Mathematical Modelling of DNA Damages in Irradiated Cells at Different Oxygenation Degrees

Abstract

In radiotherapy, the degree of oxygenation of tumors is of vital importance. Tumors with greater oxygenation are much more responsive to radiation therapy than tumors with significant hypoxia: well-oxygenated tumors react 2.5…3 times better. Mathematical modeling of DNA damage of irradiated cells at different degrees of their oxygenation is of current interest. The purpose of the paper is to develop a mathematical model of DNA damage in irradiated cells at different degrees of their oxygenation; to study the dependence of the number of radiation damages of DNA per unit volume of the irradiated medium on the radiation dose and the concentration of oxygen in the medium; to estimate the cell cycle duration depending on the oxygen concentration. Results. A mathematical model of oxygen effect in cells in the case of irradiation by X-rays or gamma-radiation is proposed. On the basis of this model, the dependence of the number of radiation DNA damages in the unit volume of the irradiated medium on the radiation dose and the concentration of oxygen in the medium is obtained. Triple damage to DNA molecules is determined by primary radiation damage and attacks of two radicals of oxygen on the DNA molecule.