title: Percutaneous radiofrequency ablation for malignant liver tumours in challenging locations.
abstract: OBJECTIVE
  To evaluate the treatment results of radiofrequency ablation (RFA) for primary and metastatic malignant liver tumours in challenging locations and also to present the treatment strategy that was used in these cases.
  
  
  METHODS
  From January 2007 to January 2010, we performed CT-guided RFA on 528 lesions in 402 patients (265 men and 137 women; mean age 65.1 years, range 19-82 years) with liver tumours (primary and metastatic) of which 98 lesions in 84 patients (55 men and 29 women; mean age 67.8 years, range 33-82 years) were located in challenging locations, defined as less than 5 mm from a large vessel or an extrahepatic organ (heart, lung, gall bladder, right kidney or gastrointestinal tract). The sizes of the tumours ranged 1.5-6 cm. We used two different RFA systems with an expandable needle electrode (RITA; Rita Medical Systems, Inc, Mountain View, CA, USA and MIRAS; Invatec S.r.l., Roncadelle, Italy).The tumours were considered as ablated completely if no viability was found on dual-phase dynamic contrast-enhanced CT at 1 month after RFA.
  
  
  RESULTS
  Complete ablation was obtained in 89.7% (88/98) of the high-risk located lesions, while 10 (10.3%) of the lesions were managed with repeated RFA because of tumour residue. The 1-, 2- and 3-year survival rates were 82.6, 67.3 and 54.1%, respectively. Minor complications occurred in eight of the 84 patients (9.5%), including small sub-capsular haematoma in four, small pleural effusion in three and partial liver infarction in one. Local tumour progression rate was 9.2% (9/98).
  
  
  CONCLUSIONS
  RFA is a safe and effective method of treatment of primary and metastatic liver tumours even located in challenging locations when performed by a well-trained and experienced interventional radiologist.
authors.affiliation: Computed Tomography and Interventional Radiology Department, Sotiria Chest Diseases Hospital, Athens, Greece. kelogre.mic@hotmail.com
authors.forename: Michalis
authors.initials: M
authors.lastname: Kelogrigoris
authors.forename: Fotios
authors.initials: F
authors.lastname: Laspas
authors.forename: Katerina
authors.initials: K
authors.lastname: Kyrkou
authors.forename: Kostas
authors.initials: K
authors.lastname: Stathopoulos
authors.forename: Vithleem
authors.initials: V
authors.lastname: Georgiadou
authors.forename: Loucas
authors.initials: L
authors.lastname: Thanos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000379:methods*; D018450:Disease Progression; D004566:Electrodes; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome