title: Long-term results of radiofrequency ablation for unresectable colorectal liver metastases: a potentially curative intervention.
abstract: OBJECTIVE
  The long-term results and prognostic factors of radiofrequency ablation (RFA) for unresectable colorectal liver metastases (CRLM) in a single centre with >10 years of experience were retrospectively analysed.
  
  
  METHODS
  A total of 100 patients with unresectable colorectal liver metastases (CRLM) (size 0.2-8.3 cm; mean 2.4 cm) underwent a total of 126 RFA sessions (237 lesions). The mean follow-up time was 29 months (range 6-93 months). Lesion characteristics (size, number and location), procedure characteristics (percutaneous or intra-operative approach) and major and minor complications were carefully noted. Local control, mean survival time and recurrence-free and overall survival were statistically analysed.
  
  
  RESULTS
  No direct procedure-related deaths were observed. Major complications were present in eight patients. Local RFA site recurrence was 12.7% (n = 30/237); for tumour diameters of <3 cm, 3-5 cm and >5 cm, recurrence was 5.6% (n = 8/143), 19.5% (n = 15/77) and 41.2% (n = 7/17), respectively. Centrally located lesions recurred more often than peripheral ones, at 21.4% (n = 21/98) vs 6.5% (n = 9/139), respectively, p = 0.009. Including additional treatments for recurring lesions when feasible, lesion-based local control reached 93%. The mean survival time from RFA was 56 (95% confidence interval (CI) 45-67) months. Overall 1-, 3-, 5- and 8-year survival from RFA was 93%, 77%, 36% and 24%, respectively.
  
  
  CONCLUSIONS
  RFA for unresectable CRLM is a safe, effective and potentially curative treatment option; the long-term results are comparable with those of previous investigations employing surgical resection. Factors determining success are lesion size, the number of lesions and location.
authors.affiliation: Department of Radiology, VU University Medical Centre, De Boelelaan 1117, Amsterdam, the Netherlands. a.vantilborg@vumc.nl
authors.forename: A A J M
authors.initials: AA
authors.lastname: Van Tilborg
authors.forename: M R
authors.initials: MR
authors.lastname: Meijerink
authors.forename: C
authors.initials: C
authors.lastname: Sietses
authors.forename: J H T M
authors.initials: JH
authors.lastname: Van Waesberghe
authors.forename: M O
authors.initials: MO
authors.lastname: Mackintosh
authors.forename: S
authors.initials: S
authors.lastname: Meijer
authors.forename: C
authors.initials: C
authors.lastname: Van Kuijk
authors.forename: P
authors.initials: P
authors.lastname: Van Den Tol
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods; D015179:Colorectal Neoplasms; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome