1. Department of Surgery; Soonchunhyang University Seoul Hospital; Seoul South Korea
2. Department of Radiation Oncology; Sungkyunkwan University School of Medicine; Seoul South Korea
3. Department of Surgery, Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
4. Department of Surgery; Hallym University Hangang Sacred Heart Hospital; Seoul South Korea
5. Department of Surgery; Hallym University Dongtan Sacred Heart Hospital; Dongtan South Korea