The role of positron emission tomography in the detection of pancreatic disease.

Abstract
Positron emission tomography (PET) was used to assess possible pancreatic disease in 100 patients. Following injection of 10-15 mCi (370-740 MBq (Becquerei) of 11C-L-methionine, 4-12 transverse sections 2 cm thick were obtained. In 85 patients with a definite diagnosis (45 normal, 9 acute pancreatitis, 18 chronic pancreatitis and 13 cancer), PET showed a sensitivity of 85.0%, a specificity of 97.8% and an accuracy of 91.8% higher than with transmission computed tomography (CT) or ultrasonography, despite relatively low spatial resolution; this can be explained by the fact that exocrine pancreatic function was altered prior to morphological change. In 22 normal subjects, 0.011 .+-. 0.003% (mean .+-. S.D.) of injected 11C was found in 1 ml of liver tissue and 0.015 .+-. 0.005% in 1 ml of pancreatic tissue; the pancreas-to-liver concentration ratio was 1.3 .+-. 0.4. Hepatic11C concentration was identical in the 4 groups of patients. Pancreatic uptake of 11C-L-methionine was significantly lower in patients with chronic pancreatitis (n = 13) and pancreatic carcinoma (n = 10) (P < 0.001); however, it was not possible to distinguish cancer from chronic pancreatitis because the same functional alteration occurred in both.