1. Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
2. Radiation and Proton Therapy Center, Nagaizumi, Shizuoka, Japan
3. Department of Urology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
4. Department of Radiological Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan