Protraction Effects in a Stochastic Cell-Cycle Tumor Model Exposed to Fractionated Radiotherapy

Abstract

The response of repair kinetics of an avascular tumor during and between fractionated irradiation and the influence on the effectiveness of radiotherapy is investigated using a model of irradiated cell survival with cell-cycle regulation. Tissue response to irradiation is defined by the linear-quadratic (LQ) model in which fractionation and dose-protraction are included through the Lea-Catchside function. It is shown that the cell survival increases by protraction in multifractionation regimes.