1. Department of Otolaryngology-Head and Neck Surgery, National Cancer Center, Goyang, Korea
2. Department of Internal Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea
3. Department of Otolaryngology-Head and Neck Surgery, Chungnam National University Hospital, Daejeon, Korea
4. Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
5. Department of Radiology, Gangneung Asan Hospital, Gangneung, Korea
6. Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
7. Department of Otolaryngology-Head and Neck Surgery, Eunpyeong St. Mary’s Hospital, Seoul, Korea
8. Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
9. Department of Otolaryngology-Head and Neck Surgery, Dankook University Hospital, Cheonan, Korea
10. Department of Otolaryngology-Head and Neck Surgery, Chungnam National University Sejong Hospital, Sejong, Korea
11. Department of Internal Medicine, Gachon Gil Hospital, Incheon, Korea
12. Department of Internal Medicine, National Cancer Center, Goyang, Korea
13. Department of Internal Medicine, Seoul St. Mary’s Hospital, Seoul, Korea
14. Department of Internal Medicine, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
15. Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea
16. Department of Otolaryngology-Head and Neck Surgery, Gangnam Severance Hospital, Seoul, Korea