A 3 CENTER STUDY ON THE DIAGNOSTIC-ACCURACY OF TC-99M-MIBI SCINTIMAMMOGRAPHY

In older to assess specificity and sensitivity of the prone scintimamm ography (PSM) in a large series with 99m-Tc MIBI, we performed a three -center study; 420 patients were studied: after mammography all the pa tients were submitted to PSM and biopsy and/or operation. PSM was cons idered positive if hot spot within the breast was observed. In palpabl e masses sensitivity was 0.98 and specificity 0.89, non palpable masse s showed a sensitivity of 0.62 and a specificity of 0.91. When the can cers 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 scatter ing from chest, as well as biological factors have a role in breast tu mor imaging. In the tumors smaller than 1cm biological factors are pro bably involved too.