A significant correlation between clonogenic radiosensitivity and the simultaneous assessment of micronucleus and apoptotic cell frequencies

Purpose: To study the relationship between clonogenic radiosensitivity and a simultaneous assessment of the percentages of radiation-induced micronuclei (MN) and apoptotic cells. Materials and methods: Five mammalian cell lines were studied. Following irradiation, measurements were made of the percentages of MN, apoptotic cells and floating cells. Each factor was compared, both alone and as the simple sum of the factors, with cell survival. The factors were also evaluated using a multiple linear regression analysis. Results: The simple sum of the MN and apoptotic cell percentages, the sum of the MN and floating cell percentages, and the sum of all three factors correlated with cell survival. However, the multiple linear regression analysis was the best method of predicting cell survival. Conclusions: These results suggest the usefulness of the simultaneous assessment of the MN frequency and the detection of floating cells in culture medium or apoptotic cells among attached cells to predict cellular intrinsic radiosensitivity. In order to predict cell survival after irradiation from these factors, the use of multivariate analyses is more useful than simple summation.