title: Progression of carotid intima media thickness after radiotherapy: a long-term prospective cohort study.
abstract: OBJECTIVE
  Carotid artery vasculopathy is a long-term complication of radiotherapy (RT) of the neck. We investigated the change in carotid intima media thickness (IMT) and the incidence of ischemic stroke in the first 7 years after radiotherapy (RT) of the neck.
  
  
  METHODS
  A multicentre prospective cohort study among patients treated for Head and Neck Cancer (HNC) assessed carotid IMT at baseline (before RT) and after a median of 7 years follow-up. We also screened for cerebrovascular risk factors and events.
  
  
  RESULTS
  48 patients underwent IMT measurement at baseline and follow-up (median age 61 years, range 29-87). Mean IMT of the irradiated common carotid arteries was 0.64mm at baseline and 0.74mm at follow-up (p=0.002). Mean delta IMT in the irradiated and non-irradiated common carotid arteries were 0.11 and 0.02mm (p=0.03). Incidence rate of stroke in our cohort, compared to the Dutch population was 8.9 versus 1.5 per 1.000 person years.
  
  
  CONCLUSIONS
  IMT in irradiated carotid arteries was significantly increased in the first 7years after RT. The incidence rate of stroke was six fold increased. Patients treated with RT for HNC have sustained risk for developing atherosclerosis of the carotid arteries and future stroke.
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Center, The Netherlands. Electronic address: Joyce.Wilbers@radboudumc.nl.
authors.forename: Joyce
authors.initials: J
authors.lastname: Wilbers
authors.affiliation: Department of Neurology, Medisch Spectrum Twente, Enschede, The Netherlands. Electronic address: L.Dorresteijn@mst.nl.
authors.forename: Lucille D
authors.initials: LD
authors.lastname: Dorresteijn
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Center, The Netherlands. Electronic address: roy.haast@maastrichtuniversity.nl.
authors.forename: Roy
authors.initials: R
authors.lastname: Haast
authors.affiliation: Maastricht University Medical Center, Department of Radiation Oncology (MAASTRO clinic), The Netherlands. Electronic address: frank.hoebers@maastro.nl.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Hoebers
authors.affiliation: Department of Radiation Oncology, University Nijmegen Medical Center, The Netherlands. Electronic address: j.kaanders@radboudumc.nl.
authors.forename: Johannes H
authors.initials: JH
authors.lastname: Kaanders
authors.affiliation: Department of Neurology, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. Electronic address: w.boogerd@nki.nl.
authors.forename: Willem
authors.initials: W
authors.lastname: Boogerd
authors.affiliation: Department of Biometrics, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. Electronic address: e.v.werkhoven@nki.nl.
authors.forename: Erik D
authors.initials: ED
authors.lastname: van Werkhoven
authors.affiliation: Department of Radiotherapy, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. Electronic address: m.nowee@nki.nl.
authors.forename: Marlies E
authors.initials: ME
authors.lastname: Nowee
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands. Electronic address: Rik.Hansen@radboudumc.nl.
authors.forename: Hendrik H G
authors.initials: HH
authors.lastname: Hansen
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands. Electronic address: Chris.deKorte@radboudumc.nl.
authors.forename: Chris L
authors.initials: CL
authors.lastname: de Korte
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Center, The Netherlands. Electronic address: Arnoud.Kappelle@radboudumc.nl.
authors.forename: Arnoud C
authors.initials: AC
authors.lastname: Kappelle
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Center, The Netherlands. Electronic address: Ewoud.vanDijk@radboudumc.nl.
authors.forename: Ewoud J
authors.initials: EJ
authors.lastname: van Dijk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000453:epidemiology*; D002339:Carotid Arteries / Q000528:radiation effects; D059168:Carotid Intima-Media Thickness / Q000706:statistics & numerical data*; D015331:Cohort Studies; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D016896:Treatment Outcome
keywords: Carotid artery; Cerebrovascular disease; Head and neck cancer; Intima media thickness; Radiation vasculopathy