There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Zirconium-89 is an attractive metallo-radionuclide for use in immuno-PET due to favorable
decay characteristics. Standardized methods for the routine production and isolation
of high-purity and high-specific-activity (89)Zr using a small cyclotron are reported.
Optimized cyclotron conditions reveal high average yields of 1.52+/-0.11 mCi/muA.h
at a proton beam energy of 15 MeV and current of 15 muA using a solid, commercially
available (89)Y-foil target (0.1 mm, 100% natural abundance). (89)Zr was isolated
in high radionuclidic and radiochemical purity (>99.99%) as [(89)Zr]Zr-oxalate by
using a solid-phase hydroxamate resin with >99.5% recovery of the radioactivity. The
effective specific-activity of (89)Zr was found to be in the range 5.28-13.43 mCi/microg
(470-1195 Ci/mmol) of zirconium. New methods for the facile production of [(89)Zr]Zr-chloride
are reported. Radiolabeling studies using the trihydroxamate ligand desferrioxamine
B (DFO) gave 100% radiochemical yields in <15 min at room temperature, and in vitro
stability measurements confirmed that [(89)Zr]Zr-DFO is stable with respect to ligand
dissociation in human serum for >7 days. Small-animal positron emission tomography
(PET) imaging studies have demonstrated that free (89)Zr(IV) ions administered as
[(89)Zr]Zr-chloride accumulate in the liver, whilst [(89)Zr]Zr-DFO is excreted rapidly
via the kidneys within <20 min. These results have important implication for the analysis
of immuno-PET imaging of (89)Zr-labeled monoclonal antibodies. The detailed methods
described can be easily translated to other radiochemistry facilities and will facilitate
the use of (89)Zr in both basic science and clinical investigations.