1. Department of Otorhinolaryngology—Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
2. Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
3. Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
5. Department of Otorhinolaryngology-Head and Neck Surgery and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
6. Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.