MRI in the evaluation of breast cancer patient response to neoadjuvant chemotherapy: predictive factors for breast conservative surgery.

PURPOSE We aimed to prospectively assess the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the evaluation of predictive factors for breast conservative surgery during neoadjuvant chemotherapy. MATERIALS AND METHODS Sixty-six patients were evaluated before the first treatment cycle, after the second cycle, and upon the completion of neoadjuvant chemotherapy according to largest tumor diameter, tumor volume, postcontrast enhancement, and tumor regression pattern. The patients were divided into responders (pathologic complete and near complete response) and nonresponders. Each subgroup was re-evaluated according to morphokinetic criteria for identification of candidates for breast conservative surgery. RESULTS In responders (n=27), the lesion size upon the completion of neoadjuvant chemotherapy was significantly smaller compared to nonresponders (1.5 ± 0.6 vs. 3.2 ± 0.9 cm; P < 0.001), as was the volume (1.2 vs. 11.0 cm(3); P < 0.001). The measured lesion size did not differ from the histologic size (1.5 ± 0.6 vs. 1.2 ± 0.6 cm; P = 0.09) and had a high correlation (r=0.93). In responders, the following parameters were significantly different before and after neoadjuvant chemotherapy: size (3.6 ± 1.4 to 1.5 ± 0.6 cm; P < 0.001), volume (17.6 to 1.2 cm(3); P < 0.001), predominant concentric regression, plateau and continuous time-intensity curves (P < 0.001). DCE-MRI has the sensitivity of 87% and the accuracy of 77% to identify candidates for breast conservative surgery. CONCLUSION Selected morphokinetic DCE-MRI parameters may contribute to the multidisciplinary decision when considering the selection of candidates for breast conservative surgery.