title: A modified technique for efficient radiolabeling of 68Ga-citrate from a SnO2-based 68Ge/68Ga generator for better infection imaging.
abstract: Our aim was to develop a practical method to prepare 68Ga-citrate using a SnO2-based 68Ge/68Ga generator and evaluate its use in infection imaging. 68Ga-citrate synthesis was performed in a straight forward, quantitative, one-step-aseptic procedure; an amended labeling method was applied using ACD-A buffered citrate as a precursor. Study participants were imaged on a Siemens Biograph 40 PET/CT scanner 60 min post intravenous injection. Our results showed: 90%-95% 68Ga-yield was obtained and subsequently used at 324-527 MBq to perform three to four parallel 68Ga-citrate syntheses. 68Ga-citrate of 96%-99% was yielded after 10 min incubation. The radiochemical purity was >99% with a pH value of 4.0-4.5. All other quality control requirements were met. The 68Ga-citrate stability was >96%. The final product was sterile, pyrogen and solvent-free, with very low 68Ge-levels, with 191±33 MBq in 6.6±2.8 mL. High quality images were obtained at 60 min post injection of 185 MBq of 68Ga-citrate. In conclusion, a fast, direct and cheap method with a quantitative preparation of 68Ga-citrate was described. We reported on the adaptations needed when using a SnO2-based 68Ge/68Ga generator and ACD-A buffered citrate as a precursor. This method allowed for multiple patient productions from one generator elution, with 300 MBq/patient of 68Ga-citrate produced in less than 30 min and excellent labeling reproducibility for routine infection imaging.
authors.affiliation: University of Pretoria and Steve Biko Academic Hospital Private Bag X169 Pretoria, 0001, South Africa. mike.sathekge@up.ac.za, sathekgemike@gmail.com.
authors.forename: Mariza
authors.initials: M
authors.lastname: Vorster
authors.forename: Brenda
authors.initials: B
authors.lastname: Mokaleng
authors.forename: Mike M
authors.initials: MM
authors.lastname: Sathekge
authors.forename: Thomas
authors.initials: T
authors.lastname: Ebenhan
mesh_terms: D002951:Citrates / Q000138:chemical synthesis*; D005708:Gallium; D005857:Germanium / Q000737:chemistry*; D006801:Humans; D007239:Infections / Q000000981:diagnostic imaging*; D007249:Inflammation / Q000000981:diagnostic imaging*; D007553:Isotope Labeling / Q000379:methods; D009369:Neoplasms / Q000000981:diagnostic imaging*; D011868:Radioisotopes / Q000737:chemistry; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D002951:Citrates; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D017971:Tin Compounds; D005857:Germanium; D005708:Gallium; C103850:gallium citrate; C045358:stannic oxide