Q Zhao1,3 *, H Wu2 , M Wolanski1 D Hecksel1,3 , D Pack1 , I Das1,4 , (1) Midwest Proton Radiotherapy Institute, Bloomington, IN, (2) IUPUI, Indianapolis, IN, (3) Purdue University, West Lafayette, IN, (4) Indiana University- School of Medicine, Indianapolis, IN