1. Department of Neurosurgery, Goethe University Hospital, Frankfurt am Main;
2. University Cancer Center Frankfurt (UCT), Goethe University Hospital, Frankfurt;
3. Department of Neurology, Goethe University Hospital, Frankfurt am Main;
4. Department of Neurosurgery, Helios Klinikum Erfurt;
5. Department of Neurosurgery, University Hospital Erlangen;
6. Department of Neurosurgery, University Hospital Aachen; and
7. Department of Neurosurgery, Vivantes Klinikum Neukölln, Berlin, Germany