Production of Zr-89 using sputtered yttrium coin targets 89Zr using sputtered yttrium coin targets

Stacy Lee Queern; Tolulope Aramide Aweda; Adriana Vidal Fernandes Massicano; Nicholas Ashby Clanton; Retta El Sayed; Jayden Andrew Sader; Alexander Zyuzin; Suzanne Elizabeth Lapi

doi:10.1016/j.nucmedbio.2017.03.004

Production of Zr-89 using sputtered yttrium coin targets ⁸⁹Zr using sputtered yttrium coin targets

Nucl Med Biol. 2017 Jul:50:11-16. doi: 10.1016/j.nucmedbio.2017.03.004. Epub 2017 Mar 23.

Authors

Stacy Lee Queern¹, Tolulope Aramide Aweda², Adriana Vidal Fernandes Massicano², Nicholas Ashby Clanton², Retta El Sayed², Jayden Andrew Sader³, Alexander Zyuzin³, Suzanne Elizabeth Lapi⁴

Affiliations

¹ Department of Chemistry, Washington University in St. Louis, USA; Department of Radiology, University of Alabama at Birmingham, USA.
² Department of Radiology, University of Alabama at Birmingham, USA.
³ Advanced Cyclotron Systems, Inc., Richmond, BC, Canada.
⁴ Department of Radiology, University of Alabama at Birmingham, USA. Electronic address: lapi@uab.edu.

PMID: 28376350
DOI: 10.1016/j.nucmedbio.2017.03.004

Abstract

An increasing interest in zirconium-89 (⁸⁹Zr) can be attributed to the isotope's half-life which is compatible with antibody imaging using positron emission tomography (PET). The goal of this work was to develop an efficient means of production for ⁸⁹Zr that provides this isotope with high radionuclidic purity and specific activity. We investigated the irradiation of yttrium sputtered niobium coins and compared the yields and separation efficiency to solid yttrium coins. The sputtered coins were irradiated with an incident beam energy of 17.5MeV or 17.8MeV providing a degraded transmitted energy through an aluminum degrader of 12.5MeV or 12.8MeV, respectively, with various currents to determine optimal cyclotron conditions for ⁸⁹Zr production. Dissolution of the solid yttrium coin took 2h with 50mL of 2M HCl and dissolution of the sputtered coin took 15-30min with 4mL of 2M HCl. During the separation of ⁸⁹Zr from the solid yttrium coins, 77.9 ± 11.2% of the activity was eluted off in an average of 7.3mL of 1M oxalic acid whereas for the sputtered coins, 91 ± 6% was eluted off in an average of 1.2mL of 1M oxalic acid with 100% radionuclidic purity. The effective specific activity determined via DFO-SCN titration from the sputtered coins was 108±7mCi/μmol as compared to 20.3mCi/μmol for the solid yttrium coin production. ICP-MS analysis of the yttrium coin and the sputtered coins showed 99.99% yttrium removed with 178μg of yttrium in the final solution and 99.93-100% of yttrium removed with remaining range of 0-42μg of yttrium in the final solution, respectively. The specific activity calculated for the solid coin and 3 different sputtered coins using the concentration of Zr found via ICP-MS was 140±2mCi/μmol, 300±30mCi/μmol, 410±60mCi/μmol and 1719±5mCi/μmol, respectively. Labeling yields of the ⁸⁹Zr produced via sputtered targets for ⁸⁹Zr- DFO-trastuzumab were >98%. Overall, these results show the irradiation of yttrium sputtered niobium coins is a highly effective means for the production of ⁸⁹Zr.

Keywords: Degrader; Isotope production; Sputtered coins; Yttrium; Zirconium-88; Zirconium-89.

MeSH terms

Cyclotrons
Radiochemistry / instrumentation
Radiochemistry / methods*
Radioisotopes / analysis
Radioisotopes / chemistry*
Radioisotopes / isolation & purification
Yttrium / chemistry*
Zirconium / analysis
Zirconium / chemistry*
Zirconium / isolation & purification

Substances

Radioisotopes
Yttrium
Zirconium
Zirconium-89