The Role of Planar Scintimammography With High-Resolution Dedicated Breast Camera in the Diagnosis of Primary Breast Cancer

Planar scintimammography (SM) acquired with a conventional gamma camera has proved a useful complementary tool to mammography (Mx) in breast cancer (BC) diagnosis, but with unsatisfactory sensitivity in small size carcinomas. In this study we assessed the role of planar SM with a high-resolution dedicated breast camera (DBC) in BC diagnosis, comparing the results with those of Mx. A consecutive series of 145 patients scheduled for biopsy for suspected BC underwent Tc-99m tetrofosmin planar SM using a newly developed DBC. Scintigraphic data were compared with Mx findings and correlated to histology. Histopathologic analysis revealed 165 lesions: 143 malignant and 22 benign. SM detected 139/143 carcinomas (overall sensitivity: 97.2%) and was true negative in 19/22 benign lesions (overall specificity: 86.4%). SM sensitivity was 91% in <= 10-mm carcinomas. SM was more accurate than Mx in 42/145 cases (29%), detecting cancer in 9 patients with Mx indetenninate for dense breasts (8/9 tumors were < 10 mm), assessing additional tumor foci (all < 10 mm) in 5 points with multifocal disease and correctly classifying 28 patients with inconclusive mammographic findings as affected by cancer or by benign disease. Mx was more accurate than SM in 3 patients, in each detecting 1 subcentimeter BC false negative on SM. DBC planar SM seems a highly sensitive diagnostic tool in the detection of BC, even when small in size, and in the assessment of multifocal disease. A wider employment of this procedure is thus suggested, especially in indeterminate, or inconclusive mammographic findings to improve sensitivity and specificity of Mx.