Significant reduction of radiation dose and DNA damage in 18F- FDG whole-body PET/CT study without compromising diagnostic image quality

Abstract

ABSTRACT Reduction of radiation dose from medical investigations still remains an important strategy. The combined effect of the reduced injected activity of 18F – FDG, low tube voltage & iodine concentration with iterative reconstruction on image quality, radiation dose, and DNA damage in patients undergoing PET/CT examination were examined. The study includes 16 patients who underwent PET/CT investigation twice using two different protocols; standard & new. A new protocol was followed during follow-up after 4–6 months. All acquisition and reconstruction parameters were the same in both protocols, except administered activity, iodine concentration and CT tube voltage which was reduced. Image quality was assessed using various parameters. Effective dose from PET/CT was assessed using CTDIvol and ICRP coefficients. DNA damage analysis was performed using comet and γ-H2AX assay. No significant difference was noted in quality parameters between two protocols (p > 0.05) except CT noise level (p < 0.05). Mean iodine dose, total radiation dose, mean foci and TM in the new protocol were found significantly lower than standard PET/CT (p < 0.05). There were 26.68% reduction in radiation dose, 10% reduction in contrast load, 20.31% reduction in the number of foci and 17.67% reduction in TM was noted with optimized protocol.