title: MR imaging-guided focal cryoablation in patients with recurrent prostate cancer.
abstract: OBJECTIVE
  To assess the feasibility of magnetic resonance (MR) imaging-guided focal cryoablation in patients with locally recurrent prostate cancer after radiation therapy.
  
  
  METHODS
  This was a prospective study, and informed consent was obtained from all patients. Ten consecutive patients with histopathologically proved recurrent prostate cancer after radiation therapy, without evidence of distant metastases, were treated while under general anesthesia in a 1.5-T MR unit. A urethral warmer was inserted. Cryoneedles were transperineally inserted under real-time MR imaging. Then, a rectal warmer was inserted. Ice ball growth was continuously monitored under MR imaging guidance. Two freeze-thaw cycles were performed. Follow-up consisted of a visit to the urologist, measurement of prostate-specific antigen level, and multiparametric MR imaging at 3, 6, and 12 months. Potential complications were recorded.
  
  
  RESULTS
  All patients were successfully treated. In one patient, the urethral warmer could not be inserted and the procedure was cancelled. Two months later, the procedure was successfully repeated. Another patient had urinary retention. Follow-up data were available for all patients. A local recurrence or remnant tumor was found in two patients after 6 months and in another patient after 12 months. These three patients underwent successful retreatment with MR imaging-guided focal cryoablation.
  
  
  CONCLUSIONS
  MR imaging-guided focal cryoablation of recurrent prostate cancer after radiation therapy is feasible and safe. Initial results are promising; however, longer follow-up is needed and more patients must be studied.
authors.affiliation: Department of Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands. j.bomers@rad.umcn.nl
authors.forename: Joyce G R
authors.initials: JG
authors.lastname: Bomers
authors.forename: Derya
authors.initials: D
authors.lastname: Yakar
authors.forename: Christiaan G
authors.initials: CG
authors.lastname: Overduin
authors.forename: J P Michiel
authors.initials: JP
authors.lastname: Sedelaar
authors.forename: Henk
authors.initials: H
authors.lastname: Vergunst
authors.forename: Jelle O
authors.initials: JO
authors.lastname: Barentsz
authors.forename: Frank
authors.initials: F
authors.lastname: de Lange
authors.forename: Jurgen J
authors.initials: JJ
authors.lastname: Fütterer
mesh_terms: D000368:Aged; D003131:Combined Modality Therapy; D003452:Cryosurgery / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D016896:Treatment Outcome