ABSTRACT
Objective To investigate radiation-induced carotid and cerebral vascular injury and its relationship with radiation-induced temporal lobe necrosis in nasopharyngeal carcinoma (NPC) patients.Methods Fifty-eight NPC patients with radiation-induced temporal lobe necrosis (TLN) were recruited in the study.Duplex ultrasonography was used to scan bilateral carotid arterials to evaluate the intima-media thickness (IMT) and occurrence of plaque formation.Flow velocities of bilateral middle cerebral arteries (MCAs),internal carotid arteries (ICAs) and basal artery (BA) were estimated through Transcranial Color Doppler (TCD).The result were compared with data from 33 patients who were free from radiation-induced temporal lobe necrosis after radiotherapy and 29 healthy individuals,to study the relationship between IMT,occurrence of plaque and ventricular diastolic dysfunction.Results Significant differences in IMT,occurrence of plaques of ICAs and flow velocities of both MCAs and ICAs were found between patients after and healthy individuals (t =18.624,8.221,P ＜0.05;x2 =17.886,P ＜0.05;t =14.367,10.112,P ＜0.05).IMT had positive correlation with post radiation interval (r =0.368,P =0.049).IMT or incidence of plaques may be related to dose of radiotherapy,course of treatment and T stage (x2 =-17.635,12.006,-3.125,P ＜ 0.05).Compared with result from patients without radiation-induced TLN,the mean IMT was significantly thicker in patients with TLN (t =10.208,P ＜ 0.05).Plaques were more common in patients with TLN than patients without TLN (x2 =13.118,P ＜0.05).In addition,flow velocities of MCAs and ICAs in patients with TLN were much faster (t =5.011,5.035,P ＜ 0.05).Among patients with unilateral TLN,flow velocity of MCAs was significantly different between ipsilateral and contralateral sides to the lesion (t =18.362,P ＜ 0.05).Conclusions Thickening of IMT,occurrence of plaque formation and hemodynamic abnormality are more common in patients after radiotherapy,especially in those with TLN,compared with healthy individuals.