1. Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands;
2. Proton Therapy Centre South-East Netherlands (ZON-PTC), Maastricht, The Netherlands;
3. Department of Radiation Oncology (The D-Lab), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands;
4. OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Cal Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden, Rossendorf, Dresden, Germany;
5. Department of Radiation Oncology, Radiotherapiegroep, Deventer, The Netherlands;
6. Department of Radiation Oncology, RadboudUMC, Nijmegen, The Netherlands;
7. Department of Medical Oncology, GROW – School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands;
8. Princess Maxima Center for Pediatric Oncology, Utrecht, The Netherlands;
9. Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands;
10. Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany;
11. Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany;
12. German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany;
13. mNational Center for Tumor Diseases (NCT) Partner Site Dresden, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, and Helmholtz Association/Helmholtz-Zentrum Dresden, Rossendorf (HZDR), Dresden, Germany