Observations and an Interpretation of Dose-response Relationships for Cellular Transformation in Terms of Induced (T) Repair

Summary

Both radiation-induced lethality and transformation frequency have been observed to plateau or diminish abruptly at relatively low dose levels and then increase with increasing doses, but at a reduced incremental rate. Discontinuities in dose—response relationships are postulated to correspond to the induction of a repair system (‘T’ repair) not functional at lower doses, i.e. below the induction threshold dose (T₁). Anomalies (discontinuities) in dose—response relationships and effects of dose fractionation previously noted are qualitatively explained in terms of this model.