Myocardial perfusion imaging in breast cancer patients treated with or without post-mastectomy radiotherapy.

摘要

PURPOSE: To assess the occurrence and location of myocardial perfusion defects in left-sided mastectomized breast cancer patients, treated with or without postoperative radiotherapy according to the guidelines from the Danish Breast Cancer Cooperative Group (DBCG). PATIENTS AND METHODS: Seventeen left-sided breast cancer patients, with a median age of 59 years (range, 47-75 years), randomized to post-mastectomy irradiation plus systemic treatment, or systemic treatment alone, were examined after a median follow-up of 7.9 years (range, 6.0-12.2 years). The chest wall and the ipsilateral internal mammary nodes had been treated through two anterior-shaped electron fields, and the electron energy was chosen according to chest wall thickness, measured individually by ultrasound. The median absorbed dose was 50 Gy in 25 fractions, with 5 fractions/week. Information on clinical history was obtained and symptoms of ischemic heart disease (IHD), as well as major risk factors, were recorded. All patients had a physical examination, blood chemistry, electrocardiogram (ECG), chest X-ray and myocardial perfusion imaging by sestamibi-single photon emission computerized tomography (SPECT). SPECT-scanning was performed as a rest/dipyridamole 2-day protocol. The evaluation of regional myocardial perfusion was based on scintigrams using a 20-segment model. RESULTS: There was no significant difference between the scintigraphic findings in the two groups. Four of ten irradiated patients and four of seven non-irradiated patients showed scintigraphic defects. An anterior defect was found in one non-irradiated patient. CONCLUSIONS: This study does not indicate that the described radiotherapy technique induces detectable coronary artery disease. However, the small number of patients does not allow strong conclusions to be drawn.