Clinico-pathological Correlation of Incidental Focal Colorectal Uptake on 18F-Labelled 2-Fluoro-2-deoxyglucose PET/CT: A Prospective Single Centre Experience

To assess the clinical and pathological implications of incidental focal uptakes during the 18F-FDG-PET/CT colorectal examination and the role of colonoscopy in the diagnostic algorithm of these uptakes. We performed a single-center prospective that recruited patients with incidental uptakes during18F-FDG-PET/CT colorectal examination over five years. Patients underwent colonoscopy and biopsies to assess the usefulness of 18F-FDG-PET/CT in patients with incidental uptakes. A total of 2231 scans were performed, and 71 (3.18%) localized colorectal uptakes were identified. The colon was normal in 45.07% of these uptakes, while the remaining cases had malignant colorectal tumors (29.57%) and neoplastic lesions (25.35%). The false-positive rate was significantly higher in the proximal colon than in the distal colorectal (53.7% vs. 39.8%, P = 0.004). The bivariate analysis showed that increased SUVmax independently increases the risk of neoplastic lesions, while proximal colon uptakes independently decrease the risk of neoplastic lesions. Our results highlight a valuable role of incidental focal uptakes during 18F-FDG-PET/CT colorectal examination in identifying patients with increased risk of neoplastic lesions. The study supports the need for a colonoscopy in such settings, particularly with increased SUVmax.