title: Role of 3T multiparametric magnetic resonance imaging without endorectal coil in the detection of local recurrent prostate cancer after radical prostatectomy: the radiation oncology point of view.
abstract: OBJECTIVE
  The aims of this study were to evaluate the role of 3 tesla multiparametric magnetic resonance imaging (3TmMRI) without endorectal coil in the detection of radiographic local recurrences (rLRs) in a contemporary cohort of patients with prostate cancer who presented with biochemical recurrence after radical prostatectomy (RP) with low prostate-specific antigen (PSA) levels, and to identify clinical parameters associated with the 3TmMRI findings.
  
  
  METHODS
  Between 2009 and 2013, 57 patients with biochemical recurrence of prostate cancer after RP who were considered for salvage radiation therapy (SRT) were included. 3TmMRI with T2-weighted imaging, diffusion weighted imaging (DWI) and dynamic contrast-enhanced imaging without endorectal coil was carried out in all patients before treatment.
  
  
  RESULTS
  In 14 out of 57 patients (24.56%) local recurrence was detected through 3TmMRI. Median pre-SRT PSA was 0.40 ng/ml (interquartile range 0.30-2.05 ng/ml). The recurrence was perianastomotic in eight out of 14 patients (57.14%) and retrovesical in six out of 14 patients (42.86%). The median size of the local recurrence was 15.2 mm (range 8.0-46.0 mm). The probability of rLR was significantly higher in patients with PSA levels above 0.5 ng/ml [adjusted odds ratio (OR) 6.25, 95% confidence interval (CI) 1.27-30.79, p = 0.02] or PSA doubling time (PSADT) over 14 months (adjusted OR 7.12, 95% CI 1.40-36.25, p = 0.01).
  
  
  CONCLUSIONS
  This is the first study to find a significant relationship between the PSADT and the rLR through MRI. Patients with PSADT longer than 14 months or pre-SRT PSA above 0.5 ng/ml benefited most from 3TmMRI. Its routine use could have significant clinical implications for SRT.
authors: a 1 Departments of Radiation Oncology, Hospital Universitario Quirón , Madrid, Spain.
authors: Felipe
authors: F
authors: Couñago
authors: a 1 Departments of Radiation Oncology, Hospital Universitario Quirón , Madrid, Spain.
authors: Elia
authors: E
authors: del Cerro
authors: b 2 Departments of Radiology, Hospital Universitario Quirón , Madrid, Spain.
authors: Manuel
authors: M
authors: Recio
authors: a 1 Departments of Radiation Oncology, Hospital Universitario Quirón , Madrid, Spain.
authors: Ana Aurora
authors: AA
authors: Díaz
authors: a 1 Departments of Radiation Oncology, Hospital Universitario Quirón , Madrid, Spain.
authors: Francisco José
authors: FJ
authors: Marcos
authors: c 3 Department of Radiation Oncology, Hospital Universitario La Princesa , Madrid, Spain.
authors: Laura
authors: L
authors: Cerezo
authors: d 4 Department of Nuclear Medicine, Hospital Universitario Quirón , Madrid, Spain.
authors: Antonio
authors: A
authors: Maldonado
authors: e 5 Departments of Urology, Hospital Universitario Quirón , Madrid, Spain.
authors: José Manuel
authors: JM
authors: Rodríguez-Luna
authors: f 6 Department of Research, Universidad Europea , Madrid, Spain.
authors: Israel
authors: I
authors: Thuissard
authors: g 7 Clinical Department, Faculty of Biomedicine, Universidad Europea , Madrid, Spain.
authors: José Luis R
authors: JL
authors: Martin
mesh_terms: D000368:Aged; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000601:surgery*; D018787:Radiation Oncology; D012189:Retrospective Studies
chemical_list: D017430:Prostate-Specific Antigen
keywords: biochemical failure; multiparametric MRI; prostate cancer; radical prostatectomy; salvage radiotherapy