1. Institute of Cell Biology (Cancer Research), University Hospital, University of Duisburg-Essen, Essen, Germany.
2. Research Unit Radiation Cytogenetics, Helmholtz–Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany and Clinical Cooperation Group ‘Personalized Radiotherapy in Head and Neck Cancer’, Helmholtz–Zentrum München, Neuherberg, Germany.
3. Institute of Anatomy, University Hospital, University of Duisburg-Essen, Essen, Germany.
4. Department of Radiotherapy, University Hospital, University of Duisburg-Essen, Essen, Germany.