1. Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan
2. Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, Sendai, Japan
3. Department of Radiation Oncology, Miyagi Cancer Center, Natori, Japan
4. Division of Radiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
5. Radiation Technology, Tohoku University Hospital, Sendai, Japan