The aim of this study was to evaluate the potential of Tc-99m citrate as a
new tumor-localizing agent in palpable breast masses. Scintimammography was
performed in 43 female patients. Of these, 10 women (group A) were conside
red to be healthy with no palpable breast masses, and the remaining 33 pati
ents (group B) had palpable breast masses. All patients with palpable breas
t masses underwent fine-needle aspiration cytology and subsequent biopsy wi
thin 2 weeks of the study. Nine patients had a primary malignant lesion of
the breast, whereas 24 patients had benign disease. The patients with breas
t cancer underwent surgery, and subsequently a histopathologic diagnosis wa
s made. Sensitivity, specificity, and accuracy values obtained in our study
were 87%, 100%, and 90%, respectively. Scintimammograms were performed in
these patients up to 24 hours. Initial uptake at 1 and 3 hours was noted in
all the breast masses. However, benign masses did not show persistence of
tracer uptake at 24 hours, whereas those that were malignant continued to s
how persistent radio-nuclide concentration. Thus, the uptake and outflow pa
ttern seemed to differentiate benign breast disease from breast cancer. The
study shows the potential of Tc-99m citrate for imaging and evaluating bre
ast masses.