EANM guideline for harmonisation on molar activity or specific activity of radiopharmaceuticals: impact on safety and...

This guideline on molar activity (A_m) and specific activity (A_s) focusses on small molecules, peptides and macromolecules radiolabelled for diagnostic and therapeutic applications. In this guideline we describe the definition of A_m and A_s, and how these measurements must be standardised and harmonised. Selected examples highlighting the importance of A_m and A_s in imaging studies of saturable binding sites will be given, and the necessity of using appropriate materials and equipment will be discussed. Furthermore, common A_m pitfalls and remedies are described. Finally, some aspects of A_m in relation the emergence of a new generation of highly sensitive PET scanners will be discussed.