1. Department of Urology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
2. Department of Urology, Asan Medical Center, Seoul, Korea.
3. Department of Surgery, SMG-SNU Boramae Medical Center, Seoul National University Collegy of Medicine, Seoul, Korea.
4. Department of Urology, SMG-SNU Boramae Medical Center, Seoul National University Collegy of Medicine, Seoul, Korea.