Emerging Radiometals forPETImaging

Abstract

Radiopharmaceuticals are drugs containing a radionuclide and are utilized for diagnosis, monitoring, and/or treatment of diseases. This article focuses on the development of emerging radiometal‐based imaging agents for positron emission tomography (PET), as well as new developments in F‐18‐labeled agents via aluminum fluoride chemistry. The incorporation of radiometals through chelation is typically simpler than the common multistep reactions to incorporate F‐18 into molecules, and radiometal‐conjugates generally require minimal if any purification. Widely studied PET radiometals (e.g., gallium‐68, copper‐64, zirconium‐89, yttrium‐86, and rubidium‐82) can be readily produced and have desirable decay properties for PET imaging. However, there are several emerging radiometals with desirable properties for PET imaging (e.g., scandium‐44, multiple isotopes of copper, terbium‐182, gallium‐66, and cobalt‐55) with unique properties (e.g., a range of half‐lives) that provide additional opportunities for PET imaging and allow for the developmental of new and unique PET radiopharmaceuticals.

Theranostic Terbium Radioisotopes: Challenges in Production for Clinical Application

“…152 Tb is also a potential SPECT candidate due its multiple gamma lines. At the same time this multiple gamma-rays emission is a drawback when it is used as PET isotope due to increased radiation burden (27). To understand the bio-kinetic behavior of radio-lanthanides in vivo, Beyer (28) probed the efficacy of 149 Tb and 152 Tb in PET imaging, where it was realized that scan quality with 152 Tb is significantly better than that obtained for 149 Tb.…”