February 2007 - 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 a body scanner.
"When we compared our findings from the PET scan with pathological results, we found 100 percent agreement in locating the focal lesions," said Olga T. Hardy, M.D., a pediatric endocrinologist at Children's Hospital who was the study's lead author. "This accuracy is superior to that of invasive, technically difficult techniques that measure insulin sampled from specific veins in an infant."
The Congenital Hyperinsulinism Center at The Children's Hospital of Philadelphia is the only facility of its kind in the country, and one of the few centers worldwide, with the knowledge and capability to successfully cure patients. Our specialists are true pioneers in the diagnosis and treatment of HI, offering patients the most innovative and compassionate care. The Center provides a multidisciplinary approach to care. Our sophisticated team of pediatric endocrinologists, surgeons, pathologists, anesthesiologists, nurses and researchers work closely together to provide seamless care on a full spectrum of services.
Charles A. Stanley, M.D. a pediatric endocrinologist at Children's Hospital and co-author of this study is world-renowned for his research and for discovering several genetic mutations in HI.
Dr. Hardy added that a later study will report on findings in all 50 patients. If the preliminary results hold up, they may suggest that [18F]-DOPA PET imaging should become a standard of care in infants with congenital HI who require surgery.
Dr. Hardy's co-authors were Miguel Hernandez-Pampaloni, M.D., Janet R. Saffer, M.D., Mariko Suchi, M.D., Eduardo Ruchell, M.D., Hongming Zhuang, M.D., Arupa Ganguly, M.D., N. Scott Adzick, M.D., Abass Alavi, M.D., and Charles A. Stanley, M.D, all of The Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine.
Source: Children’s Hospital of Philadelphia