Risk factors of carotid artery plaque formation in radiation-induced late brain injury patients received irradiation for nasopharyngeal carcinoma

Abstract

Objective To investigate the rates and risk factors of carotid artery plaques formation in radiation-induced late brain injury (RILBI) patients who have received irradiation for nasopharyngeal carcinoma. Methods Eighty-two patients with RILBI,admitted to our hospital from January 2008 to September 2011, and 40 healthy controls were recruited in this study; in these 82 patients,we chose 50 patients who did not have such risk factors of main carotid artery plaque formation as stroke,ischemic heart disease,hypertension,diabetes mellitus and smoking as our RILBI group.Their medical histories were obtained,and the levels of fasting blood glucose,triglyceride,total cholesterol,high-density lipoprotein cholesterol, low-density lipoprotein cholesterol were examined. Carotid intima-media thicknesses (CIMT) in these 82 patients were measured by Doppler ultrasound; according to the CIMT, RILBI patients were divided into plaque formation sub-group and non-plaque formation sub-group; unconditional logistic regression was employed to analyze the risk factors of carotid artery plaque formation. Results Relevance ratio of plaque formation in RILBI group (32.0％) was significantly higher than that of controls (12.5％,P＜0.05).Significant differences of age,post-radiation interval without plaque, history of stroke were noted between the RILBI patients of plaque formation sub-group and non-plaque formation sub-group (P＜0.05).Logistic regression demonstrated that age was an independent risk factor for plaque formation in RILBI patients (OR=1.103,95％CI:1.046-1.163,P=0.000). Conclusion The incidence rate of plaque formation in RILBI patients received irradiation for nasopharyngeal carcinoma is high,and age is an important risk factor.Focused screening of carotid artery injury in RILBI patients may be medically beneficial. Key words: Nasopharyngeal carcinoma; Radiation-induced late brain injury; Radiation-induced carotid artery injury; Carotid intima-media thickness