1. Department of Radiology, Duke University Medical Center, 2301 Erwin Rd, Durham, NC 27710.
2. Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, University Hospital of Palermo, Palermo, Italy.
3. University Paris Diderot, Sorbonne Paris Cité, Paris, France.
4. Istituti di Ricovero e Cura a Carattere Scientifico, Centro Neurolesi Bonino Pulejo, Messina, Italy.
5. Department of Radiation Oncology, Duke University Medical Center, Durham, NC.
6. Radiation Oncology Service, Durham VA Medical Center, Durham, NC.
7. Duke Cancer Institute-Biostatistics, Duke University Medical Center, Durham, NC.