Correlation of Preoperative MRI Staging with Postoperative Histopathology in Rectal Cancer: A Cross-sectional Study.

Accurate preoperative staging is essential for rectal cancer treatment. The revolutionary approach to treating rectal cancer is neoadjuvant treatment (NAT). NAT has a significant effect on local recurrence even though it has no effect on overall survival (OS) or disease-free survival (DFS). This is where preoperative Magnetic resonance imaging (MRI) comes in, helping to accurately stage the T and N stage and categorize patients for either upfront surgery or NAT. This study aims to compare the preoperative local MRI staging of rectal cancer with postopera-tive histopathology. This cross-sectional study comprised of patients with rectal cancer, who admitted to Bangladesh Medical University (BMU), within the period of January 2023 to December 2023. After diagnosis of rectal cancer preoperative local staging was done by MRI. Ac-cording to stage treatment was given. MRI T and N stage was compared with post operative his-topathology. Among the 45 patients 64.44% (n=29) patients were male. Mean age was 41.5 years. Patients (n=14) who had NAT had ypT downstaging in 43.0% (n=6) cases and among them two patients had pathological complete response (pCR). In this NAT group of patients 64.0% (n=9) did not re-spond to NAT. Patients who had upfront surgery (n=31) MRI successfully matches the histo-pathology in 87.0% (n=27) cases. To identify the correct nodal involvement in this upfront group MRI had 67.0% (n=21) success rate. MRI had 90.0% accuracy in identification of MRF involvement preoperatively. There was no correlation between tumor grade and CEA level. MRI is highly accurate in preoperative T and reasonably accurate in N staging for rectal cancer. Its accuracy in diagnosis influences treatment choices, providing physicians with a thorough understanding of the distinctive characteristics of the disease and enhancing the standard of care.