P09.04 * CAROTID PLAQUE MRI AND STROKE AFTER RADIOTHERAPY: A LONG-TERM PROSPECTIVE COHORT STUDY

Abstract

PURPOSE: Radiotherapy(RT) induced carotid artery vasculopathy and ischemic strokes are long-term complications after radiotherapy of the neck. The exact underlying pathofysiology of this RT induced atherosclerosis is not understood. The current study evaluated the presence and MRI characteristics of radiotherapy induced long-term carotid wall and cerebral complications in survivors of head and neck cancer (HNC). METHODS: Prospective multicenter long-term cohort study of 43 patients (mean age 60 years, SD 13) treated with RT of the neck because of head and neck cancer. Cerebrovascular risk factors were assessed at baseline (before RT). At follow-up (mean 7 years after RT) patients were evaluated with a MRA / MRI of the carotid arteries and the brain. First endpoint was frequency and characteristics (degree of stenosis, location, composition) of vessel wall changes. Secondary endpoints were frequency of white matter lesions, atrophy and (silent) brain infarctions. RESULTS: We found a vessel wall thickening in 55% of the irradiated common carotid arteries versus 18% in the non-irradiated. (p = 0.003). In the internal carotid arteries vessel wall thickening was found in 24% of the irradiated versus 6% of the non-irradiated arteries. (p = 0.02). Mean length of vessel wall thickening in the irradiated common and internal carotid arteries was 48.9 and 20 mm, respectively. In 50% of the irradiated common carotid arteries degree of stenosis was between 0 and 50%. MRI of the brain showed focal white matter lesions in 47% and mild atrophy in 33% of patients. CONCLUSION: Our study showed a significant increase in vessel wall changes on a long carotid segment in irradiated versus non-irradiated carotid arteries with a follow-up of 7 years after radiotherapy. An important proportion of patients also had intracranial vascular brain changes.