1. Department of Biomedicine, Neurosciences and Advanced Diagnostics, Neurosurgery Unit, School of Medicine, University of Palermo;
2. Department of Head and Neck Surgery, Neurosurgery Unit, Garibaldi Hospital, Catania;
3. Department of Medical Physics, IRCCS Azienda University Hospital of Bologna, Italy;
4. Department of Medicine, University of Cambridge, United Kingdom;
5. Department of Diagnostic Imaging, Neuroradiology Unit, Cannizzaro Hospital, Catania;
6. Department of Neurosurgery, Trauma Center, Gamma Knife Center, Cannizzaro Hospital, Catania; and
7. Department of Neurosurgery, Policlinico Tor Vergata, Rome, Italy