title: Does preoperative magnetic resonance imaging reduce the rate of positive surgical margins at radical prostatectomy in a randomised clinical trial?
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) has the potential to help the surgeon tailor radical prostatectomy (RP) more accurately according to the location and extent of the tumour and thereby reduce the rate of positive surgical margins (PSMs).
  
  
  OBJECTIVE
  To evaluate the benefit of performing MRI prior to RP.
  
  
  METHODS
  This single-institution randomised trial included 438 patients between December 2009 and June 2012 who were scheduled for robot-assisted laparoscopic prostatectomy. The study was registered (ClinicalTrials.gov identifier NCT01347320).
  
  
  METHODS
  Patients were preoperatively randomly assigned to non-MRI or MRI groups.
  
  
  METHODS
  The primary end point was the difference in the PSM rates between the two groups. Secondary end points were the rates of PSMs in clinical subgroups. Summary statistics were extracted from descriptive analyses, chi-square, or Fisher exact test, and logistic regression was used to analyse the data according to the intention-to-treat principle.
  
  
  CONCLUSIONS
  A total of 216 patients were randomised to non-MRI; 222 were randomised to MRI. There were 49 cases (23%) of PSMs in the non-MRI group and 43 cases (19%) in the MRI group (p=0.4). The relative and absolute risk reduction was 15% and 4%, respectively. Patients with cT1 constituted 55% of the cohort, in which the rate of PSMs was 27% in the non-MRI group and 16% in the MRI group (p=0.035). The relative and absolute risk reduction was 41% and 11%, respectively. A limitation was suboptimal communication between the radiologist and urologist.
  
  
  CONCLUSIONS
  MRI prior to RP did not reduce the overall risk for PSMs in this patient cohort. However, at subgroup analysis we observed a possible benefit of MRI in patients with cT1.
  
  
  RESULTS
  This study could not demonstrate a definite benefit of performing magnetic resonance imaging before surgery for all patients. However, there was a possible improved result in patients in which physical examination could not detect the cancer.
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway. Electronic address: p.e.rud@medisin.uio.no.
authors: Erik
authors: E
authors: Rud
authors: Department of Urology, Oslo University Hospital, Oslo, Norway.
authors: Eduard
authors: E
authors: Baco
authors: Department of Pathology, Oslo University Hospital, Oslo, Norway.
authors: Dagmar
authors: D
authors: Klotz
authors: Department of Urology, Oslo University Hospital, Oslo, Norway.
authors: Kristin
authors: K
authors: Rennesund
authors: Department of Pathology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Aud
authors: A
authors: Svindland
authors: Department of Urology, Oslo University Hospital, Oslo, Norway.
authors: Viktor
authors: V
authors: Berge
authors: Department of Urology, Oslo University Hospital, Oslo, Norway.
authors: Eskild
authors: E
authors: Lundeby
authors: Department of Urology, Oslo University Hospital, Oslo, Norway.
authors: Nicolai
authors: N
authors: Wessel
authors: Department of Urology, Oslo University Hospital, Oslo, Norway.
authors: Jon-Roar
authors: JR
authors: Hoff
authors: Department of Urology, Oslo University Hospital, Oslo, Norway.
authors: Rolf Eigil
authors: RE
authors: Berg
authors: Department of Biostatistics, Epidemiology and Health Care Economics, Oslo University Hospital, Oslo, Norway.
authors: Lien
authors: L
authors: Diep
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
authors: Heidi B
authors: HB
authors: Eggesbø
authors: Department of Urology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Lars Magne
authors: LM
authors: Eri
mesh_terms: D000368:Aged; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual; D011300:Preoperative Care; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery; D065287:Robotic Surgical Procedures / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000379:methods*
keywords: MRI; Preoperative; Prostate cancer; RCT; Randomised controlled trial; Surgical benefit; Surgical margins