Sensitivity and specificity of planar scintimammography with 99mTc-sestamibi

Purpose: The aim of our prospective study was to determine the diagnostic accuracy of planar breast imaging with 99mTc-MIBI in detecting malignant disease. Material and methods: Ninety-six consecutive patients with 121 clinically-and/or mammographically-detected breast lesions underwent preoperative planar scintimammography. Ten minutes after injection of 700 MBq 99mTc-MIBI, two lateral prone and one anterior supine projections with an acquisition time of 8 minutes each were obtained. Interpretation of scintimammographic results 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 121 breast lesions. A sensitivity of 83.7% and a specificity of 74.2% for maligancy was achieved at planar scintimammography. Conclusion: Scintimammography with 99mTc-MIBI is an imaging modality of modest usefulness in the investigation of breast lesions. The method has a low sensitivity in lesions smaller than 10 mm in diameter, which decreases the clinical use of the method. (orig.)