1. Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
2. Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg University Hospital, Heidelberg, Germany
3. Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland