Poster Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

The molecular imaging of insulinomas (#261)

Josephine McCarthy 1 , Christopher Yates 1 2
  1. Endocrinology and Diabetes, Western Health, Melbourne, Vic, Australia
  2. Endocrinology, Melbourne Health, Melbourne, Vic, Australia


The role of positron emission tomography (PET) molecular imaging for the localisation of insulinomas is yet to be determined. Recent evidence demonstrates the utility of PET molecular imaging for localisation, staging and directing therapy. We describe 2 cases of insulinomas demonstrating the utility of PET molecular imaging.


Case Summary

Case 1: A 62 year-old lady was admitted under the endocrine unit with recurrent severe hypoglycaemia. Dynamic testing was consistent with an insulinoma. Contrast enhanced Computer Tomography (CT) revealed an arterially enhancing mass in the pancreatic head >2cm raising suspicion for a malignant insulinoma. 68Ga-DOTA-TATE PET/CT revealed a 2.3cm pancreatic head lesion with high somatostatin receptor (SSR) expression, consistent with a well-differentiated insulinoma and no metastatic disease. The patient underwent a Whipple’s procedure confirming a pancreatic head insulinoma.


Case 2: A 64 year-old lady with type-2 diabetes mellitus presented with recurrent severe hypoglycaemia despite cessation of oral hypoglycaemic agents. Dynamic testing was consistent with an insulinoma. Contrast-enhanced CT was reported as a normal pancreas with a splenic hilum nodule - a splenunculus. Given the strong suspicion for an insulinoma a 68Ga-Exendin-4 PET/CT was performed which clearly localised an insulinoma at the site of the reported splenunculus. The patient underwent a laparoscopic resection of the lesion with histology confirming an insulinoma.


Learning Points

  • Whipple’s triad describes clinically significant hypoglycaemia
  • Insulinomas are the most common functional pancreatic neuroendocrine tumour
  • Malignant insulinomas are usually greater than 2cm
  • Emerging experience with combined PET/CT molecular imaging is improving patient outcomes due to greater success rates in insulinoma localisation and staging
  • 68Ga-Exendin-4 PET/CT GLP-1 receptor imaging is an effective adjunct imaging tool when conventional imaging has failed to localise an insulinoma
  • 68Ga-DOTA-TATE PET/CT SSR imaging is an effective tool in assessing for malignant and metastatic disease
  1. Cryer P., et al. Evaluation and Management of Adult Hypoglycemic Disorders: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2009; 94: 709–728
  2. Pattison D. and Hicks R. Molecular imaging in the investigation of hypoglycaemic syndromes and their management. Endocr Relat Cancer. 2017 April 11 (online).
  3. Nockel et al. Localization of Insulinoma Using 68Ga -DOTATATE PET/CT Scan. J Clin Endocrinol Metab. 2017; 102(1):195–199
  4. Srirajaskanthan R, et al. The role of 68Ga-DOTATATE PET in patients with neuroendocrine tumors and negative or equivocal findings on 111In-DTPA-octreotide scintigraphy. J Nucl Med. 2010;51(6): 875–882.
  5. Lei WY, Wang TE, Chen TL, Chang WH, Yang TL, Want CY. Insulinoma causing hypoglycemia in a patient with type 2 diabetes. J Formos Med Assoc. 2007; 106(5): 392-6.
  6. McAuley G, H Delaney, J Colville, I Lyburn, D Worsley, P Govender, W.C. Torregiani. Multimodality preoperative imaging of pancreatic insulinomas. Clinical Radiology. 2005; 60: 1039-1050.
  7. Grant C. Insulinoma. Best Practice and Research Clinical Gastroenterology 2005;19(5):783-798.
  8. Reubi JC, Waser B. Concomitant expression of several peptide receptors in neuroendocrine tumours: molecular basis for in vivo multireceptor tumour targeting. Eur J Nucl Med Mol Imaging.2003;30:781-793.
  9. Antwi K, Fani M, Nicolas G, Rottenburger C, Heye T, Reubi JC, Gloor B, Christ E, Wild D Localization of Hidden Insulinomas with ⁶⁸Ga-DOTA-Exendin-4 PET/CT: A Pilot Study. J Nucl Med 2015;56:1075-1078.
  10. Peter H Winocour, Kieran J Moriarty, C Nicholas Hales, Judy Adams, Roy Reeve, David Wynick, David Allison, Steven R Bloom, David C Anderson. Difficulties in localisation and treatment of insulinomas in type 1 multiple endocrine adenomatosis (MEA). Postgrad Med J. 1992;68:196-200.