Table 11.

Summary of radiolabeled RGD analogues for α_vβ₃ 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
- 68Ga - DOTA, TRAP, FSC, THP - glutamic acid - (RGD)3, [c(RGDfK)]2	- preclinical in vitro, in vivo - renal, head and neck - microPET/CT - the highest tumor uptake for FSC- and THP-conjugates, but further studies on binding behavior to integrins needed	[168]
- 99mTc - glucoheptonate, D-penicillamine - Ahx - c(RGDfK)	- preclinical in vitro, in vivo - glioma - microSPECT/CT - [99mTc]Tc-[Pen-Ahx-c(RGDfK)]2 with the 10-fold higher integrin affinity than the monovalent (Pen-Ahx-c(RGDfK)), but high uptake in the liver, intestine, and kidney calls for an improvement of pharmacokinetics	[169]
- 99mTc - IDA - aspartic acid - [c(RGDfK)]2	- clinical, 6 patients - x - gamma camera - radiation doses of renal and biliary system comparable to other 99mTc-labeled peptides, further dosimetry studies needed for a risk-benefit assessment	[170]
- 68Ga - NOTA-NHS - 6-Ahx, cysteine - c(RGDyK), GE11	- preclinical in vitro, in vivo - lung - PET/CT - enhanced tumor accumulation of [68Ga]Ga-NOTA-RGD-GE11 than monomeric RGD-conjugate, but a modification of linkers needed for an improvement of pharmacokinetics	[171]
- 68Ga - NOTA - PEG3, symmetric β-glutamate linker - RGD2	- preclinical in vitro, in vivo - prostate - PET - significant limitations due to high renal and bladder accumulation, but low uptake in other organs	[172]
- 99mTc - HYNIC, tricine, TPPTS - x - RGD2	- clinical, 20 patients - breast - gamma camera - good uptake in breast lesions and also metastatic sites in lymph nodes visible in 2 patients - useful easily available kit for further clinical studies	[173]
- 68Ga - DOTA - glutamic acid - (cRGDfK)2	- preclinical in vitro, in vivo - lung - PET/CT - 68Ga-labeled conjugate with highly hydrophilic properties, high tumor accumulation, moderate in vivo uptake in kidneys and intestine, with a potential for early detection of lung lesions	[174]