Sensitivity and specificity of planar scintimammography with Tc-99m-sestamibi

Purpose: The aim of our prospective study was to determine the diagnostic a ccuracy of planar breast imaging with Tc-99m-MIBI in detecting malignant di sease. Material and Methods: Ninety-six consecutive patients with 121 clinically a nd/or mammographically-detected breast lesions underwent preoperative plana r scintimammography. Ten minutes after injection of 700 MBq Tc-99m-MIBI, tw o lateral prone and one anterior supine projections with an acquisition tim e of 8 minutes each were obtained. Interpretation of scintimammographic res ults was made blindly and any focal accumulation of MIBI in the breasts was the criterion for an abnormal scintigram. All lesions were operated on and histologically verified. Results: Histologically, 86 malignant and 35 benign lesions were found in 1 21 breast lesions. A sensitivity of 83.7% and a specificity of 74.2% for ma lignancy was achieved at planar scintimammography. Conclusion: Scintimammography with Tc-99m-MIBI is an imaging modality of mo dest usefulness in the investigation of breast lesions. The method has a lo w sensitivity in lesions smaller than 10 mm in diameter, which decreases th e clinical use of the method.