1. Stuttgart Cancer Center; Zentrum für Kinder-; Jugend- und Frauenmedizin; Pediatrics 5 (Oncology, Hematology, and Immunology); Klinikum Stuttgart-Olgahospital; Stuttgart Germany
2. Department of Pediatric Surgery; University Children's Hospital Marburg; Marburg Germany
3. Institute of Radiology; Zentrum für Kinder-; Jugend- und Frauenmedizin; Klinikum Stuttgart-Olgahospital; Stuttgart Germany
4. Institute of Paidopathology; University of Kiel; Kiel Germany
5. Institute of Radiotherapy; Klinikum Stuttgart; Stuttgart Germany
6. Department of Women's and Children's Health; Pediatric Oncology; Uppsala University; Uppsala Sweden
7. Department of Pediatric Hematology and Oncology; University of Muenster; Muenster Germany
8. Department of Pediatric Oncology; University of Children's Hospital Zürich; Zürich Swizzerland
9. Department of Pediatric Oncology; St. Anna Kinderspital; Wien Austria
10. Hospital for Children and Adolescents; University of Frankfurt; Frankfurt Germany
11. Department of Pediatric Surgery and Urology; University Children's Hospital; Tuebingen Germany
12. Department of Pediatric Hematology and Oncology; Children's Hospital; Tuebingen Germany