IVIM-MRI与DWI评估及预测局部晚期宫颈癌同步放化疗疗效的临床价值

The clinical value of IVIM-MRI and DWI in evaluating and predicting the efficacy of concurrent chemoradiotherapy for locally advanced cervical cancer

目的探讨磁共振体素内不相干运动(intravoxel incoherent motion,IVIM)与扩散加权成像(diffusion weighted imaging,DWI)对局部晚期宫颈癌同步放化疗近期疗效的评估及预测价值。材料与方法对21例局部晚期宫颈癌患者在同步放化疗治疗前1周内、治疗后2周、4周及治疗结束后1个月行盆腔3.0 T MRI扫描,扫描序列包括T1WI、T2WI、DWI及IVIM(10个b值,0~1000 s/mm^2),测量治疗前后表观扩散系数(apparent diffusion coefficien,ADC),慢速扩散系数(true molecular diffusion coefficient,D)、灌注分数(perfusion fraction,f)、快速扩散系数(pseudodiffusion coefficient,D*)及同期肿瘤最大径,并计算治疗后各参数变化率与肿瘤消退率。根据RECIST 1.1标准将患者分为完全缓解(the complete remission,CR)组13例和部分缓解(the partial remission,PR)组8例,本研究入组患者均达到有效控制,因此无稳定组(no stable group,SD)及进展组(progression group,PD),应用独立样本t检验比较两组间治疗前后不同时间点参数值及其变化率的差异,应用ROC曲线分析两组间有统计学差异的参数及其变化率的疗效评价效能,应用Pearson相关性分析检验参数及其变化率与肿瘤消退率的关系。结果治疗前及治疗结束后1个月肿瘤最大径为(4.64±1.31)cm及(0.40±0.53)cm,肿瘤消退率为0.91%±0.11%,CR组13例患者,PR组8例患者。治疗前CR组ADC低于PR组,f值高于PR组(P<0.05),CR组Δ%ADC及Δ%D高于PR组(P<0.05),治疗结束后Δ%f小于PR组(P<0.05),治疗前ADC与肿瘤消退率呈负相关(r=-0.462,P<0.05),治疗前f值、治疗后2周及4周Δ%ADC及Δ%D与肿瘤消退率呈正相关(r=0.614、0.487、0.64、0.451、0.428,P值均<0.05),治疗前f值、ADC值,治疗后2周及4周的Δ%D、Δ%ADC预测宫颈癌疗效的曲线下面积(area under curve,AUC)分别为(0.904、0.788、0.868、0.846、0.803、0.798)。结论IVIM和DWI定量参数及其变化率均可在治疗前预测及在治疗中动态评估宫颈癌放化疗疗效,IVIM具有更好的价值。

Objective:To explore the value of parameters related to intravoxel incoherent motion(IVIM)and diffusion weighted imaging(DWI)in evaluating and predicting the treatment efficacy of locally advanced cervical cancer under concurrent chemoradiotherapy(CCRT).Materials and Methods:Twenty-one patients with locally advanced cervical cancer underwent pelvic 3.0 T MRI scan including T1WI,T2WI,DWI and IVIM(10 b values,0—1000 s/mm^2)within 1 week before CCRT,2 and 4 weeks after the initiation of CCRT,and 1 month after CCRT.The parameters at different time points were measured before and after CCRT.Including ADC,D,f,D*as well as the maximum tumor diameter at each scan time point,and calculate the change rate of each parameter after treatment and the tumor regression rate.Patients were divided into 13 cases in the complete remission(CR)and 8 cases in the partial remission(PR)groups according to RECIST 1.1 criteria,there were no stable group(SD)and progression group(PD).The parameters and their percentages were compared between the two groups before and after CCRT at at each time point by independent-samples-t test,ROC curves were applied to analyze the effect of the response evaluation of parameters and their change percentages(Δ%),Pearson correlation test were applied to analyze the relationship between the parameters as well as their change percentages(Δ%)and tumor regression rate(TSO).Results:The maximum diameter of the tumor before treatment and 1 month after the treatment was(4.64±1.31)cm and(0.40±0.53)cm.The tumor regression rate was 0.91%±0.11%.There were 13 patients in CR group and 8 patients in PR group.The ADC of CR group was lower than that of PR group before treatment while f value was higher than that of PR group(P<0.05),theΔ%ADC andΔ%D of CR group were higher than that of PR group(P<0.05).TheΔ%f of CR group was lower than that of PR group after 1 month of treatment(P<0.05).The TSO revealed a negative correlation with pre ADC(r=-0.462,P<0.05),and a positive correlation with pre f,Δ%ADC andΔ%D 2 and 4 weeks after trearment(r=0.614,0.487,0.64,0.451,0.428,all P<0.05).In the prediction of CR group and PR group,the AUC of pre f,pre ADC,Δ%D,Δ%ADC at 2 weeks and 4 weeks after treatment were(0.904,0.788,0.868,0.846,0.803,0.798 respectively).Conclusions:The quantitative parameters of IVIM and DWI and their change percentages are helpful in predicting and monitoring the treatment efficacy of chemoradiotherapy for cervical cancer before and after treatment and IVIM has higher evaluation efficiency.