The absorption of iodine-131 on a ceramic matrix

The retention of I-131 on ceramic rod coated with silver nitrate followed by coating with a polyurethane membrane to be applied in brachytherapy was studied. The concentration of silver nitrate (20 g/l), the Volume of I-131 as a sodium iodide solution (100 mul), the pH of the reaction mixture (pH 9) etc., were optimized to get a maximum uptake on the ceramic rod. The concentration of coating solution (5%, polyurethane in tetrahydrofuran) was also optimized to obtain a minimum leaching of I-131 activity in normal saline solution. After coating with a polyurethane membrane, the I-131 absorbed on the ceramic rod exhibited low leachability (0.03%). This method can be applied for the preparation of I-125 interstitial sources to be used in eye and prostate cancer therapy.