title: Results of Dose-adapted Salvage Radiotherapy After Radical Prostatectomy Based on an Endorectal MRI Target Definition Model.
abstract: OBJECTIVE
  To assess the outcome of patients treated with a dose-adapted salvage radiotherapy (SRT) protocol based on an endorectal magnetic resonance imaging (erMRI) failure definition model after radical prostatectomy (RP).
  
  
  METHODS
  We report on 171 relapsing patients after RP who had undergone an erMRI before SRT. 64 Gy were prescribed to the prostatic bed with, in addition, a boost of 10 Gy to the suspected local relapse as detected on erMRI in 131 patients (76.6%).
  
  
  RESULTS
  The 3-year biochemical relapse-free survival (bRFS), local relapse-free survival, distant metastasis-free survival, cancer-specific survival, and overall survival were 64.2±4.3%, 100%, 85.2±3.2%, 100%, and 99.1±0.9%, respectively. A PSA value >1 ng/mL before salvage (P=0.006) and an absence of biochemical progression during RT (P=0.001) were both independently correlated with bRFS on multivariate analysis. No significant difference in 3-year bRFS was observed between the boost and no-boost groups (68.4±4.6% vs. 49.7±10%, P=0.251).
  
  
  CONCLUSIONS
  A PSA value >1 ng/mL before salvage and a biochemical progression during RT were both independently correlated with worse bRFS after SRT. By using erMRI to select patients who are most likely expected to benefit from dose-escalated SRT protocols, this dose-adapted SRT approach was associated with good biochemical control and outcome, serving as a hypothesis-generating basis for further prospective trials aimed at improving the therapeutic ratio in the salvage setting.
authors.affiliation: *Department of Radiation Oncology, Hôpitaux Universitaires de Genève §Institute of Radiology Jean Violette, Geneva, Switzerland †Servei de Radio-oncologia ‡Servei de Radiodiagnòstic, Institut Oncòlogic Teknon, Barcelona, Spain.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zilli
authors.forename: Sandra
authors.initials: S
authors.lastname: Jorcano
authors.forename: Nicolas
authors.initials: N
authors.lastname: Peguret
authors.forename: Francesca
authors.initials: F
authors.lastname: Caparrotti
authors.forename: Alberto
authors.initials: A
authors.lastname: Hidalgo
authors.forename: Haleem G
authors.initials: HG
authors.lastname: Khan
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Vees
authors.forename: Raymond
authors.initials: R
authors.lastname: Miralbell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy* / Q000601:surgery; D011879:Radiotherapy Dosage; D012007:Rectum; D016879:Salvage Therapy; D016896:Treatment Outcome