A biophysical theory of the kinetics of organ growth as a function of age and the relationship to a predictive theory of radiation risk

The kinetics of organ growth and the process of radiation carcinogenesis share phenomenological and etiological features. These similarities suggest that theories of the age dependence of both organ growth and radiation sensitivity may rest on common axiomatic foundations. The present paper explores the conceptual and computational links between growth and sensitivity, incorporating elements of mitotic rates, cellular inactivation, cellular removal and radiation induced damage into a state-vector theory of radiation carcinogenesis. These same elements are utilised in developing a model of organ growth as a function of age. The unified model of growth and sensitivity then is employed to examine the effect of age on the probability of radiation induced cancer. (author)