Contrast Medium Can Increase DNA Breakage in CT Scan
Double-strand breaks in the peripheral blood lymphocytes increased by 30 percent with CM
THURSDAY, Dec. 3 (HealthDay News) -- The use of contrast medium (CM) in computed tomography (CT) scanning can significantly increase DNA double-strand breaks (DSBs) in the peripheral blood lymphocytes, according to a study in the December issue of Radiology.
Saskia Grudzenski, of the Darmstadt University of Technology, Radiation Biology and DNA Repair in Germany, and colleagues took blood samples from patients before and at 30 minutes, one hour, 2.5 hours, and five hours after they underwent CT scans either with the use of CM (iopromide or iomeprol) or without CM. DNA DSBs were assessed in lymphocytes by counting γH2AX foci and were compared with DSBs in lymphocytes that were irradiated in vitro.
The researchers found a 30 percent increase in DSBs in peripheral lymphocytes when CM was used during CT, and the effect was confirmed in the in vitro experiments. However, the researchers found that CM administration after irradiation did not increase DSBs, and DSBs were not increased when γ-rays were used instead of X-rays.
"The highly sensitive γH2AX foci assay shows that CM-enhanced radiation damage incurred in peripheral lymphocytes during CT. However, it is unknown whether long-term bioeffects of low-dose ionizing radiation from CT examinations, such as cancer, are increased by using CM," the authors write.
One study author reported receiving consulting fees and research funding from several pharmaceutical companies.