1 1 Department of Radiation Oncology, University Medical Center Freiburg, Freiburg, Germany.
2 2 German Cancer Consortium (DKTK), Heidelberg, Partner Site, Freiburg, Germany.
3 3 EORTC Headquarters, Brussels, Belgium.
4 4 Department of Radiation Oncology, Catharina Hospital, Eindhoven, Netherlands.
5 5 Department of Radiation Oncoiogy, Gustave Roussy, Paris Sud University, Villejuif, France.
6 6 Institute of Cancer Sciences, University of Manchester, Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, UK.
7 7 Department of Radiation Oncology, KU Leuven-University of Leuven, University Hospitals Leuven, Leuven, Belgium.
8 8 Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands.
9 9 Department of Oncology and Radiotherapy, Medical University of Gdańsk, Gdańsk, Poland.
10 10 Department of Radiology, Allgemeines Krankenhaus Celle, Celle, Germany.
11 11 Department of Radiation Oncology, University of Zurich, Zurich, Switzerland.