ESPE Abstracts

Background: Evaluation of persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) requires accurate anatomic diagnosis for appropriate medical/surgical management. ¹⁸F-DOPA PET scan is used to localise the disease in pancreas, but is not available in many centres.

Objective and hypotheses: We were highly restrained by the availability of investigations for evaluation of PHHI, especially ¹⁸F-DOPA. To localise the disease process, we use genetic testing and response to therapy as a guide. So, we tried HYNIC TOC as a new material for PET scan and tried to correlate with the genetic results and patient’s clinical course.

Method: Neonate born LGA with birth weight 4.8 kg had hyperinsulinaemic hypoglycaemia (critical sample insulin-67.07 μU/ml). Workup done for other causes of hypoglycaemia were negative. Hypoglycaemia was persistent with high dextrose requirements and refractory to oral diazoxide therapy (upto 10 mg/kg per day). But he responded to octreotide s.c. injection at 5 μg/kg per day. His genetic work up was done at Exeter Labs, UK which showed compound heterozygous mutation in ABCC8 gene (location exon 2 and intron 20; missense and aberrant splicing) inherited from both the parents. These clinical course and genetic reports suggested diffuse involvement of pancreas causing hyperinsulinism, but we were restrained by the non availability of ¹⁸F-DOPA in India. So PET scanning was done using a new radionuclide material called HYNIC TOC.

Results: HYNIC TOC PET/SPECT scan showed diffuse uptake of radionuclide material in the pancreatic tissue suggesting diffuse nesidioblastosis.

Conclusion: HYNIC TOC, used in the diagnosis of neuroendocrine tumours in adults widely can be tried in children with PHHI where ¹⁸F-DOPA is not available, suggested by the correlation we found. Also, the properties like high in vitro and in vivo stability, rapid blood clearance, predominant renal excretion, improved image quality, lower radiation dose and EASY AVAILABILTY may make it an ideal material for this indication.