University of Amsterdam - Amsterdam University Medical Centers, European Organisation for Research and Treatment of Cancer (EORTC), European Organisation for Research and Treatment of Cancer (EORTC), Leiden University, Erasmus University Rotterdam (EUR) - Erasmus Medical Center (MC), KU Leuven, Sorbonne University, Utrecht University - Department of Medical Oncology, University of Amsterdam - Amsterdam University Medical Centers, Heidelberg University - University Hospital Heidelberg, University College Hospital, Newcastle Upon Tyne Hospitals NHS Foundation Trust, European Organisation for Research and Treatment of Cancer (EORTC), European Organisation for Research and Treatment of Cancer (EORTC), European Organisation for Research and Treatment of Cancer (EORTC), Erasmus MC - Brain Tumor Centre and Independent