1. Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan
2. National Yang-Ming Medical University, Taipei, Taiwan
3. Department of Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan
4. Department of Radiation Oncology, Taichung Veterans General Hospital, Taichung, Taiwan
5. Department of Otolaryngology, Chung Shan Medical University Hospital, Taichung, Taiwan