Abstract: A method of customized breathing maneuver guidance during radiotherapy treatment by configuring to a treatment couch an augmented reality system that includes a mounting assembly, a position measurement module to measure a distance from a fixed position to a patient anatomic region during a breathing cycle, and a breath monitoring and instruction screen viewable by the patient disposed proximal to the fixed position, where the patient monitors and controls a state of their breathing cycle in real time from breath state information displayed on the instruction screen, and determining the anatomic region for monitoring to measure the distance from the fixed position, determining a patient-customized breath hold amplitude by measuring a distance between a baseline exhale position a maximum inhale position, and entering breath hold amplitude data to a computer for subsequent breath hold guidance regardless of the treatment couch model setup and patient weight variations.

Abstract: A method of real-time markerless measurement and calibration of a patient positioning system includes computing a three dimensional point cloud representation of a patient by using a camera to obtain depth points of the patient, where the z-direction corresponds to a direction along the focal length of the camera, demanding a z-limit that corresponds to a lower (z-min) and an upper (z-max) specification, computing a point cloud covariance and a point cloud mean for an optimized principle components analysis to compute a torso topography of the patient, determining a center point of the point cloud as an anchor measurement region and using the camera to determine a distance to the patient to establish an angle between a patient torso and a vector that is perpendicular to the camera, averaging the depth measurements in reference regions and compensating for parallax error in real-time during a calibration measurement or radiotherapy treatment plan.

Abstract: A patient-guided surface stereoscopic imaging and biofeedback system is provided that includes a patient couch mounting system, an array of at least two imaging sensors, a viewing screen that displays images derived from the imaging sensors to a patient, where the imaging sensors, the viewing screen, and the controller are configured to output to a user 3D surface information of the patient under test, extrapolated 2D patient under test position information, and 1D patient under test position information, where the controller is configured to control the viewing screen to display the images from the imaging sensors, where the viewing screen further displays patient position boundary markers that are configured to overlay the displayed images on the viewing screen to provide biofeedback to a patient under test during radiotherapy treatment.

Abstract: A method of customized breathing maneuver guidance during radiotherapy treatment by configuring to a treatment couch an augmented reality system that includes a mounting assembly, a position measurement module to measure a distance from a fixed position to a patient anatomic region during a breathing cycle, and a breath monitoring and instruction screen viewable by the patient disposed proximal to the fixed position, where the patient monitors and controls a state of their breathing cycle in real time from breath state information displayed on the instruction screen, and determining the anatomic region for monitoring to measure the distance from the fixed position, determining a patient-customized breath hold amplitude by measuring a distance between a baseline exhale position a maximum inhale position, and entering breath hold amplitude data to a computer for subsequent breath hold guidance regardless of the treatment couch model setup and patient weight variations.

Abstract: A method of real-time markerless measurement and calibration of a patient positioning system includes computing a three dimensional point cloud representation of a patient by using a camera to obtain depth points of the patient, where the z-direction corresponds to a direction along the focal length of the camera, demanding a z-limit that corresponds to a lower (z-min) and an upper (z-max) specification, computing a point cloud covariance and a point cloud mean for an optimized principle components analysis to compute a torso topography of the patient, determining a center point of the point cloud as an anchor measurement region and using the camera to determine a distance to the patient to establish an angle between a patient torso and a vector that is perpendicular to the camera, averaging the depth measurements in reference regions and compensating for parallax error in real-time during a calibration measurement or radiotherapy treatment plan.

Abstract: A method of optimizing 4D cone beam computed tomography (4DCBCT) imaging is provided that includes using a scanner to generate projections of a target, where the projections are used to form a cone beam computed tomography (CBCT) scan of the target, where the CBCT includes a 3D image of the target, and using an appropriately programmed computer to control rotation speed of a gantry and projection acquisition of the CBCT in real-time according to a measured patient respiratory signal, where the real-time acquisition of the 4CBCT forms an optimized 4DCBCT image set.

Abstract: A method of real-time estimation of target rotation and translation for 6 degrees of freedom using a single planar 2-dimensional imager and an algorithm, such as the iterative closest point (ICP) algorithm, that includes creating pairing, using a nearest neighbor algorithm, between a set of target points of at least three fiducial markers and a set of source points of the markers using K nearest neighbors, iteratively executing estimation of a rotation parameter R and a translation parameter T of the markers using a cost function such as root mean square error, terminating the estimation of R and T if the change in a mean distance between the set of target points of the markers and the set of source points of the markers is below a threshold or at a maximum iteration number, transforming the set of target points of the markers using estimated parameters, and re-associating a new set of the target points of the markers.

Abstract: An inverse planning method that is capable of controlling the appearance of the implanted fiducial(s) in segmented IMRT fields for cine MV or combined MV/kV image-guided IMRT is provided. The method for radiation treatment includes computing a radiation treatment plan and delivering beams to a target in accordance with the radiation treatment plan, where computing the radiation treatment plan includes introducing a penalty in an inverse planning objective function optimization calculation to discourage or avoid blockage of one or more fiducials in optimized multi-leaf collimator (MLC) apertures.

Abstract: An inverse planning method that is capable of controlling the appearance of the implanted fiducial(s) in segmented IMRT fields for cine MV or combined MV/kV image-guided IMRT is provided. The method for radiation treatment includes computing a radiation treatment plan and delivering beams to a target in accordance with the radiation treatment plan, where computing the radiation treatment plan includes introducing a penalty in an inverse planning objective function optimization calculation to discourage or avoid blockage of one or more fiducials in optimized multi-leaf collimator (MLC) apertures.

Abstract: A method of configuring an electron gun for generating and injecting an electron beam into a linac accelerating waveguide operating in magnetic fringe fields of an MRI scanner in the absence of a magnetic shield is provided using an appropriately programmed computer to determining an anode drift tube diameter at an injection point of a linac according to a magnetic field value from an MRI scanner and to a predetermined current density, where the magnetic field has an isocenter, determining a transverse diameter of a Type M cathode in an electron gun, according to the anode drift tube diameter and the current density, and minimizing an emittance value in an electron beam of the electron gun at an entry point of the anode drift tube by optimizing the distance between the cathode and the anode, where the electron beam is along an axis of symmetry of the magnetic field.

Abstract: A method of multileaf collimator (MLC) leaf positioning in tracking-based adaptive radiotherapy is provided. The method includes determining a radiotherapy beam pattern by transforming a treatment beam plan into radiotherapy beam coordinates, determining a dose discrepancy between the radiotherapy beam pattern and a deliverable MLC aperture, where the dose discrepancy includes a sum of an overdose cost and an underdose cost to a treatment volume, and minimizing the dose discrepancy, where the dose discrepancy minimization provides a determined deliverable MLC aperture for the radiotherapy beam.

Abstract: A method and system are disclosed for estimating internal position information of a target in real-time based on a single gantry-mounted x-ray imager and a respiratory signal. The x-ray imaging is done periodically to limit radiation dosage. Initial parameters for the estimation model are determined in a pre-treatment session using four dimensional computed tomography (4D CT) in combination with a respiratory signal acquired from the patient. The model parameters are updated during treatment based on the periodic x-ray image data and the respiratory signal.

Abstract: A method of minimizing radiation toxicity in image guided radiotherapy (IGRT) is provided that includes using a probabilistic prediction algorithm that is operated on a suitably programmed computer and includes multimodality inputs and provides real-time geometric and topological target estimates to compensate for system latency, using an online adaptive imaging system that provides radiographic images of the target when the geometric and topological target estimates are in a region of predefined uncertainty, and using an image dose control algorithm, operating on a suitably programmed computer, that includes parameters for controlling dose per image, where instances for image acquisition are optimized according to a planned dose pattern and delivery result.

Abstract: A method of real-time estimation of target rotation and translation for 6 degrees of freedom using a single planar 2-dimensional imager and an algorithm, such as the iterative closest point (ICP) algorithm, that includes creating pairing, using a nearest neighbor algorithm, between a set of target points of at least three fiducial markers and a set of source points of the markers using K nearest neighbors, iteratively executing estimation of a rotation parameter R and a translation parameter T of the markers using a cost function such as root mean square error, terminating the estimation of R and T if the change in a mean distance between the set of target points of the markers and the set of source points of the markers is below a threshold or at a maximum iteration number, transforming the set of target points of the markers using estimated parameters, and re-associating a new set of the target points of the markers.

Abstract: A method of optimizing 4D cone beam computed tomography (4DCBCT) imaging is provided that includes using a scanner to generate projections of a target, where the projections are used to form a cone beam computed tomography (CBCT) scan of the target, where the CBCT includes a 3D image of the target, and using an appropriately programmed computer to control rotation speed of a gantry and projection acquisition of the CBCT in real-time according to a measured patient respiratory signal, where the real-time acquisition of the CBCT forms an optimized 4DCBCT image set.

Abstract: Motion artifacts and patient dose during 4D CT imaging are reduced by adaptive control of data acquisition. The respiration signal (310) and CT data acquisition (340) are linked, such that ‘bad’ data from erratic breathing cycles that cause artifacts is not acquired by pausing CT data acquisition (360) when erratic breathing is detected, and not resuming CT data acquisition until steady-state respiration is resumed. Training data is used to develop a tolerance envelope for a respiratory signal such that for erratic breathing cycles the respiratory signal is not within the tolerance envelope (330).

Abstract: A method of estimating target motion for image guided radiotherapy (IGRT) systems is provided. The method includes acquiring by a kV imaging system sequential images of a target motion, computing by the kV imaging system from the sequential images an image-based estimation of the target motion expressed in a patient coordinate system, transforming by the kV imaging system the image-based estimation in the patient coordinate system to an estimate in a projection coordinate system, reformulating by the kV imaging system the projection coordinate system in a converging iterative form to force a convergence of the projection coordinate system to output a resolved estimation of the target motion, and displaying by the kV imaging system the resolved estimation of the target motion.

Abstract: The present invention provides a method for estimation of retrospective and real-time 3D target position by a single imager. The invention includes imaging a target on at least one 2D plane to determine 2D position and/or position components of the target, and resolving a position and/or position component along at least one imager axis of the target using a spatial probability density. The present invention provides a probability-based method for accurate estimation of the mean position, motion magnitude, motion correlation, and trajectory of a tumor from CBCT projections. The applicability of the method for tumors with periodic respiratory motion and for prostate are provided. Clinical feasibility is demonstrated for a pancreas tumor. The method includes monoscopic tracking of the 3D prostate position utilizing the spatial probability density to estimate the unresolved motion from the resolved motion. The method is applicable to prostate tracking even with a population-based probability density.

Abstract: A deliverable four dimensional (4D) intensity modulated radiation therapy (IMRT) planning method is disclosed, for delivery using a linear accelerator with a dynamic multi-leaf collimator (DMLC). A 4D computed tomography (CT) scan is used for segmenting tumor anatomy on a reference phase of periodic motion of the tumor. Deformable registration of the 4D CT data is used to generate corresponding anatomical structures on other phases. Preferably, the collimator for each beam position is aligned using the gross tumor volume (GTV) centroid motion corresponding to the periodic motion of the tumor, as determined from the two dimensional (2D) projection of a given beam position. A deliverable IMRT plan is created on the 4D CT image set in which the MLC leaf positions and beam on/off status can vary as a function of respiratory phase by solving a four dimensional optimization problem. The mechanical constraints of the MLC leaves are included in the optimization.

Abstract: The present invention provides a radiotherapy treatment apparatus that includes a treatment beam, a magnetic field disposed parallel collinear to the treatment beam, and a target that is disposed along the treatment beam. The treatment beam can be a charged particle beam, a proton beam, an electron beam, or a linear accelerator (Linac) beam. The magnetic field is from a magnetic resonance imager (MRI), a megavolt x-ray imager, or a kilovolt x-ray imager and is disposed to operate in coordination with operation of the treatment beam and to narrow the beam. The tumor is disposed to rotate with respect to the treatment beam and the magnetic field, or the treatment beam and the magnetic field are disposed to rotate up to 360° with respect to the target when mounted to a ring gantry. The apparatus can include a rotation angle dependent shim disposed to account for Earth's magnetic field.