钆塞酸二钠增强MRI在结直肠癌肝转移系统治疗疗效评价中的价值

The Value of Gd-EOB-DTPA Enhanced MRI in Predicting Response of Systemic Therapy in Colorectal Liver Metastases

目的探讨肝细胞特异性对比剂钆塞酸二钠(Gd-EOB-DTPA)在评价结直肠癌肝转移系统治疗疗效中的价值。方法回顾性分析系统治疗后经手术切除的48例结直肠癌患者的83个肝转移瘤,所有患者术前行Gd-EOB-DTPA增强MRI检查。判断动脉期强化特征(环形强化/非环形强化)、肝胆期强化特征(靶样强化/非靶样强化),测量并计算参数:长径差值(动脉期长径-肝胆期长径)、信号强度比(RatioM/L)、信号强度差值(RSID)、标准化相对强化率(NRE)、对比噪声比(CNR)、表观扩散系数(ADC)值。定性参数采用χ;检验进行分析,定量参数采用独立样本t检验或Mann-Whitney U检验进行分析;采用二元Logistic回归进行多因素分析。结果反应率范围为5%~100%,反应率中位数为60%(40%,80%),以60%做为分界值,将转移瘤对系统治疗的疗效分为反应率较高组(n=44)与反应率较低组(n=39)。肝胆期靶样强化、动脉期环形强化、长径差值≥2 mm提示对系统治疗反应率较低;反应率较高组的ADC值高于反应率较低组,NRE低于反应率较低组;多因素分析结果显示,长径差值、ADC值、NRE可做为疗效评估的独立预测因素。结论 Gd-EOB-DTPA增强MRI可用于结直肠癌肝转移系统治疗后疗效的评价。

Objective To investigate the value of the liver-specific contrast agent gadoxetic acid( GD-EOB-DTPA) in the evaluation of pathologic response rate for colorectal liver metastasis( CRLM) after systemic therapy. Methods The medical records of 48 colorectal cancer patients who underwent systemic therapy with an overall number of 83 liver metastases were reviewed. All patients underwent Gd-EOB-DTPA-enhanced MRI before operation. The enhancement pattern in arterial phase( peripheral enhancement/non-peripheral enhancement) and hepatobiliary phase( target appearance/non target appearance) were determined. The parameters were measured and calculated including the longest diameter difference( arterial-hepatobiliary phase),RatioM/L( The signal intensity ratio of metastases to liver parenchyma),RSID( The relative signal intensity difference),NRE( normalized relative enhancement),CNR( the contrast-to-noise ratio) and ADC values.The χ2 test was performed for qualitative parameters,and independent sample t test or Mann-Whitney U test for quantitative parameters. The Logistic regression was used for multivariate analysis. Results The response rate ranged from 5%-100%,and the median response rate was 60%( 40%,80%). Using 60% as the cut-offvalue,the effect of systemic treatment of metastatic tumors was divided into the high response rate group( n = 44) and low response rate group( n = 39). Peripheral enhancement in arterial phase,target appearance in hepatobiliary phase and the longest diameter difference ≥ 2 mm may predict low response rate to systemic treatment. The ADC values of high response rate group were higher than low response rate group,and the NRE was lower than low response rate group. The diameter difference,ADC values and NRE can serve as an independent predictor for therapy response in CRLM. Conclusion Gd-EOB-DTPA-enhanced MRI may predict the therapy response in CRLM.