[Principles of curietherapy]

Brachytherapy, the use of radioactive sources implanted into the tumor or placed in proximity to the tumor, makes it possible to obtain well defined, localized distributions of the irradiation dose. The word "brachytherapy" includes various techniques which are practiced most frequently with cesium-137 or iridium-192. Whether used alone or in conjunction with surgery and (or) external irradiation, brachytherapy has contributed to the development of organ conserving treatment for cancer, notably and more recently, for carcinoma of the breast, bladder and buccal cavity, in addition to its traditional applications in gynecological and cutaneous cancers. Refinements of brachytherapy techniques have been made possible by recent advances in 3-D imaging and by the development of highly active radioactive sources which are used to obtain very precise dose distributions and very short treatment times.