Indium-111 Explained

Symbol:In
Mass Number:111
Num Neutrons:62
Num Protons:49
Abundance:syn
Halflife:[1]
Decay Product:cadmium-111
Decay Symbol:Cd
Decay Mass:111
Decay Mode1:EC
Decay Energy1:0.860

Indium-111 (111In) is a radioactive isotope of indium (In). It decays by electron capture to stable cadmium-111 with a half-life of 2.8 days.[2] Indium-111 chloride (111InCl) solution 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 high 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 low energy gamma (γ) photons which can be imaged using planar or single-photon emission computed tomography (SPECT) gamma cameras (primary energies (ε) of 171.3 keV (91%) and 245.4 keV (94%))

Uses in nuclear medicine

When formulated as an 111InCl 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.

111In labeled antibodies

111In labeled peptides

111In can also be formulated in the chemical form 111In oxyquinoline (oxine)[4] for labeling blood cells and components

See also

Notes and References

  1. Book: Table of Radionuclides, Vol. 3. 2006. Bureau international des poids et mesures. 92-822-2218-7. 75. 26 June 2017.
  2. Web site: FDA Label Document:Indium In-111 Chloride Sterile Solution. www.accessdata.fda.gov. 20 Aug 2018.
  3. Takács. S.. Tárkányi. F.. Hermanne. A.. Dec 2005. Validation and upgrading of the recommended cross-section data of charged particle reactions: Gamma emitter radioisotopes. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 240. 4. 790–802. 10.1016/j.nimb.2005.06.209. 2005NIMPB.240..790T . 0168-583X.
  4. Web site: PubChem In-111 Oxyquinoline. pubchem.ncbi.nlm.nih.gov. 20 Aug 2018.
  5. Web site: IN-111 FACT SHEET. Nordion(Canada), Inc.. 23 September 2012. dead. https://web.archive.org/web/20111203082605/http://www.nordion.com/documents/products/In-111_Can.pdf. 3 December 2011.