[Brachytherapy for prostate cancer: old concept, new techniques].

Whereas it has been proposed almost one century ago, brachytherapy for prostate cancer has only recently emerged, especially thanks to endorectal echography, allowing to visualize seed implantation, to the development of seeds for permanent delivery and of micro-sources for high-dose rate delivery, and also to the development of three-dimension dosimetry programs allowing real-time implantations. For selected patients with localized prostate cancer (PSA < 10, Gleason < 7, no extracapsular extension, volume < 50-60 g), prostate brachytherapy with permanent implants (iodine 125 or, less frequently, palladium 103) gives results which appear at 10-15 years comparable to those of surgery. Incontinence and impotence rates appear lower than those of classical surgery. However, the first post-implant months are usually accompanied by urinary toxicity that should not be minimized. High-dose rate brachytherapy (HDR) could find its indications, in combination with conformal radiotherapy, in the treatment of more advanced forms, presenting an intermediate risk. It could also be an alternative to brachytherapy with permanent implants for the low-risk forms mentioned above, especially in developing countries where the cost of radioactive seeds slows down the use of this technique. Brachytherapy for prostate cancer should, therefore, find more and more indications, because of the increased incidence of prostate cancer, due to population ageing, of the increased proportion of localized forms, due to better detection, of the patient's request for less toxicity, and of the expecting lowering of the costs, which are now equivalent to those of surgery and should further lower.