Its spin-forbidden decay has a half-life of 4.41×1014 years, much longer than the currently accepted age of the Universe.
The stable isotope 113In is only 4.3% of naturally occurring indium.
All other meta-states have half-lives less than a day, most less than an hour, and many measured in milliseconds or less.
Indium-111 is used medically in nuclear imaging, as a radiotracer nuclide tag for gamma camera localization of protein radiopharmaceuticals, such as In-111-labeled octreotide, which binds to receptors on certain endocrine tumors (Octreoscan).
[4] Indium-111 is also used in indium white blood cell scans, which use nuclear medical techniques to search for hidden infections.