RT Journal Article SR Electronic T1 Improved production yield, processing and specific activity of 89Zr JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 335 OP 335 VO 58 IS supplement 1 A1 Aiman Alnahwi A1 Sebastien Tremblay A1 Brigitte Guerin YR 2017 UL http://jnm.snmjournals.org/content/58/supplement_1/335.abstract AB 335Objectives: Long half-life and β+ emitter, zirconium-89 (89Zr) is well suited for the antibody-based positron emission tomography (PET) imaging (immune-PET). 89Zr can be produced by cyclotron via an 89Y(p,n)89Zr reaction using 89Y foil targets. With the increased-importance of immune-PET, there is a need to develop less expensive yttrium-89 (89Y) targets and a more efficient purification cassette-based system. The objectives of this study are to improve production yield of foil and pressed powder 89Y targets using different thicknesses and to optimize an automated cassette-based purification process as well as obtaining high-purity and high-effective specific activity (ESA) as 89Zr-oxalate.Methods: 89Zr was produced via 89Y(p,n)89Zr reaction using a solid 89Y-foil or pressed target mounted on custom-made aluminum and niobium coin target holders/degraders. Irradiation times were between 1-5 h with a beam current between 10-25 μA. The proton-beam energies deposited to the target material were between ~11.3-13.5 MeV for all productions. Irradiated target was purified using a cassette-based purification module to produce 89Z-oxalate remotely inside a hot cell. The front panel of the module was equipped with two cassettes, one to allow easy load of the liquid vials, the other for dispensing of 3-4 vials. ESA (GBq/μmol) of 89Zr was calculated via titration with desferrioxamine. In addition, radionuclidic impurity was determined by gamma-ray (γ-ray) spectroscopy on a high purity germanium detector.Results: The highest production yield of 36.6 MBq/μA•h was found by increasing the proton-beam energy deposited to the target material to 13.3 MeV using 0.508 mm foil thickness. A similar production yield of 37.2±1.3 MBq/μA•h was obtained with 0.510 mm pressed target thickness under similar irradiation conditions. Typically, the recovered activity was 81±4 % and the maximum activity was found in the second product vial. In all isolated purified solution, the ESA of 89Zr oxalate for foil and pressed targets were found to be in the range of 48 - 452 GBq/μmol and 37 - 82 GBq/μmol respectively. Spectra of γ-ray showed no impurities of 88Zr and 88Y when irradiation was done at 11.3 MeV. However, three peaks corresponding to 88Zr and 88Y impurities were clearly observed on the γ-ray spectrum six-month post-purification of 89Zr irradiated at 13.3 MeV.Conclusion: In this work we successfully design solid target degraders/holders for 89Zr production using foil and pressed targets. Degrading the proton energy to ~13 MeV provides 89Zr with high yields sufficient for (pre)clinical use and/or commercial supply. 89Y- pressed target holds great potential and can replace favorably 89Y-foil target in view of the cost and productivity. The cassette-based purification-process described in this work is both simple and efficient and can be used for routine 89Zr production. Specific activities of purified 89Zr fractions were found to be superior to the reported 89Zr specific activities and appropriate for labeling antibody-based proteins. Research Support: Natural Sciences and Engineering Research Council of Canada (NSERC, RGPIN-2014-04354)