Iodide ion I-125 is radioisotope of iodine with half-life 59.4 days. It decays with the emission of low-energy gamma rays. It is used as a source for bone densitometry devices, protein iodination. Seeds implantations with I-125 are used in the clinics for the treatment of prostate cancer, malignant biliary obstruction, non-small cell lung cancer, colorectal cancer, uveal melanoma, and other tumors.