Accuracy of [18F] fluorodopa positron emission tomography for diagnosing and localizing focal congenital hyperinsulinism

Objectives: Focal lesions in infants with congenital hyperinsulinism ( HI) represent areas of adenomatosis that express a paternally derived ATP-sensitive potassium channel mutation due to embryonic loss of heterozygosity for the maternal 11p region. This study evaluated the accuracy of F-18-fluoro-L-dihydroxyphenylalanine ([F-18] DOPA) positron emission tomography ( PET) scans in diagnosing focal vs. diffuse disease and identifying the location of focal lesions. Design: A total of 50 infants with HI unresponsive to medical therapy were studied. Patients were injected iv with [F-18] DOPA, and PET scans were obtained for 50-60 min. Images were coregistered with abdominal computed tomography scans. PET scan interpretations were compared with histological diagnoses. Results: The diagnosis of focal or diffuse HI was correct in 44 of the 50 cases (88%). [F-18] DOPA PET identified focal areas of high uptake of radiopharmaceutical in 18 of 24 patients with focal disease. The locations of these lesions matched the areas of increased [F-18] DOPA uptake on the PET scans in all of the cases. PET scan correctly located five lesions that could not be visualized at surgery. The positive predictive value of [ 18F] DOPA in diagnosing focal adenomatosis was 100%, and the negative predictive value was 81%. Conclusions: [F-18] DOPA PET scans correctly diagnosed 75% of focal cases and were 100% accurate in identifying the location of the lesion. These results suggest that [ 18F] DOPA PET imaging provides a useful guide to surgical resection of focal adenomatosis and should be considered as a guide to surgery in all infants with congenital HI who have medically uncontrollable disease.