title: Prostatic cryosurgery: use of MR imaging in evaluation of success and technical modifications.
abstract: OBJECTIVE
  To evaluate the usefulness of contrast material-enhanced magnetic resonance (MR) imaging in objective assessment of prostatic cryosurgery and the role of MR imaging in the modification of prostatic cryosurgical technique.
  
  
  METHODS
  Thirty-eight consecutive patients with localized (T1-3, N0, M0) prostatic adenocarcinoma treated with prostatic cryosurgery underwent MR imaging without contrast enhancement before cryosurgery and unenhanced and gadolinium-enhanced MR imaging within 1-3 weeks after cryosurgery. The first 20 patients also underwent MR imaging at 3 months after cryosurgery. MR imaging findings were correlated with those from transrectal ultrasound-directed prostatic staging biopsy.
  
  
  RESULTS
  Cryonecrotic prostate was identified as avascular regions characterized by absolute signal void on contrast-enhanced images. With progressive modification of cryosurgical technique, complete cryoablation of the prostate was achieved in the latter nine of the 38 patients. When cryoablation was considered complete according to MR imaging criteria, findings invariably correlated with those at biopsy, with no residual prostate tissue or tumor.
  
  
  CONCLUSIONS
  Gadolinium-enhanced MR imaging of the prostate after cryosurgery provides a highly accurate means of monitoring success. Objective MR imaging findings allow modifications to the technology and technique, resulting in optimal therapeutic results with prostatic cryosurgery.
authors.affiliation: Department of Diagnostic Imaging, Foothills Hospital, University of Calgary, Alberta, Canada.
authors.forename: A D
authors.initials: AD
authors.lastname: Vellet
authors.forename: J
authors.initials: J
authors.lastname: Saliken
authors.forename: B
authors.initials: B
authors.lastname: Donnelly
authors.forename: E
authors.initials: E
authors.lastname: Raber
authors.forename: R F
authors.initials: RF
authors.lastname: McLaughlin
authors.forename: D
authors.initials: D
authors.lastname: Wiseman
authors.forename: N H
authors.initials: NH
authors.lastname: Ali-Ridha
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery; D000368:Aged; D001706:Biopsy; D003287:Contrast Media; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods*; D005069:Evaluation Studies as Topic; D005500:Follow-Up Studies; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000175:diagnosis; D011182:Postoperative Care; D011300:Preoperative Care; D011467:Prostate / Q000473:pathology*; D011468:Prostatectomy / Q000009:adverse effects / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D012007:Rectum / Q000473:pathology; D016896:Treatment Outcome; D014463:Ultrasonography; D001743:Urinary Bladder / Q000473:pathology
chemical_list: D003287:Contrast Media; D005682:Gadolinium