Patient position adjustment system for radiotherapy

Abstract

A patient position adjustment system for radiotherapy, comprising: a near-infrared light source (100), configured to irradiate near-infrared light to a preset area (A) on the body surface of a patient (500); a near-infrared thermal imaging sensor (200), configured to receive reflected near-infrared light and, to obtain a blood vessel texture map of the preset area (A) of the patient (500) on the basis of the reflected near-infrared light; at least one laser range finder (300), configured to measure a vertical distance between the body surface of the patient (500) and the laser range finder (300); and an analysis and processing apparatus (400), separately connected to the near-infrared thermal imaging sensor (200) and the laser range finder (300), the analysis and processing apparatus (400) being configured to receive the blood vessel texture map sent by the near-infrared thermal imaging sensor (200) and the vertical distance sent by the laser range finder (300), and, on the basis of the blood vessel texture map and the vertical distance, acquire the amount of position adjustment between the current position and an ideal position. The patient position adjustment system for radiotherapy can improve the positional accuracy of patients (500) before and during radiotherapy without increasing additional radiation doses.

Description

Patient positioning systems for radiation therapy Technical Field

[0001] The present invention relates to the field of medical equipment, and more particularly to a patient position adjustment system for radiotherapy. Background Art

[0002] Radiation therapy (RT) is the mainstay of cancer treatment, requiring over 70% of cancer patients and contributing up to 30% of overall cancer cures. The accuracy and precision of the RT process significantly impact local tumor control and treatment-related side effects. While significant advances have been made in precise planning optimization (e.g., intensity modulation, image guidance, and arc-modulated intensity modulation), the development of patient positioning and repositioning technologies has been limited, contradicting clinical needs.

[0003] Currently, skin marking combined with a 3D laser system and an onboard imaging system (e.g., electronic portal imaging devices, EPIDs (electronic portal imaging devices), and CBCT (cone-beam computed tomography)) is the most commonly used position calibration process. The former has been used for decades and requires multiple skin marking lines or tattoos on the patient's body surface to align the patient's position with the projected isocenter 3D laser line. The latter provides highly accurate perspective images and visibility of internal anatomical positions in the human body, which is considered the gold standard for patient position alignment and monitoring in radiotherapy.

[0004] However, in skin marking combined with three-dimensional laser systems, skin marking or tattooing poses potential cosmetic issues, and its accuracy and reliability depend on the therapist's subjective judgment, the patient's compliance, and the skin surface condition; the onboard imaging system uses rays for imaging, and excessive use will increase the amount of additional radiation, affecting the patient's health.

[0005] Summary of the Invention

[0006] The object of the present invention is to provide a patient position adjustment system for radiotherapy, which can improve the position accuracy of the patient before radiotherapy without increasing the additional radiation dose.

[0007] Based on the above objectives, the present invention provides a patient position adjustment system for radiotherapy, comprising:

[0008] a near-infrared light source configured to project near-infrared light onto a predetermined area of ​​a patient's body surface;

[0009] a near-infrared thermal imaging sensor configured to receive the reflected near-infrared light and obtain a vascular texture map of a preset area of ​​the patient based on the reflected near-infrared light;

[0010] at least one laser rangefinder configured to measure a vertical distance between a patient's body surface and the laser rangefinder; and

[0011] An analysis and processing device is connected to the near-infrared thermal imaging sensor and the laser rangefinder, respectively. The analysis and processing device is configured to receive the blood vessel texture map sent by the near-infrared thermal imaging sensor and the vertical distance sent by the laser rangefinder and obtain a position adjustment amount between the current position and the ideal position based on the blood vessel texture map and the vertical distance.

[0012] Furthermore, the patient is located on a treatment bed, and the position adjustment amount includes a vertical adjustment amount, a horizontal longitudinal adjustment amount, a horizontal lateral adjustment amount, and an angle adjustment amount along a preset direction; the analysis and processing device includes:

[0013] a receiving module configured to receive the blood vessel texture map sent by the near-infrared imaging sensor and the vertical distance sent by the laser rangefinder;

[0014] The registration module is configured to compare the vertical distance with the standard vertical distance to obtain a vertical adjustment amount; and compare the blood vessel texture map with the standard blood vessel texture map to obtain a horizontal longitudinal adjustment amount, a horizontal lateral adjustment amount and an angle adjustment amount along a preset direction.

[0015] Furthermore, the analysis and processing device further includes:

[0016] a sending module configured to send the vertical direction adjustment amount, the horizontal longitudinal adjustment amount, the horizontal lateral adjustment amount, and the angular adjustment amount along the preset direction to the treatment couch, so that the treatment couch moves according to the vertical direction adjustment amount, the horizontal longitudinal adjustment amount, the horizontal lateral adjustment amount, and the angular adjustment amount along the preset direction, so as to return the patient to an ideal position.

[0017] Furthermore, the registration module includes:

[0018] a first acquiring unit configured to acquire a blood vessel texture map when the patient is in an ideal position as a standard blood vessel texture map, and acquire a vertical distance when the patient is in the ideal position as a standard vertical distance;

[0019] a second acquiring unit, configured to acquire a mapping relationship between pixels of the blood vessel texture image and absolute distances;

[0020] a comparing unit configured to compare the received vertical distance with the standard vertical distance to obtain a vertical adjustment amount; and compare the received blood vessel texture map with the standard blood vessel texture map to obtain a horizontal longitudinal translation error, a horizontal lateral translation error, and a rotation angle error of the image; and

[0021] The conversion unit is configured to convert the horizontal longitudinal translation error, horizontal lateral translation error and rotation angle error of the image into horizontal longitudinal adjustment amount, horizontal lateral adjustment amount and angle adjustment amount respectively according to the mapping relationship between the pixels of the blood vessel texture image and the absolute distance.

[0022] Furthermore, the received blood vessel texture image is compared with the standard blood vessel texture image to obtain the horizontal longitudinal translation error, horizontal lateral translation error and rotation angle error of the image, specifically including:

[0023] extracting an image of a preset size from the central area of ​​the received blood vessel texture image as a registration area image;

[0024] Shifting the registration region image by m pixels in the longitudinal direction and n pixels in the transverse direction to obtain a shifted registration region image;

[0025] Rotating the translated registration area image clockwise by an angle θ to obtain a translated and rotated registration area image;

[0026] Extract an image of a preset size from the central area of ​​the standard blood vessel texture image as the standard image of the registration area, and calculate the similarity between the registration area image after translation and rotation and the standard image of the registration area;

[0027] With the goal of maximizing the similarity, m, n and θ are optimized to obtain the optimal solution of m, the optimal solution of n and the optimal solution of θ. The optimal solution of m is used as the horizontal longitudinal translation error of the image, the optimal solution of n is used as the horizontal lateral translation error of the image, and the optimal solution of θ is used as the rotation angle error of the image.

[0028] Furthermore, the similarity between the registration area image after translation and rotation and the registration area standard image is a Pearson product moment correlation coefficient.

[0029] Furthermore, the analysis and processing device further includes a display screen configured to display the received blood vessel texture image and / or position adjustment amount.

[0030] Furthermore, the display screen is a touch screen.

[0031] Furthermore, the at least one laser rangefinder includes four laser rangefinders, and the four laser rangefinders are arranged around the near-infrared light source.

[0032] Furthermore, the wavelength of the near-infrared light emitted by the near-infrared light source is a combination of one or more of 760 nm, 800 nm, 850 nm, and 940 nm.

[0033] Furthermore, the near-infrared light source and the near-infrared imaging sensor are both fixed on a bracket and located on the side opposite to the patient. The bracket is configured to be movable to adjust the angle of the near-infrared light source so that the near-infrared light emitted by the near-infrared light source is irradiated on the preset area.

[0034] The patient position adjustment system for radiotherapy of the present invention can obtain the position adjustment amount between the current position and the ideal position based on the blood vessel texture map detected by the near-infrared thermal imaging sensor and the vertical distance measured by the laser rangefinder by the analysis and processing device, so that the treatment bed can automatically adjust the patient from the current position to the ideal position according to the position adjustment amount, thereby minimizing direct contact between the therapist and the patient, eliminating subjective factors, and having high accuracy. It does not require skin markings or tattoos and is more friendly and humane to allergy patients. The patient's position is identified by near-infrared imaging technology, without the need for radiographic imaging and without increasing additional radiation. During position adjustment, the vertical height of the patient is controlled by the vertical distance measured by the laser rangefinder, and the position in the horizontal plane is then controlled by the two-dimensional blood vessel texture map, thereby achieving three-dimensional position adjustment of the patient with higher accuracy and faster adjustment speed. The blood vessel texture map can be intuitively observed through the display screen, which is very convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG1 is a schematic structural diagram of a patient position adjustment system for radiotherapy according to an embodiment of the present invention;

[0036] FIG2 is a schematic diagram showing the positional relationship among a radiation source, a patient, and a laser rangefinder according to an embodiment of the present invention;

[0037] FIG3 is a structural block diagram of an analysis and processing device according to an embodiment of the present invention;

[0038] FIG4 is a structural block diagram of a registration module of an analysis and processing device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0040] As shown in FIG1 , an embodiment of the present invention provides a patient position adjustment system for radiotherapy, comprising a near-infrared light source 100, a near-infrared thermal imaging sensor 200, at least one laser rangefinder 300, and an analysis and processing device 400. The near-infrared light source 100 is used to emit near-infrared light to a preset area (i.e., an area of ​​interest) A on the body surface of a patient 500. The near-infrared light is partially absorbed by the deoxyhemoglobin in the patient's blood and then reflected. The near-infrared thermal imaging sensor 200 is used to receive the reflected near-infrared light and obtain the patient's area of ​​interest based on the reflected near-infrared light. A distribution map of the shape of regional superficial blood vessels (i.e., a blood vessel texture map); a laser rangefinder 300 is used to measure the vertical distance between the laser rangefinder 300 and the body surface of the patient 500; an analysis and processing device 400 is respectively connected to the near-infrared thermal imaging sensor 200 and the laser rangefinder 300 (e.g., a communication connection, an electrical connection, etc.) to receive the blood vessel texture map sent by the near-infrared thermal imaging sensor 200 and the vertical distance sent by the laser rangefinder 300, and obtains a position adjustment amount (i.e., a position deviation amount) between the current position and the ideal position based on the blood vessel texture map and the vertical distance.

[0041] In some embodiments, the region of interest A refers to the area where the patient's tumor is located. The range of the region of interest varies for different tumor patients. In the patient 500 shown in FIG1 , the region of interest A is an area of ​​approximately 40 cm×40 cm on the abdomen of the patient 500 .

[0042] The near-infrared light source 100 can be any suitable device for emitting near-infrared light. The wavelength of the near-infrared light emitted by the near-infrared light source 100 can be between 760 nm and 940 nm. For example, the wavelength of the near-infrared light can be 760 nm, 800 nm, 850 nm, 940 nm, or a combination thereof. In a preferred embodiment, the near-infrared light emitted by the near-infrared light source 100 is a mixture of 760 nm and 940 nm light.

[0043] The near-infrared imaging sensor 200 may be any suitable near-infrared imaging device, and its spectral response range may be 700 nm to 950 nm. In an exemplary embodiment, the near-infrared imaging sensor 200 may use a complementary metal oxide semiconductor (CMOS) to capture near-infrared images.

[0044] In some embodiments, the near-infrared light source 100 and the near-infrared imaging sensor 200 are both located on the side opposite the patient 500, for example, 50 cm from the region of interest. Specifically, the near-infrared light source 100 and the near-infrared imaging sensor 200 can be secured to a bracket 600, which is in turn secured to a wall. The bracket 600 can be configured as a movable bracket, meaning its position can be adjusted as needed. Adjusting the position of the bracket 600 can adjust the angle of the near-infrared light source 100 so that the near-infrared light emitted by the near-infrared light source 100 is directed to the region of interest A.

[0045] The laser rangefinder 300 can be any suitable laser rangefinder, which can be placed near the near-infrared light source 100 and directly above the patient 500. The laser rangefinder 300 can be fixed to a wall by a fixing bracket or the like. The laser rangefinder 300 emits a vertical laser to the surface of the patient 500 and receives the laser reflected from the surface of the patient 500. Then, based on the emission signal and the reflection signal, the vertical distance between the laser rangefinder 300 and the surface of the patient 500 can be obtained. The number of laser rangefinders 300 can be set as needed, for example, to 2, 3 or more. In an exemplary embodiment, there are 4 laser rangefinders 300, which are arranged around the near-infrared light source 100, and the 4 laser rangefinders 300 respectively measure the vertical distances of 4 positions on the surface of the patient 500.

[0046] In some embodiments, the patient 500 may be positioned (e.g., lying flat, lying on their side, or in other positions) on a treatment couch 700. The treatment couch 700 is configured to be movable (e.g., via a motor) to adjust the position of the patient 500. The analysis and processing device 400 may be connected to the treatment couch 700 and transmit position adjustment information to the treatment couch 700, thereby controlling the movement of the treatment couch 700 to adjust the patient 500 from the current position to the desired position.

[0047] In some embodiments, the current position refers to the patient position corresponding to the received vascular texture map. This can be any position during radiotherapy, such as the real-time position of patient 500 or the position at a specified time. When patient 500 is in the ideal position, the radiation target is aligned with the tumor location within the patient's body. The ideal position is typically the initial position. Prior to radiotherapy, patient 500 is moved to the ideal position before radiotherapy begins. During radiotherapy, due to involuntary movement, the patient's position may deviate from the ideal position (i.e., the current position may deviate from the ideal position). This can cause the radiation target to deviate from the tumor location, reducing the effectiveness of radiotherapy. Therefore, during radiotherapy, the analysis and processing device 400 monitors changes in the patient's 500 position in real time using the vertical distance measured by the laser rangefinder 300 and the vascular texture map measured by the near-infrared imaging sensor 200. The device then determines the position adjustment between the current position and the ideal position, and then controls the movement of the treatment couch 700 to return the patient 500 to the ideal position.

[0048] As shown in FIG2 , in some embodiments, a radiation source (e.g., a CBCT source) 800 can be used to determine the ideal position of patient 500. Specifically, radiation source 800 irradiates the tumor area of ​​patient 500 to obtain a highly accurate fluoroscopic image. The treatment couch 700 is then moved so that the radiation source 800's target area is aligned with the tumor location. This position is then considered the ideal position. The analysis and processing device 400 stores the vascular texture map detected by the near-infrared imaging sensor 200 and the vertical distance measured by the laser rangefinder 300 when patient 500 is in the ideal position as a standard vascular texture map and a standard vertical distance, respectively. During radiotherapy, the analysis and processing device 400 compares the real-time received vascular texture map with the standard vascular texture map, and the real-time received vertical distance with the standard vertical distance, thereby determining a position adjustment for patient 500 (i.e., the offset between the current position and the ideal position). The position adjustment is then transmitted to the treatment couch 700, which then moves according to the position adjustment to compensate for the offset and return patient 500 to the ideal position.

[0049] In order to prevent potential equipment collision problems during radiotherapy, the laser rangefinder 300 can be set away from the radiation source 800, that is, there is a preset interval between the laser rangefinder 300 and the radiation source 800. For example, the X-direction distance between the isocenter of the coordinate system of the laser rangefinder 300 and the isocenter of the coordinate system of the radiation source 800 is L (for example, 80 cm).

[0050] As shown in FIG3 , the analysis and processing device 400 may include a receiving module 410 and a registration module 420 , wherein:

[0051] The receiving module 410 is used to receive the blood vessel texture map sent by the near-infrared imaging sensor 200 and the vertical distance (ie, the Z-direction distance) sent by the laser rangefinder 300 .

[0052] The registration module 420 is used to compare the received vertical distance with the standard vertical distance to obtain a vertical direction (i.e., Z-direction) adjustment amount; and compare the received vascular texture image with the standard vascular texture image to obtain a horizontal longitudinal direction (i.e., Y-direction, a direction perpendicular to the XZ plane) adjustment amount, a horizontal transverse direction (i.e., X-direction) adjustment amount, and an angular adjustment amount along a preset direction (e.g., clockwise or counterclockwise) in the horizontal plane (i.e., XY plane).

[0053] In some embodiments, the analysis and processing device 400 may further include a sending module 430. The sending module 430 is configured to send the Z-axis adjustment amount, the Y-axis adjustment amount, the X-axis adjustment amount, and the angular adjustment amount along a preset direction to the treatment couch 700, so that the treatment couch 700 moves according to the aforementioned adjustment amounts, thereby returning the patient 500 from the current position to the ideal position; that is, the treatment couch 700 moves in the Z direction by the Z-axis adjustment amount, in the Y direction by the Y-axis adjustment amount, and in the X direction by the X-axis adjustment amount, and rotates in the horizontal plane by the preset angular adjustment amount along the preset direction to compensate for the positional offset between the current position and the ideal position, thereby returning the patient 500 to the ideal position. In some embodiments, the treatment couch 700 is provided with motors in various directions to drive the treatment couch 700 to move. The sending module 430 sends the Z-axis adjustment amount, the Y-axis adjustment amount, the X-axis adjustment amount, and the angle adjustment amount along a preset direction to the treatment couch 700. This means that the sending module 430 sends a control signal to the motor in each direction, where the control signal includes the adjustment amount in that direction, thereby controlling the motor in each direction to move the treatment couch 700 according to the adjustment amount in each direction.

[0054] As shown in FIG4 , in some embodiments, the registration module 420 further includes a first acquisition unit 421 , a second acquisition unit 422 , a comparison unit 423 , and a conversion unit 424 , wherein:

[0055] The first acquiring unit 421 is configured to acquire a blood vessel texture map when the patient 500 is located in an ideal position as a standard blood vessel texture map, and acquire a vertical distance when the patient 500 is located in the ideal position as a standard vertical distance.

[0056] Before radiotherapy, the patient 500 can be moved to an ideal position, and then the near-infrared light source 100, the near-infrared imaging sensor 200 and the laser rangefinder 300 are turned on. The near-infrared imaging sensor 200 collects the vascular texture map at this time, and the laser rangefinder 300 collects the vertical distance at this time, and then sends them to the analysis and processing device 400. The first acquisition unit 421 saves the vascular texture map at this time as a standard vascular texture map, and saves the vertical distance at this time as a standard vertical distance, so that they can be used as a comparison benchmark in the subsequent radiotherapy process to adjust the position of the patient 500.

[0057] The second acquiring unit 422 is configured to acquire a mapping relationship between pixels of the blood vessel texture image and absolute distances.

[0058] To ensure the accuracy of the results, it is necessary to determine the mapping relationship between the absolute distance (i.e., actual distance) and the pixels of the vascular texture map. This is to facilitate the subsequent conversion of the image movement into an adjustment of the absolute distance. For example, the mapping relationship between absolute distance and pixels can be measured and matched by calibrating an absolute distance of 1 cm. Specifically, the mapping relationship between absolute distance and pixels can be obtained by placing the absolute distance of 1 cm next to the vascular texture map and then determining the number of pixels spanned (included) by the absolute distance of 1 cm.

[0059] The comparison unit 423 is used to compare the received vertical distance with the standard vertical distance to obtain the Z adjustment amount; and compare the received blood vessel texture image with the standard blood vessel texture image to obtain the Y translation error, X translation error and rotation angle error of the image.

[0060] In some embodiments, the received blood vessel texture image is compared with the standard blood vessel texture image to obtain the Y-direction translation error, X-direction translation error, and rotation angle error of the image, specifically including:

[0061] S11: extracting an image of a preset size from the central area of ​​the received blood vessel texture image as a registration area image;

[0062] An image is usually composed of multiple pixels, and the received blood vessel texture map can be represented as a matrix consisting of D×D pixels. In order to reduce the amount of calculation, part of the image can be selected from the vascular texture map as the registration area image for subsequent comparison and optimization. For example, the area containing the most features can be selected, usually the central area of ​​the vascular texture map. Assuming the preset size is d×d, the number of pixels contained in the registration area image is d×d.

[0063] S12: translating the registration area image by m pixels along the Y direction and n pixels along the X direction to obtain a translated registration area image;

[0064] The registered region image after translation can be expressed as

[0065] in, is the pixel value of the km-th row and ln-th column of the registration area image, (km, ln) is the pixel coordinate of the registration area image, X T (k, l) is the pixel value of the kth row and lth column of the registration area image, (k, l) is the pixel coordinate of the registration area image, m and n are both integers, and represent the number of pixels translated along the Y direction and the number of pixels translated along the X direction, respectively.

[0066] S13: rotating the translated registration area image clockwise by an angle θ to obtain a translated and rotated registration area image;

[0067] The registration area image after translation and rotation can be expressed as

[0068] in, is the pixel coordinate of the registration area image after translation and rotation, is the first image of the registration area after translation and rotation Rank The pixel value of the column, (i, j) is the pixel coordinate of the registration area image after translation, is the pixel value of the i-th row and j-th column of the registration area image after translation.

[0069] S14: extracting an image of a preset size from the central area of ​​the standard blood vessel texture image as the registration area standard image, and calculating the similarity between the registration area image after translation and rotation and the registration area standard image;

[0070] The standard blood vessel texture map can be expressed as The standard image of the registration area can be expressed as The similarity between the registered region image after translation and rotation and the registered region standard image can be measured using the Pearson product moment correlation coefficient μ PPMCC To express:

[0071] in, for The qth pixel value of for The average value of all pixel values ​​(ie d 2 The sum of the pixel values ​​divided by d 2 ), for The qth pixel value of for The average value of all pixel values.

[0072] S15: With the goal of maximizing similarity, optimize m, n, and θ to obtain the optimal solution of m, the optimal solution of n, and the optimal solution of θ. The optimal solution of m is used as the Y-direction translation error of the image, the optimal solution of n is used as the X-direction translation error of the image, and the optimal solution of θ is used as the rotation angle error of the image.

[0073] μ PPMCC The larger the value is, the greater the similarity between the registration area image after translation and rotation and the registration area standard image is, that is, the more similar the two images are. Therefore, we can maximize μ PPMCC Optimize the target to get the optimal solution m * 、The optimal solution of n * and the optimal solution θ * , which can be expressed by the following formula:

[0074] The conversion unit 424 is used to convert the Y-direction translation error and the X-direction translation error of the image into Y-direction adjustment amount and X-direction adjustment amount respectively according to the mapping relationship between the pixels of the blood vessel texture image and the absolute distance, and use the rotation angle error as the angle adjustment amount.

[0075] Since the Y-translation error, X-translation error, and rotation angle error represent the positional deviations between the vascular texture image at the current position and the ideal position, they must be converted into actual position adjustments for patient 500. The Y-translation error and X-translation error can be converted using the mapping relationship between pixels and absolute distances. For example, if the mapping relationship is 1 pixel = 10 cm, and the Y-translation error is 1 pixel in the positive Y direction and the X-translation error is 2 pixels in the negative X direction, then the converted Y-adjustment is 10 cm in the positive Y direction and 20 cm in the negative X direction. The image rotation angle has a 1:1 mapping relationship with the actual rotation angle of patient 500. That is, if the rotation angle error is 1° clockwise, then the angle adjustment is also 1° clockwise.

[0076] It is understandable that the optimal solution of m is * 、The optimal solution of n * and the optimal solution θ * It is obtained through optimization, so the registration area image after translation and rotation may not be exactly the same as the registration area standard image. That is to say, after the position of the patient 500 is adjusted according to the Y-axis adjustment amount, the X-axis adjustment amount and the angle adjustment amount, the position of the patient 500 may not be the ideal position, but a position with a very small difference from the ideal position, and its influence can be ignored. Therefore, it can be considered that the patient 500 has returned to the ideal position at this time.

[0077] In some embodiments, the analysis and processing device 400 further includes a display screen 440 (as shown in FIG1 ) for displaying the received vascular texture map. A standard vascular texture map can also be simultaneously displayed on the display screen 440 for easy comparison. In some embodiments, a user (e.g., a therapist) can directly perform various operations (e.g., zoom in, zoom out, move, etc.) on the real-time received vascular texture map on the display screen 440 to align the real-time received vascular texture map with the standard vascular texture map (just align the center area). After alignment, the analysis and processing device 400 can obtain the Y-axis adjustment amount, the X-axis adjustment amount, and the angle adjustment amount. In some embodiments, the display screen 440 can be a touch screen, so that the user can directly operate the real-time received vascular texture map on the touch screen with their hands, which is more convenient. In some embodiments, the Y-axis adjustment amount, the X-axis adjustment amount, the angle adjustment amount, etc. can also be displayed on the display screen 440 for the therapist to view.

[0078] In some embodiments, the analysis and processing device 400 may be a computer, a smart phone, a tablet, or any other suitable electronic device.

[0079] In some embodiments, the analysis and processing device 400 can receive in real time the vascular texture map transmitted by the near-infrared imaging sensor 200 and the vertical distance transmitted by the laser rangefinder 300, and process them to obtain real-time Y-axis adjustment amount, X-axis adjustment amount, angle adjustment amount and Z-axis adjustment amount, and then display them on the display screen, thereby facilitating the therapist to monitor the real-time position of the patient 500. The analysis and processing device 400 may be configured to send real-time position adjustment values ​​to the treatment couch 700 to adjust the position of the patient 500 in real time. Alternatively, the analysis and processing device 400 may be configured to compare the Y-axis adjustment value, the X-axis adjustment value, the angular adjustment value, and the Z-axis adjustment value with the Y-axis threshold value, the X-axis threshold value, the angular threshold value, and the Z-axis threshold value, respectively. When one or more of these values ​​exceed the threshold value, the position adjustment value at that moment is sent to the treatment couch 700, thereby controlling the treatment couch 700 to move the patient back to the ideal position. In this way, the treatment couch 700 is shifted only when position deviations are significant, thereby ensuring position accuracy and reducing the number of shift operations. Alternatively, the analysis and processing device 400 may be configured to send the position adjustment value to the treatment couch 700 in response to an operation by a user (e.g., a therapist) to control the movement of the treatment couch 700.

[0080] In some embodiments, after obtaining the position adjustment amount, the analysis and processing device 400 may also manually move the treatment couch 700 to return the patient 500 to the ideal position.

[0081] In the patient position adjustment system for radiotherapy according to an embodiment of the present invention, the analysis and processing device can obtain the position adjustment amount between the current position and the ideal position based on the blood vessel texture map detected by the near-infrared thermal imaging sensor and the vertical distance measured by the laser rangefinder, so that the treatment bed can automatically adjust the patient from the current position to the ideal position according to the position adjustment amount, thereby minimizing direct contact between the therapist and the patient, eliminating subjective factors, and having high accuracy. Without the need for skin markings or tattoos, it is more user-friendly and humane for allergy patients. The patient's position is identified by near-infrared imaging technology, without the need for radiographic imaging, and without increasing additional radiation. During position adjustment, the vertical height of the patient 500 is controlled by the vertical distance measured by the laser rangefinder 300, and the position in the horizontal plane is then controlled by the two-dimensional blood vessel texture map, thereby achieving three-dimensional position adjustment of the patient 500 with higher accuracy and faster adjustment speed. The blood vessel texture map can be intuitively observed through the display screen 440, which is very convenient.

[0082] To verify the feasibility and reliability of the system, the present invention also conducted simulation phantom studies and clinical trials on the system. In the simulation phantom study, QUASAR™, a four-dimensional chest simulation model from Modus Medical Devices, Inc., was used to evaluate the system's performance. Specifically, homemade artificial blood vessels with diameters of 1 mm, 2 mm, and 3 mm were fixed to the phantom to simulate real vascular distribution. The phantom was then covered with artificial skin of varying thicknesses (3, 5, 8, and 10 mm). The phantom was then placed on a linear accelerator treatment bed and simultaneously shifted in the left-right (LR-X), anteroposterior (AP-Z), and superior-inferior (SI-Y) directions (automatically moved by the treatment bed), with the isocenter offset being 3, 5, 10, 20, and 50 mm, respectively. For performance evaluation, in addition to calculating systematic and random errors, the displacement errors associated with the absolute displacement distance of the present invention's system and a CBCT system were also statistically analyzed. For the system of the present invention, a vascular texture map is acquired at each displacement position, and adjustments in each direction are generated. For the CBCT system, a CBCT scan is performed, a cross-sectional image is reconstructed, and the image is registered to the design target to generate adjustments in each direction based on the CBCT system. Comparison revealed that the system of the present invention also achieves submillimeter accuracy in position adjustment and control. Both systems achieve clinically satisfactory correction results for most displacement measurements (evaluated from absolute displacements of 3-50 mm) across various simulated tissue thicknesses (3-10 mm) and vessel sizes (1-3 mm). Furthermore, the entire adjustment calculation process can be completed within 10 seconds.

[0083] The clinical trial was conducted in a clinical setting with institutional ethics approval (registration number: ChiCTR-IP-202220092). The primary objective was to validate the principle, feasibility, and efficiency of the system of the present invention for locating superficial vascular structures. Thirty patients with a BMI ≤ 26 were enrolled in the clinical trial. All patients completed a conventional radiotherapy protocol: CT simulation images were acquired on a Siemens Somatom Definition AS CT scanner with a 1.5 mm interscanner spacing and a 1 mm slice thickness. Subsequently, a precise three-dimensional treatment plan was developed (Eclipse 15.5; Varian, Palo Alto, CA, USA). Before treatment, each patient was positioned using 3D laser-guided positioning based on body markers and also directly positioned using the system of the present invention. Following both positioning methods, patients underwent linear accelerator-based CBCT scanning. Adjustments to the two systems were recorded after CBCT image calibration (using the CBCT image as a gold standard) to compare the adjustments between the laser system and the system of the present invention. Image guidance, position adjustment correction, and adjustment recording were performed weekly throughout the radiotherapy regimen. Clinical trial results show that VIPS improves by 59.2%, 58.7% and 74.0% compared to the laser system in the SI, LR and AP directions, respectively. The system of the present invention combines a laser rangefinder to detect and correct three-dimensional displacements including rotation, and is documentable and traceable, which has obvious advantages over the three-point laser system.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention are within the scope of protection of the patent claims. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A patient position adjustment system for radiotherapy, characterized in that: include: a near-infrared light source configured to project near-infrared light onto a preset area of ​​a patient's body surface; a near-infrared thermal imaging sensor configured to receive the reflected near-infrared light and obtain a vascular texture map of a preset area of ​​the patient based on the reflected near-infrared light; at least one laser rangefinder configured to measure a vertical distance between a body surface of a patient and the laser rangefinder; and The analysis and processing device is connected to the near-infrared thermal imaging sensor and the laser rangefinder respectively, and is configured to receive the blood vessel texture map sent by the near-infrared thermal imaging sensor and the vertical distance sent by the laser rangefinder and obtain the position adjustment amount between the current position and the ideal position according to the blood vessel texture map and the vertical distance.

2. The patient position adjustment system for radiotherapy according to claim 1, characterized in that: The patient is located on the treatment bed, and the position adjustment amount includes a vertical adjustment amount, a horizontal longitudinal adjustment amount, a horizontal lateral adjustment amount, and an angle adjustment amount along a preset direction; the analysis and processing device includes: A receiving module, configured to receive the blood vessel texture map sent by the near-infrared imaging sensor and the vertical distance sent by the laser rangefinder; The registration module is configured to compare the vertical distance with the standard vertical distance to obtain a vertical adjustment amount; and compare the vascular texture map with the standard vascular texture map to obtain a horizontal longitudinal adjustment amount, a horizontal lateral adjustment amount and an angle adjustment amount along a preset direction.

3. The patient position adjustment system for radiotherapy according to claim 2, characterized in that: The analysis and processing device also includes: and a sending module, configured to send the vertical direction adjustment amount, the horizontal longitudinal adjustment amount, the horizontal lateral adjustment amount, and the angle adjustment amount along the preset direction to the treatment bed, so that the treatment bed moves according to the vertical direction adjustment amount, the horizontal longitudinal adjustment amount, the horizontal lateral adjustment amount, and the angle adjustment amount along the preset direction, so that the patient returns to an ideal position.

4. The patient position adjustment system for radiotherapy according to claim 2, characterized in that: The registration module comprises: A first acquisition unit is configured to acquire a blood vessel texture map when the patient is located in an ideal position as a standard blood vessel texture map, and acquire a vertical distance when the patient is located in an ideal position as a standard vertical distance; A second acquisition unit is configured to acquire a mapping relationship between pixels of the blood vessel texture map and absolute distances; a comparison unit, configured to compare the received vertical distance with the standard vertical distance to obtain a vertical adjustment amount; and compare the received blood vessel texture map with the standard blood vessel texture map to obtain a horizontal longitudinal translation error, a horizontal lateral translation error and a rotation angle error of the image; and The conversion unit is configured to convert the horizontal longitudinal translation error and the horizontal lateral translation error of the image into the horizontal longitudinal adjustment amount and the horizontal lateral adjustment amount respectively according to the mapping relationship between the pixels of the blood vessel texture map and the absolute distance, and use the rotation angle error as the angle adjustment amount.

5. The patient position adjustment system for radiotherapy according to claim 4, characterized in that: The received blood vessel texture map is compared with the standard blood vessel texture map to obtain the horizontal longitudinal translation error, horizontal lateral translation error and rotation angle error of the image, specifically including: Extracting an image of a preset size from a central area of ​​the received blood vessel texture image as a registration area image; The registration area image is translated horizontally by m pixels in the longitudinal direction and horizontally by n pixels in the transverse direction to obtain a translated registration area image; Rotate the translated registration region image clockwise by an angle of θ to obtain a translated and rotated registration region image; Extract an image of a preset size from the central area of ​​the standard blood vessel texture image as the standard image of the registration area, and calculate the similarity between the registration area image after translation and rotation and the standard image of the registration area; With the goal of maximizing the similarity, m, n and θ are optimized to obtain the optimal solution of m, the optimal solution of n and the optimal solution of θ. The optimal solution of m is used as the horizontal longitudinal translation error of the image, the optimal solution of n is used as the horizontal lateral translation error of the image, and the optimal solution of θ is used as the rotation angle error of the image.

6. The patient position adjustment system for radiotherapy according to claim 5, characterized in that: The similarity between the registration region image after translation and rotation and the registration region standard image is the Pearson product moment correlation coefficient.

7. The patient position adjustment system for radiotherapy according to claim 2, characterized in that: The analysis and processing device also includes a display screen configured to display the received blood vessel texture map and / or position adjustment amount.

8. The patient position adjustment system for radiotherapy according to claim 1, characterized in that: The at least one laser rangefinder includes four laser rangefinders, and the four laser rangefinders are arranged around the near-infrared light source.

9. The patient position adjustment system for radiotherapy according to claim 1, characterized in that: The wavelength of the near-infrared light emitted by the near-infrared light source is a combination of one or more of 760nm, 800nm, 850nm, and 940nm.

10. The patient position adjustment system for radiation therapy according to claim 1, characterized in that: The near-infrared light source and the near-infrared imaging sensor are both fixed on a bracket and located on a side opposite to the patient. The bracket is configured to be movable to adjust the angle of the near-infrared light source so that the near-infrared light emitted by the near-infrared light source irradiates the preset area.

Images