1. Department of Radiation Oncology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
2. German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Partner Site Freiburg, 69120 Heidelberg, Germany
3. Department of Oncology and Palliative Medicine, Nordland Hospital, 8092 Bodø, Norway
4. Department of Clinical Medicine, Faculty of Health Sciences, UiT—The Arctic University of Norway, 9037 Tromsø, Norway