1. Department of Paediatric SurgeryBicêtre HospitalHôpitaux Universitaires Paris‐Sud Le Kremlin‐Bicetre France
2. Department of Paediatric SurgeryUniversity Hospitals Bristol NHS Foundation trust Bristol United Kingdom
3. Département d'Oncologie de l'Enfant et de l'AdolescentInstitut Gustave Roussy Villejuif France
4. Department of OncologyUniversity College London Hospitals NHS Foundation Trust London United Kingdom
5. Department of Paediatric SurgeryPrinses Máxima Centrum voor Kinderoncologie Utrecht the Netherlands
6. Pediatric Surgery UnitDepartment of Woman's and Child's HealthUniversity Hospital of Padova Padova Italy
7. Department of Paediatric SurgeryUniversity Hospital Vall d'Hebron Barcelona Spain
8. Clinical Trials and Biostatistics UnitIstituto Oncologico Veneto IOV‐IRCCS Padova Italy
9. Department of Paediatric HistopathologyRoyal Manchester Children Hospital Manchester United Kingdom
10. SIREDO Oncology Center (Care, Innovation and Research for Children, Adolescents and Young Adults with Cancer)Institut CuriePSL University Paris France
11. Pediatric Oncology UnitFondazione IRCCS Istituto Nazionale Tumori Milano Italy
12. Institut d'Hématologie et d'Oncologie PédiatriqueCentre Léon Bérard Lyon France
13. Hematology Oncology DivisionDepartment of Women's and Children's HealthUniversity of Padova Padova Italy