Dose-length product of scanners correlates with DNA damage in patients undergoing contrast CT

作者：Beels Laurence^*; Bacher Klaus; Smeets Peter; Verstraete Koenraad; Vral Anne; Thierens Hubert

来源：European Journal of Radiology, 2012, 81(7): 1495-1499.

DOI：10.1016/j.ejrad.2011.04.063

• Computed tomography
• Dose-length product
• DNA damage
• gamma-II2AX

Objectives: Computed tomography (CT) exams contribute for a large part to the population%26apos;s radiation burden. This study addresses the question if dose settings of scanners expressed by dose-length product (DLP) are correlated with directly measurable biological effects in patients. %26lt;br%26gt;Methods: DLP, blood dose, effective dose and DNA damage were analyzed for patients undergoing a thoracic or abdominal contrast CT scan on two CT scanners with different dose settings. The DNA damage was assessed by scoring gamma-H2AX foci representing DNA double-strand breaks (DSBs) in patient%26apos;s lymphocytes. Blood dose was calculated using the ImPACT software. %26lt;br%26gt;Results: The CT system operating at higher dose settings represented by higher DLP values, resulted in a significantly higher number of radiation-induced gamma-H2AX foci in patient%26apos;s lymphocytes (DLP: 2.1 times higher; gamma-H2AX foci: 2.3 times higher; p %26lt; 0.05). Plotting gamma-H2AX foci versus blood dose showed a systematic increase of DNA damage with dose. In vitro experiments ruled out a possible X-ray enhancement of DNA damage effect by contrast agent. %26lt;br%26gt;Conclusions: Present study demonstrates that optimization of DLP setting of scanners results in a reduction of X-ray effects in patients.

• 出版日期2012-7