A diversity of responses displayed by a stochastic model of radiation carcinogenesis allowing for cell death.

A stochastic model is presented of carcinogenesis induced by irradiation with arbitrary time-dependent dose rate. The key feature of the model is that it allows for radiation-induced cell killing to compete with the process of tumor promotion. Two versions of the model arise when considering target tissues with slow and rapid replacement of damaged cells. These versions show dissimilar shapes of the dose-response curves in the case of short-term exposure. The model provides a natural explanation of the basic experimental findings documented in the radiobiological literature.