For early stage breast cancer, accelerated partial breast irradiation is an alternative treatment option to whole breast irradiation after breast conserving surgery. Our group has previously reported results of a Phase I/II study of permanent breast seed implant (PBSI) using palladium-103 seeds as an alternative to whole breast radiotherapy for well selected breast cancer patients. The procedure is realised in a single session under light sedation and local freezing. After a median FU of 54 months no patients has recurred on a cohort of 67 patients, and acute of delayed side effect compared favourably to external beam radiotherapy.