title: Pride or prejudice: does Phoenix flatter radiation therapy?
abstract: OBJECTIVE
  To compare disease-free survival (DFS) rates using a >0.4 ng/mL biochemical failure definition with the Phoenix (nadir+2 ng/mL) failure definition by analyzing a consecutive cohort of 1006 patients treated with low-dose-rate prostate brachytherapy (LDR-PB) monotherapy.
  
  
  METHODS
  Data for first 1006 consecutive LDR-PB implants (1998-2003) were extracted from a prospective database. Patients had low- (58%) or intermediate (42%)-risk disease. Three months neoadjuvant and 3 months concomitant androgen deprivation therapy were used in 65% of cases. The Phoenix definition was modified to "unfail" patients who had a benign prostate-specific antigen (PSA) bounce.
  
  
  RESULTS
  The median followup is 7.5 years. The median PSA at latest followup for disease-free patients was 0.04 ng/mL. The Phoenix definition yielded 5- and 10-year Kaplan-Meier DFS estimates of 96.5 ± 1.2% and 93.7 ± 2.0%, respectively. Applying the >0.4 ng/mL threshold reduced these estimates to 94.4 ± 1.6% and 88.8 ± 3.0% (log rank, p = 0.015).
  
  
  CONCLUSIONS
  Compared with Phoenix, applying a >0.4 ng/mL failure definition increased biochemical failure by ∼2% at 5 years and ∼5% at 10 years. These data show that Phoenix did not greatly exaggerate DFS estimates compared with a surgical-type threshold. However, this observation is a consequence of the exceptionally low residual PSA values characteristic of LDR-PB and cannot be generalized to other forms of radiation therapy.
authors: Division of Surgery, Department of Radiation Oncology, Faculty of Medicine, University of British Columbia, British Columbia, Canada; Department of Radiation Oncology, Vancouver Cancer Centre, 600 West 10 Avenue, Vancouver, British Columbia, Canada V5Z 4E6. Electronic address: jmorris@bccancer.bc.ca.
authors: W James
authors: WJ
authors: Morris
authors: Division of Surgery, Department of Radiation Oncology, Faculty of Medicine, University of British Columbia, British Columbia, Canada; Department of Radiation Oncology, Vancouver Cancer Centre, 600 West 10 Avenue, Vancouver, British Columbia, Canada V5Z 4E6.
authors: Tom
authors: T
authors: Pickles
authors: Division of Surgery, Department of Radiation Oncology, Faculty of Medicine, University of British Columbia, British Columbia, Canada; Department of Radiation Oncology, Vancouver Cancer Centre, 600 West 10 Avenue, Vancouver, British Columbia, Canada V5Z 4E6.
authors: Mira
authors: M
authors: Keyes
authors: Division of Surgery, Department of Radiation Oncology, Faculty of Medicine, University of British Columbia, British Columbia, Canada; Department of Radiation Oncology, Vancouver Cancer Centre, 600 West 10 Avenue, Vancouver, British Columbia, Canada V5Z 4E6.
authors: Michael
authors: M
authors: McKenzie
authors: Department of Medical Physics, Vancouver Cancer Centre, Vancouver, British Columbia, Canada.
authors: Ingrid
authors: I
authors: Spadinger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D015415:Biomarkers; D001918:Brachytherapy / Q000379:methods*; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011287:Prejudice; D011446:Prospective Studies; D017430:Prostate-Specific Antigen; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D013997:Time Factors
chemical_list: D000726:Androgen Antagonists; D015415:Biomarkers; D017430:Prostate-Specific Antigen
keywords: Biochemical failure; Biologic equivalent dose; Nadir PSA values; Phoenix threshold; Prostate brachytherapy