Table 12.

Summary of radiolabeled NT, α-MSH, substance P, and VIP analogues for other important 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
- 99mTc - HYNIC, EDDA, tricine - x - [Ac-Lys5, Pro6, βAla7, Tle12]NT(5–13)	- preclinical in vitro, in vivo - colorectal - gamma camera - useful for early tumor SPECT staging due to appropriate tumor accumulation, high stability, low liver accumulation, and high kidney excretion	[180]
- 68Ga - DOTA(tBu)3 - 4- amino piperidin-1-yl-acetic acid - Lys8-Lys9-Pro10-Tyr11-Ile12-Leu13-OH modified with TMSAla12/13	- preclinical in vitro, in vivo - colorectal - microPET/CT - good NTR1 selectivity and prolonged plasmatic half-life of [68Ga]Ga-(TMSAla13)-conjugate; further in vivo uptake and impact of other metals (111In, 177Lu, 161Tb) under investigation	[181]
- 99mTc - DPA - Ahx-βAla, ethylene glycol (EG) based linker -Nle-Asp-His-D-Phe-Arg-Trp-Gly-NH2	- preclinical in vitro, initial in vivo - melanoma - x - high in vitro stability of [99mTc]Tc-tricarbonyl-DPA base; EG linker more useful than Ahx	[182]
- 111In - NHS-DOTA (3-arm), SCN-Bn-DOTA (4-arm) - x - α-MSH	- preclinical in vitro, in vivo - melanoma - SPECT - higher lipophilicity, higher MC1-R affinity, and relatively higher stability of 4-arm DOTA-conjugates than 3-arm	[183]
- 64Cu -SCN-NOTA, bispidine carbonate, SCN-dipyridylmethyl-TACN - Ahx-β-Ala -Nle-Asp-His-D-Phe-Arg-Trp-Gly-NH2	- preclinical in vitro, initial in vivo - melanoma - gamma counter - high hydrophilicity and sufficient MC1R-affinity of 64Cu-conjugate, but lower than that of [125I]I-NDP-MSH	[184]
- 99mTc - NOTA, NODAGA - Gly-Gly-Nle -c[Asp-His-DPhe-Arg-Trp-Lys]-NH2	- preclinical in vitro, in vivo - melanoma - nanoSPECT/CT - NOTA-conjugate with better tumor targeting and biodistribution properties; study with rhenium-188 suggested	[185]
- 99mTc, 177Lu -tris(2-mercaptoethyl)-amine, isocyanobutyric acid succinimidyl ester, DOTA - x - various SP analogues	- preclinical in vitro - glioblastoma - x - lipophilic conjugates with specific tumor binding, high stability in buffer solutions, but lower stability in human serum	[186]
- 64Cu, 67Ga - NOTA - x - NK1R antagonist	- preclinical in vitro, in vivo - kidney - PET/CT - high in vivo stability, tumor uptake and good liver and renal clearance of [64Cu]Cu-NOTA-conjugate	[187]
- 68Ga - NODAGA - PEGx - BBN(7-14), PACAP-27	- preclinical in vitro - x - improved stability of heterobivalent conjugates and comparable uptakes in tumor cells to those of monomers, further evaluation for in vivo PET/CT in progress	[188]
- 68Ga - NODAGA, DOTA - x - PACAP-27	- preclinical in vitro, in vivo - breast - PET/CT - low in vivo stability, but greater VPAC-affinity and tumor delineation only for NODAGA-conjugate	[189]
- 64Cu - N2S2 chelator - x - TP3805	- preclinical in vitro, in vivo - brain - microPET/CT - more specific brain tumor delineation than [18F]FDG, further investigation for clinical translation warranted	[190]