1. University of British Columbia, Vancouver, British Columbia, Canada
2. University Medical Center Utrecht, Utrecht, Netherlands
3. Sunnybrook Odette Cancer Centre and University of Toronto, Toronto, Ontario, Canada
4. The University of Texas MD Anderson Cancer Center, Houston, TX, USA
5. Johns Hopkins University School of Medicine, Baltimore, MD, USA
6. Hospital of the University of Pennsylvania, Philadelphia, PA, USA
7. McGill University and Montreal General Hospital, Montreal, Quebec, Canada
8. University of Toronto and Toronto Western Hospital, Toronto, Ontario, Canada
9. National Center for Spinal Disorders and Buda Health Center, Budapest, Hungary
10. Mayo Clinic, Rochester, MN, USA
11. IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
12. The University of Kansas Hospital, Kansas City, Kansas, USA
13. The Warren Alpert Medical School of Brown University and Rhode Island Hospital and The Miriam Hospital, Providence, RI, USA