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

Abstract

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. Key words: Esophageal neoplasms; Magnetic resonance imaging; Pathology