Comparative value of 99mTc-sestamibi scintimammography and sonography in the diagnostic workup of breast masses

OBJECTIVE: This study was conducted to assess the relative roles of 99mTc-sestamibi scintimammography and sonography in the evaluation of breast lesions that are indeterminate or suspicious on mammography or clinical examination. SUBJECTS AND METHODS: Twenty-five patients with 33 biopsy-proven breast lesions underwent both scintimammography and sonography. Lesions were categorized as benign or requiring biopsy on the basis of the absence or presence of a focus of increased activity on scintimammography and the shape, orientation, and echogenicity of the lesion on sonography. RESULTS: Sensitivity and specificity in detecting breast cancer were 92% and 95%, respectively, for scintimammography and 100% and 48%, respectively, for sonography. The higher specificity of scintimammography was statistically significant (p < 0.01). CONCLUSION: Although the overall accuracy of 99mTc-sestamibi scintimammography in the diagnosis of breast cancer was high, it has several disadvantages in comparison with sonography. Scintimammography has a slightly higher false-negative rate for breast cancer, is unable to reveal cysts, is more expensive, takes longer to perform, and involves ionizing radiation. For these reasons, scintimammography with 99mTc-sestamibi is unlikely to either replace sonography or be frequently used in addition to sonography.