1. Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA;
2. Department of Neurosurgery, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada;
3. Department of Neurological Surgery, University of Miami School of Medicine, Miami, Florida, USA;
4. Gamma Knife Center Cairo, Nasser Institute Hospital, Cairo, Egypt;
5. Neurosurgery Department, Benha University, Qalubya, Egypt;
6. Neurosurgery Department, Ain Shams University, Cairo, Egypt;
7. Clinical Oncology Department, Ain Shams University, Cairo, Egypt;
8. Radiation Oncology Department, National Cancer Institute, Cairo University, Cairo, Egypt;
9. Department of Neurosurgery, Koc University School of Medicine, Istanbul, Turkey;
10. Department of Neurosurgery, Neurological Institute, Taipei Veteran General Hospital, Taipei, Taiwan;
11. School of Medicine, National Yang-Ming University, Taipei, Taiwan;
12. Department of Neurosurgery, Université de Sherbrooke, Centre de recherche du CHUS, Sherbrooke, Quebec, Canada;
13. Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India;
14. Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA;
15. Stereotactic and Radiation Neurosurgery, Na Homolce Hospital, Prague, Czech Republic;
16. Radiosurgery Unit, Hospital Ruber Internacional, Madrid, Spain;
17. Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan, USA;
18. Department of Neurosurgery, West Virginia University, Morgantown, West Virginia, USA;
19. Department of Radiology, Centro Gamma Knife Dominicano and Radiology Department, Cedimat, Santo Domingo, Dominican Republic