title: Percutaneous radiofrequency ablation for liver tumors: Is it safer and more effective in low-risk areas than in high-risk areas?
abstract: OBJECTIVE
  To evaluate the feasibility and safety of ultrasound-guided radiofrequency ablation (RFA) of hepatic tumors in high-risk areas (in caudate lobe, adjacent to the hilum, capsular surface, gallbladder or diaphragm) in comparison with those in low-risk areas.
  
  
  METHODS
  A total of 526 patients with hepatic tumor treated with ultrasound-guided cool-tip RFA between October 2001 and October 2008 were included. The patients were divided into two groups according to the tumor location: group I (high-risk areas, 163 patients); group II (low-risk areas, 363 patients). The two groups had similar baseline characteristics. Repeated RFA was adopted if complete ablation (CA) was not achieved.
  
  
  RESULTS
  In group I, 20 cases had tumors close to the hilum, 11 in the caudate, 79 adjacent to the capsule, 24 near the gallbladder and 29 cases against the diaphragm. The percentage of patients with primary hepatic tumors in group I was higher than that in group 2 (80.4% vs 56.2%, P < 0.01). More patients in group I felt pain (61.3%, 100/163) than in group II (33.1%, 120/363) (P < 0.01). There was no mortality or major complications in either group. No significant differences were found in the CA rate and the minor complications between the two groups.
  
  
  CONCLUSIONS
  RESULTS for RFA using cool-tip electrodes for liver tumors in high-risk areas are comparable to those in low-risk areas in the aspects of CA, complications and mortality.
authors.affiliation: Departments of Surgery Anaesthesia Ultrasound, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Tang
authors.forename: Heqing
authors.initials: H
authors.lastname: Fang
authors.forename: Muxing
authors.initials: M
authors.lastname: Kang
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Dong
authors.forename: Xiangming
authors.initials: X
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Jianke
authors.initials: J
authors.lastname: Chen
authors.forename: Yulian
authors.initials: Y
authors.lastname: Wu