Semi-quantitative dynamic contrast enhanced MRI for prediction of response to neoadjuvant chemotherapy of breast cancer

Objective: To explore the value of semi-quantitative parameters in dynamic contrast enhanced MRI (DCE-MRI) for predicting final pathologic response in primary breast cancer patients who underwent neoadjuvant chemotherapy (NAC). Methods: Totally 48 patients with pathologically proved infiltrating ductal carcinoma through core needle puncture biopsy underwent DCE-MRI before NAC and 2 cycles after the beginning of treatment. Semi-quantitative parameters (Smax, SI2% and SIpeak%) were obtained by two ROI methods (ROIwhole and ROIhs). The patients were categorized as non-major histological response (NMHR) group and major histological response (MHR) group according to histological response evaluated using Miller & Payne system. The changes of semi-quantitative parameter 2 cycles after NAC were compared between MHR group and NMHR group. Areas under ROC for parameters predicting NAC were compared between ROIwhole and ROIhs. Results: Among 48 patients, 35 were grouped into NMHR group and 13 into MHR group. Changes in kinetic parameters (Smax, SI2% and SIpeak%) obtained by ROIwhole were -54.6% (-86.8% to -19.8%), -54.5% (-88.5% to -13.3%) and -23.3% (-63.5% to 28.1%) in MHR group, while were -14.7% (-68.8% to 113.8%), -18.7% (-74.3% to 228.6%) and 1.0% (-54.5% to 29.6%) in NMHR group, respectively (all P<0.05). Changes of kinetic parameters obtained by ROIhs were -57.3% (-82.2% to 15.3%), -41.1% (-84.3% to -16.8%) and -19.3% (-58.0% to 5.8%) in MHR group, while were -10.5% (-49.4% to 130.8%), -13.0% (-55.1% to 216.7%) and -3.9% (-55.7% to 51.2%) in NMHR group, respectively (all P<0.01). No significant difference of areas under ROC curve for kinetic parameters predicting NAC between the two ROI methods (ROIwhole and ROIhs) was found (P=0.85, 0.61 and 0.84). Conclusion: Semi-quantitative dynamic parameters of DCE-MRI can predict final pathologic response of primary breast cancer 2 cycles after NAC. ROI methods have no obvious impact on DCE-MRI semi-quantitative parameters. Copyright © 2013 by the Press of Chinese Journal of Medical Imaging Technology.