Does induced repair determine the lethal effects of very low radiation doses?

As part of a programme for testing the ability of the LQ model to describe normal-tissue and tumour responses, the authors have evaluated the effect of very low X-ray doses per fraction, less than 2 Gy and typically down to 0.1 Gy, on skin and kidney. These studies have been possible by using an experimental design in which only a part of the underlying damage equivalent to full tissue tolerance is produced by the X-ray fractions of interest, and the balance is supplied by a top-up dose of low-energy (high-LET) neutrons. (Author)