title: Radiofrequency ablation of hepatic tumours: effect of post-ablation margin on local tumour progression.
abstract: OBJECTIVE
  The purpose of this study was to retrospectively evaluate the relationship between post-ablation margins and local tumour progression following radiofrequency ablation (RFA) of hepatocellular carcinomas and colorectal liver metastases.
  
  
  METHODS
  Eighty-three patients with 107 hepatic tumours who underwent RFA were divided into two groups: the hepatocellular carcinoma (HCC) group (55 patients with 69 lesions) and the colorectal liver metastases group (28 patients with 38 lesions). Post-ablation margins were calculated on 1-month follow-up contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) studies. Efficacy was evaluated at 1-month post-ablation, then at 3-month intervals for the first year and biannually thereafter.
  
  
  RESULTS
  The results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.020) and tumour size smaller than 2.5 cm (P = 0.001) significantly correlated with local control for the HCC group. In the colorectal liver metastases group, the results of the log-rank test showed that the minimum threshold post-ablation margin of 0.4 cm (P = 0.345) and tumour size smaller than 2.5 cm (P = 0.168) did not correlate with local control.
  
  
  CONCLUSIONS
  Percutaneous RFA is more effective in achieving local control in patients with HCCs than with colorectal liver metastases.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Chang-Hsien
authors.initials: CH
authors.lastname: Liu
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Arellano
authors.forename: Raul N
authors.initials: RN
authors.lastname: Uppot
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Samir
authors.forename: Debra A
authors.initials: DA
authors.lastname: Gervais
authors.forename: Peter R
authors.initials: PR
authors.lastname: Mueller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000556:secondary* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D015179:Colorectal Neoplasms / Q000556:secondary* / Q000601:surgery*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome