Au-198

Rhenium-186 (Re-186) is a radioactive isotope of rhenium with a half-life of about 3.7 days. It decays mainly by beta-minus emission to stable osmium-186, with a smaller electron-capture branch leading to tungsten-186. Its decay also produces a characteristic gamma ray at approximately 137 keV, allowing Re-186 to be detected by gamma spectroscopy.

Re-186 is primarily used and studied in nuclear medicine for radionuclide therapy. Its beta radiation can deliver a therapeutic dose to targeted tissue, while its gamma emission allows imaging and monitoring of the isotope's distribution. Re-186 has been investigated for applications including treatment of bone metastases, radiosynovectomy, and targeted radiopharmaceutical therapy.

Re-186 does not occur naturally in significant quantities and is produced artificially. It can be generated in nuclear reactors by neutron irradiation of enriched Re-185 targets and can also be produced using particle accelerators. In practice, Re-186 is mainly encountered at isotope-production facilities, radiopharmaceutical laboratories, and nuclear medicine research or treatment centers.

Re-186

Rhenium-186
Technogenic β, γ radiation

Half-life: 3.7 days Main emission lines: 137 keV