In order to develop an 125I seed for brachytherapy of prostate cancer, a carrier body consisting of Al2O3 and silver powder was developed. To optimize the adsorption conditions of 125I on the rods, various experiments were performed. The adsorption capacity was more than 95% after 4 hours at a volume of
50 μl containing about 5 mCi of 125I. Dosimetric properties were measured for the radial and longitudinal directions. Variations were below 11% in the longitudinal
distribution and 5% in the radial distribution. This method is effective for the preparation of 125I seeds to be used in brachytherapy treatment.