1. Department of Otorhinolaryngology and Head and Neck Surgery Radboud University Medical Center Nijmegen The Netherlands
2. Rare Cancers Radboud Institute for Health Sciences Nijmegen The Netherlands
3. Department of Health Evidence Radboud University Medical Center Nijmegen The Netherlands
4. Department of Otolaryngology—Head and Neck Surgery Amsterdam University Medical Centers, VU University Amsterdam The Netherlands
5. Department of Head and Neck Surgery Netherlands Cancer Institute—Antoni van Leeuwenhoek Amsterdam The Netherlands
6. Department of Otorhinolaryngology and Head and Neck Surgery Erasmus Medical Center Rotterdam The Netherlands
7. Department of Otorhinolaryngology and Head and Neck Surgery University of Groningen, University Medical Center Groningen Groningen The Netherlands
8. Department of Otorhinolaryngology and Head and Neck Surgery Leiden University Medical Center Leiden The Netherlands
9. Department of Otorhinolaryngology and Head and Neck Surgery Maastricht University Medical Center Maastricht The Netherlands
10. Department of Head and Neck Surgical Oncology University Medical Center Utrecht Cancer Center Utrecht The Netherlands
11. Department of Otolaryngology–Head and Neck Surgery Hokkaido University Graduate School of Medicine Sapporo Japan
12. ENT Department Medical University Pozna'n Poland
13. Department of Otorhinolaryngology and Head and Neck Surgery Nagoya City University Hospital Nagoya Aichi Japan
14. Department of Head and Neck Surgery Aichi Cancer Center Hospital Nagoya Aichi Japan