18F-FDG PET传统参数与影像组学特征在免疫组织化学难以明确HER2表达乳腺癌中的价值

Predictive value of 18F-FDG PET conventional parameters and radiomics features for invasive breast cancer patients with uncertain HER2 expression by immunohistochemistry

目的探讨18F-脱氧葡萄糖(FDG)PET传统代谢参数及影像组学特征对免疫组织化学(IHC)检查难以明确的人表皮生长因子受体2(HER2)表达的预测价值。方法收集天津医科大学肿瘤医院2012年4月至2017年12月间经病理证实为浸润性乳腺癌且IHC难以明确HER2表达的76例患者[均为女性,年龄(50.8±10.9)岁],回顾性分析患者治疗前18F-FDG PET/CT数据及其HER2表达资料[通过荧光原位杂交(FISH)明确]。手动分割PET图像病灶,提取、筛选图像特征。采用Wilcoxon检验比较PET传统代谢参数[最大标准摄取值(SUVmax)、肿瘤代谢体积(MTV)和病灶糖酵解总量(TLG)]及影像组学特征在HER2不同表达组间是否存在差异。通过受试者工作特征(ROC)曲线比较PET影像组学特征对HER2表达的预测效能。结果76例患者中,HER2阳性41例,HER2阴性35例;HER2不同表达组间PET传统代谢参数的差异无统计学意义(U值:-1.598~1.551,均P>0.05)。共提取出38个PET影像组学特征。2组间在灰度均值、相关性、对比度、惯性及逆差矩方面差异均有统计学意义(U值:-2.413~2.527,均P<0.05);上述指标预测HER2表达的曲线下面积分别为0.643、0.638、0.647、0.644和0.643,其中对比度的预测效能最佳。结论PET影像组学特征能在一定程度上预测浸润性乳腺癌患者HER2表达,其中对比度预测价值最高;而PET传统代谢参数预测价值有限。

Objective To explore the predictive value of 18F-fluorodeoxyglucose(FDG)PET conventional parameters and radiomics features for human epidermal growth factor receptor 2(HER2)expression which was uncertain by immunohistochemistry(IHC)detection in invasive breast cancer.Methods From April 2012 to December 2017,76 patients(all were females,age:(50.8±10.9)years)with invasive breast cancer and with uncertain HER2 expression by IHC in Tianjin Medical University Cancer Institute and Hospital were enrolled retrospectively.The 18F-FDG PET/CT images before treatment were reviewed and the expression of HER2 were confirmed by fluorescence in situ hybridization(FISH).The tumor lesions were manually outlined,and the radiomics features from PET images were extracted.Wilcoxon test was used to determine whether there was difference in PET conventional metabolic parameters(maximum standardized uptake value(SUVmax),metabolic tumor volume(MTV)and total lesion glycolysis(TLG))and radiomics features between HER2-negative and HER2-positive groups.The receiver operating characteristic(ROC)curve analysis was used to compare the predictive efficacy of PET radiomics features for HER2 expression.Results There were 41 HER2-positive patients and 35 HER2-negative patients.No significant differences in PET conventional metabolic parameters between different HER2 expression groups were observed(U values:from-1.598 to 1.551,all P>0.05).A total of 38 PET radiomics features were extracted,and there were significant differences in gray mean,correlation,contrast,inertia,and inverse different moments between 2 groups(U values:from-2.413 to 2.527,all P<0.05).The area under the curve of the above 5 parameters for prediction of HER2 expression were 0.643,0.638,0.647,0.644 and 0.643,respectively,and the contrast was the best parameter.Conclusions PET radiomics features can effectively identify HER2 expression in patients with invasive breast cancer to some extent,and the contrast may be the best.Conventional metabolic parameters have limited predictive value.