Technical aspects of prone dependent-breast scintimammography

We describe the technical aspects of scintimammography for detecting breast cancer in patients with positive mammography or positive clinical findings. Prone dependent-breast scintimammography was performed on 390 patients evaluated for the presence of breast cancer. Planar images were acquired beginning 5 min following intravenous injection of 20 mCi of 99mTc-sestamibi. Complementary imaging by SPECT was performed in 29 selected cases. The prone dependent-breast position was well tolerated by patients, and resulted in high-quality images with easily identifiable anatomic landmarks. The sensitivity of scintimammography was 96% and specificity was 85% in 62 lesions with pathologic correlation. Interobserver agreement was 96% and intraobserver diagnostic variability was <5% in the initial 137 patients studied. The high ratio or lesion-to-background sestamibi activity and excellent separation of breast tissue from the heart and liver and anterior chest wall provides a reliable noninvasive means of breast cancer detection. (author)