title: Acute radiation effects on cardiac function detected by strain rate imaging in breast cancer patients.
abstract: OBJECTIVE
  To investigate the occurrence of early radiation-induced changes in regional cardiac function using strain rate imaging (SRI) by tissue Doppler echocardiography.
  
  
  METHODS
  We included 20 left-sided and 10 right-sided breast cancer patients receiving radiotherapy (RT) to the breast or chest wall. Standard echocardiography and SRI were performed before RT (baseline), immediately after RT (post-RT), and at 2 months follow-up (FUP) after RT. Regional strain (S) and strain rate (SR) values were obtained from all 18 left ventricular (LV) segments. Data were compared to the regional radiation dose.
  
  
  RESULTS
  A reduction in S was observed post-RT and at FUP in left-sided patients (S(post-RT): -17.6 ± 1.5%, and S(FUP): -17.4 ± 2.3%, vs. S(baseline): -19.5 ± 2.1%, p < 0.001) but not in right-sided patients. Within the left-sided patient group, S and SR were significantly reduced after RT in apical LV segments (S(post-RT): -15.3 ± 2.5%, and S(FUP): -14.3 ± 3.7%, vs. S(baseline): -19.3 ± 3.0%, p < 0.01; and SR(post-RT): -1.06 ± 0.15 s(-1), and SR(FUP): -1.16 ± 0.28 s(-1), vs. SR(baseline): -1.29 ± 0.27 s(-1), p = 0.01), but not in mid- or basal segments. Furthermore, we observed that segments exposed to more than 3 Gy showed a significant decrease in S after RT (S(post-RT): -16.1 ± 1.6%, and S(FUP): -15.8 ± 3.4%, vs. S(baseline): -18.9 ± 2.6%, p < 0.001). This could not be observed in segments receiving less than 3 Gy.
  
  
  CONCLUSIONS
  SRI shows a dose-related regional decrease in myocardial function after RT. It might be a useful tool in the evaluation of modern RT techniques, with respect to cardiac toxicity.
authors.affiliation: Department of Radiotherapy, University Hospital Gasthuisberg, Leuven, Belgium. Katrien.erven@uzleuven.be
authors.forename: Katrien
authors.initials: K
authors.lastname: Erven
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Jurcut
authors.forename: Caroline
authors.initials: C
authors.lastname: Weltens
authors.forename: Sorin
authors.initials: S
authors.lastname: Giusca
authors.forename: Joris
authors.initials: J
authors.lastname: Ector
authors.forename: Hans
authors.initials: H
authors.lastname: Wildiers
authors.forename: Walter
authors.initials: W
authors.lastname: Van den Bogaert
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Voigt
mesh_terms: D000208:Acute Disease; D001943:Breast Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000528:radiation effects*; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D011832:Radiation Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011859:Radiography