Erasmus University Rotterdam (EUR) - Department of Neurology, Erasmus University Rotterdam (EUR) - Department of Neurology, Erasmus University Rotterdam (EUR) - Department of Radiology, Erasmus University Rotterdam (EUR) - Department of Neurology, Erasmus University Rotterdam (EUR) - Department of Pathology, University of Amsterdam - Department of Pathology, University of Amsterdam - Department of Neurology, University Medical Center Utrecht - Department of Neurology and Neurosurgery, University of Amsterdam - Department of Epidemiology and Biostatistics, University Medical Center Utrecht - Department of Pathology, Erasmus University Rotterdam (EUR) - Department of Neurology, Erasmus University Rotterdam (EUR) - Department of Neurology, Erasmus University Rotterdam (EUR) - Department of Neurology, Mayo Clinic - Department of Neurology, Erasmus University Rotterdam (EUR) - Department of Pathology, University of Zurich - Department of Neurology, Heidelberg University - University Hospital Heidelberg, KU Leuven, Hôpitaux Universitaires La Pitié Salpêtrière, IRCCS Istituto delle Scienze Neurologiche di Bologna (ISNB), EORTC Headquarters, European Organisation for Research and Treatment of Cancer (EORTC), University Hospital Zurich, University of Zurich - Department of Neurology, University Medical Center Utrecht - Department of Neurology and Neurosurgery, Erasmus University Rotterdam (EUR) - Department of Pathology, Erasmus University Rotterdam (EUR) - Department of Radiology and Nuclear Medicine, University of Amsterdam - Department of Epidemiology and Biostatistics, Erasmus University Rotterdam (EUR) - Department of Pathology, University of Amsterdam - Department of Neurosurgery, Erasmus MC - Brain Tumor Centre, University of Amsterdam - University Medical Center, Erasmus University Rotterdam (EUR) - Department of Pathology and Erasmus Medical Center (MC)