Gamma photon emission from indium‑111 (^111^In or In-111)

Indium-111 is a radioactive isotope (^111^In) that decays by electron capture with a half-life of approximately 2.8 days (67–68 hours). During decay, it emits gamma photons (171.3 and 245.4 keV) that serve as the basis for diagnostic imaging procedures in nuclear medicine. Indium-111 can be used to label monoclonal antibodies, white blood cells, platelets, or small molecules, allowing targeted imaging of cancers, infections, inflammation, and certain neurologic indications. Indium-111 and its gamma photon emissions are critical for nuclear imaging but are not themselves molecular targets; rather, they are tools employed to visualize the distribution and trafficking of radiolabeled compounds or cells.

Other names

Indium In-111^111^InIndium-111 chlorideIndium-111 oxyquinolineIndium-111 pentetate

Decay by electron capture — resulting in emission of gamma photons (171 and 245 keV) which can be detected by gamma cameras (planar or SPECT)