Protocol for Clinical GLP-1 Receptor PET/CT Imaging with [ 68 Ga]Ga-NODAGA-Exendin-4.

Imaging with radiolabeled exendin enables detection and characterization of glucagon-like peptide 1 receptors (GLP-1Rs) in vivo with high specificity. The novel radiotracer [68 Ga]Ga-NODAGA-exendin-4 forms a stable complex after a simple and fast labeling procedure. Beta-cell mass in the islets of Langerhans can be visualized using [68 Ga]Ga-NODAGA-exendin-4, which is promising for research into diabetes mellitus (DM) pathophysiology. Furthermore, this radiotracer enables very sensitive detection of insulinomas, resulting from vast overexpression of GLP-1Rs, and seems promising for the detection of focal lesions in congenital hyperinsulinism (CHI). Here, we describe the procedures involved in [68 Ga]Ga-NODAGA-exendin-4 positron emission tomography (PET)/computed tomography (CT) imaging including the radiolabeling of the NODAGA-exendin conjugate with 68 Ga, quality controls, and PET/CT.