Results of Dose-adapted Salvage Radiotherapy After Radical Prostatectomy Based on an Endorectal MRI Target Definition Model

Am J Clin Oncol. 2017 Apr;40(2):194-199. doi: 10.1097/COC.0000000000000130.


Objectives: 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.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Humans
  • Magnetic Resonance Imaging* / methods
  • Male
  • Middle Aged
  • Models, Anatomic
  • Prostatectomy / methods
  • Prostatic Neoplasms / diagnostic imaging*
  • Prostatic Neoplasms / radiotherapy*
  • Prostatic Neoplasms / surgery
  • Radiotherapy Dosage
  • Rectum
  • Salvage Therapy
  • Treatment Outcome