title: Prostate carcinoma: MR imaging findings after cryosurgery.
abstract: OBJECTIVE
  To determine the morphologic changes in the prostate gland after cryosurgery and to assess the value of magnetic resonance (MR) imaging in detecting residual tumor.
  
  
  METHODS
  Twenty-seven patients with prostate carcinoma underwent endorectal MR imaging after cryosurgery. Eighteen patients also underwent MR imaging before cryosurgery. MR findings were correlated with posttreatment clinical data, prostate-specific antigen level, and biopsy results.
  
  
  RESULTS
  Mean prostate volume had decreased by 52% in patients examined 8 weeks or more after cryosurgery. Zonal differentiation was lost in 22 of 27 patients (81%). Areas of intraprostatic necrosis were identified in 14 of 27 patients (52%). A thick capsule enveloped the gland and neurovascular bundles in 24 of 27 patients (89%). Osteonecrosis of the symphysis pubis was seen in six of 27 patients (22%). Positive and negative predictive values for MR assessment of recurrent tumor were 44% and 73%, respectively.
  
  
  CONCLUSIONS
  Cryosurgery-induced changes in the prostate gland preclude reliable detection of residual prostate carcinoma at MR imaging.
authors.affiliation: Department of Radiology, University of California, San Francisco 94143, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Kalbhen
authors.forename: H
authors.initials: H
authors.lastname: Hricak
authors.forename: K
authors.initials: K
authors.lastname: Shinohara
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.forename: F
authors.initials: F
authors.lastname: Parivar
authors.forename: J
authors.initials: J
authors.lastname: Kurhanewicz
authors.forename: D B
authors.initials: DB
authors.lastname: Vigneron
authors.forename: P R
authors.initials: PR
authors.lastname: Carroll
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003452:Cryosurgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000175:diagnosis; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000601:surgery