Early Prediction of Response to Neoadjuvant Chemotherapy Using Dynamic Contrast-Enhanced MRI and Ultrasound in Breast Cancer

OBJECTIVE: To determine the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and DCE ultrasound (DCE-US) for predicting response to neoadjuvant chemotherapy (NAC) in breast cancer patients. MATERIALS AND METHODS: This Institutional Review Board-approved prospective study was performed between 2014 and 2016. Thirty-nine women with breast cancer underwent DCE-US and DCE-MRI before the NAC, follow-up DCE-US after the first cycle of NAC, and follow-up DCE-MRI after the second cycle of NAC. DCE-MRI parameters (transfer constant [Ktrans], reverse constant [kep], and leakage space [Ve]) were assessed with histograms. From DCE-US, peak-enhancement, the area under the curve, wash-in rate, wash-out rate, time to peak, and rise time (RT) were obtained. After surgery, all the imaging parameters and their changes were compared with histopathologic response using the Miller-Payne Grading (MPG) system. Data from minor and good responders were compared using Wilcoxon rank sum test, chi-square test, or Fisher's exact test. Receiver operating characteristic curve analysis was used for assessing diagnostic performance to predict good response. RESULTS: Twelve patients (30.8%) showed a good response (MPG 4 or 5) and 27 (69.2%) showed a minor response (MPG 1–3). The mean, 25th, 50th, and 75th percentiles of Ktrans and Kep of post-NAC DCE-MRI differed between the two groups. These parameters showed fair to good diagnostic performance for the prediction of response to NAC (AUC 0.76–0.81, p ≤ 0.007). Among DCE-US parameters, the percentage change in RT showed fair prediction (AUC 0.71, p = 0.023). CONCLUSION: Quantitative analysis of DCE-MRI and DCE-US was helpful for early prediction of response to NAC.

Diffusion-weighted and Dynamic Contrast-enhanced MRI of Metastatic Bone Tumors: Correlation of the Apparent Diffusion Coefficient, K(trans) and ve values

PURPOSE: To investigate whether quantitative parameters derived from Diffusion-weighted magnetic resonance imaging (DW-MRI) correlate with those of Dynamic contrast-enhanced MRI (DCE-MRI). MATERIALS AND METHODS: Thirteen patients with pathologically or clinically proven bony metastasis who had undergone MRI prior to treatment were included. The voxel size was 1.367 x 1.367 x 5 mm. A dominant tumor was selected and the apparent diffusion coefficient (ADC) value and DCE-MRI parameters were obtained by matching voxels. DCE-MRI data were analyzed yielding estimates of K(trans) (volume transfer constant) and ve. (extravascular extracellular volume fraction). Statistical analysis of ADC, K(trans), and ve value was conducted using Pearson correlation analyses. RESULTS: Fifteen lesions in pelvic bones were evaluated. Of these, 11 showed a statistically significant correlation (P < 0.05) between ADC and K(trans). The ADC and K(trans) were inversely related in 7 lesions and positively related in 4 lesions. This did not depend on the primary cancer or site of metastasis. The ADC and ve of 9 lesions correlated significantly. Of these, 4 lesions were inversely related and 5 lesions were positively related. CONCLUSION: Unlike our theoretic hypothesis, there was no consistent correlation between ADC values and K(trans) or between ADC values and ve in metastatic bone tumors.