Implementing Ac-225 labelled radiopharmaceuticals: practical considerations and (pre-)clinical perspectives

Eline L. Hooijman, Valery Radchenko, Sui Wai Ling, Mark Konijnenberg, Tessa Brabander, Stijn L. W. Koolen, Erik de Blois*

*Corresponding author for this work

Research output: Contribution to journalReview articleAcademicpeer-review

2 Citations (Scopus)
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BackgroundIn the past years, there has been a notable increase in interest regarding targeted alpha therapy using Ac-225, driven by the observed promising clinical anti-tumor effects. As the production and technology has advanced, the availability of Ac-225 is expected to increase in the near future, making the treatment available to patients worldwide.Main bodyAc-225 can be labelled to different biological vectors, whereby the success of developing a radiopharmaceutical depends heavily on the labelling conditions, purity of the radionuclide source, chelator, and type of quenchers used to avoid radiolysis. Multiple (methodological) challenges need to be overcome when working with Ac-225; as alpha-emission detection is time consuming and highly geometry dependent, a gamma co-emission is used, but has to be in equilibrium with the mother-nuclide. Because of the high impact of alpha emitters in vivo it is highly recommended to cross-calibrate the Ac-225 measurements for used quality control (QC) techniques (radio-TLC, HPLC, HP-Ge detector, and gamma counter). More strict health physics regulations apply, as Ac-225 has a high toxicity, thereby limiting practical handling and quantities used for QC analysis.ConclusionThis overview focuses specifically on the practical and methodological challenges when working with Ac-225 labelled radiopharmaceuticals, and underlines the required infrastructure and (detection) methods for the (pre-)clinical application.
Original languageEnglish
Article number9
Number of pages30
JournalEJNMMI Radiopharmacy and Chemistry
Issue number1
Publication statusPublished - Dec 2024

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