18FluoroLDOPA PET Imaging for the Detection and Localization of Focal Congenital Hyperinsulinism

Congenital hyperinsulinism (HI) is the most common cause of recurrent and persistent hypoglycemia, presenting early in infancy. Patients who fail medical therapy usually require resection of the diseased pancreas(partial or subtotal pancreatectomy) to control this disorder. Over half of patients undergoing surgery have a focal area of islet cell dysfunction that is curable with resection. These focal lesions are areas of adenomatosis consisting of a clone of beta-cells that express a paternally-derived mutation of the KATP channel due to loss of heterozygosity for the maternal allele. Current imaging techniques cannot differentiate focal and diffuse forms of hyperinsulinism, nor can they locate focal areas of disease within the pancreas before surgery. L-DOPA is taken up by some neuroendocrine cells, including pancreatic islet cells, and stored as dopamine in secretory granules. Recent studies show that positron emission tomography (PET) following administration of 18F-fluoro-L-DOPA (FDOPA) can distinguish focal and diffuse forms of HI and accurately locate focal lesions within the pancreas.