1. University of Texas M. D. Anderson Cancer Center, Houston
2. Mayo Clinic, Rochester, Minnesota
3. Mayo Clinic, Jacksonville, Florida
4. Alliance Statistics and Data Center, Mayo Clinic, Rochester, Minnesota
5. Penn State Hershey Medical Center, Hershey, Pennsylvania
6. Massachusetts General Hospital, Boston
7. Mercy Medical Center, Des Moines, Iowa
8. Levine Cancer Institute, Carolinas Healthcare System, Charlotte, North Carolina
9. Princess Margaret Cancer Centre, Toronto, Ontario, Canada
10. Centre Hospitalier de l’Université de Montréal, Montréal, Québec, Canada
11. Novant Health Forsyth Medical Center, Winston-Salem, North Carolina
12. Carolina Neurosurgery and Spine Associates, Charlotte, North Carolina