Candace Correa BSE, Presenter: Nothing to Disclose

Eleanor E.R. Harris MD, Abstract Co-Author: Nothing to Disclose

Harold Ira Litt PhD, Abstract Co-Author: Nothing to Disclose

Wei-Ting Hwang PhD, Abstract Co-Author: Nothing to Disclose

Lawrence J. Solin MD, Abstract Co-Author: Nothing to Disclose

Previous studies have shown an excess of myocardial perfusion defects in patients receiving left (L) vs. right (R) side breast radiation therapy (RT). In this study we attempt to correlate irradiated heart area measurements with perfusion defects and subsequent cardiac diagnoses.

Medical records from 480 women treated with RT for early stage breast cancer at an academic medical center from 1977-1990 were reviewed. 31 L and 25 R-side patients had stress tests at a mean time of 13 years post-RT, and no pre-existing cardiac disease or subsequent chest or breast RT. The amount of heart irradiated can be estimated from 2-D radiographic images (IJROBP, 2002; 54: 963). A radiologist (H.L.) outlined the cardiac silhouette from the medial treatment beam radiograph for 22/31 L-side RT patients; the remaining patients either had internal mammary RT or films could not be located. The heart area in the treatment field was determined, and central lung distance (CLD) was measured.

The L and R patients had equal Framingham risk (8%) (J Am Coll Cardiol, 1999; 34: 1348) of developing coronary artery disease (CAD) at diagnosis. However, a higher incidence of defects was found in the L vs. R-side (22/31, 71% vs. 2/25, 8%, p=0.003). The median heart area and CLD for patients with perfusion defects (14/22) was not statistically different from those without defects (8/22) (7.4 (range 3.7-15) vs. 8.7 cm² (range 1.5-17) and 2.6 (range 2.2-3.2) vs. 2.9 cm (range 2.2-3.2), respectively, p-values>0.5). Patients with congestive heart failure (CHF) had a larger median heart area irradiated (8.4 vs. 7.0 cm², p=0.8) and CLD (2.5 vs. 2.4 cm, p=0.05) than patients without CHF. There was no significant difference between patients with and without myocardial infarctions with respect to the median heart area irradiated (6.6 vs. 9.0 cm², p=0.7), or the CLD (2.6 vs. 2.9 cm, p=0.7).

There was a higher incidence of perfusion defects for L vs. R-side RT. In L-side patients, larger CLDs are correlated with an increased incidence of CHF, however, treatment area and CLD did not correlate with presence of perfusion defects or myocardial infarction.

Correa, C, Harris, E, Litt, H, Hwang, W, Solin, L, Prediction of Nuclear Stress Perfusion Defects and Cardiac Diagnoses from Amount of Heart Irradiated in Primary Radiotherapy for Left-Side Breast Cancer.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4407886.html