动态对比增强MRI定量参数直方图分析在胃癌HER2表达中的应用价值

The value of histogram analysis of dynamic contrast-enhanced magnetic resonance imaging quantitative parameters in HER2 expression status in gastric cancer

目的:探讨动态对比增强MRI(DCE-MRI)定量参数直方图分析在胃癌人类表皮生长因子受体2(HER2)表达中的应用价值。方法:回顾性搜集65例经手术病理证实的胃癌患者。患者术前行腹部MRI检查并测量DCE-MRI直方图参数,包括容积转移常数(K trans)、速率常数(K ep)及血管外细胞外间隙容积比(V e)的均值及第10、25、50、75、90百分位数(Perc10、Perc25、Perc50、Perc75、Perc90)。根据免疫组织化学染色法(IHC)检测的HER2表达结果分为HER2阴性组、HER2不确定组和HER2阳性组。采用Kruskal-Walls H检验比较3种HER2类型的各参数组间差异,两两比较时采用Bonferroni法校正显著性水平。采用受试者工作特征(ROC)曲线评价DCE-MRI有效参数诊断HER2阳性的效能。结果:HER2阴性组34例,HER2不确定组22例,HER2阳性组9例。3种HER2表达组间的K trans均值、Perc25、Perc50、Perc75、Perc90及K ep Perc75差异有统计学意义(P<0.05)。两两比较结果显示,HER2阳性组的K trans均值、Perc25、Perc50、Perc75、Perc90及K ep Perc75高于HER2不确定组(P<0.05);HER2阳性组的K trans均值、Perc50、Perc75高于HER2阴性组(P<0.05);HER2阴性组与HER2不确定组间各参数差异均无统计学意义(P>0.05)。K trans Perc75鉴别HER2阳性组的ROC曲线下面积最大(0.802),临界值为0.592/min,敏感度为88.89%,特异度为69.64%。结论:MRI定量参数直方图分析具有评估胃癌HER2表达的潜能。

Objective:To explore the value of histogram analysis of dynamic contrast-enhanced MRI(DCE-MRI)quantitative parameter in human epidermal growth factor receptor-2(HER2)expression status in gastric cancer.Methods:The data of sixty-five patients with gastric cancer proved by pathological findings after operation were retrospectively collected.All patients underwent abdominal MRI scans before operation and DCE-MRI histogram parameters were measured,including the mean and the 10th,25th,50th,75th and 90th percentile(perc10,perc25,perc50,perc75 and perc90)of volume transfer constant(K trans),exchange rate constant(K ep)and extravascular extracellular volume fraction(V e).The patients were divided into HER2-negative group,HER2-equivocal group and HER2-positive group according to immunohistochemistry(IHC).Kruskal-Walls H test was used to compare the differences among parameter groups of the three HER2 types,and Bonferroni method was used to correct the significance level in pairwise comparison.Receiver operating characteristic(ROC)curve was used to evaluate the efficiency of these parameters of DCE-MRI in diagnosing HER2 positivity.Results:There were 34 cases in HER2-negative group,22 cases in HER2-equivocal group,and 9 cases in HER2-positive group.Among the three groups,the values of the mean,perc25,perc50,perc75 and perc90 of K trans and the perc75 of K ep showed statistical difference(P<0.05).The values of the mean,perc25,perc50,perc75 and perc90 of K trans and the perc75 of K ep of the HER2-positive group were higher than those of the HER2-equivocal group(P<0.05).And the values of the mean,perc50 and perc75 of K trans of the HER2-positive group were higher than those of HER2-negative group(P<0.05).No significant difference was found for each parameter between the HER2-negative group and the HER2-equivocal group(P>0.05).The perc75 of K trans showed the highest AUC(0.802)in the HER2-positive group,with a critical value of 0.592/min,a sensitivity of 88.89%and a specificity of 69.64%.Conclusion:DCE-MRI quantitative parameter histogram analysis has the potential to evaluate HER2 expression in gastric cancer.