Accuracy of technetium-99m sestamibi scintimammography and X-ray mammography in premenopausal women with suspected breast cancer.

The aim of this study was to evaluate the usefulness of technetium-99m sestamibi scintimammography (SSM) and combined use of SSM and X-ray mammography (MG) in premenopausal patients with small (< or =2 cm) suspicious breast lesions. Eighty-seven premenopausal women (median age 47 years, range 32-52) with breast lesions ranging from 4 to 20 mm in greatest diameter (median 12 mm) and detected by MG, underwent SSM prior to open breast biopsy. A planar camera and single-photon emission tomography (SPET) technique were used in 23 (26.4%) and 64 (73.6%) patients, respectively. At histological examination, 72 (82.8%) breast cancers (pT1a=3, pT1b=27, pT1c=42) and 15 (17.2%) benign masses were found. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of MG and SSM were 80.6% vs 80.6%, 60.0% vs 93.3% (P<0.05), 90.6% vs 98.3%, 39.1% vs 50.0% and 77.0% vs 82.8%, respectively. MG + SSM together had a sensitivity of 94.4% (P<0.05 vs SSM alone) and an accuracy of 82.8% for the detection of breast cancer. Tumours undetected by both MG and SSM were significantly (P<0.05) smaller than those correctly diagnosed. Patients with false-negative MG were younger (P<0.05) than those with tumours correctly detected, while SSM sensitivity was independent (P=NS) of age. In conclusion, in premenopausal patients with small breast lesions, the sensitivity of SSM and MG is similar (P=NS), whereas the specificity of SSM is significantly higher (P<0.05) than that of MG. Furthermore, the combination of MG and SSM offers significantly improved sensitivity and accuracy in comparison with the individual techniques, suggesting a complementary role of SSM in the detection of breast cancer in younger patients.