Breast scintigraphy with 99mTc-pertechnetate and 67Ga-citrate.

Radionuclide breast scintigraphy was evaluated as a noninvasive tumor-localizing modality. Technetium-99m-pertechnetate (99mTcO4) demonstrated good correlation between malignancy and postive scintigraphy (88% accuracy in 16 cases of breast carcinoma). The high false-positive rate (29% of proven benign breast disease) limits the use of 99mTcO4 as an aid to differential diagnosis. Gallium-67-citrate (67Ga) is limited as a diagnostic adjunct (localizing in only five of ten breast malignancies). Refined techniques of positioning, shielding, gamma camera imaging, and computer assistance have helped in visualizing abnormal radionuclide accumulation.