Tumor position determination method and electronic equipment
By acquiring and matching the projected images and phase images before radiation therapy in radiation therapy, the problem of precise positioning of thoracic and abdominal tumors in radiation therapy is solved, and the accurate positioning of tumor locations except for 10 phase image locations is achieved, which improves the accuracy of treatment.
Patent Information
- Application Number
- CN202411814029.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-05-13
AI Technical Summary
In radiation therapy, the location of the thoracic and abdominal tumor is difficult to accurately locate due to changes caused by respiratory movement, especially when the tumor is located except for the locations of 10 phase images, it is difficult to accurately locate the prior art.
By acquiring the projected image of the target object at the target angle, determining the target phase image that is most similar to the projected image image feature from the target object, and registering the target phase image and the projected image based on the target initial position to obtain the location of the tumor.
It improves the accuracy of tumor positioning and can effectively locate the tumor location except for the corresponding positions of 10 phase images, solving the extrapolation problem.
Smart Images
Figure CN119991547A_ABST
Abstract
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 position 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, 10 phase images can be obtained through four-dimensional computed tomography (4DCT), and the projection images of the patient collected during the treatment phase are matched with the 10 phase images to obtain the location of the tumor. However, when the tumor is located at a position other than the 10 positions where the 10 phase images are located, the location of the tumor cannot be accurately located. Summary of the invention
[0004] The present disclosure provides a tumor position determination method and electronic device, which can effectively improve the accuracy of tumor positioning.
[0005] In a first aspect, the present disclosure provides a method for determining a tumor location, the method comprising:
[0006] A projection image of the target object is acquired at a target angle, and a target phase image that is most similar to the image features of the projection image is determined from the phase image of the target object, and a target initial position of the tumor of the target object corresponding to the target phase image is determined. Finally, based on the target initial position, the target phase image and the projection image are registered to obtain the position of the tumor of the target object.
[0007] The projection image is a projection image obtained by imaging the tumor of the target object. The phase image includes a two-dimensional image of the target object at a target angle in multiple respiratory phases.
[0008] In some embodiments, the above-mentioned registration of the target phase image and the projection image based on the target initial position to obtain the position of the tumor of the target object can specifically include: registering the target phase image and the projection image to obtain a registration result, and determining the position of the tumor of the target object based on the target initial position and the registration result.
[0009] In some embodiments, the above-mentioned registration of the target phase image and the projection image may specifically include: registering the target phase image and the projection image using deformation registration; or registering the target phase image and the projection image using template matching.
[0010] In some embodiments, the method may further include: digitally reconstructing three-dimensional images at multiple respiratory phases at a target angle to obtain digitally reconstructed radiograph (DRR) images at multiple respiratory phases, and using the DRR images at multiple respiratory phases as phase images.
[0011] In some embodiments, the three-dimensional images at multiple respiratory phases include CT images at multiple respiratory phases and / or Cone Beam Computed Tomography (CBCT) images at multiple respiratory phases.
[0012] In some embodiments, the tumor position determination method is applied in a setup phase before radiotherapy and / or a real-time monitoring phase during radiotherapy.
[0013] In some embodiments, when the tumor location determination method is applied to the real-time monitoring stage of radiotherapy, before the above-mentioned digital reconstruction of the three-dimensional images at multiple respiratory phases at the target angle, it can also include: determining the offset of the carrier device, and adjusting the three-dimensional images at multiple respiratory phases based on the offset of the carrier device. Accordingly, the above-mentioned digital reconstruction of the three-dimensional images at multiple respiratory phases at the target angle can include: digitally reconstructing the three-dimensional images at the adjusted multiple respiratory phases at the target angle.
[0014] The carrying device is used to carry the target object.
[0015] In some embodiments, the three-dimensional images at multiple respiratory phases are CT images at multiple respiratory phases. The above-mentioned determination of the offset of the carrying device may specifically include: determining a first reference image based on the CT images at multiple respiratory phases, and registering the first reference image with a CBCT image acquired during the positioning phase before radiotherapy to obtain the offset of the carrying device.
[0016] The CBCT image is a three-dimensional image obtained by three-dimensionally reconstructing projection images of the target object acquired at different angles during the positioning stage.
[0017] In some embodiments, the three-dimensional images at multiple respiratory phases are CBCT images at multiple respiratory phases. On this basis, the method may further include: performing three-dimensional reconstruction on the projection images of the target object at the same respiratory phase in the projection images obtained by imaging the tumor of the target object at different angles to obtain CBCT images of the target object at multiple respiratory phases.
[0018] In some embodiments, the three-dimensional images under multiple respiratory phases are CBCT images under multiple respiratory phases. The above-mentioned determination of the offset of the carrying device may specifically include: determining a first reference image based on the CT images under multiple respiratory phases, determining a second reference image based on the CBCT images under multiple respiratory phases, and registering the first reference image and the second reference image to obtain the offset of the carrying device.
[0019] In some embodiments, the three-dimensional images at multiple respiratory phases are CBCT images at multiple respiratory phases. The above method may also include: for the CBCT image and the CT image at the same respiratory phase, based on the position of the tumor of the target object in the CT image, aligning the CBCT image and the CT image to obtain the position of the tumor of the target object in the CBCT image.
[0020] The position of the tumor of the target object in any CBCT image is consistent with the initial position of the tumor of the target object in the phase image corresponding to the CBCT image.
[0021] In some embodiments, the initial position of the target object's tumor in multiple respiratory phases can be represented by a tumor motion trajectory curve.
[0022] In some embodiments, the projection image is any one of a plurality of projection images acquired during a positioning phase before radiotherapy. On this basis, the method may further include: obtaining a tumor motion model based on a position of a tumor of the target object in each of the plurality of projection images and a breathing signal of the target object.
[0023] 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.
[0024] In some embodiments, the above method may further include: determining the position of the tumor of the target object in real time based on the tumor motion model.
[0025] In a second aspect, the present disclosure further provides a tumor location determination device, the device comprising:
[0026] The acquisition unit is used to acquire a projection image of the target object at a target angle. The projection image is a projection image obtained by imaging the tumor of the target object.
[0027] The determination unit is used to determine the target phase image that is most similar to the image features of the projection image from the phase image of the target object, and determine the target initial position of the tumor of the target object corresponding to the target phase image. The phase image includes a two-dimensional image of the target object at a target angle in multiple respiratory phases.
[0028] The registration unit is used to register the target phase image and the projection image based on the target initial position to obtain the position of the tumor of the target object.
[0029] 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 location determination methods in the first aspect above.
[0030] The tumor position determination method provided by the present disclosure can, after determining the target phase image that is most similar to the image features of the projection image, further align the target phase image and the projection image based on the target initial position of the tumor of the target object corresponding to the target phase image to obtain the position of the tumor of the target object. Compared with the related art in which the position of the tumor of the target object in the target phase image that is most similar to the image features of the projection image is directly used as the position of the tumor of the target object in the projection image, the accuracy of tumor positioning can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.
[0032] Figure 1 A schematic diagram of a radiotherapy system provided in an embodiment of the present disclosure;
[0033] Figure 2 A schematic diagram of a flow chart of a method for determining a tumor location provided in an embodiment of the present disclosure;
[0034] Figure 3 A schematic diagram of a flow chart of another method for determining a tumor location provided in an embodiment of the present disclosure;
[0035] Figure 4 A schematic diagram of a flow chart of another method for determining a tumor location provided in an embodiment of the present disclosure;
[0036] Figure 5 A schematic diagram of a flow chart of another method for determining a tumor location provided in an embodiment of the present disclosure;
[0037] Figure 6 A schematic diagram of a movement trajectory and a breathing trajectory of a tumor provided in an embodiment of the present disclosure;
[0038] Figure 7 A schematic diagram of a flow chart of another method for determining a tumor location provided in an embodiment of the present disclosure;
[0039] Figure 8 A schematic block diagram of an electronic device provided in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] At present, 10 phase images can be generated through the binning process of 4DCT (binning is mainly used to divide the respiratory cycle into different phase intervals), corresponding to 10 discrete positions of the tumor. The projection image of the patient collected during the treatment phase is matched with the 10 phase images to obtain the position of the tumor. However, this method has the problem of underestimating tumor movement, that is, the 10 phase images cannot contain all the positions of the tumor during movement. For example, when the tumor is located at a position other than the 10 positions corresponding to the 10 phase images, the position of the tumor cannot be accurately located, that is, there is an extrapolation problem.
[0046] Based on the above technical problems, the embodiment of the present disclosure provides a method for determining the position of a tumor, which obtains a projection image of a target object at a target angle, determines a target phase image that is most similar to the image features of the projection image from the phase image of the target object, and determines the target initial position of the tumor of the target object corresponding to the target phase image, and finally aligns the target phase image and the projection image based on the target initial position to obtain the position of the tumor of the target object. The projection image is a projection image obtained by imaging the tumor of the target object. The phase image includes images of the target object at multiple respiratory phases.
[0047] Through the above technical solution, after determining the target phase image with the image features most similar to the projection image, the target initial position of the tumor of the target object corresponding to the target phase image can be further aligned with the target phase image to obtain the position of the tumor of the target object. Compared with the related art of directly using the position of the tumor of the target object in the target phase image with the image features most similar to the projection image as the position of the tumor of the target object in the projection image, the accuracy of tumor positioning can be effectively improved.
[0048] 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.
[0049] The image-guided radiotherapy device 101 may include a frame 1011, and an image-guided device and a carrying device 1012 disposed on the frame 1011. The image-guided device includes a light source 1013 and a detector 1014. The carrying device 1012 is used to support and move the target object, and the carrying device 1012 may be a treatment bed. The light source 1013 is used to emit a light beam, and the detector 1014 is used to receive the light beam passing through the target object (patient) to generate a projection image of the target object.
[0050] In the embodiment of the present disclosure, the detector 1014 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 1014.
[0051] 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.
[0052] When the image guidance device is a CBCT device, the light source 1013 is an X-ray tube, and the detector 1014 is a flat panel detector.
[0053] In the embodiment of the present disclosure, there is no limitation on the number of light sources 1013 and the number of detectors 1014. For example, the number of light sources 1013 may be one or more. Similarly, the number of detectors 1014 may be one or more. When the number of light sources 1013 and the number of detectors 1014 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 can be generated at a certain rack angle (or time point).
[0054] In some embodiments, when the number of light sources 1013 and the number of detectors 1014 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).
[0055] In some embodiments, when the number of light sources 1013 and the number of detectors 1014 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 direction of the X-axis 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.
[0056] 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 1013 and the detector 1014 will 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.
[0057] The breathing detection device is used to detect the breathing signal of the target object.
[0058] In the embodiment of the present disclosure, the breathing detection device may include an optical camera 1041 and at least one optical marker 1042 disposed 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.
[0059] The imaging computer device 102 is respectively connected to the control device 103, the detector 1014 and the breathing detection device (such as Figure 1 The optical camera 1041) is communicatively connected, and the control device 103 and the image-guided radiotherapy equipment 101 are communicatively connected.
[0060] 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: acquiring a projection image of the target object at a target angle, determining a target phase image that is most similar to the image features of the projection image from the phase image of the target object, and determining the target initial position of the tumor of the target object corresponding to the target phase image, and finally, based on the target initial position, aligning the target phase image and the projection image to obtain the position of the tumor of the target object. Among them, the projection image is a projection image obtained by imaging the tumor of the target object. The phase image includes a two-dimensional image of the target object at multiple respiratory phases at the target angle.
[0061] 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.
[0062] 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.
[0063] 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 method for determining the tumor position provided by an embodiment of the present disclosure is described. Figure 2 A schematic diagram of a method for determining a tumor location provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the method includes the following S201-S203.
[0064] S201, acquiring a projection image of a target object at a target angle.
[0065] The projection image is a projection image obtained by imaging the tumor of the target object.
[0066] In the embodiment of the present disclosure, the number of target angles is related to the number of light sources and detectors. For example, when the number of light sources and detectors is 1, the number of target angles is 1, and when the number of light sources and detectors is 2, the number of target angles is 2. The embodiment of the present disclosure does not specifically limit the number of target angles.
[0067] Specifically, after the light beam emitted by the light source at any one or more angles (hereinafter referred to as target angles) passes through the target object and reaches the detector, the detector can obtain the projection image of the target object at the target angle. Afterwards, the detector can send the projection image of the target object at the target angle to the image computer device. In this way, the image computer device can obtain the projection image of the target object at the target angle.
[0068] S202 , determining a target phase image having the most similar image features to the projection image from the phase image of the target object, and determining a target initial position of a tumor of the target object corresponding to the target phase image.
[0069] The phase image includes a two-dimensional image of the target object at a target angle in multiple respiratory phases.
[0070] In the embodiment of the present disclosure, the number of breathing phases is not limited. For example, it may include 10 breathing phases or 8 breathing phases.
[0071] Specifically, the imaging computer device may pre-store phase images of the target object at multiple respiratory phases and the position of the target object's tumor in each phase image. On this basis, the imaging computer device may first obtain the phase images of the target object at multiple respiratory phases, and then use a preset similarity measurement algorithm to perform a similarity comparison on the image features of the projection image of the target object at the target angle and the phase image of the target object at each respiratory phase, respectively, to obtain a target phase image that is most similar to the image features of the projection image of the target object at the target angle. Afterwards, the position of the target object's tumor in the target phase image of the imaging computer device is used as the target initial position of the target object's tumor.
[0072] In the embodiment of the present disclosure, during the similarity comparison process, the similarity measurement algorithm may be a normalized cross correlation (NCC) algorithm or a normalized mutual information (NMI) algorithm, etc., and the embodiment of the present disclosure does not specifically limit this.
[0073] The specific implementation process of comparing the image features of the projection image of the target object at the target angle and the phase image of the target object at each respiratory phase can be referred to the relevant technology, which will not be repeated here.
[0074] In an optional embodiment, the imaging computer device can obtain the phase images of the target object at multiple respiratory phases by referring to the following method: digitally reconstruct the three-dimensional images at multiple respiratory phases at the target angle to obtain DRR images at multiple respiratory phases, and use the DRR images at multiple respiratory phases as the phase images of the target object at multiple respiratory phases.
[0075] The three-dimensional images in multiple respiratory phases may be CT images in multiple respiratory phases, or may be CBCT images in multiple respiratory phases.
[0076] It should be noted that, in the embodiment of the present disclosure, CT images under multiple respiratory phases may also be referred to as 4DCT images, and CBCT images under multiple respiratory phases may also be referred to as 4DCBCT images.
[0077] Specifically, the imaging computer device may store three-dimensional images of the target object at multiple respiratory phases. For each three-dimensional image at a respiratory phase, the imaging computer device may digitally reconstruct the three-dimensional image at the respiratory phase to obtain a DRR image at the respiratory phase, i.e., a phase image at the respiratory phase. By repeating the above steps, the imaging computer device may obtain a phase image of the target object at each respiratory phase.
[0078] In an optional embodiment, the initial position of the tumor of the target object at multiple respiratory phases can be represented by a tumor motion trajectory curve. In this way, the imaging computer device can not only determine the position of the tumor of the target object in the phase image at each respiratory phase based on the tumor motion trajectory curve, but also obtain the position of the tumor of the target object at the phase between any two adjacent phases, so that the position of the tumor of the target object other than the position corresponding to the phase image can be obtained.
[0079] S203, based on the target initial position, register the target phase image and the projection image to obtain the position of the tumor of the target object.
[0080] When the number of target angles is 1, the number of projection images of the target object acquired at the target angle is 1. At this time, the position of the tumor of the target object is obtained as a two-dimensional position.
[0081] When the number of target angles is multiple, the number of projection images of the target object acquired at the target angles is multiple, and in this case, the position of the tumor of the target object is obtained as an N-dimensional position (N is greater than 2). For example, when the target angle includes two angles (such as 0 degrees and 90 degrees), there are two projection images of the target object acquired at the target angles, and in this case, the position of the tumor of the target object is obtained as a three-dimensional spatial position.
[0082] In the disclosed embodiment, the manner in which the image computer device registers the target phase image and the projection image is not limited. For example, the image computer device may register the target phase image and the projection image using deformation registration. For another example, the image computer device may register the target phase image and the projection image using template matching.
[0083] In an optional embodiment, the process in which an imaging computer device registers a target phase image and a projection image to obtain the position of a tumor of a target object may specifically include: based on a target initial position of the tumor of the target object, registering the target phase image and the projection image to obtain a registration result, and then obtaining the position of the tumor of the target object based on the registration result and the target initial position of the tumor of the target object.
[0084] Specifically, the imaging computer device registers the target phase image and the projection image, and after obtaining the registration result, the registration result and the target initial position of the tumor of the target object can be superimposed to obtain the position of the tumor of the target object.
[0085] In the above technical solution, after determining the target phase image (i.e., DRR) that is most similar to the image features of the projection image, the position of the tumor of the target object in the projection image is closer to the position of the tumor of the target object in the most similar DRR. At this time, the projection image and the most similar DRR are registered (deformation registration or template matching), and the position of the tumor of the target object in the projection image can be obtained, that is, the position of the tumor of the target object in the projection image is equal to the target initial position of the tumor of the target object plus the registration result. This method can effectively improve the accuracy of tumor positioning. Compared with the related art that directly uses the position of the tumor of the target object in the target phase image that is most similar to the image features of the projection image as the position of the tumor of the target object in the projection image, the position of the tumor of the target object in the projection image determined by this method is not limited to the corresponding 10 positions in the 10 phase images generated by the binning process of 4DCT. In this way, the position of the tumor of the target object determined by the tumor position determination method provided by the embodiment of the present disclosure is more continuous, and the position outside the corresponding 10 phase images of 4DCT can be obtained.
[0086] It can be understood that the tumor position determination method provided by the embodiments of the present disclosure can be used in the positioning stage before radiotherapy and / or the real-time monitoring stage during radiotherapy. The following takes the first and second examples of the tumor position determination method used in the real-time monitoring stage during radiotherapy and the second example of the tumor position determination method used in the positioning stage before radiotherapy as examples. Figure 2 The method for determining the tumor position shown is further described.
[0087] 1. Tumor location determination methods are used in the real-time monitoring stage of radiotherapy.
[0088] When the tumor position determination method provided in the embodiment of the present disclosure is used in the real-time monitoring stage of radiotherapy, the projection image of the target object acquired at the target angle in the above S201 refers to the projection image acquired in the real-time monitoring stage of radiotherapy.
[0089] It should be noted that when the tumor position determination method provided by the embodiment of the present disclosure is used in the real-time monitoring stage of radiotherapy, the tumor position determination method provided by the embodiment of the present disclosure can be used to locate the tumor in the positioning stage before radiotherapy, or other methods can be used to locate the tumor.
[0090] On this basis, in some embodiments, the three-dimensional image of the target object at multiple respiratory phases may be a CT image of the target object at multiple respiratory phases (also referred to as a planning image, a 4DCT image). Accordingly, the phase image of the target object includes a DRR image corresponding to the CT image of the target object at multiple respiratory phases at the target angle. At this time, the CT image of the target object at multiple respiratory phases may be a 4DCT image obtained by performing 4D tomographic imaging on the tumor of the target object when formulating a treatment plan for the target object.
[0091] In other embodiments, the three-dimensional image of the target object under multiple respiratory phases may be a CBCT image (4D C BCT image) of the target object under multiple respiratory phases. Accordingly, the phase image of the target object may be a DRR image corresponding to the CBCT image of the target object under multiple respiratory phases at the target angle. At this time, the CBCT image of the target object under multiple respiratory phases may be a projection image (or KV image, which is a two-dimensional image) obtained by imaging the tumor of the target object during the positioning stage before radiotherapy, and a 4D C BCT image obtained by three-dimensionally reconstructing the projection image under the same respiratory phase. It may also be a 4D C BCT image obtained by three-dimensionally reconstructing the projection image under the same respiratory phase in the projection image obtained by imaging the tumor of the target object after the positioning stage is completed.
[0092] In the following, the three-dimensional images of the target object at multiple respiratory phases are taken as the CT images of the target object at multiple respiratory phases and the three-dimensional images of the target object at multiple respiratory phases are taken as the CBCT images of the target object at multiple respiratory phases. Figure 2 The method for determining the tumor location is introduced as shown.
[0093] Figure 3 This is a flow chart for further introducing another method for determining the tumor position provided by an embodiment of the present disclosure, taking the three-dimensional image of the target object at multiple respiratory phases as the CT image of the target object at multiple respiratory phases, i.e., the 4DCT image, and the ordinary CBCT image obtained by scanning in the setup stage before radiotherapy as an example. Figure 3 As shown, the method includes the following S301-S310.
[0094] S301, determining a first reference image based on CT images in multiple respiratory phases.
[0095] The first reference image is an average intensity projection (Average Intensity Projection, AIP) image, which is a three-dimensional image.
[0096] Specifically, the image computer device may store CT images of the target object at multiple respiratory phases. On this basis, after the image computer device obtains the CT images of the target object at multiple respiratory phases, it may average the CT images of the target object at multiple respiratory phases to obtain AIP images corresponding to the CT images at multiple respiratory phases, i.e., the first reference image.
[0097] The averaging process of the CT images of the target object in multiple respiratory phases can refer to the process of averaging multiple images in the related art, which will not be repeated here.
[0098] S302: Register the first reference image with the CBCT image acquired in the setup phase before radiotherapy to obtain an offset amount of the supporting device (also referred to as a bed shift amount).
[0099] The CBCT image is a three-dimensional image obtained by three-dimensionally reconstructing the projection images of the target object acquired at different angles during the setup phase before radiotherapy. The carrying device (such as a treatment bed) is used to carry the target object.
[0100] In the positioning stage before radiotherapy, the imaging computer device can receive the projection images of the target object at different angles sent by the detector of the CBCT device. The imaging computer device can perform three-dimensional reconstruction on the projection images of the target object at different angles to obtain the CBCT image. Afterwards, the imaging computer device can register the first reference image and the CBCT image to obtain the offset of the carrier device, and the offset of the carrier device is at least a three-dimensional offset.
[0101] S303: Adjust the CT images in multiple respiratory phases based on the offset of the carrier.
[0102] Specifically, for each CT image at a respiratory phase, the image computer device can use the offset of the carrier device to adjust the position of the tumor of the target object in the CT image at the respiratory phase to obtain the adjusted CT image at the respiratory phase. Repeating the above process, the image computer device can obtain multiple adjusted CT images at respiratory phases.
[0103] S304, in the real-time monitoring stage of radiotherapy, a projection image of the target object is acquired at a target angle.
[0104] The specific execution process of S304 can refer to the description in S201 above, which will not be repeated here.
[0105] S305 , digitally reconstructing the adjusted CT images in the multiple respiratory phases at the target angle to obtain DRR images in the multiple respiratory phases.
[0106] S306, using the DRR images in multiple respiratory phases as phase images of the target object.
[0107] S307, determining, from the phase image of the target object, a target phase image having image features most similar to those of the projection image.
[0108] S308, determining a target initial position of a tumor of the target object corresponding to the target phase image.
[0109] S309, based on the initial position of the target, register the target phase image and the projection image to obtain a registration result.
[0110] S310, determining the position of the tumor of the target object based on the target initial position and the registration result.
[0111] The above process of S306-S310 can refer to the above Figure 2 The description in will not be repeated here.
[0112] Figure 4This is a flow chart for further introducing another method for determining the tumor position provided by an embodiment of the present disclosure, taking the three-dimensional image of the target object at multiple respiratory phases as the CBCT image of the target object at multiple respiratory phases, i.e., 4DCBCT image, and the CBCT image of the target object at multiple respiratory phases is obtained at the positioning stage before radiotherapy as an example. Figure 4 As shown, the method includes the following S401-S413.
[0113] S401, in the projection images obtained by imaging the tumor of the target object at different angles during the positioning stage before radiotherapy, three-dimensionally reconstruct the projection images of the target object at the same respiratory phase to obtain CBCT images of the target object at multiple respiratory phases.
[0114] Specifically, during the positioning stage before radiotherapy, the imaging computer device can receive the projection images of the target object at different angles and the time of collecting each projection image sent by the detector of the CBCT device. The imaging computer device can determine the projection image at each respiratory phase based on the time of collecting each projection image and the time corresponding to each respiratory phase. For the projection image at each respiratory phase, the imaging computer device can perform three-dimensional reconstruction of the projection image at the respiratory phase to obtain the CBCT image of the target object at the respiratory phase. Repeating the above steps, the imaging computer device can obtain the CBCT images of the target object at multiple respiratory phases.
[0115] S402 , for the CBCT image and the CT image in the same respiratory phase, based on the position of the tumor of the target object in the CT image, register the CBCT image and the CT image to obtain the position of the tumor of the target object in the CBCT image.
[0116] The position of the tumor of the target object in any CBCT image is consistent with the initial position of the tumor of the target object in the phase image corresponding to the CBCT image. That is, the position of the tumor of the target object in the CBCT image at each respiratory phase is the initial position of the tumor of the target object in the DRR image (i.e., the phase image) obtained after digital reconstruction of the CBCT image.
[0117] The position of the tumor of the target object in the CBCT image at each respiratory phase refers to: the distance of the tumor of the target object in the CBCT image relative to the image center (Image Center), that is, the three-dimensional spatial coordinates of the tumor of the target object in the CBCT image.
[0118] Specifically, for a CBCT image and a CT image in the same respiratory phase, the imaging computer device can register the CBCT image in the respiratory phase with the CT image in the respiratory phase based on the position of the tumor of the target object in the CT image in the respiratory phase to obtain the position of the tumor of the target object in the CBCT image.
[0119] S403: Determine a first reference image based on the CT images in multiple respiratory phases.
[0120] The specific execution process of S403 may refer to the description in S301 above, which will not be repeated here.
[0121] S404: Determine a second reference image based on the CBCT images in multiple respiratory phases.
[0122] Specifically, after the imaging computer device obtains the CBCT images of the target object at multiple respiratory phases through the above S401, it can average the CBCT images of the target object at multiple respiratory phases to obtain AIP images corresponding to the CBCT images at multiple respiratory phases, that is, the second reference image.
[0123] S405: align the first reference image and the second reference image to obtain an offset of the carrying device.
[0124] S406: Adjust the CBCT images in multiple respiratory phases based on the offset of the carrier.
[0125] The specific execution process may refer to the above S303 and will not be described in detail here.
[0126] S407, in the real-time monitoring stage of radiotherapy, a projection image of the target object is acquired at a target angle.
[0127] The specific execution process of S407 can refer to the description in S201 above, which will not be repeated here.
[0128] S408 , digitally reconstructing the adjusted CBCT images in the multiple respiratory phases at the target angle to obtain DRR images in the multiple respiratory phases.
[0129] S409, using the DRR images in multiple respiratory phases as phase images of the target object.
[0130] S410, determining, from the phase image of the target object, a target phase image having image features most similar to those of the projection image.
[0131] S411, determining a target initial position of a tumor of a target object corresponding to a target phase image.
[0132] S412, based on the initial position of the target, register the target phase image and the projection image to obtain a registration result.
[0133] S413, determining the position of the tumor of the target object based on the target initial position and the registration result.
[0134] The specific implementation of S408-S413 can refer to the above Figure 2 The description in will not be repeated here.
[0135] In the above technical solution, 4DCBCT in the positioning phase is used instead of 4DCT as the three-dimensional image of the target object, and digital reconstruction is performed based on 4DCBCT to obtain the phase image of the target object in multiple respiratory phases. In this way, the phase image of the target object in multiple respiratory phases can be closer to the physical state of the target object during radiotherapy, thereby further improving the accuracy of tumor positioning.
[0136] In addition, it should be noted that: when the three-dimensional image of the target object at multiple respiratory phases is the CBCT image of the target object at multiple respiratory phases, and the CBCT image of the target object at multiple respiratory phases is obtained after the positioning stage is completed, there is no need to use the offset of the carrying device to adjust the CBCT images at multiple respiratory phases, that is, there is no need to execute the above S405 and S406. Accordingly, the above S407 can be replaced by: at the target angle, digitally reconstructing the CBCT images at multiple respiratory phases to obtain DRR images at multiple respiratory phases.
[0137] 2. The tumor location determination method is used in the positioning stage before radiotherapy.
[0138] When the tumor position determination method provided in the embodiment of the present disclosure is used in the setup stage before radiotherapy, acquiring the projection image of the target object at the target angle in S201 refers to the projection image at any angle acquired in the setup stage before radiotherapy.
[0139] It can be understood that the projection images at various angles obtained in the positioning stage can be projection images at different angles scanned when the CBCT device acquires CBCT images, or can be projection images at different angles and different respiratory phases scanned when the CBCT device and the respiratory detection device acquire 4DCBCT images.
[0140] It should be noted that, when the tumor position determination method provided in the embodiment of the present disclosure is used in the positioning stage before radiotherapy, the tumor position can be monitored by the tumor position determination method provided in the embodiment of the present disclosure during the real-time monitoring stage of radiotherapy, or other methods can be used to monitor the tumor position.
[0141] On this basis, in some embodiments, the three-dimensional image of the target object at multiple respiratory phases can be a CT image of the target object at multiple respiratory phases, that is, a 4DCT image. Accordingly, the phase image of the target object includes a DRR image corresponding to the CT image of the target object at multiple respiratory phases at the target angle.
[0142] In other embodiments, the three-dimensional image of the target object at multiple respiratory phases may be a CBCT image of the target object at multiple respiratory phases, i.e., a 4D CBCT image. Accordingly, the phase image of the target object may be a DRR image corresponding to the CBCT image of the target object at multiple respiratory phases at a target angle.
[0143] In the following, the three-dimensional images of the target object at multiple respiratory phases are taken as the CT images of the target object at multiple respiratory phases, and the three-dimensional images of the target object at multiple respiratory phases are taken as the CBCT images of the target object at multiple respiratory phases. Figure 2 The method for determining the tumor location is introduced as shown.
[0144] Figure 5 This is a flowchart for further introducing another method for determining the location of a tumor provided by an embodiment of the present disclosure, taking the three-dimensional image of the target object at multiple respiratory phases as the CT image of the target object at multiple respiratory phases, and the projection images at different angles obtained by scanning when the CBCT device acquires the CBCT image in the positioning stage before radiotherapy as an example. Figure 5 As shown, the method includes the following S501-S509.
[0145] S501, in the positioning stage before radiotherapy, a projection image of the target object is acquired at a target angle.
[0146] The target angle is any angle.
[0147] S502 , digitally reconstructing the CT images at multiple respiratory phases at a target angle to obtain DRR images at multiple respiratory phases.
[0148] S503: Using the DRR images in multiple respiratory phases as phase images of the target object.
[0149] S504, determining, from the phase image of the target object, a target phase image having image features most similar to those of the projection image.
[0150] S505 , determining a target initial position of a tumor of the target object corresponding to the target phase image.
[0151] S506: Based on the initial position of the target, the target phase image and the projection image are registered (such as deformation registration) to obtain a registration result.
[0152] S507, determining the position of the tumor of the target object in the projection image based on the target initial position and the registration result.
[0153] The specific execution process of S501-S507 can refer to the above Figure 2 The description in will not be repeated here.
[0154] S508, repeatedly executing S501-S507 until the position of the tumor of the target object in the projection images at all angles is obtained.
[0155] S509 , obtaining a tumor motion model based on the position of the tumor of the target object in each projection image and the breathing signal of the target object.
[0156] 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.
[0157] Specifically, after the imaging computer device determines the position of the tumor of the target object in each projection image, it can generate a motion trajectory of the tumor of the target object (including the motion trajectory of the tumor of the target object on the X axis, the motion trajectory of the tumor of the target object on the Y axis, and the motion trajectory of the tumor of the target object on the Z axis) based on the position of the tumor of the target object in each projection image and the time when each projection image is collected. And the expression form of each motion trajectory is as follows Figure 6 The sine function shown in (a) in FIG. 1 is a sine function, the horizontal axis represents time, and the vertical axis represents the position of the tumor of the target object (on the X-axis, Y-axis or Z-axis). The imaging computer device can also determine the breathing trajectory of the target object based on the breathing signal and acquisition frequency of the target object. And the breathing trajectory is expressed as follows Figure 6 In the sine function shown in (b), the horizontal axis represents time and the vertical axis represents the breathing state of the target object.
[0158] Afterwards, the imaging computer device can determine a first reference image based on CT images under multiple respiratory phases, and determine the bed shift amount based on the position of the target object's tumor in the first reference image and the position of the target object's tumor in the CBCT image acquired during the setup phase before radiotherapy. The imaging computer device can use the bed shift amount to adjust the motion trajectory of the target object's tumor, and use a motion model generation method to obtain a tumor motion model of the target object (including a tumor motion model of the target object's tumor on the X-axis, a tumor motion model on the Y-axis, and a tumor motion model on the Z-axis) based on the adjusted motion trajectory of the target object's tumor and the target object's respiratory trajectory, and the tumor motion model is used to characterize the mapping relationship between the target object's respiratory state and the position of the target object's tumor.
[0159] 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.
[0160] Specifically, the process of obtaining the tumor motion model of the target object based on the motion trajectory of the tumor of the target object and the breathing trajectory of the target object can refer to the relevant technology and will not be repeated here.
[0161] In an optional embodiment, after the tumor motion model is determined in the above manner, the imaging computer device can determine the location of the tumor of the target object in real time based on the tumor motion model.
[0162] Specifically, after obtaining the tumor motion model, during the real-time monitoring stage of radiotherapy, the imaging computer device can obtain the target object's respiratory state in real time through the respiratory detection device, and determine the position of the target object's tumor in real time based on the target object's respiratory state and the tumor motion model, thereby realizing the prediction of the tumor position. Afterwards, the imaging computer device can control the treatment beam to be emitted through the control device based on the determined position of the target object's tumor, and reach the target object's tumor after passing through the collimator (Multi Leaf Collimator, MLC), thereby realizing the treatment of the target object's tumor.
[0163] Figure 7 This is a flow chart for further introducing another method for determining the tumor position provided by an embodiment of the present disclosure, taking the three-dimensional image of the target object at multiple respiratory phases as the CBCT image of the target object at multiple respiratory phases, and the CBCT image of the target object at multiple respiratory phases is obtained at the positioning stage before radiotherapy as an example. Figure 7 As shown, the method includes the following S701-S712.
[0164] S701, in the positioning stage before radiotherapy, imaging the tumor of the target object at different angles to obtain projection images of the target object at multiple respiratory phases.
[0165] S702 , performing three-dimensional reconstruction on the projection image of the target object in the same respiratory phase to obtain CBCT images of the target object in multiple respiratory phases.
[0166] S703 , for the CBCT image and the CT image in the same respiratory phase, based on the position of the tumor of the target object in the CT image, register the CBCT image and the CT image to obtain the position of the tumor of the target object in the CBCT image.
[0167] The specific execution process of S701-S703 can refer to the description in the above S401-S402, which will not be repeated here.
[0168] S704, acquiring a projection image of the target object at a target angle from the projection images of the target object at multiple respiratory phases.
[0169] The target angle is any angle.
[0170] S705 , digitally reconstructing the CBCT images at multiple respiratory phases at the target angle to obtain DRR images at multiple respiratory phases.
[0171] S706: Use the DRR images in multiple respiratory phases as phase images of the target object.
[0172] S707, determining, from the phase image of the target object, a target phase image having image features most similar to those of the projection image.
[0173] S708 , determining a target initial position of a tumor of the target object corresponding to the target phase image.
[0174] S709: Based on the initial position of the target, the target phase image and the projection image are registered (such as deformation registration) to obtain a registration result.
[0175] S710, determining a position of a tumor of the target object in the projection image based on the target initial position and the registration result.
[0176] The specific execution process of S705-S710 can refer to the above Figure 2 The description in will not be repeated here.
[0177] S711, repeatedly executing S704-S710 until the position of the tumor of the target object in the projection images at all angles is obtained.
[0178] S712: Obtain a tumor motion model based on the position of the tumor of the target object in each projection image and the breathing signal of the target object.
[0179] The specific execution process of S712 can refer to the description in S509 above, which will not be repeated here.
[0180] Figure 8 A schematic block diagram of an example electronic device 800 that can be used to implement 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 may 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 may be the above-mentioned Figure 1 The image computer equipment shown in .
[0181] like Figure 8 As shown, the electronic device 800 includes a computing unit 801, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory 802 or a computer program loaded from a storage unit 808 to a random access memory 803. In the random access memory (RAM) 803, various programs and data required for the operation of the electronic device 800 can also be stored. The computing unit 801, the read-only memory (ROM) 802 and the RAM 803 are connected to each other via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.
[0182] Multiple components in the electronic device 800 are connected to the input / output interface 805, including: an input unit 806, such as a keyboard, a mouse, etc.; an output unit 807, such as various types of displays, speakers, etc.; a storage unit 808, such as a disk, an optical disk, etc.; and a communication unit 809, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 809 allows the electronic device 800 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.
[0183] The computing unit 801 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 801 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 801 performs the various methods and processes described above, such as a tumor location determination method. For example, in one embodiment, the tumor location determination method may be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 808. In one embodiment, part or all of the computer program may be loaded and / or installed on the electronic device 800 via the ROM 802 and / or the communication unit 809. When the computer program is loaded into the RAM 803 and executed by the computing unit 801, one or more steps of the tumor location determination method described above may be performed. Alternatively, in other embodiments, the computing unit 801 may be configured to perform the tumor location determination method in any other appropriate manner (e.g., by means of firmware).
[0184] 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.
[0185] 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.
[0186] 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.
[0187] 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).
[0188] 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.
[0189] 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.
[0190] 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.
[0191] 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 location, characterized in that: The method comprises: Acquire a projection image of a target object at a target angle; the projection image is a projection image obtained by imaging a tumor of the target object; Determine, from the phase image of the target object, a target phase image that is most similar to the image features of the projection image, and determine a target initial position of the tumor of the target object corresponding to the target phase image; wherein the phase image includes a two-dimensional image of the target object at the target angle in multiple respiratory phases; Based on the target initial position, the target phase image and the projection image are registered to obtain the position of the tumor of the target object.
2. The method according to claim 1, characterized in that: The registering the target phase image and the projection image based on the target initial position to obtain the position of the tumor of the target object includes: Registering the target phase image and the projection image to obtain a registration result; The position of the tumor of the target object is determined based on the target initial position and the registration result.
3. The method according to claim 1, characterized in that The registering the target phase image and the projection image comprises: Using deformation registration to register the target phase image and the projection image; or, Template matching is used to align the target phase image and the projection image.
4. The method according to claim 1, characterized in that: The method further comprises: Digitally reconstructing the three-dimensional images at the target angle under the multiple respiratory phases to obtain digitally reconstructed DRR images at the multiple respiratory phases; The DRR images in the multiple respiratory phases are used as the phase images.
5. The method according to claim 4, characterized in that The three-dimensional images at the multiple respiratory phases include computed tomography (CT) images at the multiple respiratory phases and / or cone-beam computed tomography (CBCT) images at the multiple respiratory phases.
6. The method according to claim 1, characterized in that The tumor position determination method is applied to the positioning stage before radiotherapy and / or the real-time monitoring stage during radiotherapy.
7. The method according to claim 5, characterized in that When the tumor position determination method is applied to the real-time monitoring stage in radiotherapy, before digitally reconstructing the three-dimensional images under the multiple respiratory phases at the target angle, the method further includes: Determining an offset of a carrying device; the carrying device is used to carry the target object; Adjusting the three-dimensional images in the multiple respiratory phases based on the offset of the carrier device; The digitally reconstructing the three-dimensional images at the target angle under the multiple respiratory phases comprises: At the target angle, the adjusted three-dimensional images at the multiple respiratory phases are digitally reconstructed.
8. The method according to claim 7, characterized in that The three-dimensional images under the multiple respiratory phases are CT images under the multiple respiratory phases; The determining the offset of the load-bearing device comprises: Determining a first reference image based on the CT images in the multiple respiratory phases; The first reference image and the CBCT image acquired during the setup phase before radiotherapy are registered to obtain the offset of the carrying device; wherein the CBCT image is a three-dimensional image obtained by three-dimensionally reconstructing the projection image of the target object acquired at different angles during the setup phase.
9. The method according to claim 5, characterized in that The three-dimensional images under the multiple respiratory phases are CBCT images under the multiple respiratory phases; the method further includes: Among the projection images obtained by imaging the tumor of the target object at different angles, the projection images of the target object at the same respiratory phase are three-dimensionally reconstructed to obtain CBCT images of the target object at the multiple respiratory phases.
10. The method according to claim 7, characterized in that The three-dimensional images under the multiple respiratory phases are CBCT images under the multiple respiratory phases; The determining the offset of the load-bearing device comprises: Determining a first reference image based on the CT images in the multiple respiratory phases; Determining a second reference image based on the CBCT images in the multiple respiratory phases; The first reference image and the second reference image are registered to obtain an offset of the carrying device.
11. The method according to claim 5, characterized in that The three-dimensional images under the multiple respiratory phases are CBCT images under the multiple respiratory phases; the method further includes: For a CBCT image and a CT image in the same respiratory phase, based on the position of the tumor of the target object in the CT image, register the CBCT image and the CT image to obtain the position of the tumor of the target object in the CBCT image; Wherein, the position of the tumor of the target object in any of the CBCT images is consistent with the initial position of the tumor of the target object in the phase image corresponding to the CBCT image.
12. The method according to claim 1, characterized in that The initial position of the tumor of the target object in the multiple respiratory phases is represented by a tumor motion trajectory curve.
13. The method according to claim 1, characterized in that The projection image is any one of a plurality of projection images acquired during the setup phase before radiotherapy; The method further comprises: A tumor motion model is obtained based on the position of the tumor of the target object in each of the multiple projection images and the breathing signal of the target object; 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.
14. The method according to claim 13, characterized in that The method further comprises: Based on the tumor motion model, the position of the tumor of the target object is determined in real time.
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 location determination method according to any one of claims 1-14.