TL-201 SCINTIGRAPHY IN THE EVALUATION OF PALPABLE AND NONPALPABLE BREAST-LESIONS - CORRELATION WITH MAMMOGRAPHY AND ULTRASONOGRAPHY

Aim: Our goal was to determine the clinical usefulness of TI-201 to id entify breast cancer in patients with suspicious breast lesions on cli nical examination, and/or abnormal radiologic (mammography and/or ultr asonography) findings. Methods: TI-201 scintigraphy were performed in sixty-eight patients with 70 breast abnormalities (51 palpable, 19 non palpable) and compared with mammography and ultrasonography IUS). Earl y (15 min) and late (3 h) images of the breasts were obtained followin g the injection of 111 MBq (3 mCi) of TI-201. Visual and semiquantitat ive interpretation was performed. Results: Final diagnosis confirmed 5 2 malignant breast lesions and 18 benign conditions. TI-201 visualized 47 of 52 (90%) overall malignant lesions. Thirty-eight of 40 (95%) pa lpable and 9 of 12 (75%) nonpalpable breast cancers were detected by T I-201 scintigraphy. The smallest mass lesion detected by TI-201 measur ed 1.5 x 1.0 cm. Eleven breast lesions were interpreted as indetermina te by mammography and/or sonography TI-201 scintigraphy excluded malig nancy in 7 of 8 (88%) patients with benign breast lesions interpreted as indeterminate. Five of the 18 (28%) benign breast lesions showed TI -201 uptake. None of the fibroadenoma and fibrocystic changes accumula ted TI-201. TI-201 scintigraphy, mammography and ultrasonography showe d 90%, 92%, 85% overall sensitivity and 72%, 56%, 61% overall specific ity respectively. Twenty-one of the 28 (75%) axillary nodal metastatic sites were also detected by TI-201. In malignant and benign lesions, early and late lesion/contralateral normal side (LIN) ratios were 1.58 +/- 0.38 (mean +/- SD) and 1.48 +/- 0.32 (p > 0.05), 1.87 +/- 0.65 an d 1.34 +/- 0.20 (p < 0.05) respectively The mean early and late UN rat ios of malignant and benign groups did not show statistical difference (p > 0.05). Conclusion: Overall, TI-201 scintigraphy was the most spe cific of the three methods and yielded favourable results in palpable breast cancers, while it showed lower sensitivity in nonpalpable cance rs and axillary metastases. Combined use of TI-201 scintigraphy with m ammography and US seems to be useful in difficult cases, such as dense breasts and indeterminate breast lesions.