New material for low-dose brachytherapy seeds: Xe-doped amorphous carbon films with post-growth neutron activated 125I

We report a novel material for use in 125I brachytherapy that consists of amorphous carbon films grown by ion-beam-assisted deposition and doped with Xe (5 at%) by implantation. Samples of these films grown on Si substrates were irradiated with neutrons in a TRIGA-I nuclear reactor for the production 125Xe, and latter characterized by gamma spectroscopy. The results indicate that the 124Xe was efficiently converted into 125Xe, the precursor of 125I, and support the activity calculations for a model brachytherapy seed.