1. Department of Radiation Oncology, Gil Medical Center, School of Medicine, Gachon University, Incheon 405-760, Republic of Korea
2. Department of Internal Medicine, Gil Medical Center, School of Medicine, Gachon University, Incheon 405-760, Republic of Korea
3. Department of Pathology, Ewha Womans University School of Medicine, Seoul 158-710, Republic of Korea