Contrast-Enhanced Ultrasound for Early Prediction of Response of Breast Cancer to Neoadjuvant Chemotherapy

Purpose To evaluate the time-intensity curve (TIC) parameters on contrast-enhanced ultrasound (CEUS) for early prediction of the response of breast cancer to neoadjuvant chemotherapy (NAC). Materials and Methods This prospective study included 41 patients with breast cancer. CEUS was performed before and after the first cycle of NAC. TIC parameters were analyzed for different regions of interest (ROIs). ROI 1 targeted the hotspot area of greatest enhancement, ROI 2 delineated the area of hyperenhancement, ROI 3 included the entire tumor on grayscale ultrasound, and ROI 4 encircled the normal parenchyma. The TIC perfusion values for ROI 1, 2, and 3 were divided by the ROI 4 value. Results 11 (26.8%) of the 41 patients showed a good response (Miller-Payne score 4 or 5) and 30 (73.2%) showed a minor response (Miller-Payne score 1, 2, or 3). There were significant differences in the wash-out area under the curve, the wash-in and wash-out areas under the curve on ROI 1/4 after the first cycle of NAC, pre-NAC mean transit time local (mTTl) on ROI 2/4, and pre-NAC mTTl on ROI 3/4 between good and minor responders (area under the receiver-operating characteristic curve >0.70, p<0.05). Conclusion Some TIC parameters obtained by CEUS may allow prediction of the response of breast cancer to NAC at a very early time point.