1. Department of Otolaryngology-Head and Neck Surgery; Newcastle upon Tyne Foundation Hospitals NHS Trust, Newcastle upon Tyne; Nottingham U.K
2. Department of Head and Neck Surgery and Oncology; Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital; Amsterdam
3. Department of Otolaryngology-Head and Neck Surgery; Mayo Clinic; Phoenix Arizona
4. Department of Otolaryngology-Head and Neck Surgery; Nottingham University Hospital, Queens Medical Centre; Nottingham U.K
5. Department of Otolaryngology-Head and Neck Surgery; University of Michigan; Ann Arbor Michigan
6. Department of Otolaryngology-Head and Neck Surgery; VU University Medical Center; Amsterdam
7. Departments of Otolaryngology, Faculty of Health Sciences; University of Cape Town; Cape Town South Africa
8. Department of Head and Neck Surgery, Head and Neck Oncology Program; St Luc University Hospital and Cancer Center; Brussels Belgium
9. Department of Radiation Oncology; Institute of Oncology; Ljubljana Slovenia
10. Department of Otolaryngology; Hospital Universitario Central de Asturias; Oviedo Spain
11. Instituto Universitario de Oncología del Principado de Asturias; Oviedo Spain
12. Department of Otorhinolaryngology; Mayo Clinic; Rochester Minnesota
13. Department of Otolaryngology-Head and Neck Surgery; Guthrie Health System; Sayre Pennsylvania
14. Department of Otolaryngology-Head and Neck Surgery; The Mount Sinai Medical Center; New York
15. Division Departments of Surgery and Otolaryngology-Head and Neck Surgery; Albert Einstein College of Medicine, Montefiore Medical Center; Bronx New York U.S.A
16. Department of Otolaryngology-Head and Neck Surgery; Radboud University Medical Center; Nijmegen The Netherlands
17. ENT Clinic; University of Udine; Udine Italy