1Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland
2Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
3Department of Radiation Oncology, University Medical Center Schleswig-Holstein, Kiel, Germany
4Department of Radiation Oncology, University Hospital Frankfurt, Frankfurt, Germany
5Department of Radiation Oncology, Universitätsklinikum Augsburg, Augsburg, Germany
6Department of Radiation Oncology, University Hospital Munich, Munich, Germany
7Department of Radiation Oncology, Technical University Munich (TUM), Munich, Germany
8Institute of Radiation Medicine (IRM), Helmholtz Zentrum München (HMGU), Oberschleißheim, Germany
9German Cancer Consortium, Partner Site Munich, Munich, Germany
10Department of Radiation Oncology, Charité-University Hospital Berlin, Berlin, Germany
11Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
12Department of Radiation Oncology, Philipps-University Marburg, Marburg, Germany
13Department of Radiation Oncology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
14German Cancer Consortium, Partner Site Freiburg, Freiburg, Germany
15German Cancer Research Center (DKFZ), Heidelberg, Germany
16Department of Radiation Oncology, Eberhard Karls Universität Tübingen, Tübingen, Germany
17Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
18German Cancer Consortium, Partner Site Dresden, Dresden, Germany
19Department of Radiation Oncology, University Hospital Jena, Jena, Germany
20Department of Radiation Oncology, Kantonsspital St. Gallen, St. Gallen, Switzerland
21Department of Radiation Oncology, University Hospital Rostock, Rostock, Germany
22Department of Radiation Oncology, Ordensklinikum Linz, Linz, Austria
23Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
24Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
25Department of Dermatology, University Hospital Zurich, University Zurich, Zurich, Switzerland