@article{oai:repo.qst.go.jp:00042995,
 author = {Koike, Sachiko and Ando, Koichi and Uzawa, Akiko and Takai, Nobuhiko and Fukawa, Takeshi and Furusawa, Yoshiya and Oohira, Chisa and Aoki, Mizuho and Monobe, Manami and Lee, Ryonfa and Suzuki, Masao and Nojima, Kumie and 小池 幸子 and 安藤 興一 and 鵜澤 玲子 and 高井 伸彦 and 扶川 武志 and 古澤 佳也 and 青木 瑞穂 and 物部 真奈美 and 李 玲華 and 鈴木 雅雄 and 野島 久美恵},
 journal = {Radiation Protection Dosimetry},
 month = {},
 note = {It is well established that the RBE (relative biological effectiveness) for cell killing depends on LET (linear energy transfer), and that a maximum RBE is observed at  ~150 keV/mm.   However, the therapeutic gain depends on the ratio of the RBEs for the effects on the cancer cell population and the effects on normal tissues.    The RBE of a given radiation quality depends on LET but also on dose, biological system and effect, and irradiation conditions.   There is no data available to answer the question: which LET is suitable to improve the biological therapeutic gain of carbon ions?  Here, we selected 3 different LET values of 290 MeV/u carbon ions, and compared the relative biological effectiveness between tumor-growth retardation and skin damage using a murine transplantable tumor.   Larger RBE values for tumors after than the skin type were obtained when carbon-ions of intermediate LET were daily delivered for 2 through 5 fractions.   The biological therapeutic gain would be high for the carbon-ion SOBP if the number of fractions were correctly selected in clinical trials.},
 pages = {405--408},
 title = {Significance of fractionated irradiation for the biological therapeutic gain of carbon ions},
 volume = {99},
 year = {2002}
}