The development of
gallium-68 -1,4,7,10-tetraazacyclodecane-1,4,7,10-tetraacetic
acid ((68)Ga-DOTA) compounds was made possible due to the chemistry of (68)Ga, which matches the pharmacokinetics of many
peptides, specially the
chelators DOTA and DOTAderivatives with the formation of stable (68)Ga (3+) complexes. The availability of this tracer from a germanium-68-gallium-68 generator with a relatively long half-life makes it attractive to use in busy nuclear medicine departments, particularly those with limited access to
cyclotrons. The recent clinical experience with (68)Ga-peptides includes imaging neuroendocrine tumours particularly
carcinoid, as well as neuroectodermal tumours such as phaeochromocytoma and
paraganglioma. In vitro and animal testing are still progressing alongside clinical studies, with promising results in the use of (68)Ga-DOTA-rhenium-cyclized
alpha-melanocyte stimulating hormone (
MSH) and (68)Ga-DOTA-napamide (NAP) in
melanoma, (68)Ga-DOTA-PEG(4)-BN(7-14) (PESIN) for the imaging of
bombesin receptor- positive tumours and (68)Ga-ethylene dicysteine-
metronidazole (EC-MN) for imaging tumour
hypoxia. In addition to tumours, (68)Ga-
DOTA peptide inhibitor of vascular
peptide protein 1(VAP-P1) is being assessed for imaging inflammatory reaction. An additional value following a positive scan is the use of beta emitters labelled to the same
peptides for
radionuclide treatment. In conclusion, the recent introduction of (68)Ga-peptides, made available by a convenient (68)Ga/(68)Ge generator, could greatly contribute to the management of a wide range of clinical conditions including tumours and
inflammation.