Hardy OT et al. (2007) Accuracy of [18F]-fluorodopa positron emission tomography for diagnosing and localizing focal congenital hyperinsulinism. J Clin Endocrinol Metab 92: 4706–4711

Focal congenital hyperinsulinism is caused by an embryonic loss of heterozygosity that results in the expression of a mutant β-cell ATP-sensitive potassium channel. As focal disease affects only part of the pancreas, it can be cured by surgery if the lesion can be detected. Neuroendocrine cells take up L-DOPA, and this uptake is known to be increased in focal adenomatous lesions. Hardy et al. therefore evaluated 18F-DOPA PET for the diagnosis of focal versus diffuse hyperinsulinism, and for the localization of focal lesions.

The study population comprised 50 infants (24 with focal disease, 24 with diffuse disease, and 2 with localized islet-cell nuclear enlargement) who required surgery for medically uncontrollable hyperinsulinism. As confirmed by postoperative pathology findings, 18F-DOPA PET produced an accurate diagnosis in 44 of the 50 cases. The technique had a sensitivity for diagnosis of focal disease of 75%, a positive predictive value of 100%, and a negative predictive value of 81%. For the 18 focal cases diagnosed by PET, the site of the lesion was correctly identified in all cases, allowing localization even of those lesions invisible to the surgeon. Of the 24 patients with focal hyperinsulinism, 22 were cured by surgery.

The authors conclude that 18F-DOPA PET should be considered as a guide to surgery for all infants with medically uncontrollable hyperinsulinism.