1. Division of Pulmonology and Critical Care Medicine, Chonnam National University Hwasun Hospital, Korea.
2. Department of Otolaryngology and Head and Neck Surgery, Chonnam National University Hwasun Hospital, Korea.
3. Chonnam National University Medical School Lung and Esophageal Cancer Clinic, Chonnam National University Hwasun Hospital, Korea.
4. Department of Internal Medicine, Seonam University Medical School, South Korea.