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

(68)Ga 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 (68)Ge/(68)Ga radionuclide generators, sophisticated (68)Ga 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 (68)Ge/(68)Ga generators became commercially available in the first years of the 21st century. Generator eluates based on hydrochloric acid provided "cationic" (68)Ga instead of "inert" (68)Ga-complexes, opening new pathways of Me(III) based radiopharmaceutical chemistry. Consequently, the last decade has seen a (68)Ga rush. Increasing applications of generator based (68)Ga 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 (68)Ge/(68)Ga generators both from chemical and regulatory points of view.