99Tcm-MIBI scintimammography in the evaluation of breast lesions and axillary involvement:: A comparison with mammography and histopathological diagnosis

The aim of this prospective study was to determine the diagnostic value of prone lateral Tc-99(m)-MIBI scintimammography in the detection of primary breast cancer and axillary lymph node involvement in patients with breast lesions. We evaluated 83 palpable and 22 non-palpable lesions in 77 consecutive patients with a clinically palpable mass and/or suspicious mammographic finding. Early and late scintimammograms were performed after the intravenous injection of 740 MBq Tc-99(m)-MIBI. The overall sensitivity of both scintimammography and mammography in the detection of primary breast cancer was 94%. The overall specificity was 84% and 56% for scintimammography and mammography respectively. In the patients with palpable masses, the sensitivity of scintimammography was 97% and the specificity was 84%; in those with non-palpable masses, the sensitivity was 35% and the specificity 100%. For the detection of axillary lymph node involvement, the sensitivity and specificity of scintimammography were 68% and 93% respectively. However, conventional mammography showed 37% sensitivity and 86% specificity. In conclusion, scintimammography is an accurate and clinically valuable tool for evaluating palpable and non-palpable breast abnormalities. In addition to its high sensitivity, it improves the specificity of mammography both in the evaluation of breast masses and in the detection of axillary involvement. ((C) 1999 Lippincott Williams & Wilkins).