[1] Aichi Canc Ctr Hosp, Dept Head & Neck Surg, Nagoya, Aichi 4648681, Japan
[2] Nagoya City Univ, Grad Sch Med Sci, Dept Otolaryngol Head & Neck Surg, Nagoya, Aichi 4678601, Japan
[3] Aichi Canc Ctr Hosp, Dept Radiat Oncol, Nagoya, Aichi 4648681, Japan
[4] Nagoya Univ, Grad Sch Med, Dept Otolaryngol, Nagoya, Aichi 4660065, Japan
[5] Osaka Med Ctr Canc & Cardiovasc Dis, Dept Otolaryngol Head & Neck Surg, Osaka 7100052, Japan
[6] Kurashiki Cent Hosp, Dept Otorhinolaryngol Head & Neck Surg, Kurashiki, Okayama 7100052, Japan
[7] Shiga Univ Med Sci, Dept Otorhinolaryngol, Otsu, Shiga 5202192, Japan