1. Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, Japan
2. Graduate School of Radiological Technology, Gunma Prefectural College of Health Sciences, 323-1 Kamioki, Maebashi, Gunma, Japan
3. Department of Radiology, Nagoya City University Hospital, 1-Kawasumi, Mizuho-Cho, Mizuho-Ku, Nagoya, Aichi, Japan