1. Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands;
2. Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands;
3. Department of Radiation Oncology, Radboud University Medical Center, Nijmegen, the Netherlands;
4. Department of Radiotherapy, University Medical Center Utrecht, Utrecht, the Netherlands;
5. Department of Radiotherapy, Isala Clinics Zwolle, Zwolle, the Netherlands;
6. Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, the Netherlands;
7. Faculty of Biology, Medicine & Health, Division of Cancer Sciences, University of Manchester and Christie NHS Trust, Manchester, UK;
8. Department of Medical Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands