High-Efficiency Cationic Labeling Algorithm of Macroaggregated Albumin with ⁶⁸Gallium

Area of Science:

• Radiochemistry
• Nuclear Medicine
• Medical Imaging

Background:

• Gallium-68 (⁶⁸Ga) is a key radionuclide for Positron Emission Tomography/Computed Tomography (PET/CT) imaging.
• ⁶⁸Ga-labeled Macroaggregated Albumin (MAA) offers a promising alternative to technetium-99m (^99mTc)-labeled MAA.

Purpose of the Study:

• To develop a reliable, efficient, and organic solvent-free synthesis protocol for ⁶⁸Ga-MAA.
• To adapt a commercially available ^99mTc-MAA kit for ⁶⁸Ga labeling under Good Manufacturing Practice (GMP) conditions.
• To utilize an automated synthesis unit for consistent radiopharmaceutical production.

Main Methods:

• The labeling involved incubating ⁶⁸GaCl₃ with MAA-HEPES at 90°C for 7 minutes.
• Elution was performed using a PSH⁺ cartridge and 1.5 mL of 5 M NaCl.
• Quality control and GMP compliance were maintained throughout the radiopharmaceutical production process.

Main Results:

• The generator product ⁶⁸Ga achieved >99% radiochemical purity and efficiency.
• Labeling efficiency for ⁶⁸Ga-MAA exceeded 99%.
• Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) analysis confirmed the absence of significant toxic metal impurities.

Conclusions:

• The synthesized ⁶⁸Ga-MAA exhibits excellent radiochemical and chemical purity.
• The final product is suitable for direct use in PET/CT imaging without further purification.
• This method provides a high-quality, safe, and efficient gallium-68 labeled MAA for diagnostic applications.