title: Transperineal radiofrequency interstitial tumor ablation of the prostate: correlation of magnetic resonance imaging with histopathologic examination.
abstract: OBJECTIVE
  Radiofrequency (RF) energy has recently been employed to destroy human tissue in vivo. The purpose of this study was to investigate the safety of this approach in localized carcinoma of the prostate (CaP) and specifically, the predictability of lesions obtained with radiofrequency interstitial tumor ablation (RITA).
  
  
  METHODS
  Using RITA, a total of 21 lesions were induced in 10 patients with localized CaP (mean age 70.4 years). RF was delivered transperineally under transrectal ultrasound (TRUS) guidance. All patients underwent endorectal magnetic resonance imaging (MRI) before and after treatment. Radical prostatectomy was performed in all patients 1 to 7 days after RITA. Three of the patients were treated with local anesthesia only. The predictability of the thermal lesion was assessed by correlating the findings of intraoperative TRUS, pre- and post-RITA endorectal MRI, and the histologic examination of the specimen.
  
  
  RESULTS
  Postoperatively, patients were catheterized for an average of 1.8 days (1 to 3 days). Lesions of 2 x 2 x 2 cm were targeted. Average lesion diameters obtained on MRI were 2.08 +/- 0.23 x 2.09 +/- 0.36 x 2.28 +/- 0.21 cm. Average lesion diameters defined by coagulative necrosis at histologic examination were 2.20 +/- 0.23 x 2.10 +/- 0.31 x 2.38 +/- 0.14 cm. There were no statistically significant differences (P = 0.377) between average lesion volume on MRI (5.37 +/- 1.83 cm3) and average lesion volume at histology (5.86 +/- 1.63 cm3). No complications or adverse events were noted.
  
  
  CONCLUSIONS
  In this Phase I study, RITA was shown to be safe and feasible, and to result in lesions that were predictable in size and location. MRI accurately visualized and verified the area of coagulative necrosis as documented at histology. The procedure is technically simple and can even be performed under local anesthesia.
authors.affiliation: Department of Urology, University of Vienna, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Djavan
authors.forename: A R
authors.initials: AR
authors.lastname: Zlotta
authors.forename: M
authors.initials: M
authors.lastname: Susani
authors.forename: G
authors.initials: G
authors.lastname: Heinz
authors.forename: S
authors.initials: S
authors.lastname: Shariat
authors.forename: D E
authors.initials: DE
authors.lastname: Silverman
authors.forename: C C
authors.initials: CC
authors.lastname: Schulman
authors.forename: M
authors.initials: M
authors.lastname: Marberger
mesh_terms: D000368:Aged; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D003287:Contrast Media; D005240:Feasibility Studies; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D008297:Male; D010502:Perineum; D011467:Prostate / Q000473:pathology* / Q000601:surgery*; D011468:Prostatectomy / Q000295:instrumentation / Q000379:methods*; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA