title: Image-guided radiofrequency ablation of liver malignancies: experience at Singapore General Hospital.
abstract: The aim of this paper was to study the efficacy, side effects and complications of radiofrequency (RF) ablation of primary and metastatic liver malignancies.
  
  
  METHODS
  We retrospectively reviewed 57 patients (39 men, 18 women; mean age, 63 years; age range, 44 to 83 years) who underwent RF ablation for liver malignancies from January 2002 to December 2004. A total of 87 tumours were ablated - 71 (81.6%) hepatocellular carcinomas and 16 (18.4%) metastases (from primaries in the colon, stomach and pancreas). RF ablation was performed either percutaneously (n = 71) under conscious sedation or intraoperatively (n = 16) under general anaesthesia. Follow-up ranged from 1 month to 41 months (mean, 15.2) and included computed tomography (CT) 1 day, 1 month and 3 months after ablation, and half-yearly thereafter. Patients were observed for local tumour progression and for the emergence of new tumours.
  
  
  RESULTS
  Four patients with a total of 5 tumours were lost to follow-up. Of the remaining 82 tumours treated, complete ablation was attained in 66 tumours after a single procedure, giving a primary effectiveness rate of 80.5%. Seven (8.5%) required 2 procedures to achieve complete ablation, giving a secondary effectiveness rate of 89% after 2 ablations. One tumour (1.2%) required 3 procedures to achieve complete ablation. One tumour required 4 procedures to date, with the latest follow-up CT still demonstrating incomplete ablation. Two tumours (2.4%) had an initial RF ablation and subsequent transarterial chemoembolisation (TACE). One tumour had an initial RF ablation followed by 32Phosphorus-biosilicon (BrachySil) injection, the latter as part of a Phase IIA trial. One tumour required 2 RF ablations and a subsequent TACE. Lastly, 3 tumours received initial RF ablation but subsequent local tumour progression was not treated as the patients were deemed unfit for repeat ablation. No procedure-related deaths or major complications were encountered. Minor complications were reported in 2 patients (3.8%) - subcapsular haematoma and thermal injury to the adjacent gastric antrum, both not necessitating surgical intervention.
  
  
  CONCLUSIONS
  RF ablation is an effective, safe and relatively simple procedure for the treatment of unresectable liver malignancies.
authors.affiliation: Department of Diagnostic Radiology, Singapore General Hospital, Singapore.
authors.forename: Shoen C S
authors.initials: SC
authors.lastname: Low
authors.forename: Richard H G
authors.initials: RH
authors.lastname: Lo
authors.forename: Te-Neng
authors.initials: TN
authors.lastname: Lau
authors.forename: London Lucien P J
authors.initials: LL
authors.lastname: Ooi
authors.forename: Chee-Keong
authors.initials: CK
authors.lastname: Ho
authors.forename: Bien-Soo
authors.initials: BS
authors.lastname: Tan
authors.forename: Alexander Y F
authors.initials: AY
authors.lastname: Chung
authors.forename: Wen-Hsin
authors.initials: WH
authors.lastname: Koo
authors.forename: Pierce K H
authors.initials: PK
authors.lastname: Chow
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000556:secondary / Q000601:surgery* / Q000628:therapy; D017115:Catheter Ablation; D016461:Chemoembolization, Therapeutic; D003131:Combined Modality Therapy; D005260:Female; D006769:Hospitals, General; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary / Q000601:surgery* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D019233:Retreatment; D012189:Retrospective Studies; D012846:Singapore; D025321:Surgery, Computer-Assisted