1. Radiation Oncology; McGill University Health Centre; Montreal Quebec Canada
2. Radiation Therapy Oncology Group Statistical Center; Philadelphia Pennsylvania
3. Department of Radiation Oncology; University of California-San Francisco Helen Diller Comprehensive Cancer Center; San Francisco California
4. Department of Radiation Oncology; Massachusetts General Hospital; Boston Massachusetts
5. Radiation Oncology; Medical College of Wisconsin; Madison Wisconsin
6. Radiation Oncology; Hospital of the University of Pennsylvania; Philadelphia Pennsylvania
7. Radiation Oncology; Akron City Hospital; Akron Ohio
8. Radiation Oncology; Samuel Oschin Comprehensive Cancer Institute; Cedars-Sinai Medical Center; Los Angeles California