Endocrine Abstracts

Congenital hyperinsulinism of infancy (CHI) is a rare disorder of insulin dysregulation, resulting in persistent hypoglycaemia and its sequelae. More than half of patients have loss-of-function mutations in ABCC8 or KCNJ11 genes encoding subunits of ATP-sensitive potassium (K_ATP) channels. Histologically, disease pathology is subdivided into diffuse or focal disease; the latter associated with paternal mutations and somatic loss of maternal heterozygosity in these genes.

The advent of ¹⁸F-DOPA PET-CT imaging has permitted the reliable, non-invasive diagnostic differentiation between focal and diffuse forms of disease. Pancreatic β-cells, like other neuroendocrine cells, possess the unique ability for amine-precursor uptake decarboxylation (APUD), acting as highly specific targets for the ¹⁸F-DOPA tracer, thus giving the investigation a sensitivity as high as 94%. This is particularly useful in cases unresponsive to medical treatment where pancreatic resection is undertaken. Over the last decade, with the introduction of rapid genetic analysis and ¹⁸F-DOPA PET-CT imaging, clinicians have been able to effectively differentiate between focal and diffuse CHI processes, hence altering surgical practice and limiting surgical complications by allowing limited pancreatic resection in cases of focal disease. However, the short half-life (110 min) and difficulty in manufacturing Fluorine18 has prevented its regular production in the United Kingdom (UK). Scanning of UK CHI patients has therefore been conducted in other EU nations, requiring transfer of sick infants at substantial cost and risk of morbidity. Therefore, the need for the establishment a UK ¹⁸F-DOPA PET-CT service remains paramount, and is currently being undertaken in Manchester.