1. Department of Otorhinolaryngology–Head and Neck Surgery, Institute of Clinical Sciences, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
2. Department of Otorhinolaryngology–Head and Neck Surgery Sahlgrenska University Hospital Gothenburg Sweden
3. Department of Otorhinolaryngology Northern Alvsborg County Hospital (NAL) Trollhättan Sweden
4. Department of Otorhinolaryngology Central Hospital Skövde Sweden
5. Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
6. Department of Oncology Sahlgrenska University Hospital Gothenburg Sweden