1. Division of Pediatric Neuro-Oncology, Department of Neuro-Oncology/Neurosurgery, and
2. Department of Neuro-Oncology/Neurosurgery, Saitama Medical University International Medical Center, Hidaka;
3. Department of Neurosurgery, Saitama Medical University Hospital, Moroyama; and
4. Division of Clinical Research Sciences, Department of Medicine, Teikyo University Chiba Medical Center, Ichihara, Japan