1. Department of Oral and Cranio-Maxillo and Facial Plastic Surgery, University of Cologne, Kerpener Straße 62, 50931 Cologne, Germany
2. Center of Integrated Oncology (CIO) Cologne-Bonn, Kerpener Straße 62, 50931 Cologne, Germany
3. Department of Otorhinolaryngology, Head and Neck Surgery, University of Cologne, Kerpener Straße 62, 50931 Cologne, Germany
4. Department of Radiotherapy and Radiation Oncology, University of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
5. Department of Otorhinolaryngology, Head and Neck Surgery, Jena University Hospital, Kerpener Straße 62, 50931 Cologne, Germany