A systematic review of radiation dose to the eye lens from pediatric brain computed tomography scans.

Abstract

<h4>Background</h4>With the increasing use of pediatric brain computed tomography (CT) and the International Commission on Radiological Protection's revised threshold for radiation-induced lens opacities, concerns have grown regarding cumulative radiation exposure to the eye lens.<h4>Objective</h4>This review examines the magnitude of lens doses reported in pediatric brain CT and the methodologies used to estimate these doses.<h4>Methods</h4>A systematic literature search of MedLine, Embase, and PubMed (2012-2024) identified 18 eligible studies, including direct patient measurements, phantom-based experiments, and computational modeling.<h4>Results</h4>Reported lens doses varied widely across studies. Software-based tools generally estimate higher doses than those measured directly on patients or phantoms. Multiple dose-reduction strategies such as gantry tilting, organ-based tube current modulation, and protocol optimization were effective in significantly lowering lens exposure without compromising diagnostic quality.<h4>Conclusion</h4>In all cases, individual scan doses remain below the cataractogenic threshold. However, children undergoing repeated imaging may exceed this limit over time. Cumulative lens dose tracking and routine implementation of orbit-sparing techniques are recommended to reduce long-term radiation risk in vulnerable pediatric populations.