Doxorubicin-based chemotherapy and radiation increase cardiac perfusion changes in patients treated for left-sided breast cancer
Purpose: To determine the incidence/severity of regional cardiac perfusion abnormalities in patients treated with radiation therapy (RT) to the left breast/chest wall +/- chemotherapy (CTx). Methods: 80 patients with left-sided breast cancer underwent rest cardiac perfusion imaging using single photon emission computed tomography (SPECT) with left ventricle ejection fraction (LVEF) pre-CTx, pre-RT, and 6 mos post-RT. Follow-up scans were obtained in 47 patients at 12 mos, 23 patients at 18 mos, and 9 patients at 24 mos. 49 patients received Dox-based CTx and 31 patients had no CTx. SPECT perfusion images were registered onto 3-D RT dose distributions. Regional cardiac perfusion was scored both visually (sum rest score, SRS) and by computer software that analyzes serial image changes as a function of regional RT dose. Results: The incidence of new visibly detectable perfusion defects was 59% at 6 mos post-RT, 50% at 12 mos, 63% at 18 mos, and 50% at 24 mos. The SRS was increased among patients who received CTx versus those who did not (p=0.07). As the irradiated LV volume increased, the SRS increased. At 6 mos there was a 0.18% reduction in cardiac perfusion/Gy (Fig. 1). The linear dose response curve was highly significant (p<0.0001). 4/80 patients had a decrease in LVEF to <50% following RT. 3/80 patients had pericarditis. No events of MI or CHF have occurred. Conclusions: RT causes dose-dependent defects in cardiac perfusion 6-24 mos post-RT. The severity of these defects appears to be related to the percent of LV irradiated and the use of Dox-based CTx. Long-term follow-up is needed to determine if these findings are associated with changes in global cardiac function and clinical outcome. The U.S. Army Medical Research and Materiel Command under DAMD179818071 supported this work.
Hardenbergh, P; Munley, M; Hu, C; Hollis, D; Light, K; Blazing, M; Borges-Neto, S; Prosnitz, L; Marks, L
Volume / Issue
Start / End Page
International Standard Serial Number (ISSN)