Permanent prostate brachytherapy: Lessons learned, lessons to learn

Current techniques for permanent prostate brachytherapy are associated with excellent biochemical control in patients with localized prostate cancer. Data now available confirm 5- to 10-year results with this treatment modali ty that are comparable to those with external-beam irradiation or radical p rostatectomy. Nonetheless, treatment protocols and techniques for prostate brachytherapy vary from center to center. Controversy exists regarding the selection of patients for brachytherapy alone or in combination with extern al-beam irradiation, The role of neoadjuvant androgen deprivation also rema ins undefined in patients with localized prostate cancer. Matched-pair anal ysis studies performed at Memorial Sloan-Kettering Cancer Center have exami ned the role of isotope selection, the addition of external-beam irradiatio n, and the use of neoadjuvant androgen deprivation. These studies provide i nsights into the use of permanent brachytherapy in patients with localized prostate cancer. In addition, postimplant dosimetry needs to be a requireme nt for centers performing seed implants. Data now appear to support specifi c computed tomography-based criteria to evaluate implant quality and delive red dose to the prostate, Unfortunately, prostate edema and poor imaging te chniques limit the evaluation of implant dosimetry, Treatment planning tech niques that utilize new imaging modalities, coupled with computerized treat ment planning, may help improve the implant procedure and dosimetry.