1. Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA;
2. Department of Neurosurgery, Neurological Institute, Taipei Veteran General Hospital, Taipei, Taiwan;
3. Gamma Knife Center Cairo, Cairo, Egypt;
4. Neurosurgery Department, Faculty of Medicine, Benha University, Qalubya, Egypt;
5. Neurosurgery Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt;
6. Clinical Oncology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt;
7. Radiation Oncology Department, National Cancer Institute, Cairo University, Cairo, Egypt;
8. RS Unit, Ruber International Hospital, Madrid, Spain;
9. Department of Stereotactic and Radiation Neurosurgery, Na Homolce Hospital, Prague, Czech Republic;
10. Department of Neurosurgery, Université de Sherbrooke, Centre de recherche du CHUS, Sherbrooke, Québec, Canada;
11. Department of Neurologic Surgery, University of Virginia Health System, Charlottesville, Virginia, USA;
12. Department of Neurosurgery, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
13. Department of Neurologic Surgery, Cleveland Clinic Foundation, Cleveland, Ohio, USA;
14. Departments of Neurosurgery and Medical Physics, NYU Langone Health System, New York, New York, USA;
15. Department of Neurosurgery, Gamma Knife Humanitas Research Hospital, Milan, Italy;
16. Department of Neurosurgery, Penn State Hershey Medical Center, Hershey, Pennsylvania, USA;
17. Department of Neurosurgery, Gamma Knife Center, Jewish Hospital, Mayfield Clinic, Cincinnati, Ohio, USA;
18. Department of Neurosurgery, Gamma Knife Center of Puerto Rico, San Juan, Puerto Rico;
19. Department of Neurologic Surgery, University of Miami, Coral Gables, Florida, USA;
20. Department of Neurologic Surgery, West Virginia University, Morgantown, West Virginia, USA;