Prostate brachytherapy. An overview.

Abstract

Prostate brachytherapy represents one of the oldest techniques of using radiation therapy to treat prostate cancer. Over the past 10 years, there have been major changes in the types of prostate brachytherapy that can be performed with the introduction of new radioactive isotopes, new afterloading techniques, and an improved understanding of the radiobiology associated with differing dose rates. Prostate brachytherapy can be divided into temporary implantation using high activity sources such as iridium-192, or permanent brachytherapy using the interstitial implantation of iodine-125 or palladium-103 sources. There are various techniques that can be used to actually insert the radioactive material into the prostate. This can be done as an open or closed procedure and can be performed via a suprapubic or a perineal retropubic approach. The use of remote afterloading has substantially reduced the radiation protection problems associated with manually loaded radioactive sources. Results using brachytherapeutic isotopes in the treatment of prostate cancer have been variable, but it appears that using the higher dose rate sources and delivering a high relative integral dose to the prostate can result in improved histologic control of prostate cancer. In patients with aggressive prostate cancer, the use of iodine-125 permanent implantation has not been successful. The role of brachytherapy in the treatment of prostate cancer remains an exciting alternative in the management of prostate cancer. Its role is becoming more defined in the treatment of large, bulky prostatic neoplasms as a way of improving the dose distribution achieved between normal and tumor tissue.