title: Impact of postprostatectomy prostate-specific antigen nadir on outcomes following salvage radiotherapy.
abstract: OBJECTIVE
  To evaluate the relationship between the postprostatectomy prostate-specific antigen (PSA) nadir and the outcome of patients treated with salvage radiotherapy.
  
  
  METHODS
  Seventy-eight patients received definitive external beam radiation for recurrence following radical prostatectomy (RP). The PSA nadir was undetectable in 41 patients (less than 0.05 ng/mL). All patients received salvage radiotherapy (median dose 66 Gy) for a median of 19 months (range 2 to 149) following prostatectomy. The median follow-up time was 25 months (range 1 to 59) from the date of completion of radiation.
  
  
  RESULTS
  Among patients having an undetectable or detectable postoperative PSA, 78% and 68% were free of disease, respectively, at the last follow-up. At 3 years, the disease-free survival rates were 65% and 60%, respectively (P = 0.6). Overall, the disease-free survival rate at 3 years was 78% in patients with a PSA level 2 ng/mL or less at the time of radiotherapy compared to 31% with a PSA greater than 2 ng/mL (P < 0.0001).
  
  
  CONCLUSIONS
  Many patients who never achieve an undetectable postprostatectomy PSA level may still be salvaged with therapeutic radiotherapy. The best predictor of a favorable outcome is a low (2 ng/mL or less) PSA level at the time of radiation.
authors.affiliation: Department of Radiation Oncology, Barbara Ann Karmanos Cancer Institute, Harper Hospital, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Garg
authors.forename: S
authors.initials: S
authors.lastname: Tekyi-Mensah
authors.forename: S
authors.initials: S
authors.lastname: Bolton
authors.forename: J
authors.initials: J
authors.lastname: Velasco
authors.forename: E
authors.initials: E
authors.lastname: Pontes
authors.forename: D P
authors.initials: DP
authors.lastname: Wood
authors.forename: A T
authors.initials: AT
authors.lastname: Porter
authors.forename: J D
authors.initials: JD
authors.lastname: Forman
mesh_terms: D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000401:mortality / Q000601:surgery*; D016879:Salvage Therapy; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen