A three center study on the diagnostic accuracy of 99mTc-MIBI scintimammography

In older to assess specificity and sensitivity of the prone scintimammography (PSM) in a large series with 99m-Tc MIBI, we performed a three-center study; 420 patients were studied: after mammography all the patients were submitted to PSM and biopsy and/or operation. PSM was considered positive if hot spot within the breast was observed. In palpable masses sensitivity was 0.98 and specificity 0.89, non palpable masses showed a sensitivity of 0.62 and a specificity of 0.91. When the cancers were stratified for T category the sensitivity was 0.28 in T-1s, 0.26 in the group of T-1a carcinomas, 0.56 in T-1b, 0.95 in T-1c, and 0.97 T-2 tumors. Physical factors such as attenuation, Compton scattering from chest, as well as biological factors have a role in breast tumor imaging. In the tumors smaller than 1cm biological factors are probably involved too.