The role of PET-CT in patients with incidental gallbladder cancer.

Introduction: After a cholecystectomy, incidental gallbladder cancer (IGC) requires accurate imaging studies to determine the actual extent of the disease to properly tailor subsequent treatment. The aim of this study was to evaluate the utility of (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)FDG PET-CT) to provide optimal pre-treatment staging in patients with IGC.

Material And Methods: Between January 2006 and August 2008, all patients with IGC and at least muscular layer invasion were studied with (18)FDG PET-CT. The examination was considered positive when the standardized uptake values (SUV) were >/=2.5. In all instances patients were offered to undergo definitive exploration and possible radical resection.

Results: The series included 32 patients, 26 women and 6 men, with a median age of 57 years (range 30-81 years). The examination was performed at a median time of 6 weeks after cholecystectomy (range 2-52 weeks). (18)FDG PET-CT was negative in 13 patients and positive in 19 patients: 9 with localized potentially resectable disease (PRD) and in 10 with disseminated disease. Of the 13 patients with negative PET-CT, 9 refused surgery and 4 underwent formal exploration: 3 patients were resected with no disease identified in the final pathology report (FPR) and 1 was not resected as a result of peritoneal carcinomatosis. Of the 9 with PRD, 4 patients refused reoperation and 5 underwent exploration: 3 were resected with residual disease noted in the FPR and 2 did not undergo resection because of dissemination. Two patients with disseminated disease were reoperated and in both instances disseminated disease was confirmed. The median survival for the entire group was 20.3 months (range 1.6-32.9 months). The median survival for those patients with negative PET-CT was 13.5 months (range 5.6-32.9 months), 6.2 months (range 1.6-18.7 months) for localized potentially resectable disease and 4.9 months (range 2-14.1 months) for disseminated disease (P < 0.003).

Conclusions: For patients presenting with stage T1b or greater IGC, the use of (18)FDG PET-CT will help reduce the number of patients undergoing non-therapeutic re-exploration and may help to determine the likely prognosis. (18)FDG PET-CT might be a useful tool for the selection of patients for potentially curative treatment.