INTRODUCTION: Rectal carcinoma (RC) has high incidence and rate of recurrence. Currently, routine 18- fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET-CT) is not recommend for routine monitoring for post RC treatment. We examined the utility of FDG PET-CT for the prognostication of patients with RC and what FDG PET-CT metrics are of value. METHODS: PubMed, Embase, MEDLINE, and Cochrane (Central) were comprehensively searched till 19 May 2024. A modified Newcastle Ottawa scale was used to assess for study bias. We presented our systematic review alongside pooled hazard ratios (HR) for maximum standardised uptake values (SUV) as a predictor of disease-free survival (DFS) and overall survival (OS). RESULTS: Eleven papers including 771 patients were included in our systematic review. Considering the current evidence, there is potential to consider percentage change in SUV CONCLUSIONS: Pooled meta-analysis of three homogenous parameters examines the relationship of SUV