1. Lung and Esophageal Cancer Clinic, Chonnam National University Hwasun Hospital, Hwasun, Korea.
2. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
3. Department of Thoracic & Cardiovascular Surgery, Chonnam National University Medical School, Gwangju, Korea.
4. Department of Diagnostic Radiology, Chonnam National University Medical School, Gwangju, Korea.