David Horowitz, M.D. is a board-certified radiation oncologist and Associate Professor of Radiation Oncology at New York-Presbyterian/Columbia University Irving Medical Center. His clinical focus is on gastrointestinal cancers, lymphoma and breast cancer, and his research interests focus on the development of novel ways to deliver precision radiation therapy to hard-to-treat cancers. Dr. Horowitz received his B.A. from Dartmouth College and his M.D. from the Johns Hopkins University School of Medicine, during which time he completed a research fellowship in the Department of Radiation Oncology and Molecular Radiation Sciences. He completed his internal medicine internship training at the Georgetown University/Washington Hospital Center after which he completed his radiation oncology training at New York Presbyterian Hospital (Columbia University Medical Center Campus), where he additionally served as Chief Resident. Dr.