F-FDG PET/CT-based treatment response evaluation in locally advanced rectal cancer: a prospective validation of long-term outcomes

To prospectively evaluate the usefulness of (18)F-FDG PET/CT) imaging for predicting histopathological response and long-term clinical outcomes in locally advanced rectal cancer (LARC). This prospective study included 38 patients with a confirmed diagnosis of LARC (cT3-4 or cN+) who underwent (18)F-FDG PET/CT before and after neoadjuvant therapy (NAT). Total mesorectal excision was scheduled 6 weeks after NAT and was followed by an expert histopathological analysis of the surgical specimen. Baseline variables and previously identified maximum FDG standardized uptake value (SUVmax) cut-off values before NAT (SUVmaxPRE ≥6) and after NAT (SUVmaxPOST ≥2), and the absolute and percentage reductions from baseline SUVmax (∆SUVmax