Adsorption of iodide on silver rods for 125I seed preparation

Recently, the rate of prostate cancer is increasing rapidly in Korea. Brachytherapy using 125I seeds has drawn attention as one of the treatment options of this type of cancer. 125I is a radionuclide, which emits 27 keV and 31 keV X-rays and 35 keV γ-ray with a half-life of 59.4 days. This radioisotope is produced by the bombardment of neutrons on the 124Xe target and decays via electron capture to 125Te. The brachytherapy sources are fabricated as seeds and implanted permanently to the prostate. The seed consists of a titanium capsule as a shell with a dimension of 0.8 mm in external diameter, 0.05 mm in wall thickness and 4.5 mm in length. A silver (Ag) rod with a dimension of 3 mm in length and 0.5 mm in diameter is used as the radioactive core after adsorption of 125I and is placed in the shell. The silver rod also acts as an X-ray marker to visualize by X-ray imaging and determine the location of seeds in the prostate. Currently, the supply of 125I seeds depends only on imports. Hence, national research and development are needed for local production. This research work is carried out to find the optimum conditions in the preparation of the radioactive core, more specifically in the adsorption of iodide on the silver rods