DWI对非小细胞肺癌放化疗疗效的评价

Diffusion-Weighted Imaging for the Evaluation of Chemoradiotherapy in Treating Non-Small-Cell Lung Cancers

目的探讨MRI扩散加权成像(DWI)在评价非小细胞肺癌(NSCLC)放化疗疗效中的价值。方法选择40例经病理证实为NSCLC并首次接受放化疗的患者,在治疗前1周内、治疗后1周和治疗后1个月3个时间点进行MRI-DWI扫描,并测量表观扩散系数(ADC)值。根据治疗结束后肿块最大径改变将病例分为有效组和无效组。应用独立样本t检验分析放化疗前有效组和无效组ADC值差异;治疗前后ADC值变化情况应用单因素方差分析法;两组放化疗后ADC值的变化率与肿瘤缩小率的相关性采用Pearson相关系数回归分析法。结果有效组和无效组治疗后2期ADC值均上升,有效组ADC值前后差异具有统计学意义(P<0.01),治疗后1周和1个月ADC值差异不具统计学意义;有效组和无效组治疗后1周ADC变化差异亦有统计学意义(P<0.05),选择治疗第1周ADC值变化12.5%用来监测疗效的敏感性90.9%和特异性63.4%均较高;化疗前两组ADC值存在差异(P<0.05),且疗前ADC值与肿瘤缩小率呈轻度负相关,化疗前后ADC值增大率与肿瘤缩小率存在正相关。结论 DWI在评价肺癌疗效中具有一定的临床价值,ADC值的变化可监测NSCLC的早期疗效。

Objective To investigate the clinical value of diffusion-weighted imaging（ DWI） in assessing the therapeutic effect of chemoradiotherapy for non-small-cell lung cancer（ NSCLC）. Methods A total of 40 patients with pathologically-proved NSCLC were enrolled in this study. MRI DWI scanning was performed in all patients each time at one week before treatment and one week,one month after the treatment. ADC values of the tumors were calculated on the workstation. According to the change of the tumor＇s maximal diameter after the treatment,the patients were divided into two groups： effective group and invalid group. The pretreatment ADC values were compared between the two groups by using independent-samples t test,and variance analysis was used to compare pre-treatment ADC values with post-treatment values.Pearson correlation coefficient regression analysis was applied to analyze the relevance between the post-treatment ADC values and the reduction in tumor size. Results Post-treatment ADC values of both groups were increased. In the effective group,statistically significant difference in ADC values existed between the preoperative values and postoperative ones（ P 〈0. 01）,although the difference in ADC values was not statistically significant between one week and one month after the treatment. One week after the treatment the difference in ADC values between effective and invalid group was statistically significant（ P〈 0. 05）. Using 12. 5% change of ADC value at one week after the treatment to evaluate the therapeutic effect,both the sensitivity and specificity were as high as 90. 9% and 63. 4% respectively. Before chemotherapy,significant difference in ADC values existed between the two groups（ P 〈0. 05）. Preoperative ADC values had a negative relationship with the reduction of tumor size,while postoperative ADC values had a parallel relationship with the reduction of tumor size. Conclusion DWI has certain clinical value in assessing the therapeutic effect of chemoradiotherapy for nonsmall-cell lung cancer. The changes of ADC value can be used to monitor the early therapeutic response.