Motion Analysis and Modeling in Image-Guided Radiation Therapy

The knowledge of internal organ motion is required to ensure the precise delivery of radiation to cancer patients undergoing radiation therapy. We analyze sequences of x-ray images of patients acquired during the therapy session. While impact of small irregular motion, e.g. in the prostate, can be compensated by adding a radiation treatment safety margin around the target, larger motions, such as in the lung, should incorporate a motion model. As limited visualization of soft tissues in x-ray images represents significant challenge, we use preliminary knowledge of the system setup, apply image registration methods to analyze the motion and optimization techniques to reduce computational cost.