title: MR-guided radiofrequency ablation of hepatocellular carcinoma: long-term effectiveness.
abstract: OBJECTIVE
  To evaluate long-term effectiveness of magnetic resonance (MR)-guided radiofrequency (RF) ablation of hepatocellular carcinoma (HCC).
  
  
  METHODS
  This prospective study was approved by the institutional review board. In 20 patients, 28 HCCs (mean diameter, 28.0 mm; range, 6-58 mm) were treated with 25 sessions of MR-guided RF ablation. Previous chemoembolization had been performed in nine HCCs with diameters greater than 3 cm. The entire RF ablation procedures were carried out on a 0.2-T open MR system. Placement of MR-compatible internally cooled electrodes was performed under MR fluoroscopic imaging with fast gradient-echo sequences. Therapeutic assessment was based on dynamic MR-imaging (1.5 T) at a mean follow-up of 24.2 months (range, 6-52 mo).
  
  
  RESULTS
  MR-guided RF ablation was technically successful in all 25 sessions (100%), as assessed at the end of each session. T2-weighted sequences were accurate to monitor the ablation zone and supported guidance of overlapping ablations if necessary. Technique effectiveness, defined as complete ablation confirmed at MR imaging 4 months after RF ablation, was achieved in 27 of 28 HCCs (96.4%). To achieve complete ablation, 25 of 27 tumors (92.6%) were treated in a single session and two tumors were treated twice. In one tumor initially defined as having been treated with technically effective RF ablation, local tumor progression was detected more than 4 months after ablation. Consequently, the available follow-up indicated complete ablation in 26 of 28 HCCs (92.9%). There was one major complication (4.0%) and one minor complication (4.0%).
  
  
  CONCLUSIONS
  On a long-term basis, MR-guided RF ablation is an effective therapy option in the treatment of HCC.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Hoppe-Seyler Str. 3, 72076 Tübingen, Germany. stephan.clasen@med.uni-tuebingen.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Clasen
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Rempp
authors.forename: Andreas
authors.initials: A
authors.lastname: Boss
authors.forename: Diethard
authors.initials: D
authors.lastname: Schmidt
authors.forename: Jan
authors.initials: J
authors.lastname: Fritz
authors.forename: Christina
authors.initials: C
authors.lastname: Schraml
authors.forename: Fritz
authors.initials: F
authors.lastname: Schick
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: Philippe L
authors.initials: PL
authors.lastname: Pereira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000556:secondary / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects; D005260:Female; D005858:Germany; D006801:Humans; D016018:Least-Squares Analysis; D016014:Linear Models; D008113:Liver Neoplasms / Q000473:pathology / Q000601:surgery*; D053783:Magnetic Resonance Imaging, Interventional; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden