Aim: To investigate the use of Tc-99m tetrofosmin as a breast imaging agent and to compare results of Tc-99m tetrofosmin scintimammography with plain-film mammography and pathological outcome. Patients and Methods: Forty-four patients (mean age, 51 years; range 26-79 years) with a palpable breast mass requiring fine needle aspiration biopsy (FNAB) were prospectively studied, All patients had Tc-99m tetrofosmin scintimammography. Patients over 35 years of age had two view mammography performed on the same day, FNAB was performed within 2 weeks of imaging, and patients referred for surgery as appropriate. Results of scintigraphy and plain-him mammography were correlated with pathological outcome. Results: Of the 44 patients, 21 had biopsy proven malignancy while 23 had benign lesions. Of the 21 patients with carcinoma, 20 (95.2 %) had positive Tc-99m tetrofosmin scintimammography while 21 (91.3 %) of the 23 patients with benign histology had negative scintigraphy, The sensitivity of scintimammography was 95.24%, the specificity was 91.3%, with a positive predictive value of 90.9% and a negative predictive value of 95.45%, Thirty-eight patients had two view mammography performed (six patients were <35 years of age), Of these 38 patients, 21 had biopsy proven malignancy white 17 had benign histology tall patients <35 years of age had benign histology). Of the 21 patients with malignancy, plain-film mammography was suspicious for malignancy in 17 (81%) while four were reported as benign, Of the 17 with benign disease, 14 patients (82.4%) had benign appearances on plain-film mammography while three (18%) had one or more findings suspicious for malignancy. The sensitivity of plain-film mammography in our group was 81%, with a specificity of 82.4%, a positive predictive value of 85% and a negative predictive value of 77.8%, Tc-99m tetrofosmin scintimammography correctly characterized all seven lesions where mammographic evaluation was limited because df dense breast parenchyma or previous surgery and/or radiotherapy. Conclusion: Tc-99m tetrofosmin scintimammography is an accurate. well tolerated and non-invasive method of differentiating benign from malignant palpable breast lesions. Negative Tc-99m tetrofosmin scintimammography excludes malignancy with a high degree of confidence while false-positive scintigraphy can occur in cases of proliferative dysplasia and hypercellular fibroadenoma. Tc-99m tetrofosmin scintimammography is particularly useful when plain-film mammography is indeterminate or limited in patients with dense breasts or a history of previous surgery and/or radiotherapy.
