ECE2015 Guided Posters Endocrine tumours and neoplasia – NETS (9 abstracts)
1Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland; 2Division of Experimental Pathology, Department of Pathology, University of Bern, Bern, Switzerland; 3Department of Visceral Surgery, University Hospital of Bern, Inselspital, Bern, Switzerland; 4Division of Endocrinology, Diabetology and Clinical Nutrition, Hospital of Luzern, Luzern, Switzerland; 5Division of Endocrinology, Diabetology and Clinical Nutrition, University Hospital of Bern, Inselspital, Bern, Switzerland.
Purpose: We aim at prospectively comparing the detection rate of glucagon-like peptide 1 receptor (GLP1R) PET/CT vs GLP1R SPECT/CT vs standardised contrast enhanced 3T MRI in patients with endogenous hyperinsulinaemic hypoglycaemia.
Methods: 14 patients with neuroglycopenic symptoms due to endogenous hyperinsulinaemic hypoglycaemia were already enrolled (mean age 56 years, ten females and four males). A standardized contrast enhanced 3T MRI was performed. Afterwards the patients received a SPECT/CT at 4 and 72 h after injection of 111In-DOTA-exendin-4 and a PET/CT 2.5 h after injection of 68Ga-DOTA-exendin-4, in a randomized order. Standard of comparison was the histological diagnosis after surgery.
Results: In 11 patients histological diagnosis confirmed benign insulinoma, one patient had adult nesidioblastosis. In one patient none of the imaging modalities were able to find any lesion. Another patient refused surgery despite a positive PET/CT scan. In 8/12 patients previously performed conventional imaging (CT/MRI) was not able to localise the insulinoma. Standardized 3T MRI was able to predict the correct localisation of the insulinoma in 8/12 patients. PET/CT correctly identified the insulinoma or nesidioblastosis in 12/12 patients whereas SPECT/CT correctly identified the insulinoma in 10/12 patients. PET/CT was the only modality which identified the region of islet cell hyperplasia (adult nesidioblastosis) within the pancreas.
Conclusion: GLP1R PET/CT defines a novel, non-invasive, highly sensitive tool in localizing insulinomas. Standardised contrast enhanced MRI improves the diagnostic accuracy compared to locally performed conventional imaging. Further studies will have to confirm whether PET/CT is able to localise adult nesidioblastosis.
Disclosure: This work was supported in part by the Swiss National Science Foundation grant number 320030_152938/1 (to E Christ, D Wild, and M Fani) and the Desirée and Niels Ydes Foundation Grant No, 389-12 (to D Wild).