1. Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
2. Department of Medical Oncology, Cancer Center Amsterdam, Brain Tumor Center Amsterdam, Amsterdam University Medical Centers, Location VUmc, Amsterdam, The Netherlands
3. Department of Neurosurgery, Cancer Center Amsterdam, Brain Tumor Center Amsterdam, Amsterdam University Medical Centers, Location VUmc, Amsterdam, The Netherlands
4. Department of Medical Oncology, Radboud University Medical Center, Nijmegen, The Netherlands