3.0TMRI表观系数结合动态增强早期预测肝转移瘤化疗疗效价值

The Clinical Value of 3.0 T MR DWI ADC Combined with Dynamic Contrast-Enhanced MRI in Predicting the Early Response of Hepatic Metastases to Chemotherapy

目的探讨3.0 T磁共振扩散加权成像(DWI)表观扩散系数(ADC)值结合MRI动态增强对肝脏转移瘤的化疗疗效早期评估价值。方法对52例(81个病灶)临床或病理证实肝转移瘤患者在化疗前、化疗2个疗程、4个疗程后分别进行MRI常规平扫及增强扫描,同时行DWI并测得相应病灶ADC值。依据RECIST标准作为肝脏转移瘤化疗疗效评价标准。运用受试者工作特征(ROC)曲线评估2个疗程后ADC值变化率诊断效能,获得ADC值变化率最佳阈值(cut-off value)。结果治疗前ADC均值:有效组为(1.105±0.332)×10-3mm2/s,无效组为(1.289±0.354)×10-3mm2/s,两组间差异无统计学意义(P=0.077)。化疗2个疗程后ADC均值:有效组为(1.378±0.477)×10-3mm2/s,无效组为(1.378±0.477)×10-3mm2/s,两组间差异有统计学意义(P=0.03)。化疗4个疗程后ADC均值:有效组为(1.898±0.484)×10-3mm2/s,无效组为(1.382±0.457)×10-3mm2/s,两组间差异有显著统计学意义(P=0.00)。有效组ADC值变化率与无效组ADC值变化率比较差异有统计学意义(P=0.000)。当化疗2个疗程后ADC值升高19.59%时,敏感性为79.2%,特异性为78.9%,ROC曲线下面积0.844。结论动态监测ADC值在化疗过程中的变化或将成为早期预测肝脏转移瘤化疗疗效的一种量化指标。

Objective To evaluate apparent diffusion coefficient （ADC） of diffusion-weighted imaging （DWI） with a 3.0T MR scanner combined with contrast-enhanced dynamic MRI in predicting the early response of hepatic metastatic tumors to chemotherapy. Methods A total of 52 patients with clinically-or pathologically-proved hepatic metastases （81 lesions in total） were enrolled in this study. Conventional plain and enhanced MRI together with DWI as well as ADC determination were carried out in all patients before the chemotherapy as well as after 2 and 4 courses chemotherapy treatment. According to the response evaluation criteria in solid tumors （RECIST） the therapeutic results were evaluated. By using receiver operating characteristic （ROC） curve, the variance rates of ADC values after 2 and 4 cycles of chemotherapy were assessed, and then the optimal cut-off value of ADC was determined. Based on the therapeutic results the patients were divided into effective group and invalid group. Results Before chemotherapy, no statistically significant difference in the mean ADC value existed between effective group （ 1. 105 ± 0. 332 ） × 10^-3 mm^2/s and the invalid group （ 1. 289 ± 0.354） × 10^-3mm^2/s （P =0.077）. After two cycles of chemotherapy, the mean ADC values in the effective group and the invalid group were （ 1. 378 ± 0. 477 ） × 10^-3 mm^2/s and （ 1. 378 ± 0. 477 ） × 10^-3 mm^2/s respectively, the difference between the two groups was statistically significant （ P = 0.03 ）. After four cycles of chemotherapy, the mean ADC values in the effective group and the invalid group were （ 1. 898 ± 0. 484 ）× 10^-3 mm^2/s and （ 1. 382 ± 0. 457 ） × 10^-3 mm^2/s respectively, the difference between the two groups was statistically significant （ P = 0.00 ）. The difference in variance rate of ADC values determined after two cycles chemotherapy was statistically significant between the two groups （ P = 0.00 ）. After two cycles chemotherapy the ADC value was increased by 19.59% , and at this point of time the sensitivity and specificity of predicting chemotherapy effect were 79.2% and 78.9% respectively, the area under ROC curve was 0. 844. Conelusion In treating patients with hepatic metastatic tumors, the changes of ADC value during chemotherapy course may probably become a quantitative index used in predicting early therapeutic effect.