Carotid artery stenosis in asymptomatic patients who have received unilateral head-and-neck irradiation

Purpose: To determine the prevalence of carotid artery stenosis in patients who have received ipsilateral head-and-neck radiotherapy and have no symptoms of cerebrovascular disease. Methods and Materials: Forty patients underwent ultrasound and computed tomography angiography of their carotid arteries. The vessels on the irradiated side were compared with those on the unirradiated side in a matched-pair analysis with regard to any stenosis, stenosis ≥60% in the internal carotid artery/carotid bulb, intima medial thickness (IMT), and grade of wall abnormalities. History, physical, and fasting blood levels were taken to detect risk factors for carotid disease. Results: Fourteen irradiated carotid trees bore one or more stenosis vs. five in the unirradiated ones (p = 0.03). There were six bulb/internal carotid artery stenoses ≥60% in the irradiated carotids vs. one in the unirradiated (OR 6:1, p = 0.13). IMT and grade of vessel wall abnormality were higher in the irradiated carotids, but only at doses ≥50 Gy, and only at measurement points that lay within the radiation portals. Conclusion: Radiation appears to cause carotid artery stenosis. There may be a dose threshold for carotid wall changes, which has relevance for radiotherapy in several tumor sites. Purpose: To determine the prevalence of carotid artery stenosis in patients who have received ipsilateral head-and-neck radiotherapy and have no symptoms of cerebrovascular disease. Methods and Materials: Forty patients underwent ultrasound and computed tomography angiography of their carotid arteries. The vessels on the irradiated side were compared with those on the unirradiated side in a matched-pair analysis with regard to any stenosis, stenosis ≥60% in the internal carotid artery/carotid bulb, intima medial thickness (IMT), and grade of wall abnormalities. History, physical, and fasting blood levels were taken to detect risk factors for carotid disease. Results: Fourteen irradiated carotid trees bore one or more stenosis vs. five in the unirradiated ones (p = 0.03). There were six bulb/internal carotid artery stenoses ≥60% in the irradiated carotids vs. one in the unirradiated (OR 6:1, p = 0.13). IMT and grade of vessel wall abnormality were higher in the irradiated carotids, but only at doses ≥50 Gy, and only at measurement points that lay within the radiation portals. Conclusion: Radiation appears to cause carotid artery stenosis. There may be a dose threshold for carotid wall changes, which has relevance for radiotherapy in several tumor sites.