Real-time markerless tumor tracking with MV imaging and a DMLC

Innovation/Impact: Robust real-time aperture adaptation for lung tumors during radiation therapy promises better local control while more healthy tissue can be spared. In this context we present the first implementation of a real-time adaptive therapy system using soft tissue localization (STiL) on continuously throughout the treatment acquired cine EPID images to maintain a dynamic treatment aperture centered on the current tumor location during the entire breathing cycle. This approach is superior to other proposed tumor localization methods that rely on implanted fiducial markers (pneumothorax risk), additional imaging dose, external surrogates that may be poorly correlated to the tumor location and/or non-optimal imaging perspectives [1].