Radiation Induced DNA Double-Strand Breaks in Radiology Strahleninduzierte DNA-Doppelstrangbrüche in der Radiologie

Shortly after the discovery of X-rays, their damaging effect on biological tissues was observed. The determination of radiation ex- posure in diagnostic and interventional radi- ology is usually based on physical measu- rements or mathematical algorithms with standardized dose simulations. γ-H2AX im- munofluorescence microscopy is a reliable and sensitive method for the quantification of radiation induced DNA double-strand breaks (DSB) in blood lymphocytes. The detectable amount of these DNA damages correlates well with the dose received. However, the biologi- cal radiation damage depends not only on dose but also on other individual factors like radiation sensitivity and DNA repair capacity. Iodinated contrast agents can enhance the x-ray induced DNA damage level. After their induction DSB are quickly repaired. A protec- tive effect of antioxidants has been postulated in experimental studies. This review explains the prinicple of the γ-H2AX technique and provides an overview on studies evaluating DSB in radiologic examinations. Key Points: ▶ Radiologic examinations including CT and angiography induce DNA double-strand breaks. Even after mammography a slight but significant increase is detectable in peripheral blood lymphocytes.