1. Institute of Medical Biostatistics, Epidemiology, and Informatics, University Medical Centre Mainz, 55131 Mainz, Germany
2. Department of Oncology, Oslo University Hospital, 0372 Oslo, Norway
3. Research Support Service, Oslo University Hospital 0372 Oslo, Norway
4. Faculty of Medicine, University of Oslo, 0372 Oslo, Norway
5. Faculty of Dentistry, University of Oslo, 0455 Oslo, Norway
6. Department of Otorhinolaryngology, Oslo University Hospital, 0372 Oslo, Norway
7. Department of Radiotherapy-Oncology, Faculty of Medicine and Health Sciences—Human Structure and Repair, Ghent University Hospital, Ghent University, 9000 Ghent, Belgium
8. Department of Head and Neck Surgery, Barretos Cancer Hospital, Barretos 14784-400, SP, Brazil
9. Department of Radiation Oncology, Barretos Cancer Hospital, Barretos 14784-400, SP, Brazil
10. Department of Otorhinolaryngology-Head and Neck Surgery, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital, 41345 Gothenburg, Sweden
11. Department of Radiation Oncology, Ospedale dell’Angelo, 30174 Venice, Italy
12. Department Otolaryngology-Head and Neck Surgery, Amsterdam UMC Location Vrije Universiteit, De Boelelaan 1117, 1081 HZ Amsterdam, The Netherlands
13. Cancer Center Amsterdam, Treatment and Quality of Life, 1081 HV Amsterdam, The Netherlands
14. Department Clinical, Neuro and Developmental Psychology, Vrije Universiteit Amsterdam, Van der Boechorststraat 7-9, 1081 HV Amsterdam, The Netherlands
15. Division of Radiation Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, 33081 Aviano, Italy
16. Department of Otorhinolaryngology, Jena University Hospital, 07747 Jena, Germany
17. Department of Otorhinolaryngology, Oberhavelkliniken Hennigsdorf, 16761 Hennigsdorf, Germany
18. Head and Neck Unit, Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles, 1070 Brussels, Belgium
19. Department of Radiation Oncology, University Hospital Schleswig-Holstein, 24105 Kiel, Germany
20. Department of Otorhinolaryngology, St. Georg Hospital, 04129 Leipzig, Germany
21. Cancer Center, Kobe University Hospital, Kobe 650-0017, Japan
22. Department of Oral and Maxillofacial Surgery—Plastic Surgery, University Medical Centre Mainz, 55131 Mainz, Germany
23. Radiation Oncology, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
24. Rehabilitation Medicine Unit, Strategic Health Services Department, Istituto Nazionale Tumori—IRCCS—Fondazione G. Pascale, 80131 Naples, Italy
25. Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven, 3000 Leuven, Belgium
26. Department of Radiation Oncology, Leuven Cancer Institute, University Hospitals Leuven, 3000 Leuven, Belgium
27. Department of Otolaryngology, Head and Neck Surgery, Instituto Português de Oncologia Francisco Gentil do Porto, 4200-072 Porto, Portugal
28. Department of Radiation Oncology, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
29. Berlin Institute of Health, 10178 Berlin, Germany
30. Department of Radiation Oncology, Azienda Sanitaria Locale, 72100 Brindisi, Italy
31. Department of Otorhinolaryngology, University Hospital Gießen und Marburg, 35392 Giessen, Germany
32. Department of Otorhinolaryngology—Head and Neck Surgery, “S. Chiara” Hospital, Azienda Provinciale per i Servizi Sanitari (APSS), 38122 Trento, Italy
33. Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany
34. Department of Otorhinolaryngology—Head and Neck Surgery, ASST Spedali Civili of Brescia, University of Brescia, 25123 Brescia, Italy
35. Oral Medicine Unit, Sheba Medical Center, Tel Hashomer, Ramat Gan 5262000, Israel
36. Dental Oncology Unit, Department of Oral Medicine and Pathology and Hospital Dentistry, Dental School, National and Kapodistrian University of Athens, 11527 Athens, Greece