Gregory Gagnon,MD, is Associate Professor and Acting Chair in the Department of Radiation Medicine. He is an experienced radiation oncologist with a specialty in the radiation treatment of prostate cancers, having designed the original 3D-conformal radiation treatment protocol and the high dose rate temporary brachytherapy (HDR) protocol. He also has experience with IMRT and low dose rate permanent brachytherapy. He is CyberKnife Program Director for Georgetown University Hospital and is using this superior dose-delivery technology to treat prostate cancers.