A historical perspective on the specific activity of radiopharmaceuticals: What have we learned in the 35 years of the ISRC?

Specific Activity (SA), defined as the amount of radioactivity per unit mass of a compound is arguably one of the most important parameters in radiopharmaceutical development, particularly in quality control of carbon-11 and fluorine-18 labeled compounds. This review article will outline the progression of improvements in SA over the last few decades. The International Symposium of Radiopharmaceutical Chemistry (ISRC/ISRS) abstracts were an excellent source of materials for this review and will be referenced throughout.