[Preliminary study of semi-quantitative and quantitative dynamic contrast-enhanced MRI in evaluating the response to concurrent chemoradiotherapy in patients with non-small cell lung cancer].

OBJECTIVE: To investigate the capability of semi-quantitative and quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict the response to concurrent chemoradiotherapy( CCRT) in patients with non-small cell lung cancer (NSCLC).

METHODS: A total of 24 patients with stage III or IIIB NSCLC, who underwent 3.0T DCE-MRI before CCRT, were enrolled in this study. Semi-quantitative and quantitative parameters were calculated by Funtool and Omnikinetics software. The relationship between these obtained parameters and tumor response was evaluated by Spearmen' s correlation analysis. The patients were classified into two groups according to the tumor regression rate after treatment, as response group (group A) and non-response group ( group B). Mann-Whitney U test was used to compare the parameters of responders and non-responders. The value of the parameters on predicting response was calculated by receiver operating characteristic curve (ROC).

RESULTS: The tumor regression rate after treatment was negatively correlated with time to peak (TTP) and the extravascular-extracellular volume fraction (Ve), and was positively correlated with signal enhancement ratio (SERmax) and volume transfer constant (Ktrans) (P < 0.05 for all). Statistical significant differences were found between group A and group B both in semi-quantitative and quantitative parameters (P < 0.05). Group A had a lower TTP value [(34.66 ± 16.37) s vs. (44.09 ± 17.41) s] and Ve value [(0.19 ± 0.03) vs. (0.25 ± 0.05)] than group B, whereas group A had a higher SERmax [(166.50 ± 44.95)% vs. (113.57 ± 46.62)%] and Ktrans [(0.41 ± 0.17) min(-1) vs. (0.28 ± 0.12) min(-1)] than group B (P < 0.05 for all). The ROC analysis indicated that when setting the threshold of Ve on ≤ 0.21 for predicting response, the specificity, sensitivity and accuracy were 85.7%, 80.0% and 83.3%, respectively, with an area under curve of 0.875 (P < 0.001).

CONCLUSIONS: Both the semi-quantitative and quantitative DCE-MRI parameters are helpful for predicting the response after CCRT of NSCLC. Quantitative parameters seem to be more meaningful than semi-quantitative parameters.