Effects of genome instability under irradiation in different CT scanning modes. Results of ex vivo pilot cohort study

Abstract

Introduction. Medical radiation is one of the leading sources of public exposure in the world. In recent decades, the total number of X-ray diagnostic procedures has increased significantly, and with the increase in the volume of computed tomography (CT), a significant gain in the total cumulative radiation dose is also associated. The aim of the work is to compare the genotoxic effects of irradiation of human blood lymphocytes using various CT protocols. Materials and methods. Among patients of different genders and ages who sought for a preventive examination, nine practically healthy volunteers (donors) who signed an informed consent, were randomly selected to participate in the ex vivo experiment. 4 venous blood samples from each donor were irradiated on various CT protocols (0.82–11.8 mSv) in an anthropometric phantom of the human chest. Aliquots of each sample were cultured under conditions of cytokinesis block, recorded and analyzed according to the protocol of cytomic analysis in a micronucleus test. Results. Irradiation of blood samples in the Ultra-NDCT mode (0.82 mSv) revealed a peak in the proliferation of rapidly dividing cells and the frequency of genetic damage in them, and also demonstrated a high probability of the formation and consolidation of genetic damage in generations of dividing cells. This indicates increased genotoxicity and, most likely, immunotropicity of the studied irradiation mode. Llimitation of the study is the inadmissibility of involving a person in an experiment or using biomaterials without obtaining his consent, as well as the inadmissibility of causing physical harm or harm to human honor and dignity during the experiment Conclusion. When choosing CT modes, it is necessary to take into account not only the levels of effective doses, but also the possibility of developing the effects of genome instability. However, this approach requires additional genotoxic studies of CT protocols in the range from <1 to 100 mSv.