1. Aristotle University of Thessaloniki School of Medicine, Thessaloniki, Greece
2. Department of Neurosurgery, AHEPA University Hospital, Thessaloniki, Greece
3. Department of Radiotherapy, AHEPA University Hospital, Thessaloniki, Greece
4. Pediatric Oncology Unit, 2nd Pediatric Department of Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece