1. Department of Orthopedics; University Medical Center Utrecht; Utrecht The Netherlands
2. Department of Radiation Oncology, Sunnybrook Odette Cancer Centre; University of Toronto; Toronto Ontario Canada
3. Division of Surgery, Department of Neurosurgery; The University of Texas MD Anderson Cancer Center; Houston Texas
4. Department of Neurosurgery; Johns Hopkins University School of Medicine; Baltimore Maryland
5. Department of Neurosurgery; Hospital of the University of Pennsylvania; Philadelphia Pennsylvania
6. Division of Surgery, Montreal General Hospital; McGill University; Montreal Quebec Canada
7. National Center for Spinal Disorders and Buda Health Center; Budapest Hungary
8. GSpine4 Spine Surgery Division; IRCCS Galeazzi Orthopedic Institute; Milan Italy
9. Division of Orthopedic Surgery, Toronto Western Hospital; University of Toronto; Toronto Ontario Canada
10. Department of Neurosurgery; Mayo Clinic; Rochester Minnesota
11. Department of Neurosurgery; The University of Kansas Hospital; Kansas City Kansas
12. Department of Neurosurgery; The Warren Alpert Medical School of Brown University and Rhode Island Hospital, The Miriam Hospital; Providence Rhode Island
13. Division of Spine, Department of Orthopaedics, Vancouver General Hospital; University of British Columbia; Vancouver British Columbia Canada