Longitudinal assessment of carotid atherosclerosis after radiation therapy using computed tomography: a case control study

Objectives To study the carotid artery plaque composition and its volume changes in a group of patients at baseline and 2 years after head and neck radiation therapy treatment (HNXRT). Methods In this retrospective study, 62 patients (41 males; mean age 63 years; range 52–81) who underwent HNXRT and 40 patients (24 males; mean age 65) who underwent sur- gical resection of neoplasmand did not undergoHNXRTwere assessed, with 2-year follow-up. The carotid artery plaque volumes, as well as the volume of the sub-components (fat- ty-mixed-calcified), were semiautomatically quantified. Mann-Whitney and Wilcoxon tests were used to test the hypothesis. Results In the HNXRT group, there was a statistically signif- icant increase in the total volume of the carotid artery plaques (from 533 to 746 mm3 ; p=0.001), in the fatty plaques (103 vs. 202 mm3 ; p=0.001) and mixed plaque component volume (328 vs. 419 mm3 ; p=0.034). A statistically significant varia- tion (from 21.8 % to 27.6 %) in the percentage of the fatty tissue was found. Conclusions Results of this preliminary study suggest that HNXRT pro- motes increased carotid artery plaque volume, particularly the fatty plaque component.