Dynamic tracking of moving targets

摘要

Treatment targets such as tumors or lesions, located within an anatomical region that undergoes motion (which may be periodic with cycle P), are dynamically tracked. A 4D mathematical model is established for the non-rigid motion and deformation of the anatomical region, from a set of CT or other 3D images. The 4D mathematical model relates the 3D locations of part(s) of the anatomical region with the targets being tracked, as a function of the position in time within P. Using fiducial-less non-rigid image registration between pre-operative DRRs and intra-operative x-ray images, the absolute position of the target and/or other part(s) of the anatomical region is determined. The cycle P is determined using motion sensors such as surface markers. The radiation beams are delivered using: 1) the results of non-rigid image registration; 2) the 4D model; and 3) the position in time within P.

主权项

1. A method of dynamically tracking one or more targets within an anatomical region and delivering therapeutic radiation to the one or more targets, while the anatomical region undergoes a periodic motion characterized by a motion cycle P, the anatomical region comprising one or more internal anatomical reference structures, the method comprising:
monitoring, based on one or more surface markers configured for attachment to an external surface of the anatomical region, the periodic motion to measure the cycle P; generating near real time images of the one or more targets and the one or more internal anatomical reference structures within the moving anatomical region; determining, in real time, locations, within the moving anatomical region, of the one or more targets relative to the one or more internal anatomical reference structures based on a) registering the near real time images to one or more digitally reconstructed radiographs (DRRs) generated from pre-operative images in which the one or more internal anatomical reference structures were identified and b) applying an outcome of the registration to a 4D mathematical model that describes a non-rigid deformation of the anatomical region, as a function of time within the cycle P, and which describes a 3D motion of the one or more targets relative to the one or more internal anatomical reference structures as a function of the time within the cycle P; and delivering, based on the determined locations, the therapeutic radiation in real time to the one or more targets as the anatomical region undergoes the periodic motion.