cobalt-57

Cobalt-57 (Co-57) is a synthetic gamma-emitting radioactive isotope with a half-life of approximately 271.8 days. It decays by electron capture to stable iron-57 (⁵⁷Fe), emitting characteristic gamma rays, primarily at 122.1 keV and 136.5 keV. Produced in cyclotrons or nuclear reactors, Co-57 is widely used in medical research and diagnostics for the quality control and calibration of gamma cameras, sodium iodide scintillation detectors, and SPECT systems. It is also crucial in the study of vitamin B12 metabolism; specifically, Co-57-labeled cyanocobalamin is employed in diagnostic tests for malabsorption, such as the Schilling test. Furthermore, Co-57-labeled radiopharmaceuticals, including Co-57-bleomycin, have been investigated as tumor-scanning agents, and the isotope has been explored for potential brachytherapy applications due to its low-energy gamma emissions.

Other names

cobalt co-57