1. Department of Radiation Oncology, University Medical Center, Utrecht, the Netherlands
2. Department of Radiation Oncology, MAASTRO Clinic, GROW—School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, the Netherlands
3. Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
4. OncoRay, National Center for Radiation Research in Oncology, Dresden, Germany
5. Department of Radiation Oncology, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany