Iodine 123
Channel: SarahAMAnderson
Date: 04/04/2012

On Wednesday, April 4, 2012, I was given a diagnostic dose of Iodine-123 in order to image any remaining thyroid cells in my body in preparation for a cancer treatment.  Iodine-123 decays by electron capture and emits high-energy gamma rays, which my vintage Civil Defense Geiger counter can detect.  This video shows the Geiger counter detecting my body's radioactivity about 3 hours after I took the pill.

I-123 does not hurt my body and is not dangerous to others, because of its decay mode (gamma rays rarely interact with matter).  On Thursday April 5, I will get a therapeutic dose of Iodine 131, which decays primarily by beta emission and will kill my remaining thyroid cells, curing me of thyroid cancer.  I will be considered "hot" after this treatment and will have to go into a radiation quarantine for a few days to avoid exposing others.

I-123 at Wikipedia:  http://en.wikipedia.org/wiki/Iodine-123

Electron capture at Wikipedia: http://en.wikipedia.org/wiki/Electron_capture

I-131 at Wikipedia: http://en.wikipedia.org/wiki/I-131