1. Princess Margaret Cancer Centre, Toronto, Ontario, Canada
2. NRG Oncology Statistics and Data Management Center, Philadelphia, Pennsylvania
3. Johns Hopkins University School of Medicine, Baltimore, Maryland
4. Medical College of Wisconsin, Milwaukee
5. Cleveland Clinic Foundation, Cleveland, Ohio
6. Michigan Cancer Research Consortium CCOP, Ann Arbor
7. University of Maryland Medical System, Baltimore
8. University of Rochester, Rochester, New York
9. University of Colorado, Denver
10. University of Texas Southwestern Medical Center, Dallas