Erasmus University Rotterdam (EUR) - Department of Neuro-Oncology, Counties Manukau District Health Board - Middlemore Hospital, Erasmus University Rotterdam (EUR) - HOVON Data Center, Utrecht University, University Medical Center, Cancer Center, Department of Hematology, Utrecht University - Department of Neurology, Elisabeth-Tweesteden Hospital, Sir Charles Gairdner Hospital, Maastricht University, Medical Center, Department of Hematology, Radboud University Nijmegen - Department of Hematology, VU University Amsterdam - Department of Hematology, Netherlands Cancer Institute, University of Groningen - Department of Hematology and Oncology, University of Melbourne - Royal Melbourne Hospital, Spaarne Gasthuis, Erasmus University Rotterdam (EUR) - Department of Neuro-Oncology, University of Groningen, University of Melbourne - Royal Melbourne Hospital, VU University Amsterdam and Erasmus University Rotterdam (EUR) - Department of Hematology