University of Leipzig - Department of Pediatric Oncology and Hematology, Princess Máxima Center for Pediatric Oncology, Erasmus University Rotterdam (EUR) - Department of Internal Medicine, Ulm University - Institute of Pharmacology of Natural Products and Clinical Pharmacology, Erasmus University Rotterdam (EUR), Medical Center, Department of Internal Medicine, Princess Máxima Center for Pediatric Oncology, Princess Máxima Center for Pediatric Oncology, Princess Máxima Center for Pediatric Oncology, Johannes Gutenberg University Mainz - University Medical Center, Ulm University - Institute of Epidemiology and Medical Biometry, University of Leipzig - Department of Pediatric Oncology and Hematology, Boyne Research Institute, Princess Máxima Center for Pediatric Oncology, IRCCS Istituto Giannina Gaslini - Department of Neurooncology, Johannes Gutenberg University Mainz - German Childhood Cancer Registry, Johannes Gutenberg University Mainz - German Childhood Cancer Registry, Johannes Gutenberg University Mainz - German Childhood Cancer Registry, Johannes Gutenberg University Mainz - German Childhood Cancer Registry, Danish Cancer Society Research Centre - Childhood Cancer Research Group, Danish Cancer Society Research Centre - Childhood Cancer Research Group, University of Copenhagen - Department of Pediatrics and Adolescent Medicine, Aarhus University - Department of Pediatrics, University Hospital Brno, Princess Máxima Center for Pediatric Oncology, Princess Máxima Center for Pediatric Oncology, Motol University Hospital - Department of Children Hemato-Oncology, Stuttgart Cancer Center - Department of Pediatric Oncology, Hematology, Immunology, Stuttgart Cancer Center - Department of Pediatric Oncology, Hematology, Immunology, Stuttgart Cancer Center - Department of Pediatric Oncology, Hematology, Immunology, University of Bern - Institute of Social and Preventive Medicine, University of Geneva - Department of Pediatrics, Oncology and Hematology Unit, University of Bern - Department of Otolaryngology, Head and Neck Surgery, Princess Máxima Center for Pediatric Oncology, Westphalian Wilhelm University - Department of Phoniatrics and Pedaudiology, Westphalian Wilhelm University - Department of Phoniatrics and Pedaudiology, Westphalian Wilhelm University - Department of Phoniatrics and Pedaudiology, Westphalian Wilhelm University - Department of Phoniatrics and Pedaudiology, Princess Máxima Center for Pediatric Oncology, University of Erlangen-Nuremberg-Friedrich Alexander Universität Erlangen Nürnberg - Hospital for Children and Adolescents, University of Lubeck - Institute of Social Medicine & Epidemiology, Westphalian Wilhelm University - Department of Phoniatrics and Pedaudiology, Princess Máxima Center for Pediatric Oncology, University of Leipzig - Department of Pediatric Oncology and Hematology and Independent