Breast Cancer Imaging: Can Tc-99m Sestamibi Scintimammography Fit In?

Abstract

Mammography and physical examination are currently the most frequently used screening tests for breast cancer. Considering the 85% sensitivity associated with combined mammography and physical examination and a low positive predictive value of 20% to 30% for the diagnosis of breast carcinoma, there is a critical need for a more accurate noninvasive imaging test to improve the sensitivity and specificity of mammography. This study evaluates the role of Tc-99m sestamibi scintimammography as a complementary procedure to conventional mammography for the detection of breast carcinoma. A sample of 157 women (mean age 47.9 years +/- 10.2 years) with 164 lesions appropriate for histologic and cytologic analysis on the basis of suspicious findings on a mammogram and/or physical examination underwent scintimammography. Subsequently, excisional biopsy and/or fine-needle aspiration were performed. There were 52 primary cancers (8 different histopathologic types) and 112 benign breast lesions (6 different histopathologic types). The sensitivity of Tc-99m sestamibi scintimammography for detecting primary breast cancer was 92.3%, and its specificity was 87.5%. Percent-positive and -negative predictive values associated with Tc-99m sestamibi scintimammography in this cohort were 77.4% and 96.0%, respectively.