磁共振弥散加权成像体积法对局部晚期直肠癌新辅助放化疗完全反应的评估价值

Diffusion-weighted imaging for assessing complete response of neoadjuvant chemoradiotherapy in locally advanced rectal cancer

目的探讨磁共振弥散加权成像(DWI)对局部晚期直肠癌新辅助放化疗(NCRT)病理完全反应(CR)的预测价值。方法50例局部晚期直肠癌患者在NCRT前后采用MRI、DWI技术评估肿瘤体积和表观扩散系数(ADC),并用ROC曲线分析比较DWI、MRI肿瘤体积测量及ADC对CR的诊断效能。结果DWI分析显示,CR组肿瘤体积平均减少率为91.2%,非CR组为70.1%,两者差异有统计学意义(P<0.01)。ROC分析显示,DWI肿瘤测量体积法对CR诊断的灵敏度、特异度、准确性均高于MRI肿瘤体积法和ADC法。结论NCRT后DWI肿瘤体积测量法可用于评估局部晚期直肠癌对新辅助放化疗反应。

Objective To explore the predictive value of diffusion-weighted imaging(DWI)for pathological complete response(CR)of neoadjuvant chemoradiotherapy(NCRT)in locally advanced rectal cancer(LARC).Methods Tumor volume and apparent diffusion coefficient(ADC)were evaluated by MRI and DWI in 50 LARC patients before and after NCRT.The diagnostic accuracy of tumor volume and ADC after NCRT was compared by ROC curve.Results DWI showed that the mean reduction of tumor volume was higher in CR group than in non-CR group(91.2%vs 70.1%,P<0.01).ROC analysis demonstrated that the sensitivity,specificity and accuracy of DWI for tumor volume were superior to those of MRI and ADC.Conclusion Tumor volume measurement of DWI is feasible to evaluate the NCRT response in LARC.