1. Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA;
2. Department of Neurosurgery, University of Miami, Miami, Florida, USA;
3. Department of Neurosurgery, University of Louisville, Louisville, Kentucky, USA;
4. Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
5. Department of Neurosurgery, University of Sherbrooke, Sherbrooke, Quebec, Canada;
6. Department of Neurosurgery, NYU Langone, New York, New York, USA;
7. Department of Neurosurgery, University of Puerto Rico, San Juan, Puerto Rico, USA;
8. Gamma Knife Center, Beaumont Health System, Royal Oak, Michigan, USA;
9. Department of Neurosurgery, Cleveland Clinic Foundation, Cleveland, Ohio, USA;
10. Department of Neurosurgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
11. Department of Stereotactic and Radiation Neurosurgery, Na Homolce Hospital, Prague, Czech Republic;
12. Department of Neurosurgery, Neurological Institute, Taipei Veteran General Hospital, Taipei City, Taiwan;
13. Radiosurgery Unit, Hospital Ruber Internacional, Madrid, Spain;
14. Department of Neurosurgery, Koc University School of Medicine, Istanbul, Turkey;
15. Department of Neurosurgery, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA;
16. Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India;
17. Department of Radiation Oncology, The James Comprehensive Cancer Center Ohio State University, Columbus, Ohio, USA;
18. Department of Neurosurgery, University of Southern California, Los Angeles, California, USA;
19. Department of Neurosurgery, West Virginia University, Morgantown, West Virginia, USA;
20. Gamma Knife Center Cairo, Nasser Institute Hospital, Cairo, Egypt;
21. Department of Neurosurgery, Benha University, Benha, Egypt