1. Department of Pediatric Oncology and Hematology, Hopital Nord, Saint Etienne, France
2. Department of Radiology, Centre Leon Berard, Lyon, France (PT)
3. Department of Neuropathology (AL-T) and Department of Pediatric Neurosurgery (AP-K), Hopital Necker, Paris, France
4. Department of Pediatric Oncology, Institut Gustave Roussy, Villejuif, France (CK)
5. Department of Pediatric Oncology, Bristol Royal Hospital for Sick Children, Bristol, England (EB)