动态对比增强磁共振渗透性参数早期监测肝转移瘤贝伐单抗联合常规化疗治疗敏感性的价值

摘要

目的 探讨动态对比增强磁共振(DCE-MRI)渗透性参数早期监测肝转移瘤贝伐单抗和常规化疗联合治疗敏感性的价值.方法 对28例直结肠癌的肝转移瘤患者进行常规磁共振平扫、DCE-MRI检查,分别测量化疗前及化疗第1周期后靶病灶的DCE-MRI渗透性参数,即转运常数(Ktrans)、细胞外血管外间隙的体积百分数(Ve)、回流常数(Kep)、血浆体积百分数(Vp);将所有靶病灶分为高敏感组和低敏感组,采用t检验比较两组靶病灶化疗早期渗透性参数的差异,受试者工作特征曲线分析渗透性参数早期预测转移瘤化疗敏感性的诊断效能.结果 共64个肝转移瘤靶病灶,包括高敏感组29个和低敏感组35个.化疗前,高敏感组靶病灶的Ktrans0和Kep0值明显高于低敏感组,差异有统计学意义(P=0.040,P=0.049),而Ve0、Vp0值组间比较差异无统计学意义(P＞0.05).化疗第1周期后高敏感组的Ktrans1、Kep1值较化疗前Ktrans0、Kep0值明显下降,差异有统计学意义(P =0.017,P=0.031),而Ve1、Vp1值无变化,各参数组间差异均无统计学意义(P＞0.05).Ktrans0取阈值0.149 min-1时,其敏感性、特异性和曲线下面积值分别为89.7％、62.9％和0.782;Kep0取阈值1.129 min-1时,其敏感性、特异性和曲线下面积值分别为65.5％、71.4％和0.726.结论 DCE-MRI渗透性参数有助于早期监测化疗疗效,Ktrans值可作为预测肝转移瘤对化疗敏感性的定量指标.%Objective To investigate the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) permeability parameters in monitoring the early response to bevacizumab plus chemotherapy in colorectal cancer patients with liver metastases.Methods Magnetic resonance examinations including plain and DCE-MRI were performed in 28 colorectal cancer patients with liver metastases.The permeability parameters including the volume transfer constant (Kt),extravascular extracellular volume fraction (Ve),reverse volume transfer constant (Kep),and percentage of plasma volume (Vp) were measured before chemotherapy and at the first chemotherapy cycle.All the target lesions were grouped into the hypersensitivity and hyposensitivity groups,and t test was used to calculate the statistical significance between these two groups.The receiver operating characteristic (ROC) curve analysis was also performed for evaluating the diagnostic efficacy in monitoring the early response to chemotherapy.Results Totally 64 target lesions,including 29 lesions in the hypersensitivity group and 35 lesions in the hyposensitivity group,were confirmed.The Ktrans0 and Kep0 values of the hypersensitivity group were significantly higher than those of the hyposensitivity group before chemotherapy (P =0.040,P =0.049),whereas the Ve0 and Vp0 values showed no statistically significant difference (P ＞ 0.05).The Ktrans1 and Kep1 values of the hypersensitivity group were significantly lower at the first chemotherapy cycle than the Ktrans0 and Kep0 values before chemotherapy (P =0.017,P =0.031),and the Ve1 and Vp1 values showed no significant change between these two groups (P ＞ 0.05).When the Ktrans0 value was 0.149 min-1 the area under curve was 0.782,the sensitivity was 89.7％,and the specificity was 62.9％.When the Kep0 value was 1.129 min-1,the area under curve was 0.726,the sensitivity was 65.5％,and the specificity was 71.4％.Conclusion The DCE-MRI permeability parameters is useful for monitoring the early response to chemotherapy,and the Ktrans value can be a quantitative indicator to predict early response.