Dynamic Tracking of Moving Targets

Abstract

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.

Description

Background technique In some medical applications, objects moving over time must be dynamically tracked. For example, in radiosurgery, it may be necessary to dynamically track tumors and / or lesions in a human body as it moves with breathing and / or heartbeat. In radiosurgery, the precise trajectory of the radiation beam through the patient anatomy to the lesion or tumor to be treated is critical in order to achieve the radiation dose distribution calculated during the treatment planning period. For areas of the human anatomy that move, for example due to breathing or heartbeat, it is important to take such movements into account and calculate their influence on the treatment plan to be produced. Motion tracking can also benefit other medical applications outside of radiosurgery, where parts of an anatomy move due to breathing, heartbeat, or any other type of motion. In the past, fiducial markers have been used to facilitate tracking of moving regions of anatomy. Baseline bas...

AI Technical Summary

Problems solved by technology

These methods do not account for the non-rigid motion and deformation of the surrounding anatomy as a function of the motion period

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