1. Department of Urology, Hokkaido University Graduate School of Medicine , Sapporo , Japan
2. Department of Urology, Teine-Keijinkai Hospital , Sapporo , Japan
3. Department of Urology, Obihiro Kousei Hospital , Obihiro , Japan
4. Department of Urology, Iwamizawa Municipal General Hospital , Iwamizawa , Japan
5. Department of Urology, Hakodate Central Hospital , Hakodate , Japan
6. Department of Urology, Tomakomai City Hospital , Tomakomai , Japan
7. Department of Urology, Sapporo City General Hospital , Sapporo , Japan
8. Department of Urology, Kushiro City General Hospital , Kushiro , Japan
9. Department of Urology, KKR Sapporo Medical Center , Sapporo , Japan
10. Department of Urology, Hokkaido Cancer Center , Sapporo , Japan
11. Department of Urology, Jinyukai Hospital , Sapporo , Japan
12. Department of Urology, Ebetsu City Hospital , Ebetsu , Japan
13. Department of Urology, Nayoro City General Hospital , Nayoro , Japan
14. Department of Urology, Abashiri Kousei Hospital , Abashiri , Japan
15. Department of Urology, KKR Tonan Hospital , Sapporo , Japan
16. Department of Urology, Kushiro Rosai Hospital , Kushiro , Japan
17. Department of Urology, Otaru General Hospital , Otaru , Japan
18. Department of Urology, Asahikawa Kousei Hospital , Asahikawa , Japan
19. Department of Urology, JCHO Sapporo Hokushin Hospital , Sapporo , Japan
20. Department of Urology, Hokkaido Urology Memorial Hospital , Sapporo , Japan