title: Effects of neck radiation therapy on extra-cranial carotid arteries atherosclerosis disease prevalence: systematic review and a meta-analysis.
abstract: BACKGROUND
  Radiation arteritis following neck irradiation as a treatment for head and neck malignancy has been well documented. The long-term sequelae of radiation exposure of the carotid arteries may take years to manifest clinically, and extra-cranial carotid artery (ECCA) stenosis is a well-recognised vascular complication. These carotid lesions should not be regarded as benign and should be treated in the same manner as standard carotid stenosis. Previous studies have noted increased cerebrovascular events such as stroke in this cohort of patients because of high-grade symptomatic carotid stenosis resulting in emboli.
  
  
  OBJECTIVE
  To evaluate the effect of radiation therapy on ECCA atherosclerosis progression.
  
  
  METHODS
  Online search for case-control studies and randomised clinical trials that reported on stenosis in extra-cranial carotid arteries in patients with neck malignancies who received radiation therapy (RT) comparing them to patients with neck malignancies who did not receive RT.
  
  
  RESULTS
  Eight studies were included in the final analysis with total of 1070 patients - 596 received RT compared to 474 in the control group. There was statistically significant difference in overall stenosis rate (Pooled risk ratio  =  4.38 [2.98, 6.45], P  =  0.00001) and severe stenosis (Pooled risk ratio  =  7.51 [2.78, 20.32], P <0.0001), both being higher in the RT group. Pooled analysis of the five studies that reported on mild stenosis also showed significant difference (Pooled risk ratio  =  2.74 [1.75, 4.30], 95% CI, P  =  0.0001).
  
  
  CONCLUSIONS
  The incidence of severe ECCA stenosis is higher among patients who received RT for neck malignancies. Those patients should be closely monitored and screening programs should be considered in all patients who receive neck RT.
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick (UHL), Limerick, County Limerick, Ireland.
authors.forename: Khalid
authors.initials: K
authors.lastname: Bashar
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick (UHL), Limerick, County Limerick, Ireland.
authors.forename: Donagh
authors.initials: D
authors.lastname: Healy
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick (UHL), Limerick, County Limerick, Ireland.
authors.forename: Mary
authors.initials: M
authors.lastname: Clarke-Moloney
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick (UHL), Limerick, County Limerick, Ireland.
authors.forename: Paul
authors.initials: P
authors.lastname: Burke
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick (UHL), Limerick, County Limerick, Ireland.
authors.forename: Eamon
authors.initials: E
authors.lastname: Kavanagh
authors.affiliation: Department of surgery, National University of Ireland Galway (NUIG), Galway, County Galway, Ireland.
authors.forename: Stewart-Redmond
authors.initials: SR
authors.lastname: Walsh
mesh_terms: D002340:Carotid Artery Diseases / Q000209:etiology / Q000473:pathology*; D002343:Carotid Artery, Internal / Q000473:pathology / Q000528:radiation effects*; D013700:Giant Cell Arteritis / Q000209:etiology / Q000473:pathology*; D006258:Head and Neck Neoplasms / Q000150:complications / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D011878:Radiotherapy / Q000009:adverse effects*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D018616:Ultrasonography, Doppler, Duplex