Enhanced radiation damage caused by iodinated contrast agents during CT examination

Area of Science:

• Radiology and Imaging
• Molecular Biology
• Medical Physics

Background:

• Computed tomography (CT) uses X-rays, a known mutagenic agent.
• Iodinated contrast agents (ICAs) are widely used in CT scans to enhance image quality.
• The potential genotoxic effects of ICAs, particularly on DNA damage, require thorough investigation.

Purpose of the Study:

• To evaluate the impact of iodinated contrast agents (ICAs) on DNA double-strand breaks (DSBs).
• To assess the combined effect of ICAs and CT radiation on DNA damage in human lymphocytes.
• To quantify DSBs using γH2AX foci as a biomarker.

Main Methods:

• Blood samples collected from 70 patients before and after CT scans (CT urography and unenhanced abdominal CT).
• Lymphocytes isolated and stained for γH2AX foci, a marker of DSBs.
• Statistical analysis (t-test, ANOVA) to compare DSB levels between groups.

Main Results:

• CT scans increased γH2AX foci levels in all patient groups.
• Patients receiving ICA before CTU showed a 37.9% higher DSB level compared to unenhanced CT.
• ICA alone increased DSBs by 90.3% when administered before CT, but only 3.2% when given after irradiation.

Conclusions:

• Iodinated contrast agents independently increase DNA double-strand breaks.
• ICAs can potentiate DNA damage induced by diagnostic X-ray procedures like CT scans.
• The findings suggest a need to consider the genotoxic potential of ICAs in clinical practice.