Ratios to non-target tissues (pancreas-to-muscle and pancreas-to-liver) from ex vivo radioactivity measurements (% ID/g). These were measured after [18F]FDOPA injection. Significant differences were detected between sham-operated and BxPC3 tumour-bearing pancreata (pretreatment adjusted p < 0.001 in pancreas-to-muscle and pretreatment adjusted p < 0.05 in pancreas-to-liver ratios), but pretreatment had no effect on these differences (pretreatment × group interaction effect, p = 0.245 in pancreas-to-muscle and p = 0.612 in pancreas-to-liver ratios). Carbidopa pretreatment increased uptake in the pancreata of both sham-operated and tumour-bearing mice compared with vehicle-treated mice (group adjusted p < 0.05 in pancreas-to-muscle and group adjusted p < 0.001 in pancreas-to-liver ratios). The numbers of mice exposed to vehicle, carbidopa and COMT + MAO-A inhibitors were 6, 5 and 4 for sham-operated animals, respectively, and 5, 7 and 4 for tumour-bearing animals, respectively. Values are shown as mean and standard error.