Rad-18. The many faces of Indium.

Indium-111 is a cyclotron-produced radionuclide with a physical half-life of 67 hours. It decays by electron capture and produces two gamma photons of 173 and 247 keV. It is used to label leukocytes, monoclonal antibodies, and a variety of other compounds. As a result, Indium-111 is a very versatile radionuclide. The radiopharmaceuticals that are labeled with Indium-111 are enumerated and discussed. The various uses of these compounds are listed, and the significance of tracer accumulation in human organs and tissues is explained. Case presentations document clinical efficacy. Indium-111 has the following uses: labeled oxine for inflammatory disease detection, labeled monoclonal antibodies for colorectal, ovarian, and prostate cancer detection, peptide receptor imaging for carcinoid, insulinoma, gastrinoma, pheochromocytoma, medullary thyroid carcinoma, small cell carcinoma of lung, and pituitary adenoma detection. Labeled DTPA is used for evaluation of hydrocephalus, surgical shunt patency, and cerebrospinal fluid leakage. Indium-111 oxine white blood cell (WBC) imaging is useful for identification of liver abscess, abdominal abscess, inflammatory bowel disease, and vascular graft infection. WBC imaging can separate pancreatic abscess from pseudocyst, and is used to evaluate acute osteomyelitis. Indium-111 compounds are very useful for the detection and evaluation of many neoplastic, inflammatory, and infectious conditions. The case presentations demonstrate considerable clinical utility.

Ottis G. Ball, MD, and W. Mel Flowers, Jr, MD. Department of Radiology, Division of Nuclear Medicine, University of Mississippi Medical Center, Jackson, MI.