Impact of 18F FDG PET/CT on management of incidental gallbladder carcinoma

Purpose: Incidental gallbladder carcinoma (IGBC) is identified after cholecystectomy being performed for a presumed benign disease and histopathology turns out as malignant disease. For optimal management planning, it is crucial to know the actual disease status. 18F-fluorodeoxyglucose Positron Emission Tomography/ Computed Tomography (FDG PET/CT) provides local, regional as well as distant disease i.e. restaging and identifying true burden of disease for optimal treatment planning. The aim of this study was to restage the IGBC patients on 18F FDG PET/CT and find out any change in treatment plan. Methods: : This retrospective descriptive study was performed between November 2021 to February 2023. All PET/CT scans were analyzed which came for restaging in IGBC. Results: PET/CT was performed at a median time of 9 weeks (range 6 to 12 weeks) from the date of surgery. This study included 17 patients (6 male and 11 female), with a median age of 55 years (range 38 to 76 years). From total of 17 PET/CT scans, 10 (58.8%) patients were positive and 7 (41.1%) patients were negative on PET/CT. Amongst the PET/CT positive patients, disease pattern was seen in the form of local/ residual disease/ liver infiltration, regional lymph nodes and distant metastases. Among the 17 patients, treatment plan in 5 patients (having PET/CT negative) was changed from surgical intervention to no treatment, and in 2 patients (having PET/CT positive), treatment plan was changed to Chemotherapy i.e. total 7 (5+2, 41% of total 17 patients) patients’ treatment plans were changed. By reducing the number of patients undergoing re-resection, there is improvement in overall survival and it reduces the burden on already overburdened health infra-structure especially in developing countries like India where incident is high. Conclusion: PET/CT provides the actual stage of IGBC. It changes treatment plan and reduces the number of patients undergoing re-resection, thus improving overall survival. It also decreases burden on overburdened health infrastructure.