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.
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Related Subject Headings
- Oncology & Carcinogenesis
- 3211 Oncology and carcinogenesis
- 3202 Clinical sciences
- 1112 Oncology and Carcinogenesis
- 1103 Clinical Sciences
Citation
Published In
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Oncology & Carcinogenesis
- 3211 Oncology and carcinogenesis
- 3202 Clinical sciences
- 1112 Oncology and Carcinogenesis
- 1103 Clinical Sciences