食管鳞癌新辅助化疗后动态对比增强MRI定量参数与病理分级的相关性研究

Correlation between quantitative parameters of dynamic contrast-enhanced MRI after neoadjuvant chemotherapy and pathological grades in esophageal squamous cell carcinoma

目的探讨食管鳞癌新辅助化疗后动态对比增强-MRI(DCE-MRI)定量参数与病理分级间的相关性。方法前瞻性分析2015年9月至2017年12月郑州大学附属肿瘤医院,经食管镜检查确诊为食管鳞癌,术前接受新辅助化疗,且在术前1周内行DCE-MRI扫描的56例患者的临床及影像资料。所有患者均行常规MRI和DCE-MRI扫描,测量DCE-MRI定量参数,包括容积转移常数(Ktrans)、速率常数(Kep)及血管外细胞外间隙容积比(Ve)。对手术后活体标本进行病理分级,根据病理结果分为高分化组、中分化组、低分化组及未分化组。对2名医师测量所得DCE-MRI各定量参数结果进行一致性分析,计算组内相关系数(ICC)。采用Kruskal-WallisH检验比较不同病理分级间DCE-MRI各定量参数的差异,两两比较采用Mann-WhitneyU检验。采用Spearman秩相关分析评价DCE-MRI各参数值与食管鳞癌病理分级的相关性,采用ROC曲线评价各参数诊断食管鳞癌病理分级的效能。结果56例患者中,高分化组8例、中分化组39例、低分化组9例、未分化组0例。不同病理分级组间平均Ktrans、75%Ktrans、最大Kep、平均Kep、75%Kep值的差异均有统计学意义(P均<0.05),且与病理分级呈正相关(r值分别为0.778、0.632、0.594、0.725、0.489,P均<0.05)。平均Ktrans、75%Ktrans诊断食管鳞癌病理分级的ROC曲线下面积分别为0.750、0.856,其中75%Ktrans的诊断效能最佳,诊断阈值为0.693/min,敏感度为87.5%,特异度为78.5%。结论食管鳞癌新辅助化疗后DCE-MRI定量参数对预测病理分级有一定的价值。

Objective To investigate the correlation between quantitative parameters of dynamic contrast-enhanced MRI (DCE-MRI) after neoadjuvant chemotherapy and pathological grades in esophageal squamous cell carcinoma. Methods Fifty-six patients with esophageal squamous cell carcinoma who were confirmed by esophagoscope and received neoadjuvant chemotherapy before operation between September 2015 and December 2017 in the Affiliated Cancer Hospital of Zhengzhou University were prospectively analyzed,and MRI examination was performed within one week before operation. All patients underwent routine chest MRI and DCE-MRI scanning,and quantitative parameters of DCE-MRI,including volume transfer constant (Ktrans),exchange rate constant (Kep) and extravascular extracellular volume fraction (Ve) were measured. Pathological grading was assessed as highly differentiated,moderately differentiated,poorly differentiated,and undifferentiated. Intraclass correlation coefficient (ICC) was calculated from the results of two radiologists. Kruskal-Wallis H test was used to compare the differences of quantitative parameters between different pathological grade groups of DCE-MRI,and Mann-Whitney U test was utilized to compare the intraclass differences among pathological grades. Spearman rank correlation analysis was performed for evaluating the correlation between DCE-MRI parameters and pathological grade of esophageal squamous cell carcinoma. The receiver operating characteristic (ROC) curves were used to evaluate the diagnosis accuracy of different DCE-MRI parameters in pathological grade of esophageal squamous cell carcinoma after neoadjuvant chemotherapy. Results The 56 patients were divided into four groups according to pathological findings:well differentiated group (n=8),moderately differentiated group (n=39),poorly differentiated group (n=9) and undifferentiated group (n=0). The differences of Ktransmean,Ktrans75%,Kepmax,Kepmean,Kep75% between different pathological grading groups were statistically significant (all P<0.05),and these parameters showed positive correlation significantly with pathological grading (r values were 0.778, 0.632, 0.594, 0.725, 0.489 respectively,all P<0.05). The ROC curve area of Ktransmean,Ktrans75% in the diagnosis of pathological grade for esophageal squamous cell carcinoma was 0.750,0.856,respectively. The diagnostic efficiency of Ktrans75% was the best with the diagnostic threshold of 0.693/min,sensitivity of 87.5%,specificity of 78.5%,respectively. Conclusion The quantitative parameters of DCE-MRI after neoadjuvant chemotherapy in esophageal squamous cell carcinoma have the potential value for predicting pathological grade.