title: Prostate cancer ablation with transrectal high-intensity focused ultrasound: assessment of tissue destruction with contrast-enhanced US.
abstract: OBJECTIVE
  To assess contrast material-enhanced ultrasonographic (US) findings seen after high-intensity focused ultrasound (HIFU) ablation of prostate cancer and correlate the US findings with post-HIFU biopsy findings.
  
  
  METHODS
  The study was ethics committee approved. Written informed consent was obtained from all patients. Twenty-eight patients referred for HIFU prostate cancer ablation underwent contrast-enhanced prostate US before treatment, gadolinium-enhanced magnetic resonance (MR) imaging and repeat contrast-enhanced US 1-3 days after treatment, and contrast-enhanced US-guided biopsy 30-45 days after treatment. The contrast-enhanced US enhancement patterns of the biopsy sites--assigned a score of S0 for no enhancement, S1 for mild and/or patchy enhancement, or S2 for marked enhancement--were compared with corresponding biopsy findings, which were assigned a score of B0 for necrosis and/or fibrosis without viable prostate gland tissue, B1 for vascularized tissue without viable gland tissue, or B2 for viable gland tissue (benign or malignant). Then, six additional patients underwent contrast-enhanced prostate US 15-30 minutes and 1 day after HIFU ablation, and the results of these two US examinations were compared.
  
  
  RESULTS
  Contrast-enhanced US performed on days 1-3 and days 30-45 after HIFU ablation depicted a large devascularized zone with peripheral enhancing areas that were localized anteriorly in all 28 patients, posteriorly in nine, laterally in five, and at the apex in 20 patients. MR findings were concordant. At biopsy, viable gland tissue was found at nine (6.2%) of 146 S0 sites, 10 (34%) of 29 S1 sites, and 44 (60%) of 73 S2 sites. The odds ratios for finding viable tissue (score B1 or B2) at S1 and S2 sites as opposed to S0 sites were 21 (95% confidence interval [CI]: 6, 71) and 73 (95% CI: 22, 243), respectively (P < .0001). Contrast-enhanced US performed 15-30 minutes and 1 day after treatment in the six additional patients had similar findings.
  
  
  CONCLUSIONS
  Contrast-enhanced US is a promising tool for distinguishing between ablated (devascularized) and viable (enhancing) tissue immediately after HIFU treatment.
authors.affiliation: Department of Urinary and Vascular Radiology, Hôpital Edouard Herriot, Hospices Civils de Lyon, 5 place d'Arsonval, Pavilion P Radio, Lyon F-69437, France. olivier.rouviere@netcourrier.com
authors.forename: Olivier
authors.initials: O
authors.lastname: Rouvière
authors.forename: Ludivine
authors.initials: L
authors.lastname: Glas
authors.forename: Nicolas
authors.initials: N
authors.lastname: Girouin
authors.forename: Florence
authors.initials: F
authors.lastname: Mège-Lechevallier
authors.forename: Albert
authors.initials: A
authors.lastname: Gelet
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Dantony
authors.forename: Muriel
authors.initials: M
authors.lastname: Rabilloud
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Chapelon
authors.forename: Denis
authors.initials: D
authors.lastname: Lyonnet
mesh_terms: D000368:Aged; D001706:Biopsy; D003287:Contrast Media; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine; D009942:Organometallic Compounds; D010743:Phospholipids; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D019233:Retreatment; D013459:Sulfur Hexafluoride; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D036761:Ultrasound, High-Intensity Focused, Transrectal / Q000379:methods
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D010743:Phospholipids; C420843:contrast agent BR1; D008536:Meglumine; C072417:gadoterate meglumine; D013459:Sulfur Hexafluoride