title: Salvage radiotherapy after radical prostatectomy: prediction of biochemical outcomes.
abstract: BACKGROUND
  A significant proportion of patients undergoing salvage radiotherapy (RT) for biochemical recurrence (BCR) following radical prostatectomy (RP) may again experience BCR after salvage RT. Thus, we evaluated the clinical significances of different parameters on the biochemical outcome of RT in salvage setting.
  
  
  METHODS
  We reviewed the records of 212 patients who underwent salvage RT between November 2003 and December 2012 for BCR following primary RP. BCR-free survivals after salvage RT were estimated using the Kaplan-Meier method. Cox proportional hazard regression models were used to evaluate the impacts of clinicopathologic parameters on BCR following salvage RT.
  
  
  RESULTS
  The overall median follow-up duration was 63.5 months. The BCR-free survival rate after salvage RT was 58.2% at 5 years. Multivariate analysis showed that a pre-RT prostate-specific antigen (PSA) level of ≤0.5 ng/mL, a pre-RT PSA doubling time (PSADT) of >4.5 months, concomitant androgen deprivation therapy (ADT) with salvage RT, and a positive surgical margin were independent predictors of favorable biochemical outcomes after salvage RT (hazard ratios [HR] = 3.012, 1.132, 2.000, and 1.805, respectively, p = less than 0.001, 0.013, 0.005, and 0.036, respectively). In the early (pre-RT PSA ≤0.5 ng/mL) salvage RT setting, concomitant ADT administration was also shown to be significantly associated with higher risk of BCR-free survival following salvage RT (HR = 2.611, p = 0.038).
  
  
  CONCLUSIONS
  Lower pre-RT PSA value, longer PSADT before salvage RT, concomitant ADT administration, and a positive surgical margin were significant predictors of favorable biochemical outcomes following salvage RT performed for BCR after primary RP.
authors: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Ohseong
authors: O
authors: Kwon
authors: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Ki Bom
authors: KB
authors: Kim
authors: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Young Ik
authors: YI
authors: Lee
authors: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Seok-Soo
authors: SS
authors: Byun
authors: Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Jae-Sung
authors: JS
authors: Kim
authors: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Sang Eun
authors: SE
authors: Lee
authors: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Sung Kyu
authors: SK
authors: Hong
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D005720:Gamma Rays; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D012008:Recurrence; D012189:Retrospective Studies; D016879:Salvage Therapy
chemical_list: D017430:Prostate-Specific Antigen