1. Department of Neurosurgery, Bagdasar-Arseni University Hospital, Bucharest, Romania
2. Faculty of Medicine, University of Oslo, Oslo, Norway
3. Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway
4. The Cancer Registry of Norway, Oslo, Norway
5. Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
6. Department of Research and Innovation, Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway