Predicting survival and early clinical response to primary chemotherapy for patients with locally advanced breast cancer using DCE‐MRI

Abstract

Purpose:To evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as a tool for early prediction of response to neoadjuvant chemotherapy (NAC) and 5-year survival in patients with locally advanced breast cancer.Materials and Methods: DCE-MRI was performed in patients scheduled for NAC (n ϭ 24) before and after the first treatment cycle. Clinical response was evaluated after completed NAC. Relative signal intensity (RSI) and area under the curve (AUC) were calculated from the DCE-curves and compared to clinical treatment response. Kohonen and probabilistic neural network (KNN and PNN) analysis were used to predict 5-year survival.Results: RSI and AUC were reduced after only one cycle of NAC in patients with clinical treatment response (P ϭ 0.02 and P ϭ 0.08). The mean and 10th percentile RSI values before NAC were significantly lower in patients surviving more than 5 years compared to nonsurvivors (P ϭ 0.05 and 0.02). This relationship was confirmed using KNN, which demonstrated that patients who remained alive clustered in separate regions from those that died. Calibration of contrast enhancement curves by PNN for patient survival at 5 years yielded sensitivity and specificity for training and testing ranging from 80%-92%.Conclusion: DCE-MRI in locally advanced breast cancer has the potential to predict 5-year survival in a small patient cohort. In addition, changes in tumor vascularization after one cycle of NAC can be assessed.

Monitoring neoadjuvant chemotherapy in breast cancer patients: Improved MR assessment at 3 T?

“…In addition, our results indicate that 3 T DCE-MRI can predict the response at an earlier stage in treatment, for more of the MR-derived parameters, compared to 1.5 T. The earliest significant changes for responders were reductions in MR-derived volume parameters before the second cycle of NAC, and most significant the reduction in tumor volume at 3 T (Fig. 4), which is in accordance with other studies (9,11,15,16). The most apparent reason for obtaining an improved predictive value at 3 T is the higher SNR.…”

“…Trying to differentiate between responders and nonresponders pretreatment did not prove successful at 1.5 T or 3 T, which is in agreement with other studies on 1.5 T (9,11,15,16). Using the modified RECIST criteria, the Type I and total volume were significantly different at NAC4 at 3 T. Breast cancer is a heterogeneous disease that gives rise to a range of overlapping values for responders and nonresponders.…”

“…Patients with cCR or cPR were defined as responders, whereas patients with cSD or cPD were defined as nonresponders. We compared all results using cPR !50% reduction (modified RECIST, Table 3) because this modification of the RECIST criteria has been used in several other papers (11,14,31).…”

“…Promising results have been reported for diagnosis (7), therapy response monitoring (8,9), and survival prediction (10)(11)(12). Both semiquantitative (calculated directly from the contrast uptake curves) and pharmacokinetic parameters (based on kinetic modeling of the contrast uptake curves) (13) can be obtained by analyzing MRI data from the breast.…”

“…Using a combination of semiquantitative DCE-MRI-derived parameters, pathological complete response can be predicted before treatment (14). Several investigators have found early tumor size reduction to be the strongest predictor of a response to NAC (8,9,11,(15)(16)(17)(18)(19), some after only one cycle of chemotherapy (9,11,15,16). Using pharmacokinetic modeling to analyze DCE-MRI data, responders have been shown to experience a significant reduction in K trans (the transfer constant of contrast agent between the blood plasma and the extravascular extracellular space) (15)(16)(17).…”