1. Department of Pediatric Surgery, Research Laboratories, Ludwig-Maximilians-University of Munich, Munich, Germany
2. Department of Pediatric Oncology and Hematology, University of Saarland, Homburg/Saar, Germany
3. Department of Pediatric Oncology and Hematology, Gemeinschaftsklinikum Koblenz-Mayen, Koblenz, Germany
4. Department of Pediatrics, Jena University Hospital, Jena, Germany
5. Department of Clinical Radiology, Ludwig-Maximilians-University of Munich, Munich, Germany