title: 20 Gy versus 44 Gy of supplemental external beam radiotherapy with palladium-103 for patients with greater risk disease: results of a prospective randomized trial.
abstract: OBJECTIVE
  The necessity of external beam radiotherapy (EBRT) as a supplement to prostate brachytherapy remains unknown. We report brachytherapy outcomes for patients with higher risk features randomized to substantially different supplemental EBRT regimens.
  
  
  METHODS
  Between December 1999 and June 2004, 247 patients were randomized to 20 Gy vs. 44 Gy EBRT followed by a palladium-103 boost (115 Gy vs. 90 Gy). The eligibility criteria included clinically organ-confined disease with Gleason score 7-10 and/or pretreatment prostate-specific antigen (PSA) level 10-20 ng/mL. The median follow-up period was 9.0 years. Biochemical progression-free survival (bPFS) was defined as a PSA level of ≤0.40 ng/mL after nadir. The median day 0 prescribed dose covering 90% of the target volume was 125.7%; 80 men received androgen deprivation therapy (median, 4 months). Multiple parameters were evaluated for their effect on bPFS.
  
  
  RESULTS
  For the entire cohort, the cause-specific survival, bPFS, and overall survival rates were 97.7%, 93.2%, and 80.8% at 8 years and 96.9%, 93.2%, and 75.4% at 10 years, respectively. The bPFS rate was 93.1% and 93.4% for the 20-Gy and 44-Gy arms, respectively (p = .994). However, no statistically significant differences were found in cause-specific survival or overall survival were identified. When stratified by PSA level of ≤10 ng/mL vs. >10 ng/mL, Gleason score, or androgen deprivation therapy, no statistically significant differences in bPFS were discerned between the two EBRT regimens. On multivariate analysis, bPFS was most closely related to the preimplant PSA and clinical stage. For patients with biochemically controlled disease, the median PSA level was <0.02 ng/mL.
  
  
  CONCLUSIONS
  The results of the present trial strongly suggest that two markedly different supplemental EBRT regimens result in equivalent cause-specific survival, bPFS, and overall survival. It is probable that the lack of benefit for a higher supplemental EBRT dose is the result of the high-quality brachytherapy dose distributions.
authors.affiliation: Schiffler Cancer Center/Wheeling Jesuit University, Wheeling, WV 26003, USA. gmerrick@urologicresearchinstitute.org
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Merrick
authors.forename: Kent E
authors.initials: KE
authors.lastname: Wallner
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Butler
authors.forename: Robert W
authors.initials: RW
authors.lastname: Galbreath
authors.forename: Al V
authors.initials: AV
authors.lastname: Taira
authors.forename: Peter
authors.initials: P
authors.lastname: Orio
authors.forename: Edward
authors.initials: E
authors.lastname: Adamovich
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D060787:Neoplasm Grading; D010165:Palladium / Q000627:therapeutic use*; D011446:Prospective Studies; 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*; D011879:Radiotherapy Dosage; D015996:Survival Rate
chemical_list: D000726:Androgen Antagonists; D011868:Radioisotopes; D010165:Palladium; D017430:Prostate-Specific Antigen