Carotid stenosis after radiotherapy for nasopharyngeal carcinoma

Objective: To determine the prevalence and risk factors for radiation-induc ed carotid stenosis in patients with malignant neoplasms of the head and ne ck. Design: Prospective cross-sectional screening of extracranial carotid steno sis by color-flow duplex ultrasonography with an analysis of demographic an d comorbid risk factors. Setting: Tertiary oncology and vascular referral center. Patients: The study included 96 consecutive patients (75 men and 21 women; mean age, 53.6 years) who had undergone cervical radiotherapy (RT) for naso pharyngeal carcinoma more than 12 months ago. The mean post-RT interval was 79.9 months. Fourteen patients had cerebrovascular symptoms. A group of 96 healthy individuals were used as controls. Main Outcome Measures: Internal carotid stenosis and common carotid artery stenosis were classified by duplex ultrasonography into moderate (30%-69%), severe (70%-99%), and totally occlusive. Results: Internal carotid artery stenosis of 70% or more was detected in 14 arteries in 12 patients (6 occlusions). Common carotid artery stenosis of 70% or more was found in 11 arteries in 9 patients (4 occlusions). Overall, 15 patients (16%) had critical stenosis in their common or internal caroti d arteries, and another 20 (21%) had stenosis in the moderate range. Critic al carotid stenosis was not present in any of the control subjects. Severe post-RT carotid stenosis was associated with age (P =.003), smoking (P =.00 4), heart disease (P<.001), no prior oncological surgery (P<.001), cerebrov ascular symptoms (P<.001), and interval from RT (P<.001). Smoking, interval from RT, cerebrovascular symptoms, and no head and neck surgery were signi ficant independent predictors for severe carotid stenosis on multivariate l ogistic regression analysis. Conclusions: Patients who undergo irradiation of the head and neck for more than 5 years have a higher risk of developing significant carotid stenosis (relative risk, 15), and routine duplex ultrasound screening is recommende d.