Three-mode radiotherapy dose real-time monitoring system

Abstract

The invention discloses a three-mode radiotherapy dose real-time monitoring system, and belongs to the technical field of medical instruments. The system comprises a contour scanning imaging subsystem used for collecting body surface three-dimensional information of a monitoring target so as to accurately position an affected part; the Cerenkov imaging subsystem is used for collecting Cerenkov light in the radiotherapy process, quantitatively analyzing the relationship between the Cerenkov light intensity and the radiotherapy planning dose, and verifying the accuracy of the radiotherapy dose in real time; the near-infrared imaging subsystem is used for acquiring a near-infrared image; the near-infrared imaging module is used for adding a near-infrared image dimension to an original contour three-dimensional image to form a new multi-dimensional image so as to weaken a registration sliding effect and accurately position an affected part; the method is also used for extracting a blood vessel image so as to remove blood vessels on the Cherenkov image, and blood vessel interference is avoided. According to the invention, through three-mode imaging fusion, dimension raising can be carried out on the three-dimensional contour image so as to more accurately position an affected part, interference of blood vessels on Cerenkov imaging is eliminated, and precision is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a three-modal real-time monitoring system for radiotherapy dose. Background Art

[0002] Radiotherapy plays a vital role in cancer treatment, and accurate dose control and positioning are essential to ensure treatment effectiveness and patient safety. However, statistics show that approximately 1% of patients may encounter errors during radiotherapy. These errors may arise from inaccurate dose calculations, positioning deviations, or errors in the execution of treatment plans. In traditional radiotherapy, dose monitoring is usually performed based on a pre-set treatment plan, and the effect is evaluated after the treatment is completed. Although this method can retrospectively analyze treatment results, it cannot achieve immediate feedback during the treatment process, which to some extent limits the accuracy and safety of radiotherapy.

[0003] Surface Guided Radiation Therapy (SGRT) is an advanced non-radioactive positioning technology that achieves surface-guided radiotherapy through optical surface imaging. SGRT technology has significant advantages in the field of radiotherapy, such as reducing positioning errors between fractions, monitoring patient position movement within fractions, and managing respiratory movements. Although SGRT technology can create accurate three-dimensional surface models, in actual applications, there are still some technical difficulties in ensuring the consistency of these models with the actual patient position and accurately capturing small changes in the patient's position.

[0004] With its excellent high sensitivity and non-invasive inspection characteristics, Cherenkov imaging technology has great application prospects in the field of medical imaging. This technology can estimate the radiation dose absorbed by tissues by collecting photons generated by the Cherenkov effect, and the number of photons is proportional to the absorbed dose. By sampling the entire dose field in real time and contactlessly, Cherenkov luminescence imaging can draw a dose map of the patient, capture the weak light generated by the decay of radioactive isotopes, and visualize the distribution of radioactive substances in the body. However, despite the significant theoretical advantages of Cherenkov imaging technology, it still faces some challenges and limitations in practical applications, especially in real-time monitoring of radiotherapy doses. First, the Cherenkov light signal is very weak (the radiance is about 0.1mW / cm²), and Poisson noise becomes the lower limit of the measurement. In addition, the presence of blood vessels may also interfere with the accuracy of dose measurement. Since hemoglobin in the blood has a strong absorption effect on the specific wavelength of Cherenkov, accompanied by the attenuation of the emission intensity of Cherenkov light, the emission dose calculation of the subcutaneous vascular area is inaccurate. The data of Cherenkov and near-infrared image modalities are fused to supplement the dose missing in the vascular area. Therefore, reducing the impact of vascular structure on dose detection is one of the problems that Cherenkov imaging technology needs to overcome. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the above-mentioned related art at least to a certain extent.

[0006] To this end, the purpose of the present invention is to provide a three-modal real-time monitoring system for radiotherapy dose, which can eliminate the vascular interference on the Cherenkov imaging guidance of radiotherapy dose through the fusion of three-modal imaging, improve the dose calculation accuracy, and on the other hand, upgrade the three-dimensional contour image to more accurately locate the affected area.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: An embodiment of the present invention provides a three-modal radiotherapy dose real-time monitoring system, the system comprising: Contour scanning imaging subsystem, used to collect three-dimensional information of the body surface of the monitored target for accurate positioning of the affected area; The Cherenkov imaging subsystem is used to collect Cherenkov light during radiotherapy, align the obtained Cherenkov intermediate image through the external parameter conversion matrix between cameras, and quantitatively analyze the relationship between the Cherenkov light intensity and the radiotherapy planning dose, so as to verify the accuracy of the radiotherapy dose in real time; The near-infrared imaging subsystem collects near-infrared images. It is used to cooperate with the contour scanning imaging subsystem to add near-infrared image dimensions to the original three-dimensional imaging to form a new multi-dimensional image, so as to reduce the registration sliding effect and accurately locate the affected area. It is also used to extract vascular images so as to remove blood vessels based on the images collected by the Cherenkov imaging subsystem to avoid vascular interference. The contour scanning imaging subsystem includes a two-dimensional pattern projector and a first image acquisition module; the two-dimensional pattern projector is used to project a two-dimensional pattern onto the monitoring target for the first image acquisition module to acquire and image; The near-infrared imaging subsystem includes a near-infrared light source and a second image acquisition module. The near-infrared light source is used to emit a near-infrared light beam to the monitoring target so that the second image acquisition module can collect light and form an image.

[0008] In addition, the three-modal radiotherapy dose real-time monitoring system according to the present invention may also have the following additional technical features: In some of the embodiments, the contour scanning imaging subsystem, the near infrared imaging subsystem and the Cherenkov imaging subsystem are all arranged on the same side of the monitoring target, and each is arranged to face the monitoring target at a preset angle.

[0009] In some of the embodiments, the near-infrared light source is disposed beside the second image acquisition module and faces the monitoring target at a preset angle.

[0010] In some of the embodiments, the two-dimensional pattern projector is disposed facing the monitoring target and forms a preset angle with the monitoring target and the first image acquisition module.

[0011] In some of the embodiments, the contour scanning imaging subsystem uses a structured light imaging system, a binocular or other three-dimensional imaging system.

[0012] In some of the embodiments, the emission light wave of the near-infrared light source is a near-infrared wave below 1000 nm.

[0013] In some of the embodiments, the three-dimensional point cloud image collected by the contour scanning imaging subsystem and the near-infrared image collected by the near-infrared imaging subsystem are combined, and the combined three-dimensional point cloud data are calculated to obtain the position information of the monitoring target in space.

[0014] In some of the embodiments, blood vessels are extracted from the image acquired by the near-infrared imaging subsystem to obtain a blood vessel image, and the Cherenkov image obtained by the Cherenkov imaging subsystem is data fused with the blood vessel image of the near-infrared image modality to eliminate interference from blood vessels and obtain a corrected Cherenkov radiation image.

[0015] In some of the embodiments, the relationship between the Cherenkov light intensity and the planned radiotherapy dose is quantitatively analyzed to verify the accuracy of the radiotherapy dose in real time, including: a corrected Cherenkov radiation image, parsing the radiotherapy dose corresponding to each angle of the linear accelerator through the dose in the radiotherapy plan formulated by the doctor for the patient, projecting the three-dimensional dose data onto a two-dimensional image of the corresponding viewing angle of the Cherenkov camera, comparing it with the corrected Cherenkov radiation image, calculating the difference between the two images, thereby determining the actual radiotherapy dose, comparing the difference between the planned dose and the actual dose, and performing an emergency stop operation on the accelerator when the difference reaches a preset threshold.

[0016] In some of the embodiments, the two-dimensional pattern projector is a projector.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: In the embodiment of the present invention, the three-modal real-time monitoring system for radiotherapy dose can ensure the accuracy of treatment by real-time monitoring of the patient's body position changes and combining the Cherenkov technique to instantly detect the radiotherapy dose, while overcoming the limitations of dose monitoring in traditional radiotherapy. In the embodiment of the present invention, the provided three-modal radiotherapy dose real-time monitoring system can clearly observe the vascular structure through near-infrared imaging technology, and use image processing technology to eliminate vascular interference, thereby further improving the accuracy of radiation dose calculation; In the embodiment of the present invention, the provided three-modal radiotherapy dose real-time monitoring system uses an algorithm to reduce the noise of the Cherenkov image, which can significantly improve the clarity and accuracy of the image and help to more accurately evaluate the treatment effect; In an embodiment of the present invention, a three-modal real-time monitoring system for radiotherapy dose is provided, which combines near-infrared images for coordinate system alignment. A two-dimensional pattern projector projects sinusoidal stripes onto the object to be measured, and a camera is used to capture the deformed stripe pattern modulated by the height of the object. The point cloud information is solved by phase to accurately reconstruct the three-dimensional morphology of the object, providing more accurate spatial information for radiotherapy.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a three-modal radiotherapy dose real-time monitoring system disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The embodiments of the present invention are described in detail below through specific embodiments and application scenarios in conjunction with the accompanying drawings.

[0022] See also Figure 1 As shown, in some embodiments of the present invention, a three-modal radiotherapy dose real-time monitoring system is provided, which mainly includes three imaging subsystems. The three imaging subsystems are a contour scanning imaging subsystem, a near-infrared imaging subsystem, and a Cherenkov imaging subsystem. The contour scanning subsystem includes an image acquisition module and a two-dimensional image projector; the near-infrared imaging subsystem includes an image acquisition module and a near-infrared light source; and the Cherenkov imaging subsystem consists of a Cherenkov image acquisition module. The locations of the subsystems are shown in FIG. Figure 1 As shown, there is no specific requirement for the setting angle. It is related to the field of view of the imaging system. It is required that the contour scanning imaging range and the near-infrared imaging range can be basically consistent. The field of view of the Cherenkov imaging system is within the contour scanning and near-infrared, and can cover the target area, that is, the monitoring target. The two-dimensional pattern projector and the contour scanning imaging subsystem are both located on the same side of the monitoring target or above the monitoring target. The two-dimensional pattern projector is used to project a two-dimensional pattern onto the monitoring target for the contour scanning imaging subsystem to collect and image. The contour scanning imaging subsystem is used to collect three-dimensional information on the patient's body surface for accurate positioning of the patient, thereby achieving accurate radiotherapy of the affected part. The Cherenkov imaging subsystem is used to collect Cherenkov light during radiotherapy, align the obtained Cherenkov intermediate image through the external parameter conversion matrix between the cameras, quantitatively analyze the Cherenkov light intensity and the planned dose, compare the difference between the planned dose and the actual dose, and perform an emergency stop operation on the accelerator when the difference is too large to ensure the accuracy and effectiveness of the treatment. The near-infrared imaging subsystem has two main functions: one is to cooperate with the body surface imaging system. On top of the ordinary three-dimensional imaging system, a near-infrared image dimension is added to reduce the registration sliding effect and improve the speed and accuracy of the registration; the other is to cooperate with the Cherenkov imaging system to eliminate blood vessel interference. The near-infrared light source is set next to the near-infrared imaging subsystem, facing the monitoring target at a certain angle. When the near-infrared light source is working, the emitted near-infrared light beam is shone on the monitoring target, so that the near-infrared imaging subsystem can better collect light and form an image. The way to eliminate blood vessel interference is to transfer the structured light three-dimensional imaging according to the results of blood vessel segmentation, and finally project it to the Cherenkov imaging system, and use the mean of the surrounding pixels to compensate the Cherenkov light at the blood vessel position.

[0023] In the above embodiment, the two-dimensional pattern projector may be a projector (DMD), which may project a specific pattern onto a photographing target, and the image acquisition module may acquire an image of the photographing target, thereby calculating three-dimensional information of the photographing target.

[0024] When the system is working, the contour scanning imaging subsystem includes but is not limited to the structured light imaging system. Taking structured light imaging as an example, the two-dimensional pattern projector projects the pattern onto the shooting target, and the contour scanning imaging subsystem obtains the structured light image. The near-infrared light source irradiates the monitoring target, and the near-infrared camera obtains the near-infrared image of the target (including but not limited to vascular information). Combining the structured light and near-infrared image, the three-dimensional point cloud data is calculated, that is, the position information of the monitoring target in space. The near-infrared light source used in the present invention is a near-infrared wave below 1000nm, which is different from the medium and long-wave infrared wavelengths of the human body. The near-infrared wave emitted by the near-infrared light source is compared with the visible light wave (380-780nm). The near-infrared light below 1000nm has stronger penetration ability, and can detect the blood vessels below the skin, thereby realizing the shooting of vascular information.

[0025] In some embodiments of the present invention, the working contents of the contour scanning imaging subsystem and the near-infrared imaging subsystem in cooperation with each other include: collecting two-dimensional images and near-infrared images of the patient's body surface, performing phase unfolding on the two-dimensional image, and performing structured light solution to obtain the current three-dimensional point cloud of the body surface; the two-dimensional image can be phase unfolded by a four-step phase shift method and a multi-frequency heterodyne method; special points in the current body surface point cloud are filtered, and based on a pre-set coordinate transformation relationship, the current body surface point cloud is projected onto the near-infrared image, and the target area is determined according to the near-infrared image; the body surface point cloud in the target area is extracted for point cloud registration, the difference between the current body surface point cloud and the reference body surface point cloud is calculated, and the rotation and translation relationship between the current body surface point cloud and the reference body surface point cloud is obtained; rendering is performed based on the current body surface point cloud to obtain the target image.

[0026] In some embodiments of the present invention, the process of rendering based on the current body surface point cloud to obtain the target image includes: rendering the current body surface point cloud using multi-channel rendering + surface splash + point sprite rendering technology.

[0027] In the above embodiment, the process of rendering the current body surface point cloud using multi-channel rendering includes: performing multi-channel rendering on the current body surface point cloud through three rendering channels; wherein the process of rendering through the three rendering channels is as follows: First rendering channel: enable depth test, turn off color writing, enable depth writing, turn off blending, turn off point sprites, adjust the depth of each fragment in the particle according to the particle radius, render the current surface point cloud, and output the depth texture map; second rendering channel: turn off depth test, turn on point sprites, enable color writing, turn off depth writing, enable blending, set the blending formula, use the depth value of each fragment in the first rendering channel to adjust the color value of each fragment, render the depth texture map, and output the color texture map; third rendering channel: turn off blending, draw a quadrilateral that fills the full screen in the standardized device coordinate system, and paste the color texture map of the second rendering channel.

[0028] In the above embodiment, based on a pre-set coordinate conversion relationship, the process of projecting the current body surface point cloud to the near-infrared image may include: according to the conversion relationship between the point cloud coordinate system and the near-infrared camera coordinate system, the coordinates of each point in the current body surface point cloud are converted from the point cloud coordinate system to the near-infrared camera coordinate system to obtain the near-infrared camera coordinates of each point, wherein the origin of the near-infrared camera coordinate system is the optical center of the lens, the x-axis and the y-axis are respectively parallel to the two sides of the imaging plane, and the z-axis is the optical axis of the lens; according to the conversion relationship between the near-infrared camera coordinate system and the near-infrared image coordinate system, the near-infrared camera coordinates of each point are converted from the near-infrared camera coordinate system to the near-infrared image coordinate system to obtain the near-infrared image coordinates of each point, wherein the origin of the near-infrared image coordinate system is the midpoint of the imaging plane, and the x-axis and the y-axis are respectively parallel to the two sides of the imaging plane.

[0029] The Cherenkov imaging subsystem acquires the Cherenkov light signal emitted by the monitoring target, and then obtains the vascular image through the near-infrared imaging subsystem, and fuses the Cherenkov and near-infrared image modes to eliminate the interference of blood vessels and obtain the corrected Cherenkov radiation image. The dose in the radiotherapy plan formulated by the doctor for the patient is analyzed to determine the radiotherapy dose corresponding to each angle of the linear accelerator, and the three-dimensional dose data is projected onto the two-dimensional image of the corresponding viewing angle of the Cherenkov camera, and compared with the Cherenkov light captured by the Cherenkov camera, and the difference between the two images is calculated to determine the actual radiotherapy dose, and compare the difference between the planned dose and the actual dose. If the difference is too large, the accelerator is stopped immediately.

[0030] The parts of the present invention that are not described in detail may refer to the prior art or are known to those skilled in the art.

[0031] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A three-modal radiotherapy dose real-time monitoring system, characterized in that: The system comprises: Contour scanning imaging subsystem, used to collect three-dimensional information of the body surface of the monitored target for accurate positioning of the affected area; The Cherenkov imaging subsystem is used to collect Cherenkov light during radiotherapy, align the obtained Cherenkov intermediate image through the external parameter conversion matrix between cameras, and quantitatively analyze the relationship between the Cherenkov light intensity and the radiotherapy planning dose, so as to verify the accuracy of the radiotherapy dose in real time; The near-infrared imaging subsystem collects near-infrared images. It is used to cooperate with the contour scanning imaging subsystem to add near-infrared image dimensions to the original three-dimensional imaging to form a new multi-dimensional image, so as to reduce the registration sliding effect and accurately locate the affected area. It is also used to extract vascular images so as to remove blood vessels based on the images collected by the Cherenkov imaging subsystem to avoid vascular interference. The contour scanning imaging subsystem includes a two-dimensional pattern projector and a first image acquisition module; the two-dimensional pattern projector is used to project a two-dimensional pattern onto the monitoring target for the first image acquisition module to acquire and image; The near-infrared imaging subsystem includes a near-infrared light source and a second image acquisition module. The near-infrared light source is used to emit a near-infrared light beam to the monitoring target for the second image acquisition module to acquire and form an image.

2. The three-modal radiotherapy dose real-time monitoring system according to claim 1 is characterized in that: The contour scanning imaging subsystem, the near infrared imaging subsystem and the Cherenkov imaging subsystem are all arranged on the same side of the monitoring target, and are respectively arranged facing the monitoring target at a preset angle.

3. The three-modal radiotherapy dose real-time monitoring system according to claim 1 is characterized in that: The near-infrared light source is arranged beside the second image acquisition module and faces the monitoring target at a preset angle.

4. The three-modal radiotherapy dose real-time monitoring system according to claim 1, characterized in that: The two-dimensional pattern projector is arranged facing the monitoring target and forms a preset angle with the monitoring target and the first image acquisition module.

5. The three-modal radiotherapy dose real-time monitoring system according to claim 1, characterized in that: The contour scanning imaging subsystem adopts a structured light imaging system, a binocular or other three-dimensional imaging system.

6. The three-modal radiotherapy dose real-time monitoring system according to claim 1, characterized in that: The emission light wave of the near-infrared light source is a near-infrared wave below 1000nm.

7. The three-modal radiotherapy dose real-time monitoring system according to claim 5, characterized in that: The three-dimensional point cloud image collected by the contour scanning imaging subsystem and the near-infrared image collected by the near-infrared imaging subsystem are combined, and the combined three-dimensional point cloud data are calculated to obtain the position information of the monitoring target in space.

8. The three-modal radiotherapy dose real-time monitoring system according to claim 1, characterized in that: The blood vessel is extracted from the image acquired by the near-infrared imaging subsystem to obtain a blood vessel image, and the Cherenkov image obtained by the Cherenkov imaging subsystem is data-fused with the blood vessel image of the near-infrared image modality to eliminate interference from the blood vessels and obtain a corrected Cherenkov radiation image.

9. The three-modal radiotherapy dose real-time monitoring system according to claim 8, characterized in that: Quantitative analysis of the relationship between Cherenkov light intensity and radiotherapy planning dose is used to verify the accuracy of radiotherapy dose in real time, including: corrected Cherenkov radiation image, parsing the radiotherapy dose corresponding to each angle of the linear accelerator through the dose in the radiotherapy plan formulated by the doctor for the patient, projecting the three-dimensional dose data onto the two-dimensional image of the corresponding viewing angle of the Cherenkov camera, comparing it with the corrected Cherenkov radiation image, calculating the difference between the two images, and thus judging the actual radiotherapy dose, comparing the difference between the planned dose and the actual dose, and performing an emergency stop operation on the accelerator when the difference reaches the preset threshold.

10. The three-modal radiotherapy dose real-time monitoring system according to claim 1, characterized in that: The two-dimensional pattern projector is a projector.

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