Abstract: A method for dose guidance for a radiotherapy system during a radiotherapy session includes the steps of: performing substantially real-time dose reconstruction to obtain a delivered radiation dose generated by a radiotherapy beam of the radiotherapy system in at least one volume; repeatedly estimating a remaining radiation dose based on an observed and/or simulated motion of the at least one volume; repeatedly estimating a final delivered radiation dose as a sum of the delivered radiation dose and the estimated remaining radiation dose; and providing dose guidance for a remaining part of the radiotherapy session based on the estimated final delivered radiation dose. A method of continuous estimation of final delivered radiation dose during a radiotherapy session and a decision support system for a radiotherapy system are also provided.

Abstract: The present disclosure relates to the field of radiotherapy, in particular, methods of and apparatus for treating cancer using ultra-high dose rate radiotherapy (FLASH). The apparatus may comprise a device configured to administer to the subject no more than five fractions of proton ultra-high dose rate radiotherapy (FLASH), said fractions having a range of radiation from 1.5 Gy to 60 Gy, collectively. The device may be configured such that the treatment is sufficient to prevent further growth of the tumor for at least 10% longer than standard of care radiotherapy, induce at least 10% more tumor regression than standard of care radiotherapy and/or delay tumor regrowth by at least about 2 months longer than standard of care radiotherapy.

Abstract: The present disclosure relates to a new scan technique for particle radiation therapy that may be used for cancer treatment. One embodiment relates to a method of mitigating interplay effect in particle radiation therapy in a moving target including a period of movement, where the particle radiation therapy defines a planned dose in each spot of each layer of the moving target. The method comprising dividing the planned dose in each spot into a number of spot repaintings; and generating a scan pattern for each layer by defining a beam-on time at each spot for each spot repainting, and calculating a wait time between consecutive beam-on times to distribute the spot repaintings for each spot of a respective layer are distributed over a duration of an integer number of periods of movement.

Abstract: The present disclosure relates to a new scan technique for particle radiation therapy that may be used for cancer treatment. One embodiment relates to a method of mitigating interplay effect in particle radiation therapy in a moving target including a period of movement, where the particle radiation therapy defines a planned dose in each spot of each layer of the moving target. The method comprising dividing the planned dose in each spot into a number of spot repaintings; and generating a scan pattern for each layer by defining a beam-on time at each spot for each spot repainting, and calculating a wait time between consecutive beam-on times to distribute the spot repaintings for each spot of a respective layer are distributed over a duration of an integer number of periods of movement.

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 determining a model of a marker includes obtaining projection images, each of the projection images having an image of a marker that indicates a shape of the marker, determining binary images of the marker for respective ones of the projection images, and constructing a three-dimensional model of the marker using the binary images, the three-dimensional model comprising a set of voxels in a three-dimensional space that collectively indicates a three-dimensional shape of the marker, wherein the act of constructing the three-dimensional model is performed using a processing unit.

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 determining a model of a marker includes obtaining projection images, each of the projection images having an image of a marker that indicates a shape of the marker, determining binary images of the marker for respective ones of the projection images, and constructing a three-dimensional model of the marker using the binary images, the three-dimensional model comprising a set of voxels in a three-dimensional space that collectively indicates a three-dimensional shape of the marker, wherein the act of constructing the three-dimensional model is performed using a processing unit.

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 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.