Indium-111 is a radioactive isotope of indium. It decays by electron capture to stable cadmium-111 with a half-life of 2.8 days. Indium-111 chloride solution is produced by proton irradiation of a cadmium target in a cyclotron, as recommended by International Atomic Energy Agency.

For acromegaly: SPECT imaging 4 and 24 hours after injection with 6.5 mCi of indium-111 OctreoScan, a somatostatin receptor imaging agent.