Glucagon-like peptide-1 receptor imaging with [Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4 for the detection of insulinoma

Abstract

PurposeThe objective of this article is to present a new method for the diagnosis of insulinoma with the use of [Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4.MethodsStudies were performed in 11 patients with negative results of all available non-isotopic diagnostic methods (8 with symptoms of insulinoma, 2 with malignant insulinoma and 1 with nesidioblastosis). In all patients glucagon-like peptide-1 (GLP-1) receptor imaging (whole-body and single photon emission computed tomography/CT examinations) after the injection of 740 MBq of the tracer was performed.ResultsBoth sensitivity and specificity of GLP-1 receptor imaging were assessed to be 100 % in patients with benign insulinoma. In all eight cases with suspicion of insulinoma a focal uptake in the pancreas was found. In six patients surgical excision of the tumour was performed (type G1 tumours were confirmed histopathologically). In one patient surgical treatment is planned. One patient was disqualified from surgery. In one case with malignant insulinoma pathological accumulation of the tracer was found only in the region of local recurrence. The GLP-1 study was negative in the other malignant insulinoma patient. In one case with suspicion of nesidioblastosis, a focal accumulation of the tracer was observed and histopathology revealed coexistence of insulinoma and nesidioblastosis.Conclusion[Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4 seems to be a promising diagnostic tool in the localization of small insulinoma tumours, but requires verification in a larger series of patients.

Oxidation of methionine — is it limiting the diagnostic properties of 99mTc-labeled Exendin-4, a Glucagon-Like Peptide-1 receptor agonist?

“…99m Tc-EDDA/HYNIC-Met 14 -Exendin-4, obtained from the dry kit formulation, has been proven useful in SPECT imaging of insulinomas and MTC [13,14]. Therefore, the development of the kit formulation for EDDA/HYNIC-Met 14 -Exendin-4 for labeling with technetium-99m was an important achievement in our studies.…”

“…This prompted us to further develop this tracer into the clinically suitable formulation. Moreover, in our experience, the diagnostic utility of a GLP-1receptor agonist, [Lys 40 (Ahx-HYNIC99m Tc/EDDA)NH 2 ]--Exendin-4 obtained from the developed dry kit, has been proven in a small group of patients with insulinoma [13] and MTC [14].…”

Nowotwory neuroendokrynne trzustki — zasady diagnostyki i leczenia (rekomendowane przez Polską Sieć Guzów Neuroendokrynych)

“…Other tracers that can be used in the diagnostics of PNENs include: FDG (in the diagnostics of fast-growing, aggressive PNENs and NECs with poor prognosis) [122,123], and labelled glucagon-like peptide analogues [125][126][127]. Due to the very high expression of receptors for GLP-1 in some neoplasms, estimated at nearly…”

“…100% in benign insulin-secreting tumours, scintigraphy with the use of labelled GLP-1 analogues may become a diagnostic method competing with SRI [110,125,126]. The next step to improve sensitivity of location diagnostics of small PNETs (gastrinoma, insulinoma) is using an intraoperative radioisotope probe (RGS) [6,127,128].…”

GEP-NETs update: Functional localisation and scintigraphy in neuroendocrine tumours of the gastrointestinal tract and pancreas (GEP-NETs)

“…GLP1R imaging using this compound has been studied in MTCs (71) and benign insulinomas (72). 68 Ga-DOTAexendin-3 is a promising tracer to visualise insulinomas with PET (73).…”