Scintimammography with 99M technetium - methoxyisobutylisonitrile versus X-Ray mammography in the evaluation of breast masses

ABSTRACT

To evaluate the diagnostic accuracy of scintimammography using 99m Technetium - methoxyisobutylisonitrile [99mTc-MIBI] in the detection of breast cancer in comparison with conventional mammography. A total of 113 patients with clinically suspicious breast masses and/or positive mammograms suggesting breast cancers were included in this study. After 10 minutes of 99mTc-MIBI injections, one anterior image in the prone positive and two lateral prone images were acquired for 10 minutes eash. Another set of images was taken in the same position after 60 min of injection. One-hundred and nineteen lesions [92 palpable and 27 non-palpable] were detected. There were 75 malignant and 44 benign lesions according to the histopathology findings obtained during excisional biopsies. The relation with the histopathology showed that the overall sensitivity and specificity of scintimammography were 68% and 73% respectively. However for palpable lesions, the sensitivity and specificity were 79% and 76% respectively. Sensitivity was not dependent on the density of the breast tissue. The sensitivity and specificity of mammography were 89% and 43% respectively, and did not depend on the tumor size. In 60% of false-negative mammograms, 99mTc-MIBI was able to diagnose malignancy [True-positive]. Imaging with 99mTc-MIBI showed a high diagnostic accuracy for the detection of breast cancer and could be used as a complementary imaging modality to conventional mammography in diagnosing breast cancer at an earlier stage particularly in patients with dense breasts