title: Radiofrequency ablation of large size liver tumours using novel plan-parallel expandable bipolar electrodes: initial clinical experience.
abstract: OBJECTIVE
  Although radiofrequency ablation (RFA) is a promising method for local treatment of liver malignancies, with conventional monopolar systems recurrence rates for large size tumours (≥3.5 cm) remain high. The objective of this study was to evaluate the safety, feasibility and local effectiveness of a novel bipolar plan-parallel expandable system for these larger tumours.
  
  
  METHODS
  Eight consecutive patients with either unresectable colorectal liver metastases (CRLM in 6 patients), carcinoid liver metastases (1 patient) and hepatocellular carcinoma (HCC in 1 patient) of ≥3.5 cm were treated with bipolar RFA during laparotomy with ultrasound guidance. Early and late, major and minor complications were recorded. Local success was determined on 3-8 month follow-up CT scans of the upper abdomen.
  
  
  RESULTS
  Nine CRLM, one carcinoid liver metastases and one HCC (3.5-6.6 cm) were ablated with bipolar RFA. Average ablation time was 16 min (range 6-29 min.). Two patients developed a liver abscess which required re-laparotomy. In both cases bowel surgery during the same session probably caused bacterial spill. There were no mortalities. The patients were released from hospital between 5 and 29 days after the procedure (median 12 days). The 6-12 month follow-up PET-CT scans showed signs for marginal RFA-site tumour recurrence in three patients with CRLM (3/11 lesions).
  
  
  CONCLUSIONS
  Preliminary results suggest bipolar RFA to be a reasonably safe, fast and feasible technique which seems to improve local control for large size hepatic tumour ablations.
authors.affiliation: Department of Radiology, VU University Medical Centre, Amsterdam, The Netherlands. mr.meijerink@vumc.nl
authors.forename: Martijn R
authors.initials: MR
authors.lastname: Meijerink
authors.forename: Petrousjka
authors.initials: P
authors.lastname: van den Tol
authors.forename: Aukje A J M
authors.initials: AA
authors.lastname: van Tilborg
authors.forename: Jan Hein T M
authors.initials: JH
authors.lastname: van Waesberghe
authors.forename: Sybren
authors.initials: S
authors.lastname: Meijer
authors.forename: Cornelis
authors.initials: C
authors.lastname: van Kuijk
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000556:secondary* / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006498:Hepatectomy / Q000295:instrumentation*; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D016896:Treatment Outcome