1. Depatment of Radiation Oncology, Gunma University Graduate School of Medicine, 3-39-15, Showa-machi, Maebashi, Gunma 371-8511, Japan
2. Department of Radiation Oncology, Fukushima Medical University, 1, Hikarigaoka, Fukushima, Fukushima 960-1247, Japan
3. Department of Radiation Oncology, Saitama Medical University International Medical Center, 1397-1, Yamane, Hidaka, Saitama 350-1241, Japan
4. Department of Radiation Oncology, Gunma Prefectural Cancer Center, 617-1, Takahayashinishi-cho, Ota, Gunma 373-8550, Japan
5. Department of Radiation Oncology, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo 181-8611, Japan
6. National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
7. Department of Human Pathology, Gunma University Graduate School of Medicine, 3-39-15, Showa-machi, Maebashi, Gunma 371-8511, Japan
8. Department of Diagnostic Pathology, Fujita Health University, 1-98, Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
9. Department of Diagnostic Pathology, Gunma University Hospital, 3-39-15, Showa-machi, Maebashi, Gunma 371-8511, Japan