Abstract: A method for adaptive treatment planning is provided. The method may include obtaining a planning image volume of a subject, a treatment image volume of the subject, and a first treatment plan related to the planning image volume of the subject, each of the planning image volume and the treatment image volume including an ROI of the subject. The method may also include registering the planning image volume and the treatment image volume, and determining a first contour of the ROI in the registered planning image volume and a second contour of the ROI in the registered treatment image volume. The method may also include evaluating whether an error exists in at least one of the registration or the contour determination based on the first contour and the second contour, and determining a second treatment plan with respect to the treatment image volume based on the evaluation result.

Abstract: The disclosure provides a system for EGRT. The system may include a radiotherapy device for treating a subject. The radiotherapy device may include a scintillation camera that is directed at an ROI of the subject. The subject may be injected with a radioactive tracer or implanted with a radioactive marker before treatment. The ROI may undergo a physiological motion during the treatment. The system may deliver a treatment session to the subject by the radiotherapy device. During the treatment session, the system may acquire a target image of the ROI indicative of a distribution of the radioactive tracer or the radioactive maker in the ROI by the scintillation camera, and adapt a radiation beam to be delivered to the subject with respect to the physiological motion of the ROI by adjusting the radiation beam based on the target image.

Abstract: The present disclosure provides a system and method for dose measurement in radiation therapy. The method may include obtaining a beam model and a detector model related to a radiation device, and a reference image and a treatment plan related to the subject, and determining a synthetic image based on the beam model, the detector model, and the reference image. The method may also include obtaining a treatment image by performing at least a portion of the treatment plan including delivering at least a radiation beam toward the subject using the radiation device, and determining one or more scaling factors. The method may further include determining a synthetic estimate of the treatment image based on the synthetic image and the one or more scaling factors. The method may further include estimating radiation dose deposition based on the treatment image and the synthetic estimate of the treatment image.

Abstract: The present disclosure is related to systems and methods for isocenter calibration. The method includes providing a phantom including a first member and a second member with a fixed position relationship. The method includes acquiring, using a first device, at least one first image of the first member of the phantom. The method includes determining, based on the at least one first image, a first position relationship between a first isocenter of the first device and the first member. The method includes acquiring, using a second device, at least one second image of the second member of the phantom. The method includes determining, based on the at least one second image and the fixed position relationship, a second position relationship between a second isocenter of the second device and the first member. The method includes determining, based on the first position relationship and the second position relationship, a third position relationship between the first isocenter and the second isocenter.

Abstract: A system for limited view imaging is provided. The system may obtain a reference image of an object. The system may identify, from the reference image, one or more critical boundaries between a target organ of the object and one or more adjacent organs of the target organ. The system may determine an imaging angle range of the object based on the one or more critical boundaries. The system may further cause an imaging device to scan the object based on the imaging angle range, the object being in a breath-hold state during the scan.

Abstract: A system includes determination of a first sub-matrix of a projection matrix which describes a geometrical relationship between points of a three-dimensional coordinate system of the imaging system and points of a two-dimensional coordinate system of an image detector, determination of a second sub-matrix of the projection matrix, where the first and second sub-matrixes comprise a decomposition of the projection matrix, conversion of a first point of the two-dimensional coordinate system to a first point of the three-dimensional coordinate system based on the first and second sub-matrixes, determination of an updated first sub-matrix of an updated projection matrix, where the updated projection matrix describes a second geometrical relationship between points of the three-dimensional coordinate system and points of the two-dimensional coordinate system, and conversion of a second point of the two-dimensional coordinate system to a second point of the three-dimensional coordinate system based on the updated fi

Abstract: A system and method for adapting treatment plan are provided. The method may include: obtaining a planning image of a region of interest relating to a first treatment fraction of a first treatment plan; obtaining a first image of the region of interest relating to a first scan of the region of interest with a first dose level; comparing the planning image with the first image to generate a first comparison result; determining whether the first comparison result satisfies a first replanning condition; causing, in response to a determination that the first comparison result satisfies the first replanning condition, one or more scanners to perform a second scan with a second dose level to provide a second image; and generating a second treatment plan according to the second image, wherein the second dose level is higher than the first dose level.

Abstract: The present disclosure provides a method for imaging of moving subjects. The method may include determining a motion range of a region of interest (ROI) of a subject in an axial direction. The method may also include causing a radiation source to emit, at each of a plurality of axial positions relative to the subject, radiation beams to the ROI to generate an image frame of the ROI. The radiation beams corresponding to the plurality of axial positions may jointly cover the motion range of the ROI in the axial direction. The method may further include determining a position of the ROI in the axial direction based on the image frames of the ROI, and determining, based on the positions of the ROI in the axial directions, at least one time bin in which therapeutic beams are to be emitted to the ROI.

Abstract: The present disclosure provides a system and method for medical imaging. The method may include obtaining a treatment plan, a planning image, and one or more treatment images of the subject, wherein the one or more treatment images are generated by performing at least a portion of the treatment plan including delivering at least a radiation beam towards the subject using a radiation device. The method also includes determining primary images of the subject based on the one or more treatment images, and determining inversely-attenuated primary images of the subject by inversely attenuating the primary images to a plane located between the subject and a collimator assembly of the radiation device. The method may further include estimating machine parameters of the radiation device corresponding to the inversely-attenuated primary images.

Abstract: A system and method for adapting treatment plan are provided. The method may include: obtaining a planning image of a region of interest relating to a first treatment fraction of a first treatment plan; obtaining a first image of the region of interest relating to a first scan of the region of interest with a first dose level; comparing the planning image with the first image to generate a first comparison result; determining whether the first comparison result satisfies a first replanning condition; causing, in response to a determination that the first comparison result satisfies the first replanning condition, one or more scanners to perform a second scan with a second dose level to provide a second image; and generating a second treatment plan according to the second image, wherein the second dose level is higher than the first dose level.

Abstract: A radiation system may include a treatment assembly including a first radiation source, a second radiation source, and a first radiation detector. The first radiation source may be configured to deliver a treatment beam covering a treatment region of the radiation system, and the treatment region may be located in a bore of the radiation system. The second radiation source may be configured to deliver a first imaging beam covering a first imaging region of the radiation system, and may be mounted rotatably on a first side of the treatment assembly. The first radiation detector may be configured to detect at least a portion of the first imaging beam, and may be mounted rotatably on a second side of the treatment assembly. The treatment assembly, the second radiation source, and the first radiation detector may be positioned such that the treatment region is addressable for the radiation system.

Abstract: A target assembly for generating radiation may comprise a target, a substrate and a window. The target may be capable of generating first radiation when impinged by a beam. The window may be at least partially permeable to the beam. The window and the substrate may form at least part of a hermetically sealed chamber and the target may be positioned in the chamber. The chamber may be filled with air having a normal or reduced content of oxygen.

Abstract: A method for adaptive treatment planning is provided. The method may include obtaining a planning image volume of a subject, a treatment image volume of the subject, and a first treatment plan related to the planning image volume of the subject, each of the planning image volume and the treatment image volume including an ROI of the subject. The method may also include registering the planning image volume and the treatment image volume, and determining a first contour of the ROI in the registered planning image volume and a second contour of the ROI in the registered treatment image volume. The method may also include evaluating whether an error exists in at least one of the registration or the contour determination based on the first contour and the second contour, and determining a second treatment plan with respect to the treatment image volume based on the evaluation result.

Abstract: A system, medium, and method including obtaining a plurality of positions for multiple components defined by a plan; obtaining a set of constraints that express limitations for the multiple components at the plurality of positions, the constraints being applicable to a plan where the multiple components synchronously change their positions with time to traverse a prescribed sequence of the plurality of positions, at least one of the multiple components being further constrained to change its position over time by staying within a predefined tolerance to a predefined smooth function of position over time between different positions; determining a trajectory of position and a minimum duration in which the multiple components completely synchronously traverse the prescribed sequence of positions while satisfying the constraints for the multiple components; and generating a record of the determined trajectory of position and the minimum duration for the plurality of components.

Abstract: The present disclosure is related to systems and methods for isocenter calibration. The method includes providing a phantom including a first member and a second member with a fixed position relationship. The method includes acquiring, using a first device, at least one first image of the first member of the phantom. The method includes determining, based on the at least one first image, a first position relationship between a first isocenter of the first device and the first member. The method includes acquiring, using a second device, at least one second image of the second member of the phantom. The method includes determining, based on the at least one second image and the fixed position relationship, a second position relationship between a second isocenter of the second device and the first member. The method includes determining, based on the first position relationship and the second position relationship, a third position relationship between the first isocenter and the second isocenter.

Abstract: A system for limited view imaging is provided. The system may obtain a reference image of an object. The system may identify, from the reference image, one or more critical boundaries between a target organ of the object and one or more adjacent organs of the target organ. The system may determine an imaging angle range of the object based on the one or more critical boundaries. The system may further cause an imaging device to scan the object based on the imaging angle range, the object being in a breath-hold state during the scan.

Abstract: The present disclosure provides a method for imaging of moving subjects. The method may include determining a motion range of a region of interest (ROI) of a subject in an axial direction. The method may also include causing a radiation source to emit, at each of a plurality of axial positions relative to the subject, radiation beams to the ROI to generate an image frame of the ROI. The radiation beams corresponding to the plurality of axial positions may jointly cover the motion range of the ROI in the axial direction. The method may further include determining a position of the ROI in the axial direction based on the image frames of the ROI, and determining, based on the positions of the ROI in the axial directions, at least one time bin in which therapeutic beams are to be emitted to the ROI.

Abstract: A system, medium, and method including obtaining a plurality of positions for multiple components defined by a plan; obtaining a set of constraints that express limitations for the multiple components at the plurality of positions, the constraints being applicable to a plan where the multiple components synchronously change their positions with time to traverse a prescribed sequence of the plurality of positions, at least one of the multiple components being further constrained to change its position over time by staying within a predefined tolerance to a predefined smooth function of position over time between different positions; determining a trajectory of position and a minimum duration in which the multiple components completely synchronously traverse the prescribed sequence of positions while satisfying the constraints for the multiple components; and generating a record of the determined trajectory of position and the minimum duration for the plurality of components.

Abstract: A radiation system is provided. The radiation system may include a bore accommodating an object, a rotary ring, a first radiation source and a second radiation source mounted on the rotary ring and a processor. The first radiation source may be configured to emit a first cone beam toward a first region of the object. The second radiation source may be configured to emit a second beam toward a second region of the object, the second region including at least a part of the first region. The processor may be configured to obtain a treatment plan of the object, the treatment plan including parameters associated with radiation segments. The processor may be further configured to control an emission of the first cone beam and/or the second beam based on the parameters associated with the radiation segments to perform a treatment and a 3-D imaging simultaneously.

Abstract: Systems and methods for four-dimensional CT scan are provided. The methods may include determining a first region of a subject and a second region. A movement of the subject may occur within the second region. The methods may further include generating a first image set by performing, based on a first operation parameter corresponding to a first scan, the first scan on the first region of the subject, and generating a second image set by performing, based on a second operation parameter corresponding to a second scan, the second scan on a second region of the subject. The methods may further include obtaining movement information corresponding to the movement of the subject and determining a final image set based on the first image set, the movement information, and the second image set.