Evaluation of segmental pancreatic function using 11C-methionine positron emission tomography for safe living donor operation of pancreas transplantation

For a safe living pancreas donoration for transplantation, we evaluated the function of the residual pancreas head using 11C-methionine positron emission tomography (PET) in 13 cases before and after distal pancreatectomy. After 6 hours of fasting, we intravenously administered 11C-methionine (370 to 740 MBq), performing PET at 30 minutes thereafter. 11C-methionine PET uptake in the pancreas head was expressed as a standardized uptake value (SUV) for comparison before versus after surgery: 17.3 ± 2.5 versus 17.4 ± 4.9, respectively, demonstrating no significant difference. However, the changes in SUVs of the residual pancreas head showed three patterns after surgery. The SUVs were elevated in three donors after surgery, hypermetabolite type; maintained in five donors, normometabolite type; and decreased in five donors hypometabolite type. The percentages of subjects with a postoperative HbA1c value more than 5.8%, the upper normal limit, were 33% in hypermetabolite type; 40% in the normometabolite type; and 60% in the hypometabolite type. Although diabetes mellitus has not developed in any of the 13 donors, the pancreatic head function after distal pancreatectomy was slightly decreased, especially among the hypometabolite type. To avoid postoperative diabetes mellitus for a prolonged period, donors who show decreased SUVs after surgery should be strictly followed. In conclusion, 11C-methionine PET may be a potent modality to evaluate segmental pancreatic function for a safe living donor pancreatectomy.