Evaluation of palpable breast masses with 201Tl scintigraphy.

39 female patients (age range: 31-84 years) with palpable breast masses detected by physical examination, underwent 201Tl scintigraphy in order to assess its value in the detection of breast carcinomas and to differentiate them from benign breast masses. Planar images were carried out at 20-30 min and 2-3 h after intravenous administration of 111-185 MBq (3-5 mCi) of 201Tl chloride. In 12 patients single photon emission tomography (SPET) studies were also performed. In 18 patients the scintigraphic studies were positive and in 17 of these cases, breast carcinomas were confirmed. Tumour sizes ranged from 1.3 to 6 cm in diameter. In the remaining patient a false positive result was obtained where there was benign breast change. In three of seven cases, malignant axillary nodes were also detected. All 21 patients with negative scintigraphy had benign breast lesions. There were no differences between images obtained at 20-30 min and 2-3 h or between planar images and SPET studies. In 10 patients there was disagreement between mammography and 201Tl scans. 201Tl scans confirmed the presence of carcinoma in three cases and discarded malignancy in the other six cases. In the remaining case, 201Tl scan was false positive. 201Tl scintigraphy is useful in distinguishing malignant from benign breast masses, even when compared with mammography.