Cell survival and chromosomal aberrations in CHO-K1 cells irradiated by carbon ions

Chinese hamster ovary CHO-K1 cells were exposed to high LET 12C-beam (LET: 830 keV/μm) in the dose range of 0–6 Gy and to 60Co irradiation and the RBE value was obtained. Effects of 12C-beam exposure on cell survival and chromosomal aberrations were calculated. The chromosomal aberration data were fitted with linear equation. The distribution of aberration in cells was examined with a standard u-test and used to evaluate the data according to Poisson probabilities. The variance to the mean ratio σ2/Y and the dispersion index (u) were determined. Overdispersion was significant (p<0.05) when the value of u exceeded 1.96.