Analysis of chromosome damage based on the time course of aberrations

To describe a method for the analysis of radiation induced chromosome aberrations which will in particular be suitable for the comparison of different radiation qualities. The method is applied to previously published data.

The basic idea of the approach is to use the time-course of aberrations up to the time when all cells have passed through first mitosis. Instead of comparing data obtained at a single sampling time, the number of aberrant cells or aberrations is integrated over several sampling times. The integral represents a measure of the total fraction of cells showing aberrations and the total amount of aberrations induced in the irradiated cell population. In addition, a correction factor is applied which takes into account the dilution of heavily damaged cells at late sampling times by cell division of undamaged or less severely damaged cells.

Previously published data on the induction of chromosome aberrations by 4.6 MeV/u Ar ions and X-rays are re-analysed using the new approach. It is demonstrated that this method allows a better comparison of experiments using extremely different radiation qualities and consequently different cell cycle perturbations.