Apparent Diffusion Coefficient in Assessing Early Response to Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer / 中国医学影像学杂志

ABSTRACT

[Abstact] Purpose To investigate the value of apparent diffusion coefficient (ADC) of diffusion weighted imaging (DW1) in the evaluation of the efficacy of treatment of nonsmall cell lung cancer (NSCLC) with tyrosine kinase inhibitor (TKI).Materials and Methods Nineteen patients with advanced NSCLC who treated with TKIs from May 2014 to December 2015 were recruited prospectively.All patients underwent CT and MRI scans three times before targeted therapy,after 1 week and 4 weeks of treatment.The tumor maximal diameter and mean ADC value at different time points were compared.The correlations between mean ADC value and tumor maximal diameter and maximum diameter change rate at different time points were analyzed.Bland-Altman analysis was performed to confirm the reproducibility of measurements.Results The ADC value after 1 week of treatment was significantly increased compared with that before treatment (t=-6.329,P＜0.05),but the change of tumor maximal diameter was not significant (P＞0.05).The ADC value was significantly increased after 4 weeks of treatment compared with that before treatment (t=-4.878,P＜0.05),and the change of tumor maximal diameter was also significant (t=7.054,P＜0.05).The negative correlation was detected between the ADC before treatment and the maximal diameter change ratio after 4 weeks of treatment (r2=-0.474,P＜0.05).In the group of responders,there was significant difference between the ADC value before treatment and 1 week after treatment (P＜0.05).There was significant difference in ADC value between the groups of responders and non-responders after 4 weeks of treatment (P＜0.05).The Bland-Altman analysis showed good reproducibility among the operators.Conclusion The ADC value after 1 week of targeted therapy is more sensitive to the change of tumor than the maximal diameter,and the ADC value before treatment has a certain value in predicting the maximum diameters of the target after 4 weeks of targeted therapy with repeatability.