1. Department of Radiology and Nuclear Medicine, and Department of Neurosurgery, Charité – Campus Benjamin Franklin, Berlin, Germany; Klinik für Strahlenheilkunde, Charité – Campus Virchow-Klinikum, Berlin, Germany; Institute for Biostatistics and Clinical Epidemiology I, Charité – Universitätsmedizin Berlin, Berlin, Germany; Department of Radiology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio, USA