The incidence and functional consequences of RT-associated cardiac perfusion defects

Int J Radiat Oncol Biol Phys. 2005 Sep 1;63(1):214-23. doi: 10.1016/j.ijrobp.2005.01.029.


Purpose: Radiation therapy (RT) for left-sided breast cancer has been associated with cardiac dysfunction. We herein assess the temporal nature and volume dependence of RT-induced left ventricular perfusion defects and whether these perfusion defects are related to changes in cardiac wall motion or alterations in ejection fraction.

Methods: From 1998 to 2001, 114 patients were enrolled onto an IRB-approved prospective clinical study to assess changes in regional and global cardiac function after RT for left-sided breast cancer. Patients were imaged 30 to 60 minutes after injection of technetium 99m sestamibi or tetrofosmin. Post-RT perfusion scans were compared with the pre-RT studies to assess for RT-induced perfusion defects as well as functional changes in wall motion and ejection fraction. Two-tailed Fisher's exact test and the Cochran-Armitage test for linear trends were used for statistical analysis.

Results: The incidence of new perfusion defects 6, 12, 18, and 24 months after RT was 27%, 29%, 38%, and 42%, respectively. New defects occurred in approximately 10% to 20% and 50% to 60% of patients with less than 5%, and greater than 5%, of their left ventricle included within the RT fields, respectively (p = 0.33 to 0.00008). The rates of wall motion abnormalities in patients with and without perfusion defects were 12% to 40% versus 0% to 9%, respectively; p values were 0.007 to 0.16, depending on the post-RT interval.

Conclusions: Radiation therapy causes volume-dependent perfusion defects in approximately 40% of patients within 2 years of RT. These perfusion defects are associated with corresponding wall-motion abnormalities. Additional study is necessary to better define the long-term functional consequences of RT-induced perfusion defects.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / pathology
  • Breast Neoplasms / physiopathology
  • Breast Neoplasms / radiotherapy*
  • Coronary Circulation / physiology
  • Coronary Circulation / radiation effects
  • Female
  • Heart / diagnostic imaging
  • Heart / physiopathology
  • Heart / radiation effects*
  • Humans
  • Middle Aged
  • Myocardial Contraction / physiology
  • Myocardial Contraction / radiation effects*
  • Prospective Studies
  • Radiation Dosage
  • Radiation Injuries / diagnostic imaging
  • Radiation Injuries / physiopathology*
  • Stroke Volume / physiology
  • Stroke Volume / radiation effects
  • Tomography, Emission-Computed, Single-Photon