System and method for managing respiratory movement of patient during radiotherapy

Abstract

The invention discloses a respiratory movement management system and method for a patient during radiotherapy, and the system comprises a positioning bed board which is used for the patient to lie down; the positioning scanning device is used for collecting a 4DCT image of the patient; the pressure acquisition device is arranged on the surface of the positioning bed plate and is used for acquiring pressure data when the patient lies down; the image acquisition device is used for acquiring body surface image data of the chest and abdomen of the patient; the respiratory movement management device is in communication connection with the positioning scanning device, the pressure acquisition device and the image acquisition device and is used for monitoring the patient's 4DCT image scanned by the positioning scanning device, the pressure data acquired by the pressure acquisition device and the body surface image data acquired by the image acquisition device; and positioning of the patient before radiotherapy and respiratory movement in radiotherapy are managed. According to the invention, respiratory movement monitoring, tumor position calculation and anomaly detection can be automatically completed, the workload of radiotherapy doctors is reduced, and the treatment efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tumor radiotherapy, and in particular relates to a respiratory motion management system and method for patients during radiotherapy. Background Art

[0002] During radiotherapy for thoracic and abdominal tumors, tumor movement caused by respiratory motion may lead to a lack of dose coverage of the tumor target area, ultimately resulting in a difference between the planned dose and the actual radiation dose received by the tumor. This will greatly reduce the accuracy of radiotherapy, not only making the efficacy of radiotherapy worse, but also causing the normal tissues around the tumor to receive excessive unplanned radiation doses, which in addition to causing excessive damage to normal tissues may also lead to serious side effects, such as radiation pneumonitis. Therefore, managing the respiratory motion of tumor patients is extremely important during radiotherapy for patients with thoracic and abdominal tumors.

[0003] Modern radiation therapy can use a variety of techniques to manage organ motion to reduce irradiation of adjacent normal organs while maintaining therapeutic effects on the tumor. These techniques can be divided into five different categories: motion bracketing, respiratory gating, breath holding, abdominal compression to force shallow breathing, and real-time tumor tracking.

[0004] Respiratory gating technology refers to the use of a certain method to monitor the patient's breathing during treatment and trigger the radiation beam irradiation at a specific respiratory phase. Various respiratory motion marking methods are usually used to monitor the target area in real time, and then a specific respiratory phase is selected for radiotherapy. Existing respiratory gating monitoring systems are mainly divided into two categories: surface displacement monitoring technology and abdominal pressure monitoring technology.

[0005] There are many ways to track patient breathing, including camera tracking based on infrared marker detection, breathing valve devices for passive breathing control, and abdominal pressure strap sensor tracking.

[0006] The existing surface displacement monitoring technology is a real-time positioning system based on infrared camera. A plastic block with infrared light reflective material is placed on the patient's abdomen or chest surface. An infrared light diode at a certain position in the room emits infrared light. The motion-sensitive camera captures the image of the reflected light on the plastic block and transmits it to the computer. The motion information of the surface markers is obtained by digital processing of the image, and the real-time tracking of the target area is achieved through the fixed motion relationship between the surface markers and the tumor in the body. However, for patients with excessive abdominal fat accumulation, the fat will shake with breathing, making the respiratory signal acquisition inaccurate; for some patients with sunken abdomen, the camera cannot capture the full movement of the reflective point, and gated treatment cannot be carried out; in addition, under general treatment conditions, the small plastic box is required to be attached to the patient's abdomen, which will cause certain discomfort and psychological tension.

[0007] The abdominal pressure belt gating technology wraps the air pressure belt around the abdomen and converts abdominal changes into air pressure changes in real time through the embedded pressure sensor, thereby obtaining respiratory movement signals. This method is easy to operate, but has poor repeatability and is not suitable for some patients who use abdominal compression devices. It can easily cause tension and discomfort in patients, and the tightness of the abdominal belt has a certain impact on the signal quality.

[0008] The biggest disadvantage of respiratory gating technology is that it increases the treatment time of patients. The appropriate respiratory phase selected by the radiotherapist only occupies a part of the respiratory cycle, and no radiation is emitted in most of the respiratory cycle. This causes the treatment time of patients treated with respiratory gating technology to be significantly longer than that of patients treated with conventional treatment methods. This means that when selecting appropriate patients for treatment, the requirements for the patient's lung function should be improved, and the breathing should be as even as possible. Too large or too small a respiratory amplitude cycle may affect the treatment.

[0009] If free breathing is not allowed during irradiation (i.e., breath holding or restricted shallow breathing), the movement of the tumor is also restricted according to breathing, thereby improving the accuracy of delivering the therapeutic dose to the lesion and reducing the risk to surrounding normal organs. Breath holding can be achieved by using appropriate techniques, such as deep inspiration breath holding and active respiratory control. These techniques can significantly reduce the movement of the lesion caused by the patient's breathing, thereby reducing the possibility of errors in the delivery of therapeutic doses. However, depending on the patient's clinical condition, there are many limitations to restricting natural breathing. For example, in clinical practice, elderly cancer patients often cannot tolerate respiratory restrictions. In addition, accessories that come into direct contact with the patient, such as breathing masks or compression plates, should be handled with care to avoid contamination. Summary of the invention

[0010] In order to solve the above technical problems, the present invention proposes a respiratory motion management system and method for patients during radiotherapy.

[0011] In order to achieve the above object, the technical solution of the present invention is as follows:

[0012] In one aspect, the present invention discloses a respiratory motion management system for a patient during radiotherapy, comprising:

[0013] Positioning bed board, the positioning bed board is used for patients to lie down;

[0014] A positioning scanning device, the positioning scanning device is used to collect 4DCT images of the patient;

[0015] A pressure collection device is placed on the surface of the positioning bed board and is used to collect pressure data of the patient when lying down;

[0016] An image acquisition device, the image acquisition device is used to acquire body surface image data of the patient's chest and abdomen;

[0017] A respiratory movement management device, which is communicatively connected to the positioning scanning device, the pressure acquisition device, and the image acquisition device respectively, and is used to manage the patient's pre-radiotherapy positioning and respiratory movement during radiotherapy based on the patient's 4DCT image scanned by the positioning scanning device, the pressure data acquired by the pressure acquisition device, and the surface image data acquired by the image acquisition device.

[0018] Based on the above technical solution, the following improvements can be made:

[0019] As a preferred solution, the relative position between the pressure collection device and the positioning bed plate can be adjusted.

[0020] As a preferred solution, the pressure collection device is an array-type flexible pressure sensor, which is laid flat on the surface of the positioning bed board.

[0021] As a preferred solution, the relative position between the image acquisition device and the positioning bed plate can be adjusted.

[0022] In addition, in another aspect, the present invention further discloses a method for managing respiratory motion of a patient during radiotherapy, which uses any of the above-mentioned respiratory motion management systems to manage respiratory motion, including:

[0023] In the positioning stage before radiotherapy, the positioning scanning device, the pressure acquisition device, and the image acquisition device respectively acquire the patient's 4DCT images, pressure data, and body surface image data, and record the relative position between the pressure acquisition device and the positioning bed board, and the relative position between the image acquisition device and the positioning bed board. Based on the acquired data, the body surface respiratory motion curve and the pressure respiratory motion curve in the positioning stage before radiotherapy are calculated, and an in vivo tumor respiratory motion model is established;

[0024] In the accurate stage before radiotherapy, the pressure acquisition device and the image acquisition device are reset based on the relative position between the pressure acquisition device and the positioning bed plate and the relative position between the image acquisition device and the positioning bed plate recorded in the radiotherapy positioning stage;

[0025] During the radiotherapy execution stage, the pressure acquisition device and the image acquisition device respectively collect the patient's pressure data and body surface image data, and calculate the surface respiratory motion curve and the pressure respiratory motion curve in the radiotherapy execution stage based on the acquired data. The curves are compared and analyzed with the surface respiratory motion curve and the pressure respiratory motion curve obtained in the positioning stage before radiotherapy, and the in vivo tumor respiratory motion model is used to calculate the real-time shape changes and position movements of the tumor in the radiotherapy execution stage.

[0026] As a preferred solution, the method of the positioning stage before radiotherapy includes:

[0027] Step A.1: The patient lies on the positioning bed board;

[0028] Step A.2: The positioning scanning device, the pressure acquisition device, and the image acquisition device respectively and synchronously acquire the patient's 4DCT image, pressure data, and body surface image data;

[0029] Step A.3: Calculate based on the acquired 4DCT images, pressure data and body surface image data to obtain a body surface respiratory motion curve and a pressure respiratory motion curve;

[0030] Step A.4: Synchronize the time stamps of the surface respiratory motion curve and the pressure respiratory motion curve with the phase acquisition time of the 4DCT image;

[0031] Step A.5: Based on the surface respiratory motion curve, the pressure respiratory motion curve and the tumor motion data of the 4DCT image, an in vivo tumor respiratory motion model is established. The in vivo tumor respiratory motion model is used to reflect the mapping relationship between tumor displacement and respiratory phase.

[0032] As a preferred solution, the method of the radiotherapy implementation stage includes:

[0033] Step B.1: The patient lies on the positioning bed board;

[0034] Step B.2: The pressure acquisition device and the image acquisition device synchronously acquire the patient's pressure data and body surface image data respectively;

[0035] Step B.3: Calculate based on the collected pressure data and body surface image data to obtain a body surface respiratory motion curve and a pressure respiratory motion curve;

[0036] Step B.4: Continuously monitor the frequency and amplitude changes of the surface respiratory movement curve and the pressure respiratory movement curve;

[0037] When the surface respiratory movement curve or pressure respiratory movement curve is abnormal, an alarm will be triggered;

[0038] When the deviation between the body surface respiratory motion curve and pressure respiratory motion curve in the radiotherapy execution stage and the body surface respiratory motion curve and pressure respiratory motion curve obtained in the positioning stage before radiotherapy exceeds the threshold, an alarm is triggered;

[0039] Step B.5: Input the body surface respiratory motion curve and the pressure respiratory motion curve into the in vivo tumor respiratory motion model to obtain the real-time shape change and position movement of the tumor during the radiotherapy execution phase.

[0040] As a preferred solution, step B.5 includes:

[0041] Step B.5.1: inputting the real-time surface respiratory motion curve and pressure respiratory motion curve into the in vivo tumor respiratory motion model;

[0042] Step B.5.2: Determine the current respiratory phase by performing phase matching between the real-time surface respiratory motion curve and the pressure respiratory motion curve and the surface respiratory motion curve and the pressure respiratory motion curve obtained in the positioning stage before radiotherapy;

[0043] Step B.5.3: extracting corresponding tumor position and shape information from the in vivo tumor respiratory motion model according to the matched respiratory phase;

[0044] Step B.5.4: Based on the real-time surface respiratory motion curve and pressure respiratory motion curve, combined with the tumor position and shape information extracted in step B.5.3, the real-time tumor position and shape information in the current respiratory phase is calculated by interpolation or extrapolation method.

[0045] As a preferred solution, the surface respiratory motion curve and the pressure respiratory motion curve are obtained by the following steps respectively, including:

[0046] Step a: preprocessing the obtained raw data;

[0047] Step b: Perform frame difference analysis on the preprocessed data to identify the change matrix between adjacent frames;

[0048] Step c: segmenting the change matrix based on a set dynamic threshold to identify dynamic change areas related to breathing;

[0049] Step d: generating a continuous respiratory motion curve based on the dynamic change area related to breathing.

[0050] As a preferred solution, after the resetting is completed, frame difference analysis is performed based on the pressure data collected by the pressure collection device and the body surface image data collected by the image collection device to identify one or more real-time dynamic change areas as the respiratory movement monitoring area during treatment;

[0051] The identified real-time dynamic change area is compared, analyzed and evaluated with the corresponding area collected during the positioning phase before radiotherapy, and the patient is guided to correct the patient position error according to the regional deviation until the regional deviation meets the requirements.

[0052] The present invention discloses a respiratory motion management system and method for patients during radiotherapy, which has the following beneficial effects:

[0053] First, the respiratory motion management system uses the pressure acquisition device 2 and the image acquisition device 3 to monitor the respiratory motion of the tumor patient undergoing radiotherapy, thereby avoiding the shortcomings and deficiencies of a single monitoring system.

[0054] Second, the present invention collects pressure data and body surface image data during the pre-radiotherapy positioning stage, establishes the corresponding respiratory curve and the in vivo tumor respiratory motion model. And in the pre-radiotherapy accurate stage and the radiotherapy execution stage, by continuously collecting the patient's pressure data and body surface image data, the resetting guidance, respiratory motion monitoring, abnormal monitoring and abnormal warning during treatment are carried out.

[0055] Third, the present invention can monitor the patient's respiratory movements in real time to ensure the continuity and accuracy of the respiratory signal during treatment.

[0056] Fourth, the present invention can accurately locate the real-time position of the tumor through respiratory phase matching and tumor position prediction, ensuring accurate irradiation of the radiotherapy beam.

[0057] Fifth, the present invention can detect abnormal changes in the patient's body position and respiratory movement in real time to ensure the safety and stability of the treatment process.

[0058] Sixth, the present invention can automatically complete respiratory movement monitoring, tumor position calculation and abnormality detection, reduce the workload of radiotherapy physicians, and improve treatment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0060] Figure 1 A schematic diagram of the structure of a respiratory motion management system provided by an embodiment of the present invention.

[0061] Figure 2 A schematic diagram of the structure of an image acquisition device provided in an embodiment of the present invention.

[0062] Among them: 1-positioning bed board, 11 fixing frame, 2-pressure acquisition device, 3-image acquisition device, 4-respiratory movement management device. DETAILED DESCRIPTION

[0063] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0064] 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 only 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.

[0065] The expression of “comprising” an element is an “open” expression, which merely means that a corresponding component or step exists, and should not be interpreted as excluding additional components or steps.

[0066] In order to achieve the purpose of the present invention, some embodiments of the respiratory motion management system for patients during radiotherapy, such as Figure 1-2 As shown, the respiratory exercise management system includes:

[0067] A positioning bed board 1, the positioning bed board 1 is used for the patient to lie down;

[0068] A positioning scanning device (not shown in the figure), which is used to acquire 4DCT images of the patient;

[0069] A pressure collection device 2 is placed on the surface of the positioning bed board and is used to collect pressure data of the patient when lying down;

[0070] An image acquisition device 3, which is used to acquire body surface image data of the patient's chest and abdomen;

[0071] The respiratory movement management device 4 is communicated with the positioning scanning device, the pressure acquisition device 2, and the image acquisition device 3 respectively, and is used to manage the patient's pre-radiotherapy positioning and respiratory movement during radiotherapy based on the patient's 4DCT image scanned by the positioning scanning device, the pressure data acquired by the pressure acquisition device 2, and the surface image data acquired by the image acquisition device 3.

[0072] The pressure collection device 2 is placed between the upper surface of the positioning bed board 1 and the patient's back, and is used to collect the pressure matrix of the patient lying on the bed. The relative position between the pressure collection device 2 and the positioning bed board 1 can be adjusted, and the relative position between the pressure collection device 2 and the positioning bed board 1 can be measured and recorded.

[0073] In some specific embodiments, the pressure acquisition device 2 may be, but is not limited to, an array-type flexible pressure sensor, which is laid flat on the surface of the positioning bed board 1. The array-type flexible pressure sensor is made of a thin film material with a thickness of 0.2 to 1 mm, a pressure detection area of ​​not less than 30 cm in the width direction of the bed surface, and not less than 20 cm in the length direction, a pressure detection sensitive point spacing of 0.2 to 1 cm, a single-point pressure can detect a maximum value of 1 MPa, and a data acquisition frame rate of not less than 10 Hz.

[0074] By using a two-dimensional array of flexible pressure sensors instead of a single pressure sensor, useful information for monitoring the patient's posture and breathing signals can be obtained from the 2D real-time pressure data. The pressure distribution on the patient's back can be used to identify the patient's center of gravity or weight balance. Changes in pressure distribution can be used to immediately detect abnormal conditions that are not easily identified on the video monitor screen and image acquisition device 3, such as a sudden slight twist of the patient's body.

[0075] The image acquisition device 3 is a body surface optical image scanning device, which is used to acquire the position data of the contour matrix of the patient's chest and abdomen surface.

[0076] The relative position between the image acquisition device 3 and the positioning bed plate 1 can be adjusted. Specifically, a fixed frame 11 is installed on the positioning bed plate 1, and the image acquisition device 3 is installed on the fixed frame 11, and the relative position between the fixed frame 11 and the positioning bed plate 1 can be adjusted. It is worth noting that the relative position (such as height and angle, etc.) between the image acquisition device 3 and the positioning bed plate 1 can be measured and recorded. During radiotherapy, the image acquisition device 3 is kept fixed by a locking device. Specifically, the image acquisition device 3 uses a laser light source and a binocular structured light principle to collect the patient's body surface contour data. The distance between the image acquisition device 3 and the patient's body surface is 25 to 100 cm, and the data acquisition frame rate is not less than 10 Hz.

[0077] By using the adjustable image acquisition device 3, the relative position of the image acquisition device 3 and the patient can be adjusted according to the individual tumor position and body shape difference of the patient, thereby solving the disadvantages of the current commercial system that it can only be fixedly installed in the treatment room, cannot adapt to the individual differences of different patients to obtain the optimal body surface image, and is easily affected by the rotation obstruction of the treatment machine.

[0078] The above-mentioned pressure acquisition device 2 and image acquisition device 3 are integrated on the positioning bed plate 1, which can conveniently measure and record the relative positions of the pressure acquisition device 2, image acquisition device 3 and the positioning bed plate 1 of each patient, and fix the positions of the pressure acquisition device 2 and image acquisition device 3 during treatment through a locking device.

[0079] In some other embodiments, the present invention further discloses a method for managing respiratory motion of a patient during radiotherapy, which uses the respiratory motion management system disclosed above to manage respiratory motion, including:

[0080] In the positioning stage before radiotherapy, the positioning scanning device, the pressure acquisition device 2, and the image acquisition device 3 respectively acquire the patient's 4DCT image, pressure data, and body surface image data, and record the relative position between the pressure acquisition device 2 and the positioning bed plate 1 and the relative position between the image acquisition device 3 and the positioning bed plate 1. Based on the acquired data, the body surface respiratory motion curve and the pressure respiratory motion curve in the positioning stage before radiotherapy are calculated, and an in vivo tumor respiratory motion model is established;

[0081] In the accurate stage before radiotherapy, based on the relative position between the pressure acquisition device 2 and the positioning bed plate 1 and the relative position between the image acquisition device 3 and the positioning bed plate 1 recorded in the radiotherapy positioning stage, the pressure acquisition device 2 and the image acquisition device 3 are reset;

[0082] During the radiotherapy execution stage, the pressure acquisition device 2 and the image acquisition device 3 respectively collect the patient's pressure data and body surface image data, and calculate the surface respiratory motion curve and the pressure respiratory motion curve in the radiotherapy execution stage based on the acquired data, and compare and analyze them with the surface respiratory motion curve and the pressure respiratory motion curve obtained in the positioning stage before radiotherapy, and use the in vivo tumor respiratory motion model to calculate the real-time shape change and position movement of the tumor in the radiotherapy execution stage.

[0083] Further, the methods of the pre-radiotherapy positioning phase include:

[0084] Step A.1: The patient lies on the positioning bed board 1;

[0085] Step A.2: The positioning scanning device is manually triggered or automatically triggered by the 4DCT beam emission signal to perform 4DCT image acquisition. The pressure acquisition device 2 and the image acquisition device 3 respectively synchronously acquire the patient's 4DCT image, pressure data and body surface image data, automatically align the data through the acquisition time information, and record the relative position between the pressure acquisition device 2 and the positioning bed board 1 and the relative position between the image acquisition device 3 and the positioning bed board 1 (such as height and angle);

[0086] Step A.3: Calculate based on the acquired 4DCT images, pressure data and body surface image data to obtain a body surface respiratory motion curve and a pressure respiratory motion curve;

[0087] Step A.4: Synchronize the time stamps of the surface respiratory motion curve and the pressure respiratory motion curve with the phase acquisition time of the 4DCT image;

[0088] Step A.5: Based on the surface respiratory motion curve, the pressure respiratory motion curve and the tumor motion data of the 4DCT image, an in vivo tumor respiratory motion model is established. The in vivo tumor respiratory motion model is used to reflect the mapping relationship between tumor displacement and respiratory phase.

[0089] It is worth noting that in step A.5, the timestamp of the pressure respiratory motion curve is synchronized with the phase acquisition time of the 4DCT image, and the time alignment is achieved using an interpolation algorithm (cubic spline interpolation). Then, the in vivo tumor respiratory motion model is established by combining the surface respiratory motion curve and the tumor motion data of the 4DCT image through a multimodal registration algorithm, and the model output includes the mapping relationship between tumor displacement and respiratory phase.

[0090] In the accurate stage before radiotherapy, the pressure acquisition device and the image acquisition device are reset based on the relative position between the pressure acquisition device and the positioning bed plate and the relative position between the image acquisition device and the positioning bed plate recorded in the radiotherapy positioning stage.

[0091] After the resetting is completed, frame difference analysis is performed based on the pressure data collected by the pressure collection device and the body surface image data collected by the image collection device to identify one or more real-time dynamic change areas as the respiratory movement monitoring area during treatment;

[0092] The identified real-time dynamic change area is compared, analyzed and evaluated with the corresponding area collected during the positioning phase before radiotherapy, and the patient is guided to correct the patient position error according to the regional deviation until the regional deviation meets the requirements.

[0093] In other embodiments, during the radiotherapy execution stage, the surface respiratory motion curve and pressure respiratory motion curve collected in the respiratory motion monitoring area can be compared with the respiratory motion curve collected before treatment, and when abnormal changes such as changes in the curve frequency, amplitude, etc. exceeding the set threshold are found, a respiratory abnormality alarm is issued in time; abnormal patient position detection is performed on other data collection areas outside the respiratory motion monitoring area, and when the frame difference is greater than the set threshold, an abnormal patient position alarm is issued in time.

[0094] Further, the methods of the radiotherapy implementation phase include:

[0095] Step B.1: The patient lies on the positioning bed board 1;

[0096] Step B.2: the pressure acquisition device 2 and the image acquisition device 3 synchronously acquire the patient's pressure data and body surface image data respectively;

[0097] During the treatment, the patient's pressure data and body surface image data are continuously collected at a frame rate of no less than 10 Hz;

[0098] Step B.3: Calculate based on the collected pressure data and body surface image data to obtain a body surface respiratory motion curve and a pressure respiratory motion curve;

[0099] Step B.4: Continuously monitor the frequency and amplitude changes of the surface respiratory movement curve and the pressure respiratory movement curve;

[0100] When the surface respiratory movement curve or pressure respiratory movement curve is abnormal, an alarm will be triggered;

[0101] For example, by comparing the difference between the current frame and the previous frame, abnormal changes in the patient's body position (such as sudden body twisting or movement) can be detected in real time, and abnormal alarms can be issued in time;

[0102] When the deviation between the body surface respiratory motion curve and pressure respiratory motion curve in the radiotherapy execution stage and the body surface respiratory motion curve and pressure respiratory motion curve obtained in the positioning stage before radiotherapy exceeds the threshold, an alarm is triggered;

[0103] Step B.5: Input the body surface respiratory motion curve and the pressure respiratory motion curve into the in vivo tumor respiratory motion model to obtain the real-time shape change and position movement of the tumor during the radiotherapy execution phase.

[0104] Further, according to the in vivo tumor respiratory motion model established before treatment, the real-time shape change and position movement of the tumor are calculated, recorded, displayed, and outputted. Step B.5 includes:

[0105] Step B.5.1: inputting the real-time surface respiratory motion curve and pressure respiratory motion curve into the in vivo tumor respiratory motion model;

[0106] Step B.5.2: Determine the current respiratory phase by performing phase matching between the real-time surface respiratory motion curve and pressure respiratory motion curve and the surface respiratory motion curve and pressure respiratory motion curve obtained in the positioning stage before radiotherapy. Respiratory phase matching can be achieved by time alignment or curve shape matching.

[0107] Step B.5.3: extracting corresponding tumor position and shape information from the in vivo tumor respiratory motion model according to the matched respiratory phase;

[0108] Step B.5.4: Based on the real-time surface respiratory motion curve and pressure respiratory motion curve, combined with the tumor position and shape information extracted in step B.5.3, the real-time tumor position and shape information in the current respiratory phase is calculated by interpolation or extrapolation method.

[0109] The specific operations are as follows:

[0110] First, according to the matching respiratory phase, the corresponding tumor position and shape information are extracted from the in vivo tumor respiratory motion model established in the pre-radiotherapy positioning stage. The tumor position and shape information in the model is obtained by aligning the 4DCT image with the respiratory curve.

[0111] According to the changes in the real-time respiratory curve, the real-time shape and position of the tumor in the current respiratory phase are calculated by interpolation or extrapolation.

[0112] The specific calculation steps are as follows:

[0113] Interpolation calculation: If the phase of the real-time respiratory curve is close to that of the respiratory curve collected before treatment, the real-time shape and position of the tumor are calculated by linear interpolation or nonlinear interpolation.

[0114] Extrapolation calculation: If the real-time respiratory curve exceeds the range of the respiratory curve collected before treatment, the real-time shape and position of the tumor are predicted by extrapolation based on the existing in vivo tumor respiratory motion model.

[0115] The calculated real-time tumor shape and position information is displayed in real time on the treatment control interface for the reference of the radiotherapy physician. At the same time, this information can also be output to the radiotherapy equipment for real-time adjustment of the direction and dose of the radiotherapy beam.

[0116] It is worth noting that during the treatment, the frequency and amplitude changes of the respiratory curve are continuously monitored. If a significant deviation is found between the respiratory curve and the model established before treatment (such as the frequency or amplitude exceeds the set threshold), an abnormal alarm will be issued in time, prompting the radiotherapist to take appropriate corrective measures.

[0117] Further, the surface respiratory motion curve and the pressure respiratory motion curve are obtained by the following steps respectively, including:

[0118] Step a: preprocessing the obtained raw data;

[0119] Step b: Perform frame difference analysis on the preprocessed data to identify the change matrix between adjacent frames;

[0120] For pressure data, the pressure change matrix between adjacent frames is calculated;

[0121] For body surface image data, the body surface contour change matrix between adjacent frames is calculated;

[0122] The above-mentioned change matrix is ​​used to reflect the dynamic changes of the patient's back pressure or body surface contour;

[0123] Step c: segmenting the change matrix based on a set dynamic threshold to identify dynamic change areas related to breathing;

[0124] Step d: Based on the dynamic change area related to breathing, the pressure change or body surface contour change in the area is extracted to generate a continuous breathing motion curve.

[0125] Taking the pressure breathing motion curve as an example, it includes the following steps:

[0126] 1) Preprocessing the obtained pressure data;

[0127] The raw pressure data is denoised using a low-pass filter (cut-off frequency: 0.5-2 Hz) to remove high-frequency interference signals (such as muscle tremors or equipment vibrations) and retain low-frequency components related to breathing;

[0128] 2) Perform frame difference analysis on the preprocessed pressure data;

[0129] The sliding window technique is used to perform frame-by-frame differential calculation on continuous pressure data frames at a sampling rate of 10 Hz;

[0130] The window size is 1 second (e.g., 10 frames), and the pressure change matrix between adjacent frames is calculated using the formula: ΔP(t) = P(t) - P(t-1);

[0131] Where P(t) is the pressure distribution matrix of the tth frame;

[0132] 3) Binarize the pressure change matrix based on the set dynamic threshold and identify the dynamic change area related to breathing;

[0133] Set the dynamic threshold T = μ + 3σ to distinguish valid breathing signals from noise;

[0134] Among them, μ is the mean of the difference matrix, σ is the standard deviation;

[0135] Then, the isolated noise points are removed by morphological opening operation (erosion followed by dilation), and the continuously changing areas are identified by connected domain analysis and marked as dynamically changing areas.

[0136] 4) extracting the pressure change time series of each point in the dynamic change area, using principal component analysis (PCA) to reduce the dimension, and selecting the first principal component as the respiratory motion feature vector;

[0137] The eigenvectors were then smoothed (Savitzky-Golay filter, window length 21 points) to generate a continuous pressure-breathing motion curve, which characterizes the amplitude and frequency of pressure changes during the respiratory cycle.

[0138] Through pre-treatment data analysis, the respiratory signal can be accurately extracted from the two-dimensional pressure distribution, avoiding the defect that a single sensor is susceptible to noise interference; dynamic thresholding and morphological processing improve the robustness of regional segmentation; principal component analysis and multimodal registration further improve the accuracy of the in vivo tumor respiratory motion model, laying a data foundation for real-time monitoring and abnormal warning in subsequent treatment.

[0139] It is worth noting that the present invention continuously records the pressure data and body surface image data of each treatment of the patient. The pressure data and body surface image data collected during each radiotherapy execution phase are compared and analyzed with the pre-radiotherapy preparation phase and the pre-radiotherapy positioning phase. The surface respiratory motion curve and pressure respiratory motion curve between fractions and during the pre-radiotherapy positioning phase are analyzed for coincidence, and the frequency, amplitude and other parameters of the respiratory curve are statistically analyzed. When the coincidence and stability of the respiratory curve exceed the set threshold or the trend changes significantly, an abnormal respiratory warning is issued to prompt the clinic to take countermeasures.

[0140] The present invention discloses a method, device, equipment and storage medium for determining a dominant vertex of an alternating group network, which has the following beneficial effects:

[0141] First, the respiratory motion management system uses the pressure acquisition device 2 and the image acquisition device 3 to monitor the respiratory motion of the tumor patient undergoing radiotherapy, thereby avoiding the shortcomings and deficiencies of a single monitoring system.

[0142] Second, the present invention collects pressure data and body surface image data during the pre-radiotherapy positioning stage, establishes the corresponding respiratory curve and the in vivo tumor respiratory motion model. And in the pre-radiotherapy accurate stage and the radiotherapy execution stage, by continuously collecting the patient's pressure data and body surface image data, the resetting guidance, respiratory motion monitoring, abnormal monitoring and abnormal warning during treatment are carried out.

[0143] Third, the present invention can monitor the patient's respiratory movements in real time to ensure the continuity and accuracy of the respiratory signal during treatment.

[0144] Fourth, the present invention can accurately locate the real-time position of the tumor through respiratory phase matching and tumor position prediction, ensuring accurate irradiation of the radiotherapy beam.

[0145] Fifth, the present invention can detect abnormal changes in the patient's body position and respiratory movement in real time to ensure the safety and stability of the treatment process.

[0146] Sixth, the present invention can automatically complete respiratory movement monitoring, tumor position calculation and abnormality detection, reduce the workload of radiotherapy physicians, and improve treatment efficiency.

[0147] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A respiratory motion management system for patients during radiotherapy, characterized in that: include: A positioning bed board, wherein the positioning bed board is used for a patient to lie down; A positioning scanning device, wherein the positioning scanning device is used to acquire 4DCT images of the patient; A pressure collection device, which is placed on the surface of the positioning bed board and is used to collect pressure data of the patient when lying down; An image acquisition device, the image acquisition device is used to acquire body surface image data of the patient's chest and abdomen; A respiratory movement management device, which is communicatively connected to the positioning scanning device, the pressure acquisition device, and the image acquisition device respectively, and is used to manage the patient's pre-radiotherapy positioning and respiratory movement during radiotherapy based on the patient's 4DCT image scanned by the positioning scanning device, the pressure data acquired by the pressure acquisition device, and the surface image data acquired by the image acquisition device.

2. The respiratory motion management system according to claim 1, characterized in that: The relative position between the pressure collection device and the positioning bed plate can be adjusted.

3. The respiratory motion management system according to claim 1, characterized in that: The pressure collection device is an array-type flexible pressure sensor, which is laid flat on the surface of the positioning bed board.

4. The respiratory motion management system according to claim 1, characterized in that: The relative position between the image acquisition device and the positioning bed plate can be adjusted.

5. A method for managing respiratory movements of patients during radiotherapy, characterized in that: Using the respiratory motion management system according to any one of claims 1 to 4 to perform respiratory motion management, comprising: In the positioning stage before radiotherapy, the positioning scanning device, the pressure acquisition device, and the image acquisition device respectively acquire the patient's 4DCT images, pressure data, and body surface image data, and record the relative position between the pressure acquisition device and the positioning bed board, and the relative position between the image acquisition device and the positioning bed board. Based on the acquired data, the body surface respiratory motion curve and the pressure respiratory motion curve in the positioning stage before radiotherapy are calculated, and an in vivo tumor respiratory motion model is established; In the accurate stage before radiotherapy, the pressure acquisition device and the image acquisition device are reset based on the relative position between the pressure acquisition device and the positioning bed plate and the relative position between the image acquisition device and the positioning bed plate recorded in the radiotherapy positioning stage; During the radiotherapy execution stage, the pressure acquisition device and the image acquisition device respectively collect the patient's pressure data and body surface image data, and calculate the surface respiratory motion curve and the pressure respiratory motion curve in the radiotherapy execution stage based on the acquired data. The curves are compared and analyzed with the surface respiratory motion curve and the pressure respiratory motion curve obtained in the positioning stage before radiotherapy, and the in vivo tumor respiratory motion model is used to calculate the real-time shape changes and position movements of the tumor in the radiotherapy execution stage.

6. The respiratory movement management method according to claim 5, characterized in that: Methods used in the pre-radiotherapy positioning phase include: Step A.1: The patient lies on the positioning bed board; Step A.2: The positioning scanning device, the pressure acquisition device, and the image acquisition device respectively and synchronously acquire the patient's 4DCT image, pressure data, and body surface image data; Step A.3: Calculate based on the acquired 4DCT images, pressure data and body surface image data to obtain a body surface respiratory motion curve and a pressure respiratory motion curve; Step A.4: Synchronize the time stamps of the surface respiratory motion curve and the pressure respiratory motion curve with the phase acquisition time of the 4DCT image; Step A.5: Based on the surface respiratory motion curve, the pressure respiratory motion curve and the tumor motion data of the 4DCT image, an in vivo tumor respiratory motion model is established, wherein the in vivo tumor respiratory motion model is used to reflect the mapping relationship between tumor displacement and respiratory phase.

7. The respiratory movement management method according to claim 5, characterized in that: Methods during the delivery phase of radiation therapy include: Step B.1: The patient lies on the positioning bed board; Step B.2: The pressure acquisition device and the image acquisition device synchronously acquire the patient's pressure data and body surface image data respectively; Step B.3: Calculate based on the collected pressure data and body surface image data to obtain a body surface respiratory motion curve and a pressure respiratory motion curve; Step B.4: Continuously monitor the frequency and amplitude changes of the surface respiratory movement curve and the pressure respiratory movement curve; When the surface respiratory movement curve or pressure respiratory movement curve is abnormal, an alarm will be triggered; When the deviation between the body surface respiratory motion curve and pressure respiratory motion curve in the radiotherapy execution stage and the body surface respiratory motion curve and pressure respiratory motion curve obtained in the positioning stage before radiotherapy exceeds the threshold, an alarm is triggered; Step B.5: Input the body surface respiratory motion curve and the pressure respiratory motion curve into the in vivo tumor respiratory motion model to obtain the real-time shape change and position movement of the tumor during the radiotherapy execution phase.

8. The respiratory movement management method according to claim 7, characterized in that: The step B.5 comprises: Step B.5.1: inputting the real-time surface respiratory motion curve and pressure respiratory motion curve into the in vivo tumor respiratory motion model; Step B.5.2: Determine the current respiratory phase by performing phase matching between the real-time surface respiratory motion curve and the pressure respiratory motion curve and the surface respiratory motion curve and the pressure respiratory motion curve obtained in the positioning stage before radiotherapy; Step B.5.3: extracting corresponding tumor position and shape information from the in vivo tumor respiratory motion model according to the matched respiratory phase; Step B.5.4: Based on the real-time surface respiratory motion curve and pressure respiratory motion curve, combined with the tumor position and shape information extracted in step B.5.3, the real-time tumor position and shape information in the current respiratory phase is calculated by interpolation or extrapolation method.

9. The respiratory motion management method according to any one of claims 6 to 8, characterized in that: The surface respiratory motion curve and the pressure respiratory motion curve are obtained respectively by the following steps, including: Step a: preprocessing the obtained raw data; Step b: Perform frame difference analysis on the preprocessed data to identify the change matrix between adjacent frames; Step c: segmenting the change matrix based on a set dynamic threshold to identify dynamic change areas related to breathing; Step d: generating a continuous respiratory motion curve based on the dynamic change area related to breathing.

10. The respiratory motion management method according to claim 9, characterized in that: After the resetting is completed, frame difference analysis is performed based on the pressure data collected by the pressure collection device and the body surface image data collected by the image collection device to identify one or more real-time dynamic change areas as the respiratory movement monitoring area during treatment; The identified real-time dynamic change area is compared, analyzed and evaluated with the corresponding area collected during the positioning phase before radiotherapy, and the patient is guided to correct the patient position error according to the regional deviation until the regional deviation meets the requirements.

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