Receptors for the incretin glucagon-like peptide-1 (GLP-1R) have been found overexpressed in selected types of human tumors and may, therefore, play an increasingly important role in endocrine gastrointestinal tumor management. In particular, virtually all benign insulinomas express GLP-1R in high density. Targeting GLP-1R with indium-111, technetium-99m or gallium-68-labeled exendin-4 offers a new approach that permits the successful localization of small benign insulinomas. It is likely that this new non-invasive technique has the potential to replace the invasive localization of insulinomas by selective arterial stimulation and venous sampling. In contrast to benign insulinomas, malignant insulin-secreting neuroendocrine tumors express GLP-1R in only one-third of the cases, while they more often express the somatostatin subtype 2 receptors. Importantly, one of the two receptors appears to be always overexpressed. In special cases of endogenous hyperinsulinemic hypoglycemia (EHH), that is, in the context of MEN-1 or adult nesidioblastosis GLP-1R imaging is useful whereas in postprandial hypoglycemia in the context of bariatric surgery, GLP-1R imaging is probably not helpful. This review focuses on the potential use of GLP-1R imaging in the differential diagnosis of EHH.
Emanuel Christ, Kwadwo Antwi, Melpomeni Fani, and Damian Wild
Yulong Li and William F Simonds
neoplasia type1 . Clinical Nuclear Medicine 33 778 – 779 . (doi: 10.1097/RLU.0b013e318187efef ) Altemir Trallero J Armengod Grao L Aguillo Gutierrez E Cabrejas Gomez C Ocon Breton J Garcia Garcia B 2012 Thymic carcinoid in
Jerena Manoharan, Max B Albers, and Detlef K Bartsch
Okumura T Shioyama Y Kiyoshima M Asato Y Saito H Iijima T Amemiya R Nagai H 2008 FDG PET/CT findings of thymic carcinoid and bronchial carcinoid in a patient with multiple neuroendocrine neoplasia type1 . Clinical Nuclear
C R C Pieterman, E B Conemans, K M A Dreijerink, J M de Laat, H Th M Timmers, M R Vriens, and G D Valk
T Amemiya R Nagai H 2008 FDG PET/CT findings of thymic carcinoid and bronchial carcinoid in a patient with multiple neuroendocrine neoplasia type 1 . Clinical Nuclear Medicine 33 778 – 779 . ( doi:10.1097/RLU.0b013e318187efef ). Agarwal