DNA double-strand breaks of human peripheral blood lymphocyte induced by CT examination of oral and maxillofacial region

Objectives To explore whether a computed tomography (CT) examination of the head and neck region induces biological damage and whether the damage was correlated with the radiation dose. Materials and methods Peripheral blood was taken from 33 individuals who received head and neck CT examinations. Blood samples were divided into three groups: the control group and the in vivo and in vitro irradiation groups. The number of DNA double-strand breaks was estimated by comparing the changes in the rates of gamma-H2AX foci formation in the peripheral blood before and after CT examination. The absorbed dose and effective dose were calculated with the software VirtualDose based on the Monte Carlo method, and the absorbed doses in blood were estimated accordingly. Results The gamma-H2AX foci rates were increased in the in vivo (p < 0.001) and in vitro irradiation groups (p < 0.001) after CT examination when compared with those in the control group. The rate of gamma-H2AX foci formation showed linear dose-responses for the CT dose index volume (CTDIvol), dose-length product (DLP), and blood dose after CT examination. Conclusions A CT examination of the head and neck region provides a high enough radiation dose to induce DNA double-strand breaks in cells in the peripheral blood. There was a linear correlation between the formation of DNA double-strand breaks and radiation doses after CT examination.