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

In order 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 T1a 0.26 in the group of T1a carcinomas, 0.56 in T1b 0.95 in T1c and 0.97 T2 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 1 cm biological factors are probably involved too.