Original Research Paper Accuracy of Magnetic Resonance Imaging in Preoperative Staging of Carcinoma Rectum

Introduction: Rectal cancer staging provides critical information concerning the extent of the disease. The information gained from staging is used to determine prognosis, to guide management, and to assess response to therapy. Accurate staging is essential for directing the multidisciplinary approach to therapy. This study focuses on the evaluation of MRI in preoperative staging of rectal cancer. Material and methods: A prospective cohort study of patients with diagnosis of rectal cancer admitted in the Department of Surgical Oncology for surgical treatment over the period from January 2015 to December 2016. The sensitivity, specicity, positive predictive accuracy, and negative predictive accuracy for magnetic resonance imaging in predicting a curative resection based on the histological yardstick of presence or absence of tumour at the margins of the specimen. Results: A total of 72 patients with complete pathology and MRI data were available for comparison. The mean difference of EMD in both assessment was 0.06mm±3.82 (95% CI -0.42, 0.37). The mean difference was within predened limit of 0.5mm which supported the equivalence of assessment. The accuracy for predicting the status of circumferential resection margin by initial imaging or imaging after treatment but before surgery in 72 patients was 90.3% (65/72, 86% to 94%) and negative predictive value was 70% (7/10). Conclusion: MRI of rectal cancer is accurate, feasible, reproducible, and a robust standard for preoperative staging for multidisciplinary team protocol conjunct with clinical assessment to plan individualised treatment. This study enabled the accurate pre-operative prognostication and has a potential benets to avoid unnecessary preoperative treatment in many patients, an objective staging system for future clinical trials.