title: Risk of tumour seeding after percutaneous radiofrequency ablation for hepatocellular carcinoma.
abstract: BACKGROUND
  A recent small study reported a high rate of neoplastic seeding after cooled-tip radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) in patients who had undergone previous needle biopsy. Tumour seeding was associated with subcapsular tumour location, poorly differentiated tumours and a high alpha-fetoprotein (AFP) level. The aim of the present study was to determine the rate of neoplastic seeding after RFA in a large series of unselected patients with HCC who had a long follow-up.
  
  
  METHODS
  A total of 1314 patients with 2542 nodules were treated in three centres. Median follow-up was 37 months. Needle biopsy had been performed before RFA in 241 patients (18.3 per cent). The influence of subcapsular location, high AFP level and previous biopsy on risk of tumour seeding was assessed.
  
  
  RESULTS
  Neoplastic seeding was identified in 12 patients (0.9 per cent); the rate was comparable at the three centres (0.9, 0.7 and 1.4 per cent). Only previous biopsy was significantly associated with tumour seeding (P = 0.004).
  
  
  CONCLUSIONS
  RFA with a cooled-tip needle was associated with a low risk of neoplastic seeding, even in unselected patients. The use of biopsy before RFA is to be discouraged, particularly when liver transplantation is a possibility at a later date.
authors.affiliation: Department of Radiology, Ospedale Civile, Vimercate, Milan, Italy. tito.livraghi@aovimercate.org
authors.forename: T
authors.initials: T
authors.lastname: Livraghi
authors.forename: S
authors.initials: S
authors.lastname: Lazzaroni
authors.forename: F
authors.initials: F
authors.lastname: Meloni
authors.forename: L
authors.initials: L
authors.lastname: Solbiati
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000556:secondary* / Q000601:surgery; D017115:Catheter Ablation / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000601:surgery*; D009366:Neoplasm Seeding; D012307:Risk Factors