[1] Med Univ Vienna, Dept Neurosurg, Waehringer Guertel 18-20, A-1090 Vienna, Austria
[2] Med Univ Vienna, Ctr Comprehens Canc, Cent Nervous Syst Tumors Unit CCC CNS, Vienna, Austria
[3] Med Univ Vienna, Dept Pediat & Adolescence Med, Vienna, Austria
[4] Med Univ Vienna, Inst Neurol, Vienna, Austria
[5] Med Univ Vienna, Dept Radiotherapy, Vienna, Austria