A permanent breast seed implant (PBSI) technique of partial breast irradiation using palladium (103Pd) seeds has been proposed. Similar to a permanent seed implant used to treat prostate cancer, permanent breast seed implant (PBSI) involves the insertion of stranded radioactive seeds under ultra-sound guidance. The advantages of the permanent breast seed implant (PBSI) technique over other brachytherapy techniques include: i/- it is an out-patient procedure performed in a single one-hour session under local anesthesia and light sedation; ii/- it is performed after the surgery when the final pathology report is available and the scar is completely healed; and iii/- the use of a low dose rate technique presents the possible advantage to be more efficient and better tolerated compared to high dose rate techniques.