Impact of radiotherapy for nasopharyngeal carcinoma on carotid stenosis risk: a meta-analysis

OBJECTS: Radiotherapy (RT) serves as the most effective treatment for Nasopharyngeal Carcinoma (NPC) and can cause carotid stenosis. The aim of this study is to assess the impact of RT on carotid stenosis in NPC patients, as well as to explore the risk factors for significant carotid stenosis. METHODS: Studies reporting the carotid stenosis in NPC patients who underwent RT were found on PubMed, Embase and Web of Science. Outcomes of our interest included incidence of overall/significant stenosis, Common Carotid Artery (CCA) stenosis, External Carotid Artery (ECA) stenosis, Internal Carotid Artery (ICA) stenosis, and risk factors for significant carotid stenosis. RESULTS: Sixteen studies met the inclusion criteria and were included in this meta-analysis. Pooled estimate showed that RT was associated with a significantly higher incidence of overall stenosis (Risk Ratio [RR = 3.53], 95% CI: 2.32‒5.37; p < 0.001) and significant stenosis (RR = 7.06, 95% CI: 3.61‒13.79; p < 0.001) as compared with controls. Moreover, patients treated with RT had a significantly higher risk of stenosis in CCA (RR = 6.87, 95% CI: 4.08‒11.58; p < 0.001), ICA (RR = 3.43, 95% CI: 1.35‒8.73; p = 0.010), ECA (RR = 9.37, 95% CI: 2.06‒42.68; p = 0.004), and ECA/ICA (RR = 2.18, 95% CI: 1.52‒3.13; p < 0.001). Meta-analysis indicated that age (RR = 1.46, 95% CI: 1.05‒2.04; p = 0.024), smoking habit (RR = 1.20, 95% CI: 1.02‒2.78; p = 0.045) and time interval from radiotherapy (RR = 1.56, 95% CI: 1.07‒2.28; p = 0.02) were independent predictors of significant carotid stenosis. CONCLUSION: Our results suggested that RT increased the risk of carotid stenosis in patients with NPC. Prevention and control measurements should be made for older NPC patients with longer interval from RT, especially those with smoking habit. LEVEL OF EVIDENCE: 3.