1. Center of Neurosurgery, Department of General Neurosurgery, University of Cologne, Cologne, Germany
2. Neurosurgical Department, Metropolitan Hospital, Athens, Greece and Center of Neurosurgery, Department of General Neurosurgery, University of Cologne, Cologne, Germany
3. Department of Neurosurgery, The Walton Centre NHS Foundation Trust, Liverpool, UK
4. Department of Neuropathology, University Hospital Heidelberg, Heidelberg, Germany
5. Department of Neuropathology, University of Magdeburg, Magdeburg, Germany
6. Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
7. Department of Medicine I, Comprehensive Cancer Center Vienna, Medical University of Vienna, Vienna, Austria
8. Radiation Oncology Unit, Sant’Andrea Hospital, Sapienza University, Rome, Italy
9. Department of Neurosurgery, Bergen University Hospital, Bergen, Norway
10. Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
11. Department of Neurosurgery, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
12. Service de Neuroradiologie, Hopital Lariboisiere, Paris, France
13. Department of Neurosurgery, University Hospital San Carlos, Universidad Complutense de Madrid, Madrid, Spain
14. Hospital Clinico Universitario San Carlos, Madrid, Spain
15. CyberKnife Centre, Genesiscare Madrid, Madrid, Spain
16. Department of Neurology and Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
17. Department of Neurology, Amphia Hospital, Breda, the Netherlands
18. Center for Neurooncology, Comprehensive Cancer Center, University Hospital Tübingen, Tübingen, Germany
19. Department of Neuro-Oncology, City of Health and Science University Hospital, Turin, Italy
20. Department of Neurology, Clinical Neuroscience Center, University Hospital and University of Zurich, Zurich, Switzerland