Carcinogenesis and Heritable Effects

Abstract

Radiation carcinogenesis is considered a stochastic effect. For radiation safety purposes, equivalent dose is defined as physical dose multiplied by a weighting factor, correcting for the type of radiation. Effective dose is defined as equivalent dose multiplied by tissue weighting factor, correcting for the volume of tissue irradiated. Carcinogenesis is modeled by the linear no threshold (LNT) model. The excess risk of dying from a radiation related cancer (above the natural baseline) is based on age at exposure, gender, total dose and dose rate. Secondary leukemias may show up after just a few years with a decrease in incidence after about a decade, while secondary solid tumors typically occur after a decade or more. Genetic risk is another late radiation toxicity, with increased rate of mutations in the offspring of irradiated animals. It is generally recommended to avoid conception for at least 6 months after radiation to the gonads.