The noninvasive imaging technology called positron-emission tomography (PET scan) is extremely accurate in diagnosing a type of congenital hyperinsulinism (HI), a rare but severe imbalance of insulin levels in newborns. When that disease is confined to a limited section of the baby's pancreas, the PET scan is 100 percent accurate in locating the abnormal spot, and guiding surgeons to curative, organ-sparing surgery.
A research team from The Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine reported highly encouraging preliminary results from a study of 24 infants referred to the Hyperinsulinism Center at Children's Hospital between December 2004 and November 2005. All the children had congenital hyperinsulinism that could not be controlled with medicine. If this condition goes uncontrolled, abnormally high insulin levels may cause irreversible brain damage. The study appeared in the February issue of the Journal of Pediatrics.
Congenital HI is caused by mutations that damage the insulin-secreting beta cells in the pancreas, which in an infant is smaller than an adult's little finger. When the abnormal cells are limited to a discrete portion of the pancreas, the disease is focal; when the abnormal cells are distributed throughout the organ, the disease is diffuse. Accurate diagnosis is important because focal disease can be cured by surgically removing the focal lesions. In diffuse disease, surgeons may remove nearly the total pancreas, but that leaves the child at risk for later diabetes.
Using a mildly radioactive compound called 18F-fluoro-L-dihydroxyphenylalanine, or [18F]-DOPA, the researchers diagnosed focal or diffuse hyperinsulinism correctly in 23 of the 24 cases, for an accuracy of 96 percent. In the 11 cases with focal hyperinsulinism, the technique was 100 percent accurate in pinpointing the abnormal lesions. [18F]-DOPA binds to the lesions, which then are visible to the naked eye on
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Contact: Joey Marie McCool
McCool@email.chop.edu
267-426-6070
Children's Hospital of Philadelphia
29-Jan-2007