Models for dose intensity

Abstract Hryniuk has recently advanced the proposal that the dose intensity of a therapeutic regimen, defined as the ratio of cumulative drug dose to therapeutic period, is an important predictor of the therapeutic outcome. We discuss two simple models of chemotherapeutic effect in cancer treatment and show how they lead to consideration of a time-dependent function, the dose-intensity function, which is a generalization of Hryniuk's dose intensity. Both models show that the therapeutic outcome is dependent upon the dose-intensity function; however, the nature of the dependence varies with the model selected.