EPI-CT: in vitro assessment of the applicability of the gamma-H2AX-foci assay as cellular biomarker for exposure in a multicentre study of children in diagnostic radiology

Purpose : To conduct a feasibility study on the application of the gamma-H2AX foci assay as an exposure biomarker in a prospective multicentre paediatric radiology setting. A set of in vitro experiments was performed to evaluate technical hurdles related to biological sample collection in a paediatric radiology setting, processing and storing of blood samples the reliability of foci scoring for low doses, as well as the impact of contrast agent administration as potential confounding factor. Given the exploratory nature of this study and the ethical constraints related to paediatric blood sampling, blood samples from adult volunteers were used for these experiments. In order to test the feasibility of pooling the gamma-H2AX data when different centres are involved in an international multicentre study, two intercomparison studies in the low-dose range (10 – 500 mGy) were performed.