Carotid Artery Stenosis and Ischemic Stroke in Patients with Head and Neck Cancer Treated with Radiotherapy: A Critical Review

Purpose The purpose of this review is to summarize the literature on carotid artery stenosis (CAS) and ischemic stroke (IS) in head and neck cancer (HNC) patients treated with radiotherapy (RT) to guide assessment, screening, and management strategies. Results Patients treated with RT for HNC are at an elevated risk of developing CAS with published meta-analyses demonstrating that CAS >50% occurs in approximately 25% of patients. Previous research suggests a 10-year cumulative incidence of stroke between 5.7% and 12.5%. Cardiovascular (CVD) risk prediction tools such as QSTROKE, QRISK-2 and Framingham risk score perform poorly for predicting IS for HNC patients who received RT. Duplex US is the most common imaging modality to assess CAS, but controversy remains as to the utility of screening asymptomatic individuals. Only three of the five major HNC survivorship guidelines acknowledge RT as a risk factor for CAS or IS, whilst only one makes a specific recommendation on screening for CAS (American Head and Neck Society). Within the general population only one CVD guideline discusses RT as a risk factor for CAS (Society for Vascular Surgery). Conclusions Clinicians involved in the care of HNC patients treated with RT should be aware of the increased risk of CAS and IS and the challenges in risk prediction. While there is a lack of evidence to make firm recommendations, HNC survivorship recommendations should ensure HNC survivors and primary care providers are informed of these risks and the importance of assessment and management of CVD risk factors. Future studies are required to refine risk prediction models in HNC patients, and to determine those most likely to benefit from targeted screening and initiation of early preventative strategies.