Brachytherapy boost techniques for locally advanced prostate cancer

Brachytherapy boosts in combination with external-beam radiation therapy allow a highly conformal dose of radiation to be delivered to the prostate in a safe, efficient manner. Several types of brachytherapy boost techniques are used currently. Techniques based on transrectal ultrasound (TRUS) guidance clearly provide the most accurate method of radioactive source placement with reduced toxicity. Temporary implants employing remote afterloading systems with high-dose-rate (HDR) brachytherapy offer the added advantage of further optimizing dose distribution after needle placement. Novel brachytherapy programs using intraoperative real-time dosimetric analyses provide additional options for performing truly conformal dose escalation. Results with these newer boost techniques appear to be as good as or better than other forms of therapy in comparably staged patients. Until standardized methods of reporting treatment data are uniformly applied and longer follow-up is obtained with other treatment modalities, brachytherapy boosts combined with external-beam radiation should be considered an acceptable treatment option for patients with locally advanced prostate cancer. The challenge for the future will be to determine which treatment approach is optimal given certain critical pretreatment prognostic factors. In addition, the role of adjuvant androgen deprivation in controlling this malignancy will be critical and awaits the results of several recently initiated or completed randomized trials.