%0 Journal Article %T Protection Strategy of Sensitive Body Organs in Radiation Therapy %A Ramin M. Abolfath %A Lech Papiez %J Physics %D 2009 %I arXiv %X In this paper, we investigate protection strategies of sensitive body anatomy against the irradiation to the cancerous moving tumors in intensity modulated radiation therapy. Inspired by optimization techniques developed in statistical physics and dynamical systems, we deploy a method based on variational principles and formulate an efficient genetic algorithm which enable us to search for global minima in a complex landscape of irradiation dose delivered to the radiosensitive organs at risk. We take advantage of the internal motion of body anatomy during radiation therapy to reduce the unintentional delivery of the radiation to sensitive organs. We show that the accurate optimization of the control parameters, compare to the conventional IMRT and widely used delivery based on static anatomy assumption, leads to a significant reduction of the dose delivered to the organs at risk. %U http://arxiv.org/abs/0907.4943v1