title: Distant metastases following permanent interstitial brachytherapy for patients with clinically localized prostate cancer.
abstract: OBJECTIVE
  Recent publications have suggested high-risk patients undergoing radical prostatectomy have a lower risk of distant metastases and improved cause-specific survival (CSS) than patients receiving definitive external beam radiation therapy (XRT). To date, none of these studies has compared distant metastases and CSS in brachytherapy patients. In this study, we evaluate such parameters in a consecutive cohort of brachytherapy patients.
  
  
  METHODS
  From April 1995 to June 2007, 1,840 consecutive patients with clinically localized prostate cancer were treated with brachytherapy. Risk groups were stratified according to National Comprehensive Cancer Network (www.nccn.org) guidelines. Subgroups of 658, 893, and 289 patients were assigned to low, intermediate, and high-risk categories. Median follow-up was 7.2 years. Along with brachytherapy implantation, 901 (49.0%) patients received supplemental XRT, and 670 (36.4%) patients received androgen deprivation therapy (median duration, 4 months). The mode of failure (biochemical, local, or distant) was determined for each patient for whom therapy failed. Cause of death was determined for each deceased patient. Multiple parameters were evaluated for impact on outcome.
  
  
  RESULTS
  For the entire cohort, metastases-free survival (MFS) and CSS at 12 years were 98.1% and 98.2%, respectively. When rates were stratified by low, intermediate, and high-risk groups, the 12-year MFS was 99.8%, 98.1%, and 93.8% (p < 0.001), respectively. CSS rates were 99.8%, 98.0%, and 95.3% (p < 0.001) for low, intermediate, and high-risk groups, respectively. Biochemical progression-free survival was 98.7%, 95.9% and 90.4% for low, intermediate, and high-risk patients, respectively (p < 0.001). In multivariate Cox-regression analysis, MFS was mostly closely related to Gleason score and year of treatment, whereas CSS was most closely associated with Gleason score.
  
  
  CONCLUSIONS
  Excellent CSS and MFS rates are achievable with high-quality brachytherapy for low, intermediate, and high-risk patients. These results compare favorably to alternative treatment modalities. In particular, our MFS and CSS rates for high-risk patients appear superior to those of published radical prostatectomy series.
authors.affiliation: Western Radiation Oncology, Mountain View, California, USA.
authors.forename: Al V
authors.initials: AV
authors.lastname: Taira
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Merrick
authors.forename: Robert W
authors.initials: RW
authors.lastname: Galbreath
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Butler
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lief
authors.forename: Edward
authors.initials: E
authors.lastname: Adamovich
authors.forename: Kent E
authors.initials: KE
authors.lastname: Wallner
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000379:methods*; D002423:Cause of Death; D018572:Disease-Free Survival; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D010165:Palladium / Q000627:therapeutic use; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D011868:Radioisotopes / Q000627:therapeutic use; D012044:Regression Analysis; D018570:Risk Assessment
chemical_list: D000726:Androgen Antagonists; D007457:Iodine Radioisotopes; D011868:Radioisotopes; D010165:Palladium; D017430:Prostate-Specific Antigen