1. From the Department of Otolaryngology, Chung Shan Medical University Hospital, Taichung, Taiwan
2. School of Medicine, Chung Shan Medical University, Taichung, Taiwan
3. Department of Anesthesiology, Chung Shan Medical University Hospital, Taichung, Taiwan
4. and the Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
5. and Department of Radiation Oncology, Chung Shan Medical University Hospital, Taichung, Taiwan