作者单位:Department of Radiation Medicine, Hokkaido University School of Medicine, Kita-15, Nishi-7, Kita-ku[1]Faculty of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo 060-0812, Japan[2]Graduate School of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo 060[3]