Indium-111 (¹¹¹In) is a

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...

indium Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts ...

(In). It decays by

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Thi ...

to stable

cadmium-111 Naturally occurring cadmium (48Cd) is composed of 8 isotopes. For two of them, natural radioactivity was observed, and three others are predicted to be radioactive but their decays have not been observed, due to extremely long half-lives. The tw ...

with a half-life of 2.8 days. Indium-111 chloride (¹¹¹InCl) solution is produced by proton irradiation of a

cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

target (¹¹²Cd(p,2n) or ¹¹¹Cd(p,n)) in a

cyclotron A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. Lawrence, Ernest O. ''Method and apparatus for the acceleration of ions'', filed: Jan ...

, as recommended by

International Atomic Energy Agency (IAEA) The International Atomic Energy Agency (IAEA) is an intergovernmental organization that seeks to promote the peaceful use of nuclear energy and to inhibit its use for any military purpose, including nuclear weapons. It was established in 195 ...

. 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 Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is " radiology done inside out" because it records radiation emi ...

diagnostic imaging by

radiolabeling A radioactive tracer, radiotracer, or radioactive label is a chemical compound in which one or more atoms have been replaced by a radionuclide so by virtue of its radioactive decay it can be used to explore the mechanism of chemical reactions by ...

targeted molecules or cells. During its radioactive decay, it emits low energy gamma (γ) photons which can be imaged using

planar Planar is an adjective meaning "relating to a plane (geometry)". Planar may also refer to: Science and technology * Planar (computer graphics), computer graphics pixel information from several bitplanes * Planar (transmission line technologies), ...

or single-photon emission computed tomography (SPECT) gamma cameras (primary energies (ε) of 171.3

keV Kev can refer to: Given name * Kev Adams, French comedian, actor, screenwriter and film producer born Kevin Smadja in 1991 * Kevin Kev Carmody (born 1946), Indigenous Australian singer-songwriter * Kev Coghlan (born 1988), Scottish Grand Prix moto ...

(91%) and 245.4 keV (94%))

Uses in nuclear medicine

When formulated as an ¹¹¹InCl solution, it can be used to bind antibodies,

peptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. ...

s, 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/

process, which is tailored to the desired product.

¹¹¹In labeled antibodies

* Ibritumomab Tiuxetan; Zevalin - For dosimetry estimates prior to ⁹⁰Y immunotherapy for

lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enla ...

* ¹¹¹In ProstaScint — PSMA antibody imaging of prostate cancer

¹¹¹In labeled peptides

* ¹¹¹I
pentetreotide
(including in ¹¹¹In ( diethylenetriaminopentaacetic (DTPA)-

octreotide Octreotide, sold under the brand name Sandostatin among others, is an octapeptide that mimics natural somatostatin pharmacologically, though it is a more potent inhibitor of growth hormone, glucagon, and insulin than the natural hormone. It was ...

) and

Octreoscan An octreotide scan is a type of SPECT scintigraphy used to find carcinoid, pancreatic neuroendocrine tumors, and to localize sarcoidosis. It is also called somatostatin receptor scintigraphy (SRS). Octreotide, a drug similar to somatostatin, is rad ...

) ** Octreotide is an somatostatin receptor inhibitor pharmaceutical which binds with high affinity to somatostatin receptors 2 and 5, interfering with normal receptor function. It is used as a drug to treat several neuroendocrine tumors in which somatostatin receptors are overexpressed or overactive. Examples include: *** Sympathoadrenal system tumors:

pheochromocytoma Pheochromocytoma (PHEO or PCC) is a rare tumor of the adrenal medulla composed of chromaffin cells, also known as pheochromocytes. When a tumor composed of the same cells as a pheochromocytoma develops outside the adrenal gland, it is referred t ...

, neuroblastoma, ganglioneuroma, paraganglioma *** Gastroenteropancreatic (GEP) tumors: carcinoid, insulinoma *** Medullary thyroid cancer, pituitary adenoma, small cell lung cancer ** ¹¹¹I
pentetreotide
imaging can identify the presence, levels of somatostatin receptor 2,5 expression, extent of disease and response to therapy * ¹¹¹In can also be formulated in the chemical form ¹¹¹In oxyquinoline (oxine) for labeling blood cells and components * Platelets for

thrombus A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of ...

detection *Leukocytes for localization of

inflammation Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molec ...

and

abscesses An abscess is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends ...

, detect and monitor

osteomyelitis Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...

, and detect

mycotic aneurysm An infected aneurysm is an aneurysm arising from bacterial infection of the arterial wall. It can be a common complication of the hematogenous spread of bacterial infection. William Osler first used the term "mycotic aneurysm" in 1885 to describe ...

s, vascular graft and shunt infections and determination of leukocyte kinetics;

References

{{Radiopharmaceuticals Indium-111

Uses in nuclear medicine

111In labeled antibodies

111In labeled peptides

See also

References

¹¹¹In labeled antibodies

¹¹¹In labeled peptides