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

Abstract

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.

Prediction of treatment responses to neoadjuvant chemotherapy in breast cancer using contrast-enhanced ultrasound

“…A combination of CEUS parameters and molecular subtype (model 2) exhibited a good performance (AUC =0.841) in the prediction of a good response when compared to a combination of the conventional US and molecular subtype (model 1). Studies have documented that CEUS parameters can be used to predict responses to NAC (17,21,23,24). Lee et al (21) reported that, in breast cancer, mTT changes were correlated with responses to NAC.…”

“…Studies have documented that CEUS parameters can be used to predict responses to NAC (17,21,23,24). Lee et al (21) reported that, in breast cancer, mTT changes were correlated with responses to NAC. In addition, RT has been shown to have a fair predictive value for responses during treatment (AUC =0.710) (23).…”

“…Previous studies used sample sizes of 17 to 92 cases, while we used a sample size of 143 cases. Other studies tried to established an early prediction window at first cycle of chemotherapy (21,23). We performed the CEUS examination after two cycles, which was considered a better assessment point to provide accurate and early information (28).…”

“…It is, therefore, possible to evaluate qualitative as well as quantitative tumor blood flow changes during NAC treatment (19). Blood perfusion changes in CEUS are highly correlated with pathological response efficacies (20)(21)(22). So far, studies using CEUS to evaluate of the efficacy of NAC in breast cancer have been limited to small sample sizes (17-92 patients), without incorporating clinic-pathological predictors (17,20,21,23,24).…”

“…An ROI with optimum visualization of the tumor was selected, avoiding areas with ligaments, fascia, calcifications, and necrosis. Among various algorithms (17,20,21,(23)(24)(25) the following 4 yielded the most promising results and were, therefore, selected and used to calculate the imaging parameters for analysis in this study (Figure 1 were measured three times, and the average value calculated. When there was no agreement, a third radiologist (S.C.Z., with 10 years of experience in breast CEUS) reviewed the images to reach a consensus.…”