Late cardiac effects in patients with left breast cancer treated with hypofractionated radiotherapy

In this study we aimed to analyse the late cardiac effects in patients with left sided breast cancer treated with hypofractionated radiotherapy.

Between January 1990 to December 2005, patients treated for left side breast cancer who had received radiotherapy at least 10 years earlier were included in this study. Radiotherapy dose was 35-40 Gy/15-16#/3 weeks. These patients underwent echocardiography, stress myocardial perfusion scintigraphy (MPS) to look for any myocardial perfusion defect (MPD). MPD extent was defined as not significant, mild, moderate and large if it was < 5%, 5-10%, > 10-20% and > 20%, whereas severity was defined as mild moderate and severe, respectively.

A total of 87 patients underwent stress myoperfusion scan (MPS). MPDs were observed in 31 (36%) patients. MPDs were not significant, mild and moderate in 5 (6%), 25 (28%) and 1 (1%) patients, respectively. In majority of patients [30 (97%)], MPDs were observed in the apex and apical anterior segment of the left ventricle myocardium. MPD intensity was mild, mild to moderate and moderate in 21 (68%), 4 (13%) and 6 (19%) patients, respectively. MPDs were reversible, partially reversible, minimally reversible and fixed in 22 (71%), 3 (10%) 1 (3%) and 5 (16%) patients, respectively. Central lung distance (CLD) ≥ 2.5 cm was a significant factor for MPDs (p = 0.027). Left ventricular ejection fraction deterioration was observed in 2 (6%) patients only. Coronary events occurred in 4 (4.5%) patients.

In patients with left sided breast radiotherapy majority of MPDs were mild. Moderate and fixed MPDs were associated with CLD ≥ 2.5 cm. Left ventricular functional deterioration was observed in few patients only.