Detection of defects in myocardial perfusion imaging in patients with early breast cancer treated with radiotherapy.
OBJECTIVE
To evaluate radiation-induced defects in myocardial perfusion imaging in early breast cancer patients treated with modern technique radiotherapy.


METHODS
Twenty-four patients with left-breast tumours and 12 control patients with right-breast tumours, relapse-free since treatment for primary disease, who had undergone radiotherapy at least 5 years previously and with no history of ischaemic heart disease prior to radiotherapy underwent study. In left-breast patients, at least 1 cm of heart was required to have been in the treatment field. Patients underwent cardiac assessment and single photon emission computerized tomography myocardial perfusion imaging.


RESULTS
Myocardial perfusion tracer uptake was abnormal in 17 (70.8%) left-breast and two (16.7%) right-breast patients (P = 0.002). Of the 17 abnormal scans in left-breast patients, abnormalities were confined to the cardiac apex in 16 patients, and perfusion defects were reversible (n = 7), fixed (n = 7) or mixed (n = 3). Reversible perfusion defects that were not confined to the cardiac apex were observed in two right-breast patients. Left ventricular ejection fraction was normal in all 33 patients in whom it was measured, and no myocardial perfusion abnormalities were judged to require treatment or follow-up.


CONCLUSIONS
In this selected study population modern technique radiotherapy to the left breast was associated with a significantly greater number of myocardial perfusion abnormalities than radiotherapy to the right breast. These abnormalities were both reversible and irreversible, suggesting that radiotherapy can lead to both myocardial damage and to epicardial coronary disease. With a minimum of 5 years follow-up since treatment, no abnormalities were considered to be clinically significant.
Seddon
Beatrice
B
Department of Radiotherapy, Royal Marsden Hospital NHS Trust, Sutton, Surrey, UK.
Cook
Audrey
A
Gothard
Lone
L
Salmon
Emma
E
Latus
Kate
K
Underwood
S Richard
SR
Yarnold
John
J
D000368:Aged; D001943:Breast Neoplasms / Q000532:radiotherapy*; D003326:Coronary Circulation; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging / Q000528:radiation effects; D006801:Humans; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D011878:Radiotherapy / Q000009:adverse effects; D012307:Risk Factors; D015899:Tomography, Emission-Computed, Single-Photon
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin