[Comparative study of 201Tl and 99mTc-MIBI in breast tumor]

A comparative study of 201Tl and 99mTc-MIBI was performed in 39 breast tumors. 201Tl scintigraphy was carried out in 24 breast tumors and 99mTc-MIBI scintigraphy in 15. The sensitivity of 201Tl for malignant tumors was 100% (22/22), but specificity was 0% (0/2). On 99mTc-MIBI scintigraphy, the sensitivity for the malignant tumors was 83.3% (10/12) and specificity was 100% (3/3). 99Tc-MIBI might be more useful for the diagnosis of breast tumors, because the tumor/background ratio of 99mTc-MIBI was significantly higher than that of 201Tl. In addition, 201Tl scintigraphy and 99mTc-MIBI scintigraphy showed the same degree of accuracy (93.3%) in diagnosis of lymph node reached. Moreover, when either US and 201Tl or 99mTc-MIBI scintigraphy was positive for lymph node metastasis, accuracy of detection of lymph node metastasis became 94.4%. A combined study of US and scintigraphy might improve the accuracy for diagnosis of lymph node metastasis.