1. aDepartment of Radiation Oncology, Duke University, Durham, North Carolina;
2. bDepartment of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; and
3. cCooperative Studies Program Epidemiology Center-Durham, Durham Veterans Administration Medical Center,
4. dDivision of Medical Oncology, Department of Medicine, Duke University, and
5. eDivision of Hematology-Oncology, Medical Service, Durham Veterans Administration Medical Center, Durham, North Carolina.