1 Department of Radiotherapy and Radiation Oncology, Franziskus Hospital Bielefeld, Bielefeld, Germany.
2 Center for Radiotherapy and Radiation Oncology, Hamburg, Germany.
3 Department of Radiotherapy and Radiation Oncology, Marien Hospital Herne, Ruhr University Bochum, Bochum, Germany.
4 Institute of Medical Informatics and Biometry, University Rostock, Rostock, Germany.
5 Department of Radiotherapy, Lippe Hospital Lemgo, Lemgo, Germany.
6 Department of Radiotherapy and Radiation Oncology, Marien Hospital Herne, Ruhr University Bochum, Bochum, Germany; Radiotherapy RheinMainNahe, Bad Kreuznach Germany.