Improvement and Optimization of Clinically Potent Positron Emitter ⁷⁶Br Isolation Using the Dry Distillation Approach for its Future Automation

Abstract

  Dry distillation has been mainly used for the isolation of bromine-76 (⁷⁶Br), a clinically potent radionuclide for positron emission tomography (PET). However, dry distillation systems are not considered suitable for an automated isolation module, which is necessary for routine clinical production. Therefore, a new dry distillation system including a water trap for the recovery of ⁷⁶Br was investigated. Prior to isolation studies, isotopically enriched Cu₂ ⁷⁶Se, the target material for ⁷⁶Br production, was prepared by heating a mixture of Cu and ⁷⁶Se under high vacuum; formation of Cu₂ ⁷⁶Se was confirmed by X-ray diffractometer (XRD). Isolation studies using ⁷⁷Br demonstrated reasonable recovery efficiency (66.5 ± 5.3%) from the new system. Large-scale isolation studies using ⁷⁶Br led to recovery of highly pure ⁷⁶Br with radioactivity on the order of GBq under optimized conditions. This improved dry distillation method shows promise as a future automated isolation process.