title: Prospective cohort study of carotid intima-media thickness after irradiation.
abstract: BACKGROUND
  Carotid artery vasculopathy is a potential long-term complication after radiotherapy (RT) of the neck, resulting in cerebrovascular events. The underlying pathophysiology is not well understood and early markers are lacking. We aimed to study whether RT of the neck is associated with increase in carotid intima-media thickness (IMT) and stroke in the first 2 years after RT in patients with head and neck cancer (HNC).
  
  
  METHODS
  In this prospective cohort study patients treated with RT of the neck were assessed for measurement of IMT before and 2 years after RT. Endpoints were changed in IMT and incidence of first-ever stroke.
  
  
  RESULTS
  Between 2003 and 2008 we included 69 patients (median age, 57 years [25%-75% quartile, 51-64 years], median dose of RT 66 Gy [interquartile range, 60-70]) with baseline and follow-up measurement of IMT. Median IMT at baseline and follow-up was .60 and .62 mm (ratio of geometric means 1.01; 95% confidence interval, .96-1.08; P = .63). Four of 69 patients suffered from a stroke. Mean interval from RT to stroke was 6.8 months.
  
  
  CONCLUSIONS
  Our study showed no increase of carotid IMT in the first 2 years after RT of the neck in patients treated for HNC. This indicates that the IMT is not a reliable early marker for postirradiation vasculopathy. However, a high rate of strokes was observed. A longer follow-up period is needed to find the starting point of RT-induced vascular changes.
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Joyce
authors.initials: J
authors.lastname: Wilbers
authors.affiliation: Maastricht University Medical Center, Department of Radiation Oncology (MAASTRO clinic), GROW School for Oncology and Developmental Biology, Maastricht, The Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Hoebers
authors.affiliation: Department of Neurology/Radiotherapy/Biometrics, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Willem
authors.initials: W
authors.lastname: Boogerd
authors.affiliation: Department of Neurology/Radiotherapy/Biometrics, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Erik D
authors.initials: ED
authors.lastname: van Werkhoven
authors.affiliation: Department of Neurology/Radiotherapy/Biometrics, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Marlies E
authors.initials: ME
authors.lastname: Nowee
authors.affiliation: Department of Neurology/Radiotherapy/Biometrics, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Guus
authors.initials: G
authors.lastname: Hart
authors.affiliation: Department of Neurology/Radiotherapy/Biometrics, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: Bartelink
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. Electronic address: Ewoud.vanDijk@radboudumc.nl.
authors.forename: Ewoud J
authors.initials: EJ
authors.lastname: van Dijk
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Arnoud C
authors.initials: AC
authors.lastname: Kappelle
authors.affiliation: Department of Neurology, Medisch Spectrum Twente, Enschede, The Netherlands.
authors.forename: Lucille D
authors.initials: LD
authors.lastname: Dorresteijn
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000528:radiation effects*; D059168:Carotid Intima-Media Thickness / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011832:Radiation Injuries / Q000150:complications* / Q000453:epidemiology; D011878:Radiotherapy / Q000009:adverse effects*; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome
keywords: Head and neck cancer; carotid artery; carotid intima media thickness; radiotherapy; stroke