Table 10.

Summary of radiolabeled exendin analogues for GLP-1 receptor-positive tumor imaging over past 3 years.

Composition of Studied Compounds - Metal Radionuclide - BFCA - Linker - Peptide	Results and Findings - Phase of Trials - Cancer Type Studied - Imaging Technique Used - Benefits/Limitations/Conclusion	Reference
- 111In - DTPA - lysine - exendin-3	- preclinical in vitro, in vivo - insulinoma - SPECT - hexendin40–45 conjugate (with 6 Lys and 6 DTPA residues) as the most useful due to the 7-fold higher specific activity than simpler conjugates and improved visualization of the pancreas	[67]
- 111In - NODAGA - albumin-binding moiety (ABM) - exendin-4	- preclinical in vitro, in vivo - insulinoma - SPECT/CT - significantly reduced kidney uptake and improved GLP1R targeting, but a further assessment of whole-body doses needed	[68]
- 68Ga - NOTA - methylaminolevulinate - Cys39-exendin-4	- preclinical in vitro, in vivo - pheochromocytoma (PCM) - microPET - specific GLP1R targeting in both poorly and highly differentiated PCM cells, but high accumulation in kidneys; more studies needed to establish association between GLP-1R PET and a risk stratification of PCM	[165]
- 64Cu - NODAGA x - Lys40-exendin-4	- preclinical in vivo - insulinoma - PET/MRI - high background signal from the exocrine pancreas observed during an early time points; the positive correlation between [64Cu]Cu-Ex4, reflecting β-cell mass, and Mn-retention demonstrated by a simultaneous PET/MRI	[166]