1. Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
2. Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
3. Södra Älvsborgs Hospital, Borås, Sweden
4. Department of Otorhinolaryngology Head and Neck Surgery, Clinical Sciences, Lund, Sweden