1. Department of Internal Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea.
2. Department of Thoracic and Cardiovascular surgery, Chonnam National University Hwasun Hospital, Hwasun, Korea.
3. Department of Radiation Oncology, Chonnam National University Hwasun Hospital, Hwasun, Korea.
4. Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.