Affiliation: | 1. Department of Radiation Oncology, University of Pennsylvania, Abramson Cancer Center, , Philadelphia, Pennsylvania;2. Department of Biostatistics, University of North Carolina, Lineberger Comprehensive Cancer Center, , Chapel Hill, North Carolina;3. Department of Human Oncology, University of Wisconsin, , Madison, Wisconsin;4. Radiation Oncology Associates, Pennsylvania, , Manchester, New Hampshire;5. Department of Radiation Oncology, University of North Carolina, Lineberger Comprehensive Cancer Center, , Chapel Hill, North Carolina |