1. Head and Neck Cancer Center of The University Cancer Center Hamburg (UCCH), Department of Otorhinolaryngology and Head and Neck Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
2. Head and Neck Cancer Center of The University Cancer Center Hamburg (UCCH), Laboratory of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
3. Department of Otorhinolaryngology and Head and Neck Surgery, Ulm University Medical Center, Ulm, Germany
4. Department of Otorhinolaryngology - Head and Neck Surgery and Department of Medical Biochemistry and Genetics, Turku University and University Hospital of Turku, Turku, Finland
5. Head and Neck Cancer Center of The University Cancer Center Hamburg (UCCH), Department of Radiotherapy and Radiooncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany