Efficient production of high specific activity 64Cu using a biomedical cyclotron

Area of Science:

• Nuclear Chemistry
• Radiopharmaceutical Chemistry
• Medical Imaging

Background:

• Copper-64 (Cu-64) is a valuable positron-emitting radionuclide for PET imaging and cancer radiotherapy.
• Current production methods at research reactors have limited availability due to weekly access constraints.
• Increased availability of Cu-64 is crucial for broader biomedical applications.

Purpose of the Study:

• To develop an efficient method for producing high specific activity Cu-64 using a small biomedical cyclotron.
• To overcome the limited availability of Cu-64 from current reactor-based production.
• To establish a reliable cyclotron-based production for Cu-64 radiotracer.

Main Methods:

• Irradiation of nickel-64 (Ni-64) targets with protons via the 64Ni(p,n)64Cu nuclear reaction.
• Utilized enriched Ni-64 (95-98%) electroplated on gold disks, with specialized water-cooled targets for cyclotron bombardment.
• Separation of Cu-64 from Ni-64 and byproducts using ion exchange chromatography.

Main Results:

• Achieved production of 150-600 mCi of Cu-64 per run with specific activities of 94-310 mCi/microgram Cu.
• Demonstrated efficient separation of Cu-64 using ion exchange chromatography.
• Successfully radiolabeled biomolecules including PTSM, MAb 1A3, and octreotide with cyclotron-produced Cu-64.
• Developed a recycling technique for Ni-64 targets with over 90% efficiency.

Conclusions:

• Biomedical cyclotron production of Cu-64 is feasible and efficient, significantly increasing its availability.
• The developed method provides high specific activity Cu-64 suitable for radiolabeling various diagnostic and therapeutic agents.
• Recycling of Ni-64 targets enhances the economic viability of this production method.