1. Department of Otorhinolaryngology - Head and Neck Surgery; University of Gothenburg, Sahlgrenska University Hospital; Göteborg Sweden
2. Department of Oncology; Sahlgrenska University Hospital; Göteborg Sweden
3. Department of Otorhinolaryngology; NU Hospital Group; Trollhättan Sweden
4. Department of Otorhinolaryngology; Central Hospital; Skövde Sweden