1. Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA;
2. Department of Radiotherapy and Stereotactic Radiosurgery, Mediterraneo Hospital, Glyfada, Greece;
3. Department of Neurological Surgery, Hospices Civils de Lyon, Lyon, France;
4. Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
5. Department of Stereotactic and Radiation Neurosurgery, Na Homolce Hospital, Prague, Czech Republic;
6. Radiosurgery Unit, Hospital Ruber Internacional, Madrid, Spain;
7. Department of Neurosurgery, Koc University School of Medicine, Istanbul, Turkey;
8. Gamma Knife Center Cairo, Nasser Institute Hospital, Cairo, Egypt;
9. Neurosurgery Department, Benha University, Qalubya, Egypt;
10. Neurosurgery Department and Clinical Oncology Department, Ain Shams University, Cairo, Egypt;
11. Radiation Oncology Department, National Cancer Institute, Cairo University, Cairo, Egypt;
12. Department of Neurosurgery, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA