title: Comparison of PSA relapse-free survival in patients treated with ultra-high-dose IMRT versus combination HDR brachytherapy and IMRT.
abstract: OBJECTIVE
  We report on a retrospective comparison of biochemical outcomes using an ultra-high dose of conventionally fractionated intensity-modulated radiation therapy (IMRT) vs. a lower dose of IMRT combined with high-dose-rate (HDR) brachytherapy to increase the biologically effective dose of IMRT.
  
  
  METHODS
  Patients received IMRT of 86.4Gy (n=470) or HDR brachytherapy (21Gy in three fractions) followed by IMRT of 50.4Gy (n=160). Prostate-specific antigen (PSA) relapse was defined as PSA nadir+2. Median followup was 53 months for IMRT alone and 47 months for HDR.
  
  
  RESULTS
  The 5-year actuarial PSA relapse-free survival (PRFS) for HDR plus IMRT vs. ultra-high-dose IMRT were 100% vs. 98%, 98% vs. 84%, and 93% vs. 71%, for National Comprehensive Cancer Network low- (p=0.71), intermediate- (p<0.001), and high-risk (p=0.23) groups, respectively. Treatment (p=0.0006), T stage (p<0.0001), Gleason score (p<0.0001), pretreatment PSA (p=0.0037), risk group (p<0.0001), and lack of androgen-deprivation therapy (p=0.0005) were significantly associated with improved PRFS on univariate analysis. HDR plus IMRT vs. ultra-high-dose IMRT (p=0.0012, hazard ratio [HR]=0.184); age (p=0.0222, HR=0.965); and risk group (p<0.0001, HR=2.683) were associated with improved PRFS on multivariate analysis.
  
  
  CONCLUSIONS
  Dose escalation of IMRT by adding HDR brachytherapy provided improved PRFS in the treatment of prostate cancer compared with ultra-high-dose IMRT, independent of risk group on multivariate analysis, with the most significant benefit for intermediate-risk patients.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center New York, New York, NY10021, USA. yamadaj@mskcc.org
authors.forename: Israel
authors.initials: I
authors.lastname: Deutsch
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zelefsky
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Qianxing
authors.initials: Q
authors.lastname: Mo
authors.forename: Marco
authors.initials: M
authors.lastname: Zaider
authors.forename: Gil'ad
authors.initials: G
authors.lastname: Cohen
authors.forename: Oren
authors.initials: O
authors.lastname: Cahlon
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D017430:Prostate-Specific Antigen