1. Department of Pediatrics, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany;
2. Pediatric Hematology and Oncology, Justus-Liebig University, Gieβen, Germany;
3. Division of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany;
4. St Anna Kinderspital, Vienna, Austria;
5. Division of Pediatric Pulmonology and Neonatology, Hannover Medical School, Hannover, Germany;
6. Department of Pediatrics, Klinikum Oldenburg, Oldenburg, Germany;
7. Pediatric Hematology/Oncology, University Children's Hospital, Homburg/Saar, Germany;
8. Hematology/Oncology, Robert-Rössle-Klinik at the HELIOS Klinikum, Charité, Berlin, Germany;
9. Pediatric Hematology/Oncology, University Children's Hospital, Münster, Germany;
10. Department of Pediatric Oncology, University Children's Hospital, Zürich, Switzerland;
11. Pediatric Hematology/Oncology, Ostschweizer Kinderspital, St Gallen, Switzerland;
12. Pediatric Hematology and Oncology, Charité Medical Center, Humboldt University, Berlin, Germany;
13. Department of Pediatric Oncology, University Hospital, Erlangen, Germany;
14. Pediatric Hematology and Oncology, University Hospital, Frankfurt, Germany;
15. Division of Pediatric Hematology and Oncology, University of Freiburg, Freiburg, Germany;
16. Department of Pediatric Hematology and Oncology, University Hospital, Jena, Germany;
17. Division of Pediatric Hematology and Oncology, University Hospital, Bonn, Germany;
18. Division of Pediatric Hematology and Oncology, Medical University Graz, Graz, Austria;
19. Department of Pediatrics, Municipal Hospital, Kassel, Germany; and
20. Department of Pediatric Hematology and Oncology, University Hospital, Tübingen, Germany