Comparison Of Diagnostic Value Of Endoscopic Ultrasound And Magnetic Resonance Imaging In The Preoperative TN Staging Of Rectal Cancer

Background and purpose:Rectal cancer remains one of the world's major health problems,and the incidence remains high.With the development of imaging technology,it is not difficult to diagnose rectal cancer.But,preoperative accurate staging is still a question for further study by clinicians.The prognosis of rectal cancer is related to many factors,such as the depth of tumor infiltration,number of lymph node metastasis,tumor size,circumferential resection margin,External vascular invasion,etc.The treatment strategies of patients were determined by different stages of preoperative treatment,and different stages also indicated different prognosis of patients.Therefore,the accurate staging of preoperative rectal cancer plays an important role in the diagnosis and treatment of rectal cancer.Endoscopic Ultrasound(EUS)and Magnetic Resonance Imaging(MRI)are simple and effective diagnostic methods,and several studies have shown that they have good accuracy in the TN staging of rectal cancer.We retrospectively analyzed data to explore diagnostic value of Endoscopic Ultrasound and Magnetic Resonance Imaging in the preoperative TN staging of rectal cancer.Methods:We retrospectively analyzed the patient of the people's Hospital of Yichun City from July,2015 to December,2017.All patients who performed EUS and MRI before surgery and pathologic diagnosis were rectal cancer after surgery.SPSS Version 24 was used to compare the accuracy of preoperative staging of EUS with MRI and the pathological stage.Results:There were 42 patients,including 26 males and 16 females.Their Age ranged from 57±10.8 years old.The overall accuracy of EUS for T stage was 78.5%(33/42),and the accuracy of T1,T2,T3 and T4 were 100%(1/1),62.5%(5/8),89.7%(26/29)and 25%(1/4).The overall accuracy of MRI in T stages were 85.71%(36/42),and the accuracy of T1,T2,T3 and T4 was 0(0/1),75%(6/8),93.1%(27/29)and 75%(3/4).The sensitivity and specificity of EUS for T1,T2,T3 and T4 were 100% and 100%,62.5% and 100%,89.7% and 53.8%,25% and 92.1% respectively.The sensitivity and specificity of MRI for T1,T2,T3 and T4 were 0% and 100%,75% and 94.1%,93.1% and 76.9%,75% and 97.3% respectively.Due to the small sample size of T1,T2 and T4,the reliability of T1,T2 and T4 accuracy was poor,So descriptive analysis was performed for them only.By chi-square test,The accuracy of T3 between EUS and MRI was of no significance(P=0.429 > 0.05).In T3 stage,The combined sensitivity of EUS and MRI was 99%,and the combined specificity was 41.4%.By matching chi-square test and Kappa test analysis,the accuracy of EUS for T3 stage which compares to the postoperative pathological stage was of no significant difference(P = 0.508>0.05),and was of good consistency with the postoperative stage(kappa = 0.465,P = 0.005 < 0.05).The accuracy of EUS and MRI in the diagnosis of lymph node metastasis was 66.67%(28/42)and 85.7%(36/42).The accuracy of diagnosis of lymph node metastasis between EUS and MRI was significant(P=0.04< 0.05).Conclusion:1.EUS is similar to MRI in the diagnosis of rectal cancer in the T3 stage.It can be used as an alternative to MRI if necessary,and provide a reliable basis for the preoperative staging of rectal cancer.2.MRI is more valuable for identifying lymph node metastasis than EUS.