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

OBJECTIVE. This study was conducted to assess the relative roles of Tc-99m- sestamibi scintimammography and sonography in the evaluation of breast lesi ons that are indeterminate or suspicious on mammography or clinical examina tion. SUBJECTS AND METHODS. Twenty-five patients with 33 biopsy-proven breast les ions underwent both scintimammography and sonography. Lesions were categori zed as benign or requiring biopsy on the basis of the absence or presence o f a focus of increased activity on scintimammography and the shape, orienta tion, and echogenicity of the lesion on sonography. RESULTS. Sensitivity and specificity in detecting breast cancer were 92% an d 95%, respectively, for scintimammography and 100% and 48%, respectively, for sonography. The higher specificity of scintimammography was statistical ly significant (p < 0.01). CONCLUSION. Although the overall accuracy of Tc-99m-sestamibi scintimammogr aphy in the diagnosis of breast cancer was high, it has several disadvantag es in comparison with sonography. Scintimammography has a slightly higher f alse-negative rate for breast cancer, is unable to reveal cysts, is more ex pensive, takes longer to perform, and involves ionizing radiation. For thes e reasons, scintimammography with Tc-99m-sestamibi is unlikely to either re place sonography or be frequently used in addition to sonography.