| General | |
|---|---|
| Symbol | 111In |
| Names | indium-111 |
| Protons (Z) | 49 |
| Neutrons (N) | 62 |
| Nuclide data | |
| Natural abundance | syn |
| Half-life (t1/2) | 2.8048 d [1] |
| Decay products | 111Cd |
| Decay modes | |
| Decay mode | Decay energy (MeV) |
| EC | 0.862 [2] |
| Isotopes of indium Complete table of nuclides | |
Indium-111 (111In) is a radioactive isotope of indium (In). It decays by electron capture to stable cadmium-111 with a half-life of 2.8048 days. The isotopes is produced by proton irradiation of a cadmium target (112Cd(p,2n) or 111Cd(p,n)) in a cyclotron, as recommended by International Atomic Energy Agency (IAEA). [3] The former method is more commonly used as it results in a higher level of radionuclide purity.
Indium-111 is commonly used in nuclear medicine diagnostic imaging by radiolabeling targeted molecules or cells. During its radioactive decay, it emits gamma (γ) photons which can be imaged using planar or single-photon emission computed tomography (SPECT) gamma cameras (primary energies: 171.3 keV (91%) and 245.4 keV (94%) [2] ).
When formulated as an 111InCl3 solution, it can be used to bind antibodies, peptides, or other molecular targeted proteins or other molecules, typically using a chelate to bind the radionuclide (in this case 111In) to the targeting molecule during the radiosynthesis/ radiolabeling process, which is tailored to the desired product.