Yoshinori Handa1, Yasuhiro Tsutani1, Morihito Okada2. 1. Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3-Kasumi, Minami-ku, Hiroshima, 734-8551, Japan. 2. Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3-Kasumi, Minami-ku, Hiroshima, 734-8551, Japan. morihito@hiroshima-u.ac.jp.