The Application Of Three-Dimensional Endorectal Ultrasound And MRI In Preoperative T Staging And Circumferential Resection Margin Of Rectal Cancer

Objective:To compare the results of three-dimensional endorectal ultrasound(3D-ERUS)and magnetic resonance image(MRI)in preoperative evaluation of T stage and circumscribed margin(CRM)of rectal cancer,and to explore the value of 3D-ERUS in preoperative evaluation of T-stage and CRM of rectal cancer.Methods:A total of 59 patients admitted to the gastrointestinal surgery department of our hospital from June 2018 to January 2020 who were diagnosed with rectal cancer by colonoscopy biopsy were selected.Before operation,3D-ERUS and MRI were performed to evaluate the T stage and CRM of each patient,and the results were recorded in detail.The interval between the two examinations was no more than three days.The diagnostic value of the two methods in preoperative T stage and CRM evaluation of rectal cancer was compared with the results of postoperative pathological diagnosis.Results:1.T stage:in 59 patients with rectal cancer,postoperative pathology showed 7 cases in T1 stage,10 cases in T2 stage,27 cases in T3 stage and 15 cases in T4 stage.(1)The accuracy of 3D-ERUS for T1,T2,T3,T4 and overall accuracy in T staging was 96.6%,91.5%,81.4%,86.4%and 78.0%respectively.The sensitivity of 3D-ERUS for T1,T2,T3 and T4 was 71.4%,80.0%,88.9%and 60.0%respectively.The specificity of 3D-ERUS for T1,T2,T3 and T4 was 100%,93.9%,75.0%and 95.5%respectively.The results of 3D-ERUS were consistent with those of pathological T staging(kappa1=0.668,P<0.05)。(2)The accuracy of MRI for T1,T2,T3,T4 and overall accuracy in T staging was 91.5%,79.7%,78.0%,89.8%and 69.5%respectively.The sensitivity of MRI for T1,T2,T3 and T4 stages was 42.9%,50.0%,74.1%and 86.7%respectively.The specificity for T1,T2,T3 and T4 stages was 98.1%,85.7%,81.3%and 90.9%respectively.The results of preoperative evaluation of MRI in T stage were consistent with those of pathological T stage(kappa2=0.553,P<0.05).2.CRM:among the 54 patients with rectal cancer who underwent TME,7 patients showed positive CRM and 47 patients showed negative CRM.(1)The evaluation of CRM in rectal cancer patients by 3D-ERUS and MRI was compared with postoperative pathology,the accuracy of the two methods was 98.1%and 96.3%,the sensitivity was 85.7%and 71.4%,the specificity was 100%and 100%,respectively.(2)The results of 3D-ERUS were consistent with those of pathological CRM(kappa3=0.913,P<0.05),and MRI was consistent with pathological CRM(kappa4=0.813,P<0.05).Conclusions:1.Both 3D-ERUS and MRI can be used to evaluate preoperative T staging and CRM status of rectal cancer,and can provide reliable imaging information for preoperative local staging of rectal cancer.2.3D-ERUS is better than MRI in preoperative T staging of rectal cancer,especially in T1-T3 rectal cancer.3.The clinical value of 3D-ERUS and MRI in predicting CRM status of rectal cancer is equivalent.