Gallium-68 -- a new opportunity for PET available from a long shelf-life generator - automation and applications

Abstract

(68)Ge/(68)Ga generators have received tremendous attention in the last years based on the success of (68)Ga-labelled Somatostatin analogues for Positron-Emission Tomography (PET), which are today used routinely worldwide. Various commercially available generator types are based on different column matrices including TiO(2), SnO(2) or organic (68)Gechelate coated silica, providing (68)Ga as Ga(3+) in HCl for radiolabeling procedures. These systems can serve as a stable source of (68)Ga for PET applications over periods of more than one year with high yields. A number of methods for post processing of the eluate including fractionation, anion or cation exchange purification have been developed. These methods are particularly important for high specific activity labeling of biomolecules such as peptides ensuring small volumes, low metallic contamination and low (68)Ge breakthrough. These systems have been implemented into fully automated modules allowing generator elution, post processing radiolabeling and formulation, complying with high regulatory demands. Quality aspects regarding the clinical use of (68)Ga for patient applications including limit of (68)Ge content, metal contamination, microbiological safety and radiochemical purity have been addressed. Overall, the establishment of (68)Ge/(68)Ga generator technology together with the development of novel (68)Ga-radiopharmaceuticals make (68)Ga a most promising radionuclide for PET in the years to come.