动态对比增强磁共振成像定量参数与半定量参数评估晚期肺癌患者放化疗敏感性的价值分析

Effects of quantitative parameters and semi-quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging in evaluating chemoradiotherapy sensitivity of patients with advanced lung cancer

目的探讨动态对比增强磁共振成像(DCE-MRI)定量参数与半定量参数评估晚期肺癌患者放化疗敏感性的价值。方法36例局部晚期肺癌患者均采用同步放化疗治疗。所有病例均在同步放化疗前后进行常规磁共振平扫及DCE-MRI扫描,计算DCE-MRI半定量参数与定量参数。根据肿瘤退缩及病理学检查将患者分为敏感组(21例)与低敏感组(15例),比较两组各项参数差异。采用受试者工作特征(ROC)曲线分析定量参数与半定量参数评估晚期肺癌患者放化疗敏感性的价值。结果敏感组患者达峰时间(TIP)短于低敏感组,最大信号增强比率(SERmax)、正性增强积分(PEI)均高于低敏感组,差异均有统计学意义(P﹤0.05)。敏感组患者容量转移常数(Ktrans)、速率常数(Kep)均高于低敏感组,血管外细胞外间隙容积比(Ve)低于低敏感组,差异均有统计学意义(P﹤0.05)。半定量参数中TIP、SERmax、PEI的曲线下面积分别为0.586、0.482、0.599。TIP最佳诊断阈值是41.7 s,此时诊断灵敏度为78.3%,特异度为62.4%;PEI最佳诊断阈值是116.5,此时诊断灵敏度为66.4%,特异度为63.7%。定量参数中Ktrans、Kep、Ve的曲线下面积分别为0.735、0.688、0.711,所有曲线下面积均﹥0.6。Ktrans最佳诊断阈值是0.37 min-1,此时诊断灵敏度为81.6%,特异度为72.5%;Kep最佳诊断阈值是1.54 min-1,此时诊断灵敏度为65.2%,特异度为83.3%;Ve最佳诊断阈值是0.18,此时诊断灵敏度为85.4%,特异度为74.5%。结论DCE-MRI的半定量、定量参数均能有效评价晚期肺癌肿瘤消退情况,尤其是定量参数在评估放化疗敏感性方面较强。

Objective To explore the quantitative parameters and semi-quantitative parameters of dynamic contrast enhanced magnetic resonance imaging(DCE-MRI)in evaluating chemoradiotherapy sensitivity of patients with advanced lung cancer.Method A retrospective study was used to select 36 patients with locally advanced lung cancer confirmed by pathology as study subjects,and all patients were treated with concurrent chemoradiotherapy.All cases underwent rou-tine MRI plain scan and DCE-MRI scan before and after concurrent radiotherapy and chemotherapy,and the semi quanti-tative and quantitative parameters of DCE-MRI were calculated.Patients were divided into sensitivity group(n=21)and low-sensitivity group(n=15)according to the tumor regression and pathological examination,and the parameters were compared between the two groups.The receiver operating characteristic(ROC)curve was used to analyze the value of quantitative and semi quantitative parameters in evaluating the chemoradiotherapy sensitivity of patients with advanced lung cancer.Result The time to peak(TIP)of the sensitivity group was significantly shorter than that of low-sensitivity group,and the maximum ratio of signal enhancement(SERmax)and positive enhancement integral(PEI)were significantly higher than those of the low-sensitivity group(P<0.05).The volume transfer constant(Ktrans)and rate constant(Kep)of the sensitivity group were significantly higher than those of the low-sensitivity group,and the extracellular space volume ra-tio(Ve)value was significantly lower than that of low-sensitivity group(P<0.05).In the semi quantitative parameters,the areas under the curve of TIP,SERmax and PEI were 0.586,0.482 and 0.599 respectively.The best diagnostic threshold of tip was 41.7 s.At this time,the diagnostic sensitivity was 78.3%and the specificity was 62.4%.The optimal diagnostic threshold of PEI was 116.5.At this time,the diagnostic sensitivity was 66.4%and the specificity was 63.7%.In the quan-titative parameters,the areas under the curves of Ktrans,Kep and Ve were 0.735,0.688 and 0.711 respectively,and the areas under all curves were>0.6.The best diagnostic threshold of Ktrans was 0.37 min-1.At this time,the diagnostic sensitivity was 81.6%and the specificity was 72.5%.The best diagnostic threshold of Kep was 1.54 min-1.At this time,the diagnostic sensitivity was 65.2%and the specificity was 83.3%;The best diagnostic threshold of Ve was 0.18.At this time,the diag-nostic sensitivity was 85.4%and the specificity was 74.5%.Conclusion Semi-quantitative and quantitative parameters of DCE-MRI can effectively evaluate the regression of advanced lung cancer tumors,especially the quantitative parame-ters are strong in assessing the chemoradiotherapy sensitivity.