1. Pediatric Oncology Unit; Fondazione IRCCS Istituto Nazionale Tumori; Milano Italy
2. Department of Preventive and Predictive Medicine; Evaluative Epidemiology Unit; Fondazione IRCCS Istituto Nazionale Tumori; Milano Italy
3. Clinical Trials and Biostatistics Unit; IRCCS Istituto Oncologico Veneto; Padova Italy
4. Department of Pediatric Oncology; Institut d'Hematologie et d'Oncologie Pédiatrique, Centre Léon Bérard; Lyon France
5. Department of Pediatric Oncology; Emma Children's Hospital-Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
6. Department of Pediatric Oncology; Children's Hospital for Wales, Heath Park; Cardiff United Kingdom
7. Department of Pediatric, Adolescent and Young Adult Oncology; Institut Curie; Paris France
8. Department of Paediatric Oncology; Royal Marsden Hospital; London United Kingdom
9. Department of Paediatric Oncology; Hospital Universitario Vall d'Hebron; Barcelona Spain
10. Department of Pediatrics; University Hospital Oslo, Rikshospitalet; Oslo Norway
11. Pediatric Hematology and Oncology Division; Padova University; Padova Italy