radiometal

Radiometal is a term used for radioactive isotopes of metallic elements that are employed as tracers, imaging agents, or therapeutic agents in nuclear medicine and related research. These isotopes are produced in nuclear reactors or cyclotrons and are handled under strict radiological controls to ensure purity, specific activity, and patient safety. Their radioactive decay provides the signal or dose that enables noninvasive study or treatment.

Chemically, radiometals are typically delivered to biological targets via chelating ligands such as DOTA, NOTA, or DTPA that bind the metal and attach to peptides, antibodies, or small molecules. The stability of the metal-chelate complex in vivo is crucial to minimize unintended release of radioactivity. Half-lives range from minutes to days, which influences choice of isotope, production logistics, and clinical workflow.

Common radiometals include technetium-99m and gallium-68 for diagnostic imaging, copper-64 and zirconium-89 for PET imaging, and lutetium-177 and yttrium-90 for targeted radiotherapy. Rhenium isotopes, such as rhenium-188, are also used in therapeutic radiopharmaceuticals. These isotopes enable targeted delivery to specific tissues, improving diagnostic accuracy or therapeutic efficacy while reducing systemic exposure.

Safety, regulation, and logistics are central to radiometal use. Production facilities require licensed operation, shielding, and waste management. Short half-lives demand coordinated production, radiopharmacy infrastructure, and rapid transport or regional distribution networks.