1. Princess Máxima Center for Pediatric Oncology , 3584 CS Utrecht , The Netherlands
2. Medical Statistics, Department of Biomedical Data Science, Leiden UMC , Leiden 2333 ZA , The Netherlands
3. Mathematical Institute Leiden University , Leiden 2333 ZA , The Netherlands
4. Department of Radiology & Nuclear Medicine, UMC Utrecht , Utrecht 3584 CX , The Netherlands
5. Department of Radiation Oncology, UMC Utrecht , Utrecht 3584 CX , The Netherlands
6. Department of Pediatric Oncology/Hematology, Sophia Children's Hospital/Erasmus MC , Rotterdam 3015 CN , The Netherlands
7. Department of Internal Medicine, Leiden UMC , Leiden 2333 ZA , The Netherlands
8. Department of Health Services Research, Carl von Ossietzky University of Oldenburg , Oldenburg 26129 , Germany
9. Department of Pediatric Oncology and Hematology, Wilhelmina Children's Hospital/UMC Utrecht , Utrecht 3584 EA , The Netherlands
10. Department of Pediatric Oncology, Emma Children's Hospital/Amsterdam UMC , Amsterdam 1105 AZ , The Netherlands
11. Department of Hematology, Radboud UMC , Nijmegen 6525 GA , The Netherlands
12. Department of Pediatric Oncology/Hematology, University of Groningen, UMC Groningen , Groningen 9713 GZ , The Netherlands
13. Department of Pediatric Endocrinology, Wilhelmina Children's Hospital/UMC Utrecht , Utrecht 3584 EA , The Netherlands
14. Department of Medicine, Section Endocrinology, Erasmus MC , Rotterdam 3015 GD , The Netherlands