Initial evaluation of breast cancer using Tc-99m sestamibi scintimammography

Aim: Aim of the study was to elaborate on the diagnostic role of Tc-99m sestamibi scintimammography (SMM) in the initial diagnosis of breast cancer, partially in comparison to MRI. The study presents an update of previously published data. Materials and methods: Out of a total of 464 scintimammograms findings of 252 studies were correlated with the histopathologic outcome. A subgroup of 68 patients with indeterminate preliminary diagnosis underwent additional MRI. SMM and MRI findings were correlated to the final hisopathological outcome. Results: Overall sensitivity and specificity for SMM were 84 and 85%, respectively. Depending on tumor size sensitivity ranged from 60% for stage pT1a,b carcinomas to 94% stage pT1c or higher. In the subgroup with indeterminate preliminary diagnosis sensitivity of SMM decreased to 76% which was lower as compared to MRI (84%). Specificity of SMM was 86% in this subgroup which was evidently higher as compared to MRI (51%). Conclusion: SMM has severe limitations in the diagnosis of small carcinoma and therefore should not be used for breast cancer screening. SMM can be used to further evaluate indeterminate or probably benign mammographic findings, especially when conventional mammography is inconclusive due to dense breast tissue