1. Department of Urology, Yamagata Tokushukai Hospital, Yamagata 990-0834, Japan
2. Department of Urology, Kameda Daiichi Hospital, Niigata 950-0165, Japan
3. Sendai Radiation Oncology & Imaging Clinic, Sendai City 981-3121, Japan
4. Department of Urology, Yamagata City Hospital Saiseikan, Yamagata 990-8533, Japan
5. Department of Urology, Yamagata Prefectural Central Hospital, Yamagata 990-2292, Japan