Background: Colorectal carcinoma (CRC) ranked as the second most prevalent form of cancer among individuals. Diagnostic imaging helps in planning before surgery by establishing a relationship between the carcinoma's mass and the surrounding anatomy, which consequently helps in selecting the optimal surgical approach and limiting the probability of injury to the neighboring structures. It could additionally help in estimating and predicting the therapeutic response and detecting the recurrence of the tumor. MR imaging has proven to be the most prevalent cross-sectional imaging technique for post-rectal cancer patients' follow-up, it's mainly used to diagnose pelvic cancer recurrence and assess the extent of recurrence, which enables early resection and prolonged survival.
Aim of the work: In the current study, we have attempted to evaluate the role of both functional and dynamic MRI in the staging of patients having cancer in their rectum before surgical operation and following up after it.
Material and Methods: After signing a written consent, thirty patients were enrolled in this prospective clinical trial at Tanta University Hospitals - the Department of Radio Diagnosis and Medical Imaging. Duration from November 2018 to March 2022. All patients had a full patient history, medical examination, lab investigations (CBC, carbohydrate antigen 19-9 (CA 19-9), Renal function test, and carcinoembryonic antigen(CEA)), and dynamic and functional MRI which include: Weighted fast spin echo sequences, pre-contrast three-dimensional T, pre-contrast two-dimensional T, weighted fast gradient echo sequences, pre-contrast two-dimensional proton density-weighted sequences (saturation recovery turbo fast gradient echo, SRTF, or fast gradient echo, FLASH); and Pre- and post-dynamic contrast-enhanced T Weighted SRTF or FLASH sequences MRI examination included: Pre contrast (2D T2 weighted images, 2D T1 weighted images, Diffusion-weighted images. And Post-contrast (T1 weighted images after IV administration of contrast).
Results: The most common location of the tumor found by MRI was in the Middle rectum. MRI findings after chemoradiotherapy of 12 cases revealed a downstaging of cases, 9 of them became eligible for surgery. MRI findings of our studied cases after surgery revealed: 21 studied cases were free-restricted and 4 cases were restricted diffusion, 21(84%) cases had clear operative beds, and 4 (16%) cases had unclear operative beds.
Conclusion: We conclude that post-operative MRI has a golden standard value not only for follow-up post-operative complication and detection of recurrent rectal carcinoma but furthermore for predicting the appropriateness of curative surgery and facilitating decisions on palliative resection, which have a significant impact on survival rate.