1. From the Roswell Park Cancer Institute, Buffalo, NY; Beth Israel Cancer Center, New York, NY; Radiation Therapy Oncology Group, Philadelphia, PA; Massachusetts General Hospital; Francis H. Burr Proton Therapy Center, Boston, MA; Johns Hopkins Medical Center, Baltimore, MD; University of Michigan Medical Center, Ann Arbor, MI; H. Lee Moffitt Cancer Center, Tampa, FL; Dartmouth Hitchcock Medical Center, Lebanon, NH