title: Percutaneous treatment of liver tumors with an adapted probe for cooled-tip, impedance-controlled radio-frequency ablation under open-magnet MR guidance: initial results.
abstract: Percutaneous radio-frequency (RF) ablation of liver tumors is usually performed under guidance of real-time US, but some tumor nodules in some patients cannot be adequately visualized with this technique. We report our preliminary results with an MR-compatible, internally perfused 17-G RF probe adapted to a standard RF generator for impedance-controlled RF ablation under MR guidance. Following initial testing of the probe for MR compatibility, artifacts and macroscopic effects on an ex vivo pig liver, four patients with eight neoplastic liver nodules (five metastatic and three primary), which could not be properly targeted by US, were treated with the cooled-tip technique under MRI guidance in an open 0.23-T magnet. Metallic artifacts produced by the probe were useful for accurate placement and did not interfere with MRI monitoring at the end of the procedure. Based on imaging findings, the immediate result of RF was considered adequate in all instances. Local recurrence occurred in one instance after 6 months, requiring repeat treatment. No adverse effects were noted. Initial experience suggests that the probe we used allows to perform impedance-controlled cooled-tip RF ablation of liver tumors under open-magnet MR guidance.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital, 24 rue Micheli-du-Crest, 1211, Geneva, Switzerland.
authors.forename: Alexis D
authors.initials: AD
authors.lastname: Kelekis
authors.forename: Sylvain
authors.initials: S
authors.lastname: Terraz
authors.forename: André
authors.initials: A
authors.lastname: Roggan
authors.forename: François
authors.initials: F
authors.lastname: Terrier
authors.forename: Pietro
authors.initials: P
authors.lastname: Majno
authors.forename: Gilles
authors.initials: G
authors.lastname: Mentha
authors.forename: Arnaud
authors.initials: A
authors.lastname: Roth
authors.forename: Christoph D
authors.initials: CD
authors.lastname: Becker
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation*; D003080:Cold Temperature; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000556:secondary / Q000601:surgery; D003287:Contrast Media; D017097:Electric Impedance; D004564:Electrocoagulation; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009336:Necrosis; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media