Comparative Analysis of MRI and Pathological Findings in a Resected Specimen of Rectal Cancer

Abstract BackgroundThe aim of this study is to examine the diagnostic value of MRI of the resected specimen (smr) of rectal cancer in terms of pathological circumferential resection margin (pCRM).MethodsTwenty-three patients with middle to low rectal cancer underwent laparoscopic radical surgery from March 2017 to April 2018, and smr was performed. Two radiologists interpreted smr with the pathological findings blinded. We examined two categories in the accuracy comparison with pCRM; 1) correlation betweenzand pCRM and correlation between smr CRM and pCRM. 2) diagnostic accuracy of smr in identifying the mesorectal lymph-nodes (LN) and tumor deposit (TD) that should be taken into consideration in the CRM measurements.ResultsPatient characteristics (median): male 18, female 5, Age 67 years (45-79), Anal verge 8.0cm (0-13.0), pre-operative chemoradiotherapy + / -:10/13, Surgical procedure low anterior reaction (LAR)/ abdominoperineal resection (APR)/ total pelvic exenteration (TPE):20/2/1. pT x/1/2/3:1/1/3/18, pN 0/1a/1b/1c/2b:12/5/2/3/1. pStage X/I/IIA/ IIIA/IIIB/IIIC:1/3/8/1/9/1.1) Sixteen cases of TME surgery were examined correlation between in-vivoCRM, smrCRM and pCRM. Spearman’s rank correlation coefficient and a simple regression analysis revealed a significant correlation between in-vivoCRM (p <0·001, p<0.05), smrCRM(p <0·001, p<0.01) and pCRM. The correlation coefficient between smrCRM and pCRM was stronger than that between in-vivoCRM and pCRM. 2) Ninety-six mesorectal nodules included: pLN (-) 77, pLN (+) 10, TD 9, and kappa value of diagnostic agreement for each radiologist was 0.105 and 0.138. Inter-observer agreement was 0.204.Conclusionsmr could become a tool for assessing CRM accurately.