直肠腔内三维超声对中下段直肠癌术前N分期的诊断价值

Diagnostic value of three-dimensional transrectal ultrasound in preoperative N-staging of middle and lower rectal cancer

目的:探讨直肠腔内三维超声(3D-ERUS)对中下段直肠癌术前有无淋巴结转移和N分期的诊断价值,并分析直肠癌病灶和肠周淋巴结的超声影像与临床病理特征和淋巴结转移的关联性。方方法法:选取94例术后病理均诊断为直肠癌的患者,术前均行3D-ERUS和盆腔核磁共振成像(MRI)检查。3D-ERUS和MRI诊断淋巴结转移的结果采用受试者工作特征曲线(ROC曲线)评价,3DERUS和MRI诊断N分期的结果采用精确率、召回率和F1评分评价,二者对有无淋巴结转移和N分期的诊断结果与病理结果之间的一致性均采用Kappa系数评价。采用χ~2检验比较超声影象与临床病理特征和淋巴结转移的差异,差异有统计学意义的因素作为自变量纳入多因素Logistic回归分析。结果:3D-ERUS诊断有无淋巴结转移的准确性为80.85%(Kappa=0.615,P<0.01),ROC曲线下面积(AUC)为0.831;MRI诊断有无淋巴结转移的准确性为70.21%(Kappa=0.415, P<0.01),AUC为0.728;二者AUC比较差异有统计学意义(Z=2.039,P=0.041),二者诊断准确性比较差异无统计学意义(χ~2=2.33, P=0.126)。3D-ERUS对N分期的总体准确性为74.47%(Kappa=0.562,P<0.01),高于MRI (63.44%)(Kappa=0.394,P<0.01),二者准确性比较差异亦无统计学意义(χ~2=2.17,P=0.141)。单因素分析,有4个因素有统计学意义,即病理T分期、癌胚抗原(CEA)、分化程度和3D-ERUS术前T分期(uT-stage);多因素回归分析,病理T分期是有无淋巴结转移的主要危险因素(P<0.01),与T_(is)-T_2期直肠癌比较,T_4期[比值比(OR)=12.000,95%可信区间(CI):3.141~45.839]发生淋巴结转移的风险更高。结论:3D-ERUS在术前诊断中下段直肠癌的N分期中具有较高临床应用价值,病理T4期的直肠癌发生肠周淋巴结转移的风险最高。

Objective:To explore the diagnosis value of three-dimensional transrectal ultrasound(3D-ERUS)in the preoperative lymph node metastasis and N-stage in middle and lower rectal cancer,and to explore the correlations between the ultrasound features and the clinicopathologic factors and lymph node metastasis of rectal cancer.Method:A total of 94 patients with rectal cancer confirmed by pathology were selected,and all patients were examined by 3D-ERUS and magnetic resonance imaging(MRI).Receiver operating characteristic(ROC)curve was used to evaluate the results of 3D-ERUS and MRI in the diagnosis of lymph node metastasis;the precision,recall and F1 score were used to evaluate the results of3D-ERUS and MRI in the diagnosis of N staging.Kappa coefficient was used to evaluate the consistency between the results of 3D-ERUS and MRI in the diagnosis of lymph node metastasis and N staging and the pathological results.Chi square test was used to compare the differences between the ultrasound features and clinicopathologic factors and lymph node metastasis of rectal cancer,and the factors with statistical differences were analyzed by multivariate Logistic regression.Results:The accuracy of 3D-ERUS in the diagnosis of lymph node metastasis was 80.85%(Kappa=0.615,P<0.01),respectively,and the area under curve(AUC)was 0.831;the accuracy of MRI in the diagnosis of lymph node metastasis was 70.21%(Kappa=0.415,P<0.01),respectively,and the AUC was 0.728.The AUC of 3D-ERUS and MRI had statistical difference(Z=2.039,P=0.041),and there was no statistical difference in the accuracy of diagnosis between them(χ2=2.33,P=0.126).The overall accuracies of 3D-ERUS and MRI in distinguishing N staging were 74.47%and 63.44%,and there was no statistical difference(χ2=2.17,P=0.141).The univariate analysis results showed that the related factors of lymph node metastasis were pathological T stage,carcinoembryonic antigen(CEA),histological differentiation and 3D-ERUS T stage(uT-stage).The multivariate analysis results showed that the main risk factor of lymph node metastasis was pathological T stage(P<0.01);compared with stage Tis-T2 rectal cancer,stage T4 rectal cancer[odds ratio(OR)=12.000,95%confidence interval(CI):3.141-45.839]had the higher risk in the occurrence of lymph node metastasis.Conclusion:3D-ERUS has high accuracy and clinical value in the preoperative diagnosis of N staging of middle and lower rectal cancer,and pathological T4 rectal cancer has the highest risk of perienteral lymph node metastasis.