磁共振扩散加权成像早期预测肺癌化疗疗效的价值

目的：评价磁共振扩散加权成像（DWI）对肺癌化疗疗效的早期预测价值。方法：对30例经病理证实的肺癌患者，在化疗前及第一周期化疗后进行MRI检查，包括常规T1wI，T2 wI及DWI检查。根据第二周期化疗后肿瘤最大径退缩率，按RECIST标准将患者分为治疗有效组和无效组，比较两组中肿瘤的表观扩散系数（ADC值）和最大径的差异，分析ADC值变化率的受试者工作特征曲线（ROc），获得预测治疗有效的ADC值变化率临界值（cut—offvalue）。结果：第一周期化疗后，有效组化疗前后病灶的平均ADC值的差异有统计学意义（P值d0．001）；有效组和无效组中肿瘤ADC值的差异有统计学意义（P-0．031）；肿瘤最大径在两组间的差异无统计学意义（P-0．210）。以ADC值升高8．5％作为ADC值变化率诊断分界点，预测治疗获得PR的敏感度为85．7％，特异度为72．9％。结论：ADC值可以对肺癌化疗疗效进行早期监测。

Value of diffusion weighted MR imaging in early prediction of chemotherapy effect for lung cancer

Objective： To assess the value of diffusion weighted MR imaging （DWI） in early prediction of chemothera- py effect for lung cancer. Methods：The prospective study included 30 patients with lung cancer undergoing chemotherapy. MRI examinations were performed before chemotherapy （the first time point） and after the first cycle of chemotherapy （the second time point）, with conventional Tl WI, T2 WI and DWI. On the basis of RECIST standard, all patients were divided in- to responding and non-responding group based on tumor maximum diameter shrinkage rate after the second cycle of chemo therapy. ADC value of the tumor and the tumor maximum diameter between the two groups were compared. The cut-off value of ADC for responding prediction was evaluated by analyzing the ROC curve of the change rate of ADC. Results：After first cycle of chemotherapy, there was statistical significant difference of mean ADC value between tumors of pretherapy group and posttherapy group in responding group （P〈0. 001）. There was also statistical significant difference of ADC value of tumors between responding group and non-responding group （P= 0. 031）. These was no significant difference of tumor maximum diameter in both groups （P= 0. 210）. When the ADC value increased 8.5% being set as cutoff point for the prediction of responding （including partial and complete response） after chemotherapy,the sensitivity was 85.7% and the specificity was 72.9%. Conclusion： ADC value is a promising biomarker for predicting chemotherapy responses at an early stage in lung cancer.