Novel Use of Somatostatin Receptor Scintigraphy in Localization of Focal Congenital Hyperinsulinism: Promising but Fallible

Abstract

Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycemia in infants and children. The pre-operative differentiation of focal from diffuse forms is extremely important from the management point of view. The current methods for pre-operative differentiation are invasive. We report a patient with CHI where somatostatin receptor scintigraphy was used to diagnose CHI but with limited^ -TQ ^ŝ uccess. A preoperative gallium DOTATOC-PET scan was performed which revealed highly localized radiotracer uptake in the body of the pancreas. 80% of the pancreas including the body was resected. The clinical problems did not completely resolve after surgery. Histopathology revealed hyperplastic islet cells at the resected margin and randomly throughout the pancreas. This case highlights the use of 68 gallium DOTATOC-PET scan in a patient with severe CHI. The satellite foci that were missed may be either an inherent limitation of 68 Ga DOTATOC scan or an underinterpretation due to lack of expertise. This report opens up a new option of using somatostatin analogue scintigraphy for pre-operative localization of hyperplastic islet cells in patients with CHI.

Diffuse nesidioblastosis diagnosed on a Ga-68 DOTATATE positron emission tomography/computerized tomography

“…[ 9 ] Previously only one case report was published where Ga-68 DOTATOC PET scan was used to differentiate focal versus diffuse nesidioblastosis with limited success. [ 10 ] This is the first case where Ga-68 DOTATATE PET scan had been used to successfully differentiate focal versus diffuse nesidioblastosis and thus help in tailoring the management in the infant.…”

Striking Visualization of Diffuse Congenital Nesidioblastosis on Ga-68 DOTATATE PET/CT

“…Congenital hyperinsulinism is the most common cause of persistent hypoglycemia in infancy, existing in two forms of either focal or a diffuse adenomatous hyperplasia of insulin secretion in the pancreas. The pre-operative differentiation of these two conditions is crucial for disease management (1,2). Focal type can be treated by selective surgical resection in contrast to the diffuse form which requires near total pancreatectomy when resistant to medical treatment (3).…”

“…F-18-fluoro-dihydroxyphenylalanine PET scan has been used in case of hyperinsulinemia with a reported accuracy of 96% in diagnosing focal or diffuse disease, and of 100% in localizing the focal lesion (3,7). To the best of our knowledge, only few case reports have been published regarding the role of somatostatin receptor imaging to distinguish focal disease from diffuse involvement, where Ga-68 DOTATATE PET scan had been applied successfully in one case and Ga-68 DOTATOC PET scan has been reported to have limited success in another report (1,8). The presented case is evident with an enlarged pancreas showing diffuse increased Ga-68 DOTATATE uptake and indicates somatostatin receptor imaging as a valuable option to guide the type of pancreatectomy in patients with persistent hyperinsulinemic hypoglycemia…”

Could 68Ga-somatostatin analogues be an important alternative to 18F-DOPA PET/CT in pediatrics?

“…The aim of the study was to validate the use of 68 Ga-DOTANOC as effective and widely available alternative to 18 F-DOPA in CHI. Although, somatostatin analogues (e.g., 68 Ga-DOTANOC) with high affinity to the somatostatin receptor (SSTR) subtypes 2, 3, and 5, should be taken up by the endocrine cells of the islets of Langerhans expressing all SSTR subtypes [11], only little information is available in the literature regarding the usefulness of radiolabelled somatostatin analogues in CHI [12,13]. Indeed, this is the first and well-conducted comparison of such radiotracers in CHI.…”