1. Department of Hematology and Oncology, Division of Clinical Research, Research Institute for Radiation Biology and Medicine, Hiroshima University, Japan
2. International Radiation Information Center, Research Institute for Radiation Biology and Medicine, Hiroshima University, Japan
3. Department of National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, Japan
4. Department of Anatomical Pathology, Hiroshima University, Japan