@inproceedings{oai:repo.qst.go.jp:00054421,
 author = {平山, 亮一 and 鵜澤, 玲子 and 松本, 孔貴 and 金子, 由美子 and 尾崎, 匡邦 and 山下, 慶 and 李, 惠子 and 古澤, 佳也 and 平山 亮一 and 鵜澤 玲子 and 松本 孔貴 and 金子 由美子 and 尾崎 匡邦 and 山下 慶 and 李 惠子 and 古澤 佳也},
 book = {NIRS & MedAustron  Joint Symposium on Carbon Ion Radiotherapy},
 month = {Nov},
 note = {We measured the RBE (relative biological effectiveness) and OER (oxygen enhancement ratio) and evaluated their correlations with the cell survival within implanted solid tumors following exposure to 290 MeV/nucleon clinical carbon-ion beams. SCCVII (squamous cell carcinoma) cells were transplanted into the right hind legs of syngeneic C3H/He male mice. Irradiation with either carbon-ion beams with a 6-cm spread-out Bragg peak (SOBP) or X-rays was delivered to tumors 5mm or smaller in diameter. We used two different oxygen conditions for the irradiated tumors. Hypoxic or normoxic conditions in tumors were produced by clamping the leg to stop the blood flow or by leaving the leg unclamped. After irradiation, single-cell suspensions were prepared from excised and trypsinized tumors, and were used for in vivo-in vitro colony formation assays to obtain cell survival curves. The OER value was 1.87 after X-irradiation. The OER values (1.20 ~ 1.52) of carbon-ion irradiated samples were smaller than those of X-ray irradiated samples. However, no significant changes of the OER at the proximal, middle or distal positions within the SOBP carbon-ion beams were observed. To conclude, we found that the OER values changed little with increasing LET within the SOBP carbon-ion beams. Therefore, the OERs within the SOBP carbon-ion beams can be considered to be constant values in the patient treatment plan.},
 pages = {77--84},
 title = {The Oxygen Effect in Carbon Ion Radiotherapy},
 year = {2013}
}