1. Department of Pediatric SurgeryUniversity Children´s Hospital Marburg Marburg Germany
2. Department of Pediatric Surgery and UrologyUniversity Children´s Hospital Tuebingen Germany
3. Klinikum Stuttgart – OlgahospitalStuttgart Cancer CenterZentrum für Kinder‐Jugend‐ und FrauenmedizinPediatrics 5 (Oncology, Hematology, Immunology) Stuttgart Germany
4. Department of RadiotherapyUniversity Hospital Münster Germany
5. Department of Pediatric PathologyUniversity Hospital Schleswig‐Holstein Kiel Germany
6. Department of Pediatric Hematology and OncologyUniversity Hospital Frankfurt/Main Germany
7. Department of Pediatric Bone Marrow TransplantationOncology and HematologyWroclaw Medical University Wroclaw Poland