[1] Tohoku Univ, Sch Med, Hlth Sci Course Radiol Technol, Sendai, Miyagi, Japan
[2] Tohoku Univ, Grad Sch Med, Dept Radiat Oncol, Sendai, Miyagi, Japan
[3] Tohoku Univ Hosp, Dept Radiat Technol, Sendai, Miyagi, Japan
[4] Tohoku Univ, Grad Sch Med, Dept Urol, Sendai, Miyagi, Japan