent embodiments.

[0152] In several embodiments provided by this invention, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer data storage medium. Based on this understanding, certain technical solutions of this invention, or the parts that contribute to the prior art, or parts of such technical solutions, can be embodied in the form of software products as described below.

[0153] It should be noted in particular that the storage medium may refer to a server or a similar computer device, specifically, that is, the aforementioned computer program or the aforementioned device is stored in the storage device of the server or similar computer device.

[0154] (3) A computer program product (which may include the above-mentioned device), which, when run on a terminal device, causes the terminal device to execute the accelerator-based online adaptive radiotherapy planning quality control method of the foregoing embodiments or equivalent implementations.

[0155] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that all or part of the steps in the above implementation methods can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the above-mentioned computer program products may include, but are not limited to, APPs.

[0156] In this embodiment of the invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0157] Those skilled in the art will recognize that the modules, units, and method steps described in the embodiments disclosed in this specification can be implemented using electronic hardware, computer software, and a combination of electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0158] Furthermore, the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. In particular, for embodiments such as apparatus and devices, since they are basically similar to the method embodiments, the relevant parts can be referred to the description of the method embodiments. The apparatus, devices, and other embodiments described above are merely illustrative, and the modules, units, etc., described as separate components may or may not be physically separate, that is, they may be located in one place or distributed in multiple places, such as nodes in a system network. Specifically, some or all of the modules and units can be selected according to actual needs to achieve the purpose of the above-described embodiment solutions. Those skilled in the art can understand and implement this without creative effort.

[0159] The above description of the structure, features, and effects of the present invention is based on the embodiments shown in the figures. However, the above are only preferred embodiments of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched by those skilled in the art to form a variety of equivalent solutions without departing from or changing the design concept and technical effects of the present invention. Therefore, the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A method for quality control of online adaptive radiotherapy planning based on accelerators, characterized in that, include: Before creating an online adaptive radiotherapy plan, configure the verification system and check the status of the accelerator and optical surface system; The system acquires the latest CT images and registers them with historical CT images to generate the current online adaptive radiotherapy plan. Before radiotherapy is administered, the current online adaptive radiotherapy plan is validated in the first phase, which includes at least: simulating dose delivery in a real accelerator treatment environment and deciding whether the generated plan is allowed to be used for treatment. After determining that the current plan is available, the optical body surface tracking system performs positioning error calibration; Radiotherapy was initiated after the setup error was calibrated, and the current online adaptive radiotherapy plan was validated in the second phase during radiotherapy, including at least: in vivo dose validation of the electronic field imager; After the radiotherapy is completed, the current online adaptive radiotherapy plan will be validated in the third phase, which includes at least the following: comparing and calculating the difference in dose through three-dimensional dose reconstruction.

2. The accelerator-based online adaptive radiotherapy planning quality control method according to claim 1, characterized in that, The first stage of verification specifically includes: Export the online adaptive radiotherapy planning dataset; Automatically capture and import online adaptive radiotherapy planning datasets to complete image, structure, and plan registration; The three-dimensional dose distribution of the current online adaptive radiotherapy plan is reconstructed based on the real beam model and CT density information to simulate dose delivery in the real accelerator head treatment environment; The three-dimensional dose distribution was compared and validated with the original planned dose in multiple dimensions. After multidimensional comparison and verification, it was determined that the current online adaptive radiotherapy plan can be approved for actual radiotherapy implementation; After the plan is approved, the flux distribution map of the electronic field imager is calculated based on the planned dose distribution and the physical density of the CT.

3. The accelerator-based online adaptive radiotherapy planning quality control method according to claim 1, characterized in that, The positioning error calibration performed by the optical body surface tracking system includes: Import the patient's planned external contour and positioning coordinates into the optical body surface tracking system; Delineate the region of interest for optical surface tracking; Automatically compare the real-time outer contour of the body surface with the planned region of interest, and obtain the six-dimensional positioning error; The position of the accelerator treatment bed is adjusted based on the six-dimensional positioning error until the preset standard is reached, thus completing the error correction.

4. The accelerator-based online adaptive radiotherapy planning quality control method according to claim 2, characterized in that, The second phase of verification specifically includes: The in vivo dose verification module of the electron field imager is automatically activated by the accelerator, and the field flux map and electron field imager verification parameters for in vivo verification are set and adjusted. During the current execution of the plan, the accelerator continuously emits beams. The dose output from each planned field is received by the electron field imager detector plate in the form of photon flux, and the comparison results of the flux distribution measured by the electron field imager and the flux distribution calculated in the plan are output simultaneously. After the project is completed, save the flux map and throughput analysis results measured by the electronic field imager.

5. The accelerator-based online adaptive radiotherapy planning quality control method according to claim 4, characterized in that, The third stage of verification specifically includes: The flux information acquired by the electronic field imager is reconstructed in three dimensions onto the patient's anatomical structure, and the actual radiation dose of each voxel of the patient is recovered through the back projection reconstruction algorithm. Comparing dose-volume histogram parameters is used to assess the execution of the current online adaptive radiotherapy plan during treatment; If the evaluation results show significant differences, the online adaptive radiotherapy plan will be adjusted again.

6. The accelerator-based online adaptive radiotherapy planning quality control method according to any one of claims 1 to 5, characterized in that, The registration with historical CT images specifically includes: Rigid registration is performed based on bony landmarks, which is used as the initial alignment of CT images; The historical CT images are deformed until they match the tissue anatomy information in the latest CT images; Copy the target area outlined in the historical CT image onto the latest CT image; If the deformed target area is found to differ from the latest CT image, or if the automatically delineated organs at risk show structural abnormalities, modifications and adjustments will be made until the problem is determined to be resolved. Then, the online adaptive radiotherapy plan will proceed to automatic optimization and calculation.

7. An accelerator-based online adaptive radiotherapy planning quality control device, characterized in that, include: The preparation module is used to configure the verification system and detect the status of the accelerator and optical surface system before creating an online adaptive radiotherapy plan; The CT registration module is used to acquire the latest CT images and register them with historical CT images to generate the current online adaptive radiotherapy plan. The first verification module is used to perform a first-stage verification of the current online adaptive radiotherapy plan before radiotherapy is implemented, which includes at least: simulating dose delivery in a real accelerator treatment environment and deciding whether the generated plan can be used for treatment; The positioning calibration module is used by the optical body surface tracking system to calibrate positioning errors after determining that the current plan is available; The second verification module is used to begin radiotherapy after the setup error is calibrated and to perform a second-stage verification of the current online adaptive radiotherapy plan during radiotherapy, which includes at least: in vivo dose verification of the electronic field imager; The third verification module is used to perform a third-stage verification of the current online adaptive radiotherapy plan after the radiotherapy is performed, which includes at least: measuring and calculating the difference in dose by comparing the three-dimensional dose reconstruction.

8. An electronic device, characterized in that, include: One or more processors, a memory, and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the electronic device, cause the electronic device to perform the accelerator-based online adaptive radiotherapy planning quality control method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the accelerator-based online adaptive radiotherapy planning quality control method as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the accelerator-based online adaptive radiotherapy planning quality control method as described in any one of claims 1 to 6.

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