全容积表观扩散系数直方图定量分析术前预测不同亚型乳腺癌新辅助化疗后病理完全缓解的价值

目的 探讨全容积表观扩散系数(ADC)直方图参数在预测乳腺癌新辅助化疗(NAC)后获得病理完全缓解(PCR)的价值。方法 回顾性分析2016年1月至2017年12月南京医科大学第一附属医院经穿刺病理证实为浸润性乳腺癌的117例患者,在进行NAC前均行常规3.0 T乳腺MRI检查,化疗后手术病理采用Miller-Payne分级系统评价化疗反应,分为病理完全缓解组(PCR)和非病理完全缓解组(nPCR)。人表皮生长因子受体2(HER2)过表达型21例(PCR者5例),三阴性型26例(PCR者6例)。采用Firevoxel软件生成ADC直方图,记录多个ADC直方图参数,包括ADC最小值(ADCmin)、ADC平均值(ADCmean)、ADC最大值(ADCmax)、偏度系数、峰度系数,利用SPSS 24.0计算出ADC第10百分位数(ADC10%)、ADC第50百分位数(ADC50%)、ADC第90百分位数(ADC90%)。采用两独立样本t检验(正态分布)或Mann-Whitney U检验(偏态分布)比较PCR组和nPCR组各ADC直方图参数的差异。采用受试者操作特征(ROC)曲线评价有统计学意义的ADC参数的诊断效能。结果 HER2过表达型在PCR组与nPCR组患者间,峰度系数的差异有统计学意义(P=0.039),ROC曲线下面积为0.813,截断点为1.861,其灵敏度为100.0%,特异度为68.7%。PCR组和nPCR组三阴性型患者间,ADCmean及ADC50%的差异有统计学意义(P值分别为0.028和0.013),ADCmean及ADC50%在三阴性型中预测PCR的ROC曲线下面积分别为0.800、0.842。当ADCmean取1.030×10-3 mm2/s、ADC50%取0.976×10-3 mm2/s作为截断点,诊断灵敏度分别为75.0%、80.0%,特异度均为83.3%。结论 峰度系数对预测HER2过表达型患者NAC后PCR具有一定的价值,ADC50%对预测三阴性乳腺癌NAC后PCR具有较高的应用价值。

Whole-lesion histogram analysis of apparent diffusion coefficient for the prediction of pathological complete response to neoadjuvant chemotherapy in different subtypes of breast cancer

Objective To investigate the value of whole-lesion histogram parameters of apparent diffusion coefficient(ADC)in evaluating and predicting the pathological complete response(PCR)to neoadjuvant chemotherapy(NAC)in different subtypes of breast cancer.Methods This retrospective study included 117 patients with breast cancer who underwent MRI examination before NAC prior to surgery from January 2016 to December 2017 in the First Affiliated Hospital of Nanjing University.All cases were divided into Luminal B,HER2 positive(n=21)and triple negative(n=26)groups.The surgical pathology after chemotherapy was evaluated by Miller-Payne(M-P)system and the patients were divided into PCR group and non-PCR(nPCR)group.Firevoxel software was used to generate the whole-lesion ADC histogram.The parameters included mean(ADCmean),skewness,kurtosis,the minimum(ADCmin),the maximum(ADCmax),10th percentile(ADC10%),50th percentile(ADC50%)and 90th percentile(ADC90%).The two independent samples t test or Mann-Whitney U test was used to compare the differences between PCR and nPCR groups in each subtype.The diagnostic performance of statistically different ADC parameters for predicting PCR was evaluated by receiver operating characteristic(ROC)curve.Results Kurtosis was significantly higher in PCR group than that in nPCR group in HER2 positive subtype(P=0.039).It achieved an area under the curve(AUC)of 0.813 with sensitivity of 100%and specificity of 68.7%at the optimal cutoff value(1.861)for differentiating PCR from nPCR cases.In triple negative subtype,ADCmean and ADC50%were smaller in PCR group than those in nPCR group(P=0.028,0.013).They achieved AUCs of 0.800,0.842,respectively.When ADCmean of 1.030×10-3 mm2/s and ADC50%of 0.976×10-3 mm2/s were used as cutoff value to differentiate PCR from nPCR,the sensitivities were 75.0%,80.0%and the specificities were 83.3%,83.3%,respectively.Conclusion Kurtosis can predict post-NAC PCR in patients with HER2 positive breast cancer,while ADC50%has a high value in predicting post NAC PCR of triple negative breast cancer patients.