Production of radioimmunoPET grade zirconium-89

Introduction: Particular characteristics of 89Zr to produce various labeled compounds are crucial for developing radioimmunopharmaceuticals for clinical trials. This study aimed to produce 89Zr for radiolabeling purposes as radioimmunoPET grade precursor.  Methods: The computational calculations for 89Zr production via 89Y(p,n)89Zr reaction were performed using TALYS-1.8 and ALICE-91. 89Zr was produced by the proton bombardment of the yttrium pellet using a 30 MeV cyclotron. ZR resin was used for the separation of 89Zr from the target. The radionuclidic purity was assessed by a high purity germanium detector. The inductively coupled plasma spectrometry and instant thin layer chromatography methods were considered for chemical and radiochemical purity assessments, respectively. The biodistribution of [89Zr]Zr-oxalate was studied in Wistar rats by both sacrification and imaging. [89Zr]Zr-DFO-trastuzumab was produced as a proof of concept for a radioimmunoPET labeling.Results: Considering the cross-section of 89Y(p,n)89Zr reaction, 14 MeV proton energy was selected for 89Zr production, while the yttrium pellet target was irradiated at least for 125 µAh,. 89Zr was finally prepared with a yield of 25.9±1.48 MBq/µAh, a specific activity of 344.1 MBq/µg, the radionuclidic and radiochemical purity higher than 99.99% and 99%, respectively. Total amount of the metal ions in the final solution was less than 0.1 ppm. Biodistribution of [89Zr]Zr-oxalate demonstrated high accumulation in the bone, lungs, and heart. [89Zr]Zr-DFO-trastuzumab was produced with a radiochemical purity higher than 99% and specific activity of 74 GBq/g in about 2 hours.Conclusion: [89Zr]Zr-oxalate was produced with suitable activity and high purity for the preparation of the radioimmunopharmaceuticals.

Production of radioimmunoPET grade zirconium-89 Keywords:

Zirconium-89 , Production , Radiolabeled compounds , cyclotron