Past, present and future of 68Ge/68Ga generators

Ga-68 represents one of the very early radionuclides applied to positron emission tomography (PET) imaging at a time when even the wording PET itself was not established. Today it faces a renaissance in terms of new Ge-68/Ga-68 radionuclide generators, sophisticated Ga-68 radiopharmaceuticals, and state-of-the-art clincial diagnoses via positron emission tomography/computed tomography (PET/CT). Thanks to the pioneering achievement of radiochemists in Obninsk, Russia, a new type of Ge-68/Ga-68 generators became commercially available in the first years of the 21st century. Generator eluates based on hydrochloric acid provided cationic Ga-68 instead of inert Ga-68-complexes, opening new pathways of Me-III based radiopharmaceutical chemistry. Consequently, the last decade has seen a 68Ga rush. Increasing applications of generator based Ga-68 radiopharmaceuticals (for diagnosis alone, but increasingly for treatment planning, thanks to the inherent option as expressed by THERANOSTICS, ask for new developments towards the optimisation of Ge-68/Ga-68 generators both from chemical and regulatory points of view. (C) 2012 Elsevier Ltd. All rights reserved.