Application Of Magnetic Resonance Tumor Regression Grading In Locally Advanced Rectal Cancer After Neoadjuvant Therapy

Objective : To evaluate the diagnostic performance of mrTRG in locally advanced rectal cancer after neoadjuvant therapy,and to analyze its correlation with pTRG,,so as to provide relevant referencefor clinical application.Methods : A retrospective analysis was made on 57 patients who underwent neoadjuvant therapy combined with total mesorectal resection in the first affiliated Hospital of Chongqing Medical University from January2015 to September 2019.The Kappa and Chi-square tests were used to analyze the inter-test agreement in TRG between MRI and pathology,and to explore the effect of different time intervals on the consistency rate.Results:The consistency between mrTRG and pTRG is moderately low,κ=0.245(0.133 to 0.356),accuracy is 64.9%(52.5 to 77.3%),when TRG1+2 is separated from other groups,the consistency is medium,κ=0.526(0.397 to 0.656),accuracy is 75.4%(64.3 to 86.6%).25.0% of pCR patients belong to mrTRG1 and 87.5% pCR patients belong to mrTRG1+2.The group time interval ≥ 9 weeks has higher consistency,andthe difference is statistically significant,(P<0.05).Conclusions:The application of mrTRG still has controversy,the consistency between mrTRG and pTRG is poor,and it can not replace pTRG,。Further prolonging the time of MRI reevaluation is beneficial to improve the consistency between the mrTRG and pTRG.