1. Department of Head and Neck Surgery Tokyo Medical and Dental University Tokyo Japan
2. Department of Head and Neck Surgery Aichi Cancer Center Hospital Nagoya Japan
3. Division of Head and Neck Cancer Institute Hospital of Japanese Foundation for Cancer Research Tokyo Japan
4. Department of Head and Neck Surgery National Cancer Center Hospital East Kashiwa Japan
5. Department of Head and Neck Surgery Osaka International Cancer Institute Osaka Japan
6. Department of Otorhinolaryngology The Jikei University School of Medicine Tokyo Japan
7. Division of Head and Neck Surgery Shizuoka Cancer Center Shizuoka Japan
8. Department of Head and Neck Surgery National Cancer Center Hospital Tokyo Japan
9. Department of Otolaryngology – Head and Neck Surgery Kobe University Graduate School of Medicine Kobe Japan
10. Department of Otolaryngology – Head and Neck Surgery University of Tokyo Tokyo Japan
11. Department of Head and Neck Surgery Miyagi Cancer Center Natori Japan
12. Department of Otorhinolaryngology – Head and Neck Surgery Kansai Medical University Osaka Japan
13. Department of Otolaryngology – Head and Neck Surgery Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Okayama Japan
14. Otolaryngology Head and Neck Surgery Jichi Medical University Shimotsuke City Japan
15. Department of Otorhinolaryngology – Head and Neck Surgery Yokohama City University School of Medicine Yokohama Japan
16. Department of Head Neck Surgery Saitama Medical University International Medical Cancer Saitama Japan
17. Department of Head and Neck Surgery Tokyo Medical University Tokyo Japan
18. Department of Otolaryngology – Head and Neck Surgery Nara Medical University Kashihara Japan
19. Department of Otorhinolaryngology – Head and Neck Surgery Hiroshima University Hospital Hiroshima Japan
20. Department of Otolaryngology – Head and Neck Surgery Tokai University Isehara Japan
21. Department of Head and Neck Surgery National Hospital Organization Kyushu Cancer Center Fukuoka Japan
22. Department of Otolaryngology – Head and Neck Surgery Kyoto Prefectural University of Medicine Kyoto Japan
23. Department of Otolaryngology – Head and Neck Surgery, School of Medicine Fujita Health University Toyoake Japan
24. Department of Otorhinolaryngology Nagoya University Graduate School of Medicine Nagoya Japan
25. Department of Head and Neck Surgery Hyogo Cancer Center Akashi Japan
26. Department of Medical Oncology and Hematology Kobe University Hospital Kobe Japan
27. Department of Otolaryngology – Head and Neck Surgery, Faculty of Medicine and Graduate School of Medicine Hokkaido University Sapporo Japan