@article{oai:repo.qst.go.jp:00045880,
 author = {Takiguchi, Yasuo and Miyamoto, Tadaaki and Nagao, Keiichi and Kuriyama, Takayuki and 宮本 忠昭},
 issue = {6},
 journal = {Radiation Medicine},
 month = {Jul},
 note = {PURPOSE: The aim of this study was to assess the radiosensitivities and homogeneous efficacy in the spread-out Bragg peak (SOBP) for lung cancer cell lines exposed to carbon ions. MATERIALS AND METHODS: The dose-dependent survival rates of seven cell lines exposed to carbon ions, fast neutrons, and photons were obtained using colony-forming assays in vitro. The relative biological effectiveness (RBE) of carbon ions and fast neutrons to photons was determined by comparing the doses at the 10% and 1% survival levels. RESULTS: The RBEs at 13, 40, 50, and 80 keV/microm were 1.20-1.29, 1.55-1.80, 1.57-2.00, and 1.69-2.58, respectively, at the 10% survival level. The RBE of 290 MeV carbon ions increased with increasing linear energy transfer. The biological dose (relative physical dose x RBE) distributions in the SOBP did not statistically differ at the proximal, mid, or distal points at the 10% (p = 0.945) and 1% (p = 0.211) survival levels, respectively; however, deviation of the biological dose at 10% and 1% survival were 3%-16% and 6%-24%, respectively. Furthermore, 290 MeV carbon ions at 80 keV/microm in the SOBP were nearly equivalent to 30 MeV fast neutrons. CONCLUSION: Our results demonstrate nearly homogeneous effectiveness in the SOBP, although we are aware of the deviation in some cell lines},
 pages = {272--277},
 title = {Assessment of the homogeneous efficacy of carbon ions in the spread-out Bragg peak for human lung cancer cell lines},
 volume = {25},
 year = {2007}
}