Iodine-125 is a radioactive isotope of iodine which is used in radiation therapy to treat prostate, lung, and cancer. Its half-life is around 60 days and it emits gamma-rays with maximum energies of 35 keV, some of which are internally converted to x-rays.


  • Prostate Cancer
  • Lung Cancer
  • Brain Cancer
  • Eye Plaques

Iodine-125 in Prostate Cancer Brachytherapy

Iodine 125 is used in permanent radiation brachytherapy.

Manufacturers of Iodine-125 sources

AAPM Source Registry