1. Department of Otolaryngology-Head and Neck Surgery; Newcastle upon Tyne Hospitals; Newcastle upon Tyne United Kingdom
2. Head and Neck Unit; The Royal Marsden Hospital NHS Foundation Trust; Fulham Road London UK
3. Department of Radiation Oncology; Institute of Oncology; Ljubljana Slovenia
4. Division of Radiation Oncology; Peter MacCallum Cancer Centre; Melbourne Victoria Australia
5. Department of Radiation Oncology; Université Catholique de Louvain, St Luc University Hospital and Cancer Center; Brussels Belgium
6. Department of Head and Neck Surgery; Université Catholique de Louvain, St Luc University Hospital and Cancer Center; Brussels Belgium
7. Department of Radiation Oncology; University of Michigan; Ann Arbor Michigan
8. Department of Radiation Oncology; University of Florida; Gainesville Florida
9. Departments of Surgery and Otolaryngology-Head and Neck Surgery; Albert Einstein College of Medicine, Montefiore Medical Center; Bronx New York
10. ENT Clinic; University of Udine; Udine Italy
11. Department of Otolaryngology-Head and Neck Surgery; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands