Modelling radiation-induced chromosome aberrations.

PURPOSE: To review the data and models on the induction of chromosomal aberrations by a single acute dose of radiation, then critically to assess progress that has been made so far to make a judgement about prospects for increased understanding.

MATERIALS AND

METHODS

Drawing upon many years of personal experience, a consistent set of data on the radiation-induced dicentric yield in human lymphocytes was produced. Other data concerning the production of complex rearrangements and the time-course of the appearance of dicentrics has also been reviewed. Three basic models have been reviewed and compared with respect to their ability to predict the judged dose-effect relationships as well as the time-course and complexity of the aberration production.

CONCLUSIONS

None of the three basic models alone can explain adequately all of the available data. A combination of the models has succeeded to a greater extent, but there is still no complete agreement. The major reason for the discrepancy between the measured yield curves and their predictions lies in the variation of the quadratic term in the dose-response relationship with increasing linear energy transfer. Further experimental work is required to resolve this.