1. Department of Radiation Oncology, Presbyterian Medical Center, Jeonju, Jeonbuk, Republic of Korea
2. Department of Medicine, Jeonbuk National University, Jeonju, Jeonbuk, Republic of Korea
3. Department of Radiation Oncology, Jeonbuk National University Hospital-Jeonbuk National University Medical School, Jeonju, Jeonbuk, Republic of Korea
4. Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Jeonbuk, Republic of Korea.