1. Department of Urology, Seoul National University Hospital, Seoul, Korea.
2. Department of Urology, Dongguk University Ilsan Hospital, Goyang, Korea.
3. Department of Urology, Inje University Sanggye Paik Hospital, Seoul, Korea.
4. Department of Surgery, Hai Phong University of Medicine and Pharmacy, Hai Phong, Vietnam.
5. Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
6. Department of Urology, Seoul National University College of Medicine, Seoul, Korea.