title: Percutaneous sonographically guided radio frequency ablation of hepatocellular carcinoma: causes of mistargeting and factors affecting the feasibility of a second ablation session.
abstract: OBJECTIVE
  The purposes of this study were to evaluate the causes of mistargeting during percutaneous sonographically guided radio frequency ablation in patients with hepatocellular carcinoma and to determine factors affecting the feasibility of a second ablation session.
  
  
  METHODS
  This study received Institutional Review Board approval, and informed consent was waived. Among 2213 percutaneous sonographically guided radio frequency ablations performed in our hospital, we searched for mistargeting cases and analyzed the causes of mistargeting. To determine which factors affected the feasibility of a second ablation session, univariate and multivariate analyses were performed.
  
  
  RESULTS
  Forty-one cases of mistargeting occurred during the first ablation session, and 4 cases occurred during the second session. Of the 41 patients with mistargeted hepatocellular carcinomas during the first session, 39 who underwent replanning sonography were able to be analyzed for causes of mistargeting. The most common cause of mistargeting was confusion with cirrhotic nodules (87.2% [34 of 39]), followed by poor conspicuity of the hepatocellular carcinoma (69.2% [27 of 39]), a poor sonic window (28.2% [11 of 39]), a poor electrode path (7.7% [3 of 39]), and inaccurate electrode placement (2.6% [1 of 39]). Artificial ascites (P = .035) and the presence of more than 3 mistargeting causes (P = .017) were independent factors affecting feasibility.
  
  
  CONCLUSIONS
  The most common cause of mistargeting was confusion with cirrhotic nodules, followed by poor conspicuity of the hepatocellular carcinoma, a poor sonic window, a poor electrode path, and inaccurate electrode placement. The use of artificial ascites and the presence of more than 3 mistargeting causes were factors affecting the feasibility of a second radio frequency ablation session.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Kangnam-Ku, Seoul 135-710, Korea.
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Hyo K
authors.initials: HK
authors.lastname: Lim
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Kim
authors.forename: Dongil
authors.initials: D
authors.lastname: Choi
authors.forename: Young-Sun
authors.initials: YS
authors.lastname: Kim
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Dong Ik
authors.initials: DI
authors.lastname: Cha
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Park
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Rhim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000601:surgery*; D017115:Catheter Ablation / Q000706:statistics & numerical data*; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012086:Reoperation / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D056910:Republic of Korea / Q000453:epidemiology; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D014463:Ultrasonography