Background: This study evaluated the usefulness of positron emission tomography with 2-deoxy-2-[18F]fluoro-D-glucose (FDG-PET) in monitoring the response to continuous arterial infusion chemotherapy (CAI) combined with external radiation therapy (ERT) for unresectable pancreatic carcinomas.
Methods: Ten patients with unresectable pancreatic cancer were enrolled in this study. Computed tomography (CT) and FDG-PET were done before and after CAI (5-fluorouracil [FU], 500 mg/body per day) combined with ERT (50.4 Gy total dose). Tumor regression was evaluated by standardized uptake value (SUV) with FDG-PET, tumor size on CT, and changes in blood levels of carbohydrate antigen (CA) 19-9. The three methods of evaluation were compared.
Results: The ten patients were classified in three categories. In category I, tumor changes evident on CT and FDG-PET were consistent. In category II, CT could not accurately detect the area of the tumor. However, tumor uptake on FDG-PET decreased markedly after the treatment in category II patients. In category III, both CT and FDG-PET detected the tumor, as in category I. Although there was no definite change in tumor size on CT, FDG-PET uptake was markedly reduced immediately after the treatment. Reduction in tumor size did not appear on CT until 2 months later.
Conclusions: FDG-PET aids in analysis of the effectiveness of chemotherapy and/or radiotherapy.