1. Stanford University; Stanford California
2. NRG Oncology Statistics and Data Management Center; Philadelphia Pennsylvania
3. University of Wisconsin; Madison Wisconsin
4. Maimonides Cancer Center; Brooklyn New York
5. University of Michigan; Ann Arbor Michigan
6. The University of Texas MD Anderson Cancer Center; Houston Texas
7. Vanderbilt-Ingram Cancer Center; Nashville Tennessee
8. Marlene & Stewart Greenebaum Cancer Center; University of Maryland; Baltimore Maryland
9. University of Colorado Denver; Aurora Colorado
10. Academic Radiation Oncology; Wayne State University; Detroit Michigan
11. University of Alabama at Birmingham; Birmingham Alabama
12. University of Washington; Seattle Washington
13. H. Lee Moffitt Cancer Center; Tampa Florida
14. Mayo Clinic; Rochester Minnesota
15. Medical College of Wisconsin; Milwaukee Wisconsin
16. Washington University School of Medicine in St. Louis; St. Louis Missouri