Abstract
BACKGROUND AND OBJECTIVE: DWI-MRI could detect the microscopic motion of water molecules which is sensitive to microcirculation change of many kinds of tumors after therapy. The aim of this study is to investigate the value of diffusion-weighted imaging (DWI) in monitoring and predicting lung cancer response to chemotherapy. METHODS: Nineteen patients pathologically diagnosed as lung cancer were included in this study, all of whom received both conventional MRI and DWI examinations one week before and one month after the initiation of chemotherapy. The response of lung cancers to therapy were classified into four groups: complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) based on the change of lesion diameter measured on axial T₂-weighted MR imaging. Apparent diffusion coefficients (ADCs) were measured for each lesion at pre- and post-chemotherapy and were compared with t-test. The correlations between the percentage changes of ADCs and the percentage changes of diameters (long, short, and mean) were further evaluated with Pearson correlation coefficient, as well as that between pre-chemotherapy ADCs and the percentage changes of diameters. RESULTS: The mean pre-chemotherapy ADCs was significantly higher than that of the post-chemotherapy ADCs (1.482 ± 0.456 vs 1.675±0.485, P=0.004). A positive correlation was found between the percentage changes of ADCs and the percentage changes of the long, short, and the mean diameter, respectively (r=0.635, r=0.612, r=0.539, P < 0.05). A negative correlation was found between pre-chemotherapy ADCs and the percentage change of the long diameter after chemotherapy in PR and SD group (r=-0.806, r=-0.632, P < 0.05). CONCLUSIONS: The change of ADCs can sensitively reflect the early change of lung cancer response to chemotherapy and has the potential ability to dynamically monitor the lung cancer response to chemotherapy combined with the morphological measurement.