Initial evaluation of breast cancer using Tc-99m sestamibi scintimammography.

AIM: Aim of the study was to elaborate on the diagnostic role of Tc-99m sestamibi scintimammography (SMM) in the initial diagnosis of breast cancer, partially in comparison to MRI. The study presents an update of previously published data. MATERIALS AND METHODS: Out of a total of 464 scintimammograms findings of 252 studies were correlated with the histopathologic outcome. A subgroup of 68 patients with indeterminate preliminary diagnosis underwent additional MRI. SMM and MRI findings were correlated to the final hisopathological outcome. RESULTS: Overall sensitivity and specificity for SMM were 84 and 85%, respectively. Depending on tumor size sensitivity ranged from 60% for stage pT1a,b carcinomas to 94% stage pT1c or higher. In the subgroup with indeterminate preliminary diagnosis sensitivity of SMM decreased to 76% which was lower as compared to MRI (84%). Specificity of SMM was 86% in this subgroup which was evidently higher as compared to MRI (51%). CONCLUSION: SMM has severe limitations in the diagnosis of small carcinoma and therefore should not be used for breast cancer screening. SMM can be used to further evaluate indeterminate or probably benign mammographic findings, especially when conventional mammography is inconclusive due to dense breast tissue.

Gadobenate dimeglumine-enhanced MRI of the breast: analysis of dose response and comparison with gadopentetate dimeglumine.

OBJECTIVE: The purpose of this study was to evaluate the clinical efficacy and dose response relationship of three doses of gadobenate dimeglumine for MRI of the breast and to compare the results with those obtained after a dose of 0.1 mmol/kg of body weight of gadopentetate dimeglumine. SUBJECTS AND METHODS. Gadobenate dimeglumine at 0.05, 0.1, or 0.2 mmol/kg of body weight or gadopentetate dimeglumine at 0.1 mmol/kg of body weight was administered by IV bolus injection to 189 patients with known or suspected breast cancer. Coronal three-dimensional T1-weighted gradient-echo images were acquired before and at 0, 2, 4, 6, and 8 min after the administration of the dose. Images were evaluated for lesion presence, location, size, morphology, enhancement pattern, conspicuity, and type. Lesion signal intensity-time curves were acquired, and lesion matching with on-site final diagnosis was performed. A determination of global lesion detection from unenhanced to contrast-enhanced and combined images was performed, and evaluations were made of the diagnostic accuracy for lesion detection and characterization. A full safety evaluation was conducted. RESULTS: Significant dose-related increases in global lesion detection were noted for patients who received gadobenate dimeglumine (p < 0.04, all evaluations). The sensitivity for detection was comparable for 0.1 and 0.2 mmol/kg of gadobenate dimeglumine, and specificity was highest with the 0.1 mmol/kg dose. Higher detection scores and higher sensitivity values for lesion characterization were found for 0.1 mmol/kg of gadobenate dimeglumine compared with 0.1 mmol/kg of gadopentetate dimeglumine, although more variable specificity values were obtained. No differences in safety were observed, and no serious adverse events were reported. CONCLUSION: Gadobenate dimeglumine is a capable diagnostic agent for MRI of the breast. Although preliminary, our results suggest that 0.1 mmol/kg of gadobenate dimeglumine may offer advantages over doses of 0.05 and 0.2 mmol/kg of gadobenate dimeglumine and 0.1 mmol/kg of gadopentetate dimeglumine for breast lesion detection and characterization.