Prospective Cohort Study of Carotid Intima-media Thickness after Irradiation

Background: Carotid artery vasculopathy is a potential long-term complication after radiotherapy (RT) of the neck, resulting in cerebrovascular events. The underlying pathophysiology is not well understood and early markers are lacking. We aimed to study whether RT of the neck is associated with increase in carotid intima-media thickness (IMT) and stroke in the first 2 years after RT in patients with head and neck cancer (HNC). Methods: In this prospective cohort study patients treated with RT of the neck were assessed for measurement of IMT before and 2 years after RT. Endpoints were changed in IMT and incidence of first-ever stroke. Results: Between 2003 and 2008 we included 69 patients (median age, 57 years [25%-75% quartile, 51-64 years], median dose of RT 66 Gy [interquartile range, 60-70]) with baseline and follow-up measurement of IMT. Median IMT at baseline and follow-up was .60 and .62 mm (ratio of geometric means 1.01; 95% confidence interval,.96-1.08; P = .63). Four of 69 patients suffered from a stroke. Mean interval from RT to stroke was 6.8 months. Conclusions: Our study showed no increase of carotid IMT in the first 2 years after RT of the neck in patients treated for HNC. This indicates that the IMT is not a reliable early marker for postirradiation vasculopathy. However, a high rate of strokes was observed. A longer follow-up period is needed to find the starting point of RT-induced vascular changes.