18F-FDOPA and 68Ga-dotatate PET imaging in congenital hyperinsulinism.

Congenital hyperinsulinism (CHI) occurs most commonly in infants but may also be discovered in older children. It presents with recurrent episodes of hypoglycemia due to high endogenous insulin levels. There is a focal and diffuse form of the disease depending on the extent of pancreatic involvement. Hyperplasia of the islet cells results in hyperfunctioning pancreatic β cells and the ensuing clinical disease. Medical treatment fails in several patients and surgery has been shown to be very effective in improving prognosis and even resolution of disease in the focal form. Several genetic mutations have been uncovered and these may also be predictive of prognosis. Anatomical imaging alone including ultrasound, CT and MRI are rarely able to detect any abnormality in the pancreas. PET plays a major role in the distinction between the focal and diffuse forms of the disease. It also guides surgical intervention by providing information on the location of the focal hyperfunctioning islet cells. Imaging children and infants in this disease is quite challenging. We propose to show the benefit of using two PET tracers in this disease. 18F-FDOPA has been used quite successfully in the evaluation of CHI. 68Ga-DOTATATE has also been described to be helpful although inferior to 18F-FDOPA. We illustrate imaging of CHI patients in 3 different scans and briefly review the literature. 18F-FDOPA as described in the literature is superior but when unavailable 68Ga-DOTATATE may be a reasonable alternative. AJNMMI