Tumor motion model determination method and electronic equipment

Abstract

The invention provides a tumor motion model determination method and electronic equipment, and relates to the technical field of medical treatment, in particular to the technical field of tumor tracking. The method comprises the steps of obtaining a scanning image of a target object in a positioning stage and a breathing signal of the target object, and determining a tumor motion model based on a plan image of the target object, the position of a tumor of the target object in the scanning image and the breathing signal. Wherein the tumor motion model is used for representing the position change condition of the tumor of the target object in the breathing process of the target object. By means of the method, the steps of determining the tumor motion model can be effectively simplified, the duration of determining the tumor motion model is effectively shortened, and time is saved.

Description

Technical Field

[0001] The present disclosure relates to the field of medical technology, in particular to the field of tumor tracking technology, and specifically to a method for determining a tumor motion model and an electronic device. Background Art

[0002] During radiotherapy, maintaining accurate tumor positioning is one of the key technologies of radiotherapy. During radiotherapy, the patient's breathing movement can cause significant changes in the position of chest and abdominal (lung, liver and pancreas) tumors. Therefore, accurate positioning of chest and abdominal tumors has become a very challenging problem.

[0003] Currently, after completing the positioning phase, multiple projection images can be collected and a tumor motion model can be established based on the multiple projection images to determine the location of the tumor based on the tumor motion model during the treatment phase. However, this method is too complicated and takes a lot of time. Summary of the invention

[0004] The present disclosure provides a tumor motion model determination method and electronic device, which can effectively simplify the steps of determining the tumor motion model, effectively shorten the time for determining the tumor motion model, and save time.

[0005] In a first aspect, the present disclosure provides a method for determining a tumor motion model, the method comprising:

[0006] The scanning image of the target object in the positioning phase and the breathing signal of the target object are obtained, and the tumor motion model is determined based on the planning image of the target object, the position of the tumor of the target object in the scanning image, and the breathing signal.

[0007] The tumor motion model is used to characterize the position change of the tumor of the target object during the breathing process of the target object.

[0008] In some embodiments, the above method also includes: when the distance between the position of the tumor of the target object in the planning image and the imaging point is less than or equal to a preset threshold, determining the tumor motion model based on the planning image, the position of the tumor of the target object in the scanning image, and the breathing signal.

[0009] In some embodiments, the scanned image may include multiple projection images.

[0010] On this basis, before determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal, the above method may also include: determining a reference projection image from the scanned image, and determining a target respiratory signal corresponding to the moment of acquiring the reference projection image from the respiratory signal.

[0011] Accordingly, determining the tumor motion model based on the planning image of the target object, the position of the tumor of the target object in the scanned image, and the breathing signal may include: determining the tumor motion model based on the planning image, the position of the tumor of the target object in the reference projection image, and the target breathing signal.

[0012] The reference projection image refers to an image of a tumor of the target object among the multiple projection images.

[0013] In some embodiments, determining a reference projection image from a scanned image may include: acquiring a reference projection image from a projection image at a reference projection angle in the scanned image at a preset sampling interval.

[0014] In some embodiments, the reference projection angle can be determined based on at least one of a first projection angle, a second projection angle, and a third projection angle. The first projection angle refers to a projection angle range in which the path of the light beam emitted by the light source to the tumor of the target object does not contain a preset tissue. The second projection angle refers to a projection angle range corresponding to a respiratory cycle in which the fit between the movement trajectory of the tumor and the preset trajectory is the highest. The third projection angle refers to an available angle range for halffield imaging (HF).

[0015] In some embodiments, in the semi-field imaging mode, the reference projection angle is the intersection of the first projection angle and the third projection angle.

[0016] In some embodiments, the second projection angle can be determined in the following manner: based on the position of the tumor of the target object in each projection image contained in the scanned image, the movement trajectory of the tumor is determined, and from the movement trajectory, the sub-motion trajectory with the highest fit with the preset trajectory is determined, and the angle range of the projection image corresponding to the respiratory cycle of the captured sub-motion trajectory is used as the second projection angle.

[0017] In some embodiments, the third projection angle can be determined in the following manner: at different angles, the position of the tumor projection on the plane where the detector is located is determined; for any angle, if the position of the tumor projection on the plane where the detector is located at this angle is in the area where the detector is located, the angle is determined as the third projection angle.

[0018] In some embodiments, for any angle, determining the position of the tumor projection on the plane where the detector is located may include: determining the position of the tumor projection on the plane where the detector is located based on the angle, the position of the tumor of the target object in the scanned image, the distance between the light source and the detector, and the distance between the light source and the imaging point.

[0019] In some embodiments, the first projection angle is determined by using a digital reconstruction projection algorithm to determine an angle where a path of a light beam emitted by a light source reaching a tumor of a target object in a planned image does not contain a preset tissue as the first projection angle.

[0020] In some embodiments, before determining the angle at which the path of the light beam emitted by the light source to the tumor of the target object in the planning image does not contain the preset tissue as the first projection angle, the method further includes: obtaining a first offset, and adjusting the planning image based on the first offset. The first offset is an offset obtained based on the registration of the scanned image and the planning image.

[0021] On this basis, the above-mentioned determination of the angle at which the path of the light beam emitted by the light source to the tumor of the target object in the planned image does not contain the preset tissue as the first projection angle may include: determining the angle at which the path of the light beam emitted by the light source to the tumor of the target object in the adjusted planned image does not contain the preset tissue as the first projection angle.

[0022] In some embodiments, the number of reference projection images is multiple. The above-mentioned determination of the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal may include: obtaining the planned image adjusted based on the first offset, for each reference projection image, digitally reconstructing the adjusted planned image at the projection angle of the reference projection image, obtaining a first digitally reconstructed radiograph (DRR) image, and aligning the reference projection image with the first DRR to obtain the second offset corresponding to the reference projection image. Finally, the tumor motion model is determined based on the second offset corresponding to each reference projection image and the target respiratory signal.

[0023] The first offset is an offset obtained based on the registration of the scanned image and the planned image.

[0024] In some embodiments, the number of reference projection images is multiple. Determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal may include: for each reference projection image, digitally reconstructing the planned image at the projection angle of the acquired reference projection image to obtain a second DRR image, and aligning the reference projection image and the second DRR to obtain a third offset corresponding to the reference projection image. Obtaining the first offset, and using the first offset to adjust the third offset corresponding to each reference projection image, and determining the tumor motion model based on the adjusted third offset corresponding to each reference projection image and the target respiratory signal.

[0025] The first offset is an offset obtained based on the registration of the scanned image and the planned image.

[0026] In some embodiments, the number of reference projection images is multiple. Determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal may include: obtaining a first offset, adjusting the position of the tumor of the target object in each reference projection image using the first offset, and determining the tumor motion model based on the adjusted position of the tumor of the target object in each reference projection image and the target respiratory signal.

[0027] The first offset is an offset obtained based on the registration of the scanned image and the planned image.

[0028] In a second aspect, the present disclosure further provides a device for determining a tumor motion model, the device comprising:

[0029] The acquisition unit is used to acquire the scanned image of the target object during the positioning phase and the breathing signal of the target object.

[0030] The determination unit is used to determine a tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the breathing signal. The tumor motion model is used to characterize the position change of the tumor of the target object during the breathing process of the target object.

[0031] In a third aspect, the present disclosure further provides an electronic device comprising: a processor and a memory configured to store processor executable instructions; wherein the processor is configured to execute the instructions to implement any one of the optional tumor motion model determination methods in the first aspect above.

[0032] The tumor motion model determination method provided by the present disclosure can directly obtain the tumor motion model of the target object based on the scanned image in the positioning stage, the planned image of the target object and the respiratory signal, without collecting multiple projection images to determine the tumor motion model after the positioning stage is completed. In this way, the steps of determining the tumor motion model can be effectively simplified, the time for determining the tumor motion model can be effectively shortened, and time can be saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.

[0034] Figure 1 A schematic diagram of a radiotherapy system provided in an embodiment of the present disclosure;

[0035] Figure 2 A schematic diagram of a flow chart of a method for determining a tumor motion model provided in an embodiment of the present disclosure;

[0036] Figure 3 A schematic diagram of a coordinate system of an imaging point provided in an embodiment of the present disclosure;

[0037] Figure 4 A schematic diagram of a flow chart of another method for determining a tumor motion model provided by an embodiment of the present disclosure;

[0038] Figure 5 A schematic diagram of a flow chart of another method for determining a tumor motion model provided by an embodiment of the present disclosure;

[0039] Figure 6 A schematic diagram of a method for determining the location of a tumor of a target object in real time provided by an embodiment of the present disclosure;

[0040] Figure 7 A schematic block diagram of an electronic device provided in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0042] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "first", "second", and "third" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0043] In the description of the present disclosure, the word "exemplary" is used to mean "used as an example, illustration, or illustration". Any embodiment described in the present disclosure as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present disclosure. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present disclosure can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present disclosure with unnecessary details. Therefore, the present disclosure is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present disclosure.

[0044] It should be noted that since the method of the embodiment of the present disclosure is executed in an imaging computer device, the processing objects of each imaging computer device exist in the form of data or information. For example, time is actually time information. It can be understood that if size, quantity, position, etc. are mentioned in subsequent embodiments, they are all corresponding data to facilitate processing by the computer device. The details will not be repeated here.

[0045] During radiotherapy, maintaining accurate tumor positioning is one of the key technologies of radiotherapy. During radiotherapy, the patient's breathing movement can cause significant changes in the position of chest and abdominal (lung, liver and pancreas) tumors. Therefore, accurate positioning of chest and abdominal tumors has become a very challenging problem.

[0046] Currently, after completing the positioning phase, multiple projection images can be collected and a tumor motion model can be established based on the multiple projection images to determine the location of the tumor based on the tumor motion model during the treatment phase. However, this method is too complicated and takes a lot of time.

[0047] Based on the above technical problems, the disclosed embodiment provides a method for determining a tumor motion model. After acquiring the scanned image of the target object in the positioning stage and the breathing signal of the target object, the tumor motion model can be determined based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the breathing signal. The tumor motion model is used to characterize the position change of the tumor of the target object during the breathing process of the target object.

[0048] Through the above technical solution, the tumor motion model of the target object can be directly obtained based on the scanned images in the positioning phase, as well as the planned images and respiratory signals of the target object, without having to collect multiple projection images to determine the tumor motion model after the positioning phase is completed. In this way, the steps of determining the tumor motion model can be effectively simplified, the time for determining the tumor motion model can be effectively shortened, and time can be saved.

[0049] Figure 1 A schematic diagram of a scene of a radiotherapy system provided in an embodiment of the present disclosure, the system may include an image-guided radiotherapy device 101, an imaging computer device 102, a control device 103 and a breathing detection device.

[0050] The image-guided radiotherapy device 101 may include a gantry 1011 and an image-guided device disposed on the gantry 1011, wherein the image-guided device includes a light source 1012 and a detector 1013. The light source 1012 is used to emit a light beam, and the detector 1013 is used to receive the light beam passing through a target object (patient) to generate a projection image of the target object.

[0051] In the embodiment of the present disclosure, the detector 1013 may be a flat-panel detector or a curved-surface detector. The embodiment of the present disclosure does not specifically limit the shape of the detector 1013.

[0052] In the disclosed embodiment, the image guidance device may be at least one of a cone beam computed tomography (CBCT) device, a computed tomography (CT) device, and a magnetic resonance (MR) device, that is, the image guidance device may be a CBCT device, a CT device, or an MR device, or may include any two of a CBCT device, a CT device, and an MR device, and the image guidance device may also include a CBCT device, a CT device, and an MR device. The disclosed embodiment does not specifically limit the form of the image guidance device.

[0053] When the image guidance device is a CBCT device, the light source 1012 is an X-ray tube, and the detector 1013 is a flat panel detector.

[0054] In the embodiment of the present disclosure, there is no limitation on the number of light sources 1012 and the number of detectors 1013. For example, the number of light sources 1012 may be one or more. Similarly, the number of detectors 1013 may be one or more. When the number of light sources 1012 and the number of detectors 1013 are both multiple, two-dimensional images (i.e., projection images, also referred to as kilovolt (KV) images) of two-dimensional (2D) planes inside multiple target objects may be generated at a certain rack angle (or time point).

[0055] In some embodiments, when the number of light sources 1012 and the number of detectors 1013 is 1, the light source and the detector may be located at Figure 1The direction of the Z axis shown in the figure, in this way, the position of the tumor of the target object in the direction of the X axis and the Y axis can be obtained. Among them, the position of the tumor of the target object in the direction of the Y axis represents the position of the tumor of the target object in the head and foot direction. The position of the tumor of the target object in the direction of the X axis represents the position of the tumor of the target object in the left and right direction (left and right of the target object).

[0056] In some embodiments, when the number of light sources 1012 and the number of detectors 1013 are both 2, a set of light sources and detectors can be located at Figure 1 In order to obtain the position of the tumor of the target object in the direction of the X-axis and the Y-axis, another set of light sources and detectors can be located in Figure 1 The X-axis direction shown in the figure can be used to obtain the position of the tumor of the target object in the directions of the Z-axis and the Y-axis. In this way, the three-dimensional spatial position of the tumor of the target object can be obtained based on the position of the tumor of the target object in the directions of the X-axis and the Y-axis, and the position of the tumor of the target object in the directions of the Z-axis and the Y-axis. The position of the tumor of the target object in the direction of the Z-axis represents the front and back of the tumor of the target object (front and back of the target object, Figure 1 The position in the up and down directions.

[0057] The rack 1011 can be a ring rack, a C-arm rack, a drum rack, a multi-layer bowl-shaped / cylindrical structure rack, etc. The rack 1011 is a rotating rack that can move around a rotation axis or a fixed rack that cannot move. When the rack 1011 rotates, the light source 1012 and the detector 1013 can rotate around the Y axis at any angle, so that a two-dimensional image (i.e., a projection image) of any 2D plane of the target object can be generated.

[0058] The breathing detection device is used to detect the breathing signal of the target object.

[0059] In the embodiment of the present disclosure, the breathing detection device may include an optical camera 1041 and at least one optical marker 1042 arranged on the chest surface of the target object. Exemplarily, the optical camera 1041 may be an infrared camera, and correspondingly, the optical marker 1042 may be an infrared marker, or may be other types of optical cameras and corresponding optical markers. The embodiment of the present disclosure does not specifically limit the form of the breathing detection device.

[0060] The imaging computer device 102 is respectively connected to the control device 103, the detector 1013 and the breathing detection device in communication, and the control device 103 is connected to the support device supporting the target object in communication. The control device 103 is used to control the movement of the support device based on the offset sent by the imaging computer device 102, thereby adjusting the position of the target object.

[0061] In some embodiments, the imaging computer device 102 is a computer device with a graphical user interface (GUI), and the computer device includes: one or more processors, a memory, and one or more applications. For example, the imaging computer device 102 may include an image guidance system (IGS) application, and the processor of the imaging computer device executes the IGS application to achieve: obtaining a scanned image of the target object in the positioning stage, and a respiratory signal of the target object, and determining a tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal. Among them, the tumor motion model is used to characterize the position change of the tumor of the target object during the breathing process of the target object.

[0062] In the embodiment of the present disclosure, the image computer device 102 and the control device 103 can be independent servers, or a server network or server cluster composed of servers. For example, the computer device described in the embodiment of the present disclosure includes but is not limited to a computer, a network host, a single network server, a plurality of network server sets or a cloud server composed of a plurality of servers. The cloud server is composed of a large number of computers or network servers based on cloud computing.

[0063] In the embodiment of the present disclosure, the imaging computer device 102 and the control device 103 can be general-purpose computer devices or special-purpose computer devices. In a specific implementation, the computer device can be a desktop computer, a portable computer, a network server, a PDA (Personal Digital Assistant), a mobile phone, a tablet computer, a wireless terminal device, a communication device, an embedded device, etc. This embodiment does not limit the type of computer device.

[0064] The following will be combined Figure 1 ,by Figure 1 Taking the imaging computer device in which the number of light sources and the number of detectors are 1 as an example, the tumor motion model determination method provided by the embodiment of the present disclosure is described. It should be noted that the tumor motion model determination method provided by the embodiment of the present disclosure can be performed in the positioning stage.

[0065] Figure 2 A schematic diagram of a flow chart of a method for determining a tumor motion model provided by an embodiment of the present disclosure, such as Figure 2 As shown, the method includes the following S201-S202.

[0066] S201, acquiring a scan image of the target object in the positioning phase and a breathing signal of the target object.

[0067] The scanned image includes multiple projection images, and the projection images are two-dimensional images.

[0068] Specifically, the image computer device may store the acquisition frequency and the acquisition duration. In the positioning stage before radiotherapy, the image computer device may obtain the acquisition frequency and the acquisition duration, and send the acquisition frequency and the acquisition duration to the image guidance device and the breathing detection device respectively.

[0069] After receiving the acquisition frequency and acquisition duration, the image guidance device can control the light source to emit a light beam according to the acquisition frequency within the acquisition duration. After the light beam emitted by the light source passes through the target object and reaches the detector, the detector can obtain a projection image of the target object in the positioning stage. The detector can send the projection image of the target object in the positioning stage to the image computer device. By repeating the above steps, the image computer device can obtain multiple projection images of the target object in the positioning stage, that is, scanned images, such as CBCT scanned images.

[0070] After receiving the acquisition frequency and the acquisition duration, the breathing detection device can detect the breathing state of the target object according to the acquisition frequency within the acquisition duration to obtain the breathing signal of the target object, and send the breathing signal of the target object to the image computer device. In this way, the image computer device can obtain the breathing signal of the target object.

[0071] The process of the breathing detection device detecting the breathing signal of the target object can refer to the relevant technology and will not be described in detail here.

[0072] Among them, the collection frequency and collection duration can be preset.

[0073] In the embodiment of the present disclosure, the acquisition frequency may be 9 Hz or 10 Hz. The embodiment of the present disclosure does not specifically limit the value of the acquisition frequency.

[0074] The acquisition time can be set according to the duration of a respiratory cycle. For example, assuming that the duration of a complete respiratory cycle is 5 seconds (s), the acquisition time can be 10s or 15s. The embodiment of the present disclosure does not specifically limit the value of the acquisition time.

[0075] S202, determining a tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal.

[0076] The planned image (eg, CT image) is an image obtained by performing tomographic imaging on a tumor of the target object when a treatment plan is formulated for the target object.

[0077] The tumor motion model is used to characterize the position change of the tumor of the target object during the target object's breathing process.

[0078] Specifically, the imaging computer device can acquire and store the planned image of the target object. After obtaining the scanned image and the respiratory signal of the target object in the positioning stage, the imaging computer device can acquire the planned image of the target object stored in itself, and determine the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal.

[0079] Through the above technical solution, the imaging computer device can directly obtain the tumor motion model of the target object based on the scanned images in the positioning phase, as well as the planned images and respiratory signals of the target object, without having to collect multiple projection images to determine the tumor motion model after the positioning phase is completed. In this way, the steps of determining the tumor motion model can be effectively simplified, the time for determining the tumor motion model can be effectively shortened, and time can be saved.

[0080] In an optional embodiment, the imaging computer device may also determine the distance between the position of the tumor of the target object and the imaging point in the planned image of the target object before executing the above S202. Accordingly, the above S202 may be replaced by: when the distance between the position of the tumor of the target object in the planned image and the imaging point is less than or equal to a preset threshold, determining the tumor motion model based on the planning image, the position of the tumor of the target object in the scanned image, and the respiratory signal.

[0081] Among them, the imaging points are manually marked by medical workers in the planning image of the target object during the treatment planning process.

[0082] In the disclosed embodiment, the location of the tumor of the target object can be represented by the location of the tumor's centroid, or by the location of the tumor's center, or by the location of the tumor's center of gravity. The disclosed embodiment does not limit the location of the target object's tumor.

[0083] In the embodiment of the present disclosure, the preset threshold value (thresh) may be 9 millimeters (mm) or 5 mm. The embodiment of the present disclosure does not specifically limit the value of the preset threshold value.

[0084] Specifically, take the position of the tumor of the target object as an example, where the position of the tumor's centroid is represented. Figure 3 As shown, ellipse 301 represents the planned image of the target object, point A is the imaging point marked by the medical staff in the planned image of the target object, and point B is the mass center of the tumor of the target object marked by the medical staff in the planned image. The imaging computer device can use point A as the origin of the coordinates, the left and right direction of the target object as the X-axis, and the front and back of the target object (such as Figure 1 The up and down direction in the image is the Z axis. Figure 3The image computer device can determine the position of the center of mass of the tumor of the target object in the planning image, that is, the coordinates of point B. The image computer device can determine the distance between the position of the tumor of the target object in the planning image of the target object and the imaging point, that is, the distance between point B and point A, based on the following formula 1.

[0085]

[0086] Wherein, d represents the distance between the position of the tumor of the target object in the planning image of the target object and the imaging point, and (x0, z0) represents the position of the center of mass of the tumor of the target object in the planning image.

[0087] After determining the distance between the position of the tumor of the target object in the planning image and the imaging point in the above manner, the imaging computer device can compare the distance between the position of the tumor of the target object in the planning image and the imaging point with a preset threshold. If the distance between the position of the tumor of the target object in the planning image and the imaging point is less than or equal to the preset threshold, the imaging computer device can determine the tumor motion model based on the position of the tumor of the target object in the planning image and the scanned image, and the breathing signal. If the distance between the position of the tumor of the target object in the planning image and the imaging point is greater than the preset threshold, it indicates that the magnification ratio of the tumor of the target object at different angles is too different, and the imaging computer device may not establish a tumor motion model.

[0088] Figure 4 A flow chart of another method for determining a tumor motion model provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the method includes the following S401-S405.

[0089] S401, acquiring a scan image of the target object in the positioning phase and a breathing signal of the target object.

[0090] The specific implementation of S401 can refer to the description of S201 above, which will not be repeated here.

[0091] S402, determining the position of the tumor of the target object and the distance between the imaging points in the planned image of the target object.

[0092] The specific implementation of S402 can refer to the above description and will not be repeated here.

[0093] S403: When the distance between the position of the tumor of the target object and the imaging point in the planning image is less than or equal to a preset threshold, determine a reference projection image from the scanned image.

[0094] The reference projection image refers to an image including a tumor of the target object among the plurality of projection images included in the scanned image.

[0095] The number of reference projection images is multiple. For example, the number of reference projection images can be 10 or 15. The embodiment of the present disclosure does not specifically limit the number of reference projection images.

[0096] In an optional implementation, the process of determining the reference projection image from the scanned image by the imaging computer device may specifically include: acquiring the reference projection image from the projection image at the reference projection angle in the scanned image according to a preset sampling interval.

[0097] The preset sampling interval may be 1, in which case the image computer device may obtain a projection image as a reference projection image at every interval of 1 image from the projection image at the reference projection angle in the scanned image. The preset sampling interval may also be 2, in which case the image computer device may obtain a projection image as a reference projection image at every interval of 2 images from the projection image at the reference projection angle in the scanned image. This is not limited in the embodiments of the present disclosure.

[0098] The reference projection angle can be determined based on at least one of the first projection angle, the second projection angle, and the third projection angle. The first projection angle refers to the projection angle range in which the path of the light beam emitted by the light source to the tumor of the target object does not contain the preset tissue. The second projection angle refers to the projection angle range corresponding to the respiratory cycle with the highest fit between the movement trajectory of the tumor and the preset trajectory. The third projection angle refers to the available angle range for half-field imaging (the third projection angle may also be referred to as the HF available angle).

[0099] The following will respectively describe the process of determining the first projection angle, the second projection angle and the third projection angle by the image computer device.

[0100] (1) Determine the first projection angle.

[0101] In an optional embodiment, the planning image may include the contours of multiple tissues (such as liver, lungs, heart, spine, etc.) that are automatically or manually marked, and the multiple tissues include the tumor of the target object. On this basis, after acquiring the planning image of the target object, the imaging computer device may use a digital reconstruction projection algorithm to determine the angle at which the path of the tumor of the target object in the planning image of the target object emitted by the light source does not include the preset tissue as the first projection angle.

[0102] The preset tissues may include the remaining tissues among the above-mentioned multiple tissues except the tumor of the target object.

[0103] Specifically, after the imaging computer device acquires the planned image of the target object stored in itself, it can use a preset path simulation algorithm to simulate the path (also called ray path) of the light beam emitted by the light source through the tumor of the target object to reach the detector at various projection angles based on the positions of multiple tissues and the position of the light source in the planned image. And determine at least one target projection angle in which the path does not include tissues other than the tumor of the target object, that is, at the first projection angle, the light beam emitted by the light source can be free from interference from objects other than the tumor in the planned image (such as liver, lungs, heart, spine, etc.).

[0104] In the embodiment of the present disclosure, the path simulation algorithm may be a digitally reconstructed radiograph (DRR) algorithm, or a ray tracing algorithm or a Monte Carlo algorithm. The embodiment of the present disclosure does not specifically limit the path simulation algorithm.

[0105] (2) Determine the second projection angle.

[0106] In an optional embodiment, the imaging computer device can determine the motion trajectory of the tumor (hereinafter referred to as the first motion trajectory) based on the position of the tumor of the target object in each projection image contained in the scanned image, and then determine the sub-motion trajectory with the highest fit with the preset trajectory from the first motion trajectory, and finally use the angle range of the projection image corresponding to the respiratory cycle of the captured sub-motion trajectory as the second projection angle.

[0107] In the embodiment of the present disclosure, the preset trajectory may coincide with the curve of the sine function or the curve of the cosine function. The embodiment of the present disclosure does not specifically limit the preset trajectory.

[0108] Specifically, taking the coincidence of the preset trajectory and the curve of the sine function as an example, after the image computer device determines the position of the tumor of the target object in each projection image contained in the scanned image, it can generate a first motion trajectory of the tumor of the target object based on the position of the tumor of the target object in each projection image and the time when each projection image is collected. Afterwards, the image computer device can determine the sub-motion trajectory with the highest fit to the curve of the sine function from the first motion trajectory. The image computer device can use the respiratory cycle corresponding to the sub-motion trajectory as the optimal respiratory cycle, and use the angle range of the projection image corresponding to the optimal respiratory cycle as the second projection angle.

[0109] (3) Determine the third projection angle.

[0110] In an optional embodiment, the imaging computer device can determine the position of the tumor projection on the plane where the detector is located at different angles. For any angle, if the position of the tumor projection on the plane where the detector is located at this angle is located in the area where the detector is located, the angle is determined as the third projection angle.

[0111] Specifically, take the position of the tumor of the target object as represented by the position of the mass center of the tumor. For any angle, the imaging computer device can determine the position of the tumor projection on the plane where the detector is located based on the angle, the position of the tumor of the target object in the scanned image, the distance between the light source and the detector, and the distance between the light source and the imaging point. If the position of the tumor projection on the plane where the detector is located at this angle is located in the area where the detector is located, the imaging computer device can determine this angle as the third projection angle.

[0112] The position of the tumor of the target object in the scanned image refers to the position of the tumor in a three-dimensional reconstructed image (eg, a CBCT image) obtained by three-dimensionally reconstructing the scanned image.

[0113] The imaging computer device may determine the position of the tumor of the target object in the scanned image in the following manner: obtaining a first offset, and determining the position of the tumor of the target object in the scanned image based on the first offset and the position of the tumor of the target object in the planned image.

[0114] The first offset is an offset obtained by registering the scanned image with the planned image.

[0115] In an optional implementation, the imaging computer device may determine the first offset by performing three-dimensional reconstruction on the scanned image of the target object acquired during the positioning phase to obtain a three-dimensional reconstructed image, and registering the three-dimensional reconstructed image with the planned image of the target object to obtain the first offset.

[0116] The first offset may include: a displacement offset (including displacement offsets on the X-axis, Y-axis, and Z-axis) and a rotation offset (including rotation offsets on the X-axis, Y-axis, and Z-axis). That is, the first offset may include: the position of the tumor of the target object in the planning image, and the displacement offset Δx and the rotation offset of the position of the tumor of the target object in the three-dimensional reconstructed image on the X-axis. The position of the tumor of the target object in the planning image, and the displacement offset Δz and the rotation offset of the position of the tumor of the target object in the three-dimensional reconstructed image on the Z-axis. The position of the tumor of the target object in the planning image, and the displacement offset Δy and the rotation offset of the position of the tumor of the target object in the three-dimensional reconstructed image on the Y-axis.

[0117] It should be noted that the distance between the position of the tumor of the target object in the scanned image of the target object and the imaging point when the scanned image of the target object is acquired, and the distance between the position of the tumor of the target object in the planned image and the imaging point marked by the medical staff are consistent. Therefore, the above-mentioned first offset, and the offset between the position of the imaging point when the imaging computer device acquires the scanned image of the target object in the positioning stage and the position of the imaging point marked by the medical staff in the planned image are the same.

[0118] For example, the first offset includes a displacement offset Δx on the X-axis and a displacement offset Δz on the Z-axis. Figure 3 , ellipse 302 represents the CBCT image, point C is the position of the imaging point when the scanned image of the target object is acquired in the positioning stage, and point D is the centroid of the tumor of the target object in the CBCT image. The imaging computer device can determine the position x1 of the tumor of the target object in the scanned image on the X axis by the following formula 2, and determine the position z1 of the tumor of the target object in the scanned image on the Z axis by the following formula 3.

[0119] x1=x0+Δx (Formula 2)

[0120] z1=z0+Δz (Formula 3)

[0121] After determining the position of the tumor of the target object in the scanned image in the above manner, for any angle, the imaging computer device determines the position of the tumor projected on the plane where the detector is located at the angle by the following formula 4.

[0122]

[0123] Among them, sid represents the distance between the light source and the detector, θ represents the angle, sad represents the distance between the light source and the imaging point, and (x1, z1) represents the position of the centroid of the tumor of the target object in the scanned image.

[0124] By repeating the above steps, the imaging computer device can obtain the position of the tumor projected on the plane where the detector is located at each angle. For each angle, the imaging computer device can compare the position of the tumor projected on the plane where the detector is located at the angle with the area where the detector is located. If the position of the tumor projected on the plane where the detector is located at the angle is within the area where the detector is located, the imaging computer device can determine the angle as the third projection angle.

[0125] After determining the first projection angle, the second projection angle and the third projection angle in the above manner, the image computer device may use the intersection of at least two projection angles among the first projection angle, the second projection angle and the third projection angle as a reference projection angle.

[0126] In an optional implementation, when the imaging mode is a semi-field imaging mode, the image computer device may use the intersection of the first projection angle and the third projection angle as a reference projection angle.

[0127] S404, determining a target respiratory signal corresponding to the time when the reference projection image is acquired from the respiratory signal.

[0128] Specifically, after determining the reference projection image, the image computer device may determine the time (hereinafter referred to as time A) at which the reference projection image is acquired. Thereafter, the image computer device may use the respiratory signal corresponding to time A as the target respiratory signal.

[0129] S405 , determining a tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the reference projection image, and the target breathing signal.

[0130] In an optional implementation, before executing S405, the imaging computer device may also obtain a first offset, and then determine the tumor motion model based on the first offset with reference to the following method a, method b, or method c.

[0131] Method a

[0132] The planned image adjusted based on the first offset is obtained. For each reference projection image, the imaging computer device can digitally reconstruct the adjusted planned image at the projection angle of the reference projection image to obtain the first DRR image, and align the reference projection image and the first DRR image to obtain the second offset corresponding to the reference projection image. Finally, the tumor motion model is determined based on the second offset corresponding to each reference projection image and the target respiratory signal.

[0133] The second offset refers to a relative offset between the position of the tumor in the reference projection image and the position of the tumor in the first DRR image.

[0134] Specifically, taking the reference projection image as KV image B as an example, assuming that the projection angle of acquiring KV image B is angle P, the first DRR image obtained by digitally reconstructing the planned image after adjustment of the target object at angle P is DRR image b.

[0135] After obtaining the DRR image b, the imaging computer device may register the DRR image b and the KV image B to obtain the position of the tumor of the target object in the KV image B. The imaging computer device may obtain the second offset corresponding to the KV image B by using the position of the tumor of the target object in the KV image B, the position of the tumor of the target object in the DRR image b, and the magnification ratio of the tumor when the KV image B is acquired.

[0136] For example, it is assumed that the position of the tumor of the target object in the KV image B is p cbct (P), the position of the tumor of the target object in the DRR image b is p drr (P), the magnification ratio of the tumor when acquiring KV image B is M(P) cbct The image computer device can use the following formula 5 to obtain the second offset D(P) corresponding to the KV image B.

[0137]

[0138] Among them, the magnification ratio of the tumor when acquiring KV image B is M(P) cbct It can be determined by the following formula 6.

[0139]

[0140] By repeating the above steps, the image computer device can obtain the second offset corresponding to each reference projection image.

[0141] The imaging computer device can generate a second motion trajectory of the tumor of the target object based on the second offset corresponding to each reference projection image and the time when each reference projection image is collected. The imaging computer device can use a motion model generation method to obtain a tumor motion model of the target object based on the second motion trajectory of the tumor of the target object and the target breathing signal.

[0142] In the embodiment of the present disclosure, the motion model generation method may be a polynomial fitting method, a linear regression method, or a neural network method (such as a multilayer perceptron), and the embodiment of the present disclosure does not specifically limit this.

[0143] The second motion trajectory of the tumor of the target object and the target breathing signal can be used to obtain the tumor motion model of the target object, and reference can be made to related technologies, which will not be repeated here.

[0144] Method b

[0145] For each reference projection image, the imaging computer device can digitally reconstruct the planned image of the target object at the projection angle of the reference projection image to obtain a DRR image (hereinafter referred to as the second DRR image), and align the reference projection image and the second DRR image to obtain a third offset corresponding to the reference projection image. The imaging computer device can use the first offset to adjust the third offset corresponding to each reference projection image, and determine the tumor motion model based on the adjusted third offset corresponding to each reference projection image and the target breathing signal.

[0146] The third offset refers to a relative offset between the position of the tumor in the reference projection image and the position of the tumor in the second DRR image.

[0147] Specifically, taking the reference projection image as KV image A as an example, assuming that the projection angle of acquiring KV image A is angle θ, the second DRR image obtained by digitally reconstructing the planned image of the target object at angle θ is DRR image a.

[0148] After the imaging computer device obtains the DRR image a, it can register the DRR image a and the KV image A to obtain the position of the tumor of the target object in the KV image A. The imaging computer device can use the position of the tumor of the target object in the KV image A and the magnification ratio of the tumor when the KV image A is acquired to determine the real position of the tumor in the target object in the KV image A. The imaging computer device can also use the position of the tumor of the target object in the DRR image a and the magnification ratio of the tumor when the planning image is scanned at the angle θ to determine the real position of the tumor in the target object in the DRR image a.

[0149] Afterwards, the image computer device can obtain the third offset corresponding to the KV image A based on the actual position of the tumor in the target object in the KV image A and the actual position of the tumor in the target object in the DRR image a. The image computer device can superimpose the offset in the head-foot direction (i.e., Y axis) of the first offset and the third offset corresponding to the KV image A to obtain the adjusted third offset corresponding to the KV image A.

[0150] For example, assuming that the position of the tumor of the target object in the KV image A is p cbct (θ), the position of the tumor of the target object in the DRR image a is p drr (θ), the magnification ratio of the tumor when acquiring KV image A is M(θ) cbct , the magnification ratio of the tumor when scanning the planning image at angle θ is M(θ) drr The image computer device can use the following formula 7 to obtain the third offset corresponding to the KV image A as D(θ).

[0151]

[0152] Among them, the magnification ratio of the tumor when acquiring KV image A is M(θ) cbct It can be determined by the above formula 6 that the magnification ratio of the tumor when scanning the planning image at angle θ is M(θ) drr It can be determined by the following formula eight.

[0153]

[0154] After the imaging computer device obtains the third offset corresponding to the KV image A as D(θ) through the above formula, the following formula nine can be used to implement the operation of superimposing the offset Δy in the head-foot direction (i.e., the Y axis) and the third offset corresponding to the KV image A to obtain the adjusted third offset D(θ)' corresponding to the KV image A.

[0155] D(θ)'=D(θ)+Δy (Formula 9)

[0156] By repeating the above steps, the imaging computer device can obtain the third offset corresponding to each adjusted reference projection image. The imaging computer device can determine the tumor motion model based on the third offset corresponding to each adjusted reference projection image and the target breathing signal. For details, please refer to the description in method a, which will not be repeated here.

[0157] Method c

[0158] The position of the tumor of the target object in each reference projection image is adjusted using the first offset, and the tumor motion model is determined based on the adjusted position of the tumor of the target object in each reference projection image and the target breathing signal.

[0159] Specifically, for each reference projection image, the imaging computer device can digitally reconstruct the planned image of the target object at the projection angle of the reference projection image to obtain a second DRR image corresponding to the reference projection image. The imaging computer device can register the second DRR image corresponding to the reference projection image with the reference projection image to obtain the position of the tumor of the target object in the reference projection image. The imaging computer device can use the first offset to adjust the position of the tumor of the target object in the reference projection image. Repeating the above steps, the imaging computer device can obtain each adjusted reference projection image.

[0160] The imaging computer device can determine the tumor motion model based on the position of the tumor of the target object in each adjusted reference projection image and the target breathing signal. For details, please refer to the description in method a, which will not be repeated here.

[0161] The following uses the half-field imaging mode as an example to introduce the method for determining the tumor motion model provided by the embodiment of the present disclosure. Figure 5 A flow chart of another method for determining a tumor motion model provided by an embodiment of the present disclosure is shown in FIG. Figure 5 As shown, the method includes the following S501-S512.

[0162] S501, acquiring a scan image of the target object in the positioning phase and a breathing signal of the target object.

[0163] S502, determining the position of the tumor of the target object and the distance between the imaging points in the planned image of the target object.

[0164] S503: When the distance between the position of the tumor of the target object and the imaging point in the planning image is less than or equal to a preset threshold, obtain a first offset.

[0165] S504: Acquire a planned image adjusted based on the first offset.

[0166] S505: Determine a first projection angle based on the adjusted planning image.

[0167] S506: Determine a third projection angle.

[0168] S507: Taking the intersection of the first projection angle and the third projection angle as a reference projection angle.

[0169] S508 , acquiring a reference projection image from the projection images at the reference projection angle in the scanned image according to a preset sampling interval.

[0170] S509 , determining a target respiratory signal corresponding to the time when the reference projection image is acquired from the respiratory signal.

[0171] S510 , for each reference projection image, digitally reconstruct the adjusted planned image at the projection angle for acquiring the reference projection image to obtain a first DRR image.

[0172] S511, registering the reference projection image and the first DRR to obtain a second offset corresponding to the reference projection image.

[0173] S512: Determine a tumor motion model based on the second offset corresponding to each reference projection image and the target respiratory signal.

[0174] Optionally, the above S504-S505 can be replaced by step a: determining a first projection angle based on the planning image. On this basis, the above S510-S512 can be replaced by the following steps b-d.

[0175] Step b: For each reference projection image, digitally reconstruct the planned image at the projection angle at which the reference projection image is acquired to obtain a second DRR image.

[0176] Step c: registering the reference projection image and the second DRR to obtain a third offset corresponding to the reference projection image.

[0177] Step d: Determine a tumor motion model based on the third offset corresponding to each reference projection image and the target breathing signal.

[0178] In an optional embodiment, after the tumor motion model is determined in the above manner, during the real-time monitoring stage of radiotherapy, the imaging computer device can determine the location of the tumor of the target object in real time based on the tumor motion model.

[0179] Specifically, Figure 6 As shown, after obtaining the tumor motion model, in the real-time monitoring stage of radiotherapy, the imaging computer device can obtain the respiratory state of the target object in real time through the respiratory detection device, and based on the respiratory state of the target object and the tumor motion model, determine in real time the offset between the position of the tumor of the target object and the position of the tumor in the DRR image (such as: the second DRR image or the first DRR image). The imaging computer device can superimpose the position of the tumor in the DRR image and the offset of the tumor of the target object determined in real time to obtain the position of the tumor of the target object, thereby realizing the prediction of the tumor position.

[0180] Afterwards, the imaging computer device can control the treatment beam to be emitted based on the determined location of the tumor of the target object through the control device, and reach the tumor of the target object after passing through the collimator (Multi Leaf Collimator, MLC), thereby achieving treatment of the tumor of the target object.

[0181] During radiotherapy, if the center of motion of the tumor of the target object is inconsistent with the center of the target area, the tumor may exceed the target area during the movement, resulting in the problem that the tumor beyond the target area cannot be treated. In order to avoid the above phenomenon, in an optional embodiment, the imaging computer device can determine the adjustment parameters for adjusting the position of the target object in the positioning stage before radiotherapy when the center of motion of the tumor of the target object is inconsistent with the center of the target area, and determine the tumor motion model corresponding to the adjusted position of the target object based on the adjustment parameters.

[0182] The target area is an area calibrated by medical workers based on the location of the tumor in the planned image of the target object.

[0183] Specifically, the imaging computer device may first determine whether the motion center of the tumor of the target object is consistent with the center of the target area by referring to the following method: obtaining the maximum value and the minimum value of the second motion trajectory of the tumor of the target object, and when the absolute value of the maximum value of the second motion trajectory and the absolute value of the minimum value of the second motion trajectory are the same, the imaging computer device may determine that the motion center of the tumor of the target object is consistent with the center of the target area. When the absolute value of the maximum value of the second motion trajectory and the absolute value of the minimum value of the second motion trajectory are different, the imaging computer device may determine that the motion center of the tumor of the target object is inconsistent with the center of the target area.

[0184] When the center of motion of the tumor of the target object is inconsistent with the center of the target area, the imaging computer device can determine the adjustment parameters using the following formula 10 based on the maximum and minimum values ​​of the second motion trajectory of the tumor of the target object, and send the adjustment parameters to the control device. The control device can control the movement of the support device based on the adjustment parameters to adjust the position of the target object.

[0185]

[0186] Among them, deltaCouch represents the adjustment parameter, V max represents the maximum value of the second motion trajectory, V min Indicates the minimum value of the second motion trajectory.

[0187] Accordingly, the above-mentioned imaging computer device may determine the tumor motion model corresponding to the adjusted position of the target object by referring to the following two methods.

[0188] Method 1: The imaging computer device adjusts the second motion trajectory of the tumor of the target object based on the adjustment parameters, and determines the tumor motion model corresponding to the adjusted position of the target object based on the adjusted second motion trajectory and the target breathing signal of the target object.

[0189] Specifically, assuming that the second motion trajectory of the tumor of the target object is trajectory K, the adjusted second motion trajectory is trajectory K ′ , the image computer device can use the following formula 11 to obtain the trajectory K ′ .

[0190] K ′ =K-deltaCouch (Formula 11)

[0191] Get the trajectory K ′ After that, the image computer device can be based on the trajectory K ′ and a target breathing signal of the target object to obtain a tumor motion model corresponding to the adjusted position of the target object.

[0192] Method 2: The imaging computer device adjusts the zero-order term (or constant term) in the polynomial of the tumor motion model of the target object determined above based on the adjustment parameters to obtain a tumor motion model corresponding to the adjusted position of the target object.

[0193] Specifically, assuming that the zero-order term in the tumor motion model is G, the adjusted zero-order term is G ′ , the image computer device can use the following formula 12 to obtain the adjusted zero-order term G ′ .

[0194] G ′=G-deltaCouch (Formula 12)

[0195] Get the zero-order term G ′ After that, the imaging computer device can be based on the zero-order term G ′ The zero-order term in the polynomial of the tumor motion model of the target object is replaced to obtain a tumor motion model corresponding to the adjusted position of the target object.

[0196] Figure 7 A schematic block diagram of an electronic device 700 that can be used to implement an example of an embodiment of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or claimed herein. In some embodiments, the electronic device can be the above-mentioned Figure 1 The image computer equipment shown in .

[0197] like Figure 7 As shown, the electronic device 700 includes a computing unit 701, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 702 or a computer program loaded from a storage unit 708 to a random access memory (RAM) 703. In RAM 703, various programs and data required for the operation of the electronic device 700 can also be stored. The computing unit 701, ROM 702 and RAM 703 are connected to each other via a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0198] Multiple components in the electronic device 700 are connected to the I / O interface 705, including: an input unit 706, such as a keyboard, a mouse, etc.; an output unit 707, such as various types of displays, speakers, etc.; a storage unit 708, such as a disk, an optical disk, etc.; and a communication unit 709, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 709 allows the electronic device 700 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0199] The computing unit 701 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 701 include, but are not limited to, a central processing unit, a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors, and any appropriate processors, controllers, microcontrollers, etc. The computing unit 701 performs the various methods and processes described above, such as a tumor motion model determination method. For example, in one embodiment, the tumor motion model determination method may be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 708. In one embodiment, part or all of the computer program may be loaded and / or installed on the electronic device 700 via the ROM 702 and / or the communication unit 709. When the computer program is loaded into the RAM 703 and executed by the computing unit 701, one or more steps of the tumor motion model determination method described above may be performed. Alternatively, in other embodiments, the computing unit 701 may be configured to execute the tumor motion model determination method in any other appropriate manner (eg, by means of firmware).

[0200] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays, application specific integrated circuits, application specific standard parts (ASSPs), system on chip systems (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0201] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0202] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. More specific examples of machine-readable storage media may include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories, read-only memories, erasable programmable read-only memories, optical fibers, portable compact disk read-only memories, optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0203] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user, such as a cathode ray tube (CRT) or a liquid crystal display (LCD) monitor; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and the input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0204] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0205] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0206] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of this disclosure can be achieved, and this document is not limited here.

[0207] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for determining a tumor motion model, characterized in that: The method comprises: Acquire a scanned image of the target object during the positioning phase, and a respiratory signal of the target object; A tumor motion model is determined based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the breathing signal; the tumor motion model is used to characterize the position change of the tumor of the target object during the breathing process of the target object.

2. The method according to claim 1, characterized in that The method further comprises: When the distance between the position of the tumor of the target object in the planning image and the imaging point is less than or equal to a preset threshold, the tumor motion model is determined based on the planning image, the position of the tumor of the target object in the scanned image, and the respiratory signal.

3. The method according to claim 1, characterized in that The scanned image includes a plurality of projection images; Before determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal, the method further includes: Determine a reference projection image from the scanned image; the reference projection image refers to an image of the tumor of the target object among the multiple projection images; Determining, from the respiratory signal, a target respiratory signal corresponding to the moment when the reference projection image is acquired; The step of determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal comprises: The tumor motion model is determined based on the planning image, the location of the tumor of the target object in the reference projection image, and the target breathing signal.

4. The method according to claim 3, characterized in that Determining a reference projection image from the scanned image comprises: The reference projection image is acquired from the projection image at the reference projection angle in the scanned image according to a preset sampling interval.

5. The method according to claim 4, characterized in that The reference projection angle is determined according to at least one of the first projection angle, the second projection angle and the third projection angle; The first projection angle refers to a projection angle range in which the path of the light beam emitted by the light source to the tumor of the target object does not include a preset tissue; The second projection angle refers to a projection angle range corresponding to a respiratory cycle in which the degree of fit between the movement trajectory of the tumor and the preset trajectory is the highest; The third projection angle refers to the available angle range of half-field imaging.

6. The method according to claim 5, characterized in that In the semi-field imaging mode, the reference projection angle is the intersection of the first projection angle and the third projection angle.

7. The method according to claim 5, characterized in that The second projection angle is determined by: determining a movement trajectory of the tumor based on a position of the tumor of the target object in each of the projection images contained in the scanned image; From the motion trajectory, determine the sub-motion trajectory with the highest degree of fit to the preset trajectory; The angle range of the projection image corresponding to the respiratory cycle of the sub-motion trajectory is used as the second projection angle.

8. The method according to claim 5, characterized in that The third projection angle is determined by: Determine the position of the tumor projection on the plane where the detector is located at different angles; For any angle, when the position of the tumor projection on the plane where the detector is located at the angle is located in the area where the detector is located, the angle is determined as the third projection angle.

9. The method according to claim 8, characterized in that For any angle, determining the position of the tumor projection on the plane where the detector is located includes: Based on the angle, the position of the tumor of the target object in the scanned image, the distance between the light source and the detector, and the distance between the light source and the imaging point, the position of the tumor projected on the plane where the detector is located is determined.

10. The method according to claim 5, characterized in that The first projection angle is determined by: A digital reconstruction projection algorithm is used to determine an angle of a path where the light beam emitted by the light source reaches the tumor of the target object in the planned image and does not contain a preset tissue as the first projection angle.

11. The method according to claim 10, characterized in that Before determining the angle at which the path of the light beam emitted by the light source reaching the tumor of the target object in the planning image does not contain a preset tissue as the first projection angle, the method further includes: Acquire a first offset; the first offset is an offset obtained based on the registration of the scanned image and the planned image; adjusting the planned image based on the first offset; The step of determining an angle where a path of the light beam emitted by the light source and the tumor of the target object in the planned image does not contain a preset tissue as the first projection angle comprises: An angle of a path where the light beam emitted by the light source reaches the tumor of the target object in the adjusted planning image and does not include a preset tissue is determined as the first projection angle.

12. The method according to claim 3, characterized in that The number of the reference projection images is multiple; The step of determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal comprises: Acquire a planned image adjusted based on a first offset; the first offset is an offset obtained based on registration of the scanned image and the planned image; For each of the reference projection images, digitally reconstruct the adjusted planned image at the projection angle of the reference projection image to obtain a first digitally reconstructed image DRR image, and register the reference projection image with the first DRR to obtain a second offset corresponding to the reference projection image; The tumor motion model is determined based on the second offset corresponding to each of the reference projection images and the target breathing signal.

13. The method according to claim 3, characterized in that The number of the reference projection images is multiple; The step of determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal comprises: For each of the reference projection images, digitally reconstruct the planned image at the projection angle of the reference projection image to obtain a second digitally reconstructed image DRR image, and register the reference projection image with the second DRR to obtain a third offset corresponding to the reference projection image; Acquire a first offset; the first offset is an offset obtained based on the registration of the scanned image and the planned image; Using the first offset to adjust a third offset corresponding to each of the reference projection images; The tumor motion model is determined based on the adjusted third offset corresponding to each of the reference projection images and the target respiratory signal.

14. The method according to claim 3, characterized in that The number of the reference projection images is multiple; The step of determining the tumor motion model based on the planned image of the target object, the position of the tumor of the target object in the scanned image, and the respiratory signal comprises: Acquire a first offset, where the first offset is an offset obtained based on registration of the scanned image and the planned image; Using the first offset to adjust the position of the tumor of the target object in each of the reference projection images; The tumor motion model is determined based on the adjusted position of the tumor of the target object in each of the reference projection images and the target breathing signal.

15. An electronic device, characterized in that: The electronic device comprises: processor; a memory configured to store instructions executable by the processor; The processor is configured to execute the instructions to implement the tumor motion model determination method as described in any one of claims 1-14.

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