Lookup NU author(s): Dr Richard Harbron,
Dr Simon Bouffler,
Professor Mark Pearce
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).
Studies suggest iodinated contrast media (ICM) may increase organ dose and blood cell DNA damage for a given X-ray exposure. The impact of ICM on dose/damage to extravascular cells and cancer risks is unclear.Methods: We used Monte Carlo modelling to investigate the microscopic distribution of absorbed dose outside the lumen of arteries, capillaries and interstitial fluids containing blood and various concentrations of iodine. Models were irradiated with four X-ray spectra representing clinical procedures.Results: For the artery model, The average dose enhancement factors (DEF) to blood were 1.70, 2.38, 7.38, and 12.34 for mass concentrations of iodine in blood (ρiI) of 5, 10, 50 and 100 mg/ml, respectively, compared to 0 mg/ml. Average DEFs were reduced to 1.26, 1.51, 3.48 and 5.56, respectively, in the first micrometre of the vessel wall, falling to 1.01, 1.02, 1.06 and 1.09 at 40–50 μm from the lumen edge. For the capillary models, DEF for extravascular tissues was on average 48% lower than DEF for the whole model, including capillaries. A similar situation was observed for the interstitial model, with DEF to the cell nucleus being 35% lower than DEF for the whole model.Conclusions: While ICM may modify the absorbed doses from diagnostic X-ray examinations, the effect is smaller than suggested by assays of circulating blood cells or blood dose enhancement. Conversely, the potentially large increase in dose to the endothelium of blood vessels means that macroscopic organ doses may underestimate the risk of radiation induced cardiovascular disease for ICM-enhanced exposures.
Author(s): Harbron RW, Ainsbury EA, Bouffler SD, Tanner RJ, Pearce MS, Eakins JS
Publication type: Article
Publication status: Published
Journal: Physica Medica
Online publication date: 07/02/2018
Acceptance date: 01/02/2018
Date deposited: 09/02/2018
ISSN (print): 1120-1797
ISSN (electronic): 1724-191X
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