title: Percutaneous radiofrequency ablation of hepatocellular carcinomas adjacent to the gallbladder with internally cooled electrodes: assessment of safety and therapeutic efficacy.
abstract: OBJECTIVE
  The objective of this study was to evaluate the safety and therapeutic efficacy of percutaneous radiofrequency (RF) ablation for the treatment of hepatocellular carcinomas (HCCs) adjacent to the gallbladder with the use of internally cooled electrodes.
  
  
  METHODS
  We retrospectively assessed 45 patients with 46 HCCs (mean size, 2.2 cm) adjacent to the gallbladder (<or=1.0 cm) treated with RF ablation using an internally cooled electrode system. An electrode was inserted into the tumor either parallel (n = 38) or perpendicular (n = 8) to the gallbladder wall. The safety and therapeutic efficacy of the procedures were assessed with clinical and imaging follow-up examinations. Follow-up with the use of CT ranged from four to 45 months (mean, 19 months). The association between variables (electrode direction, electrode type, tumor size, tumor location, lobar location) and the presence of a residual tumor or local tumor progression was also analyzed.
  
  
  RESULTS
  There were no major complications and minor complications were noted in three patients (7%) including one case of vasovagal syncope and two cases of bilomas. Wall thickening of the gallbladder adjacent to the RF ablation zone was noted in 14 patients (41%) as determined on immediate follow-up CT imaging. Wall thickening showed complete disappearance on subsequent follow-up CT imaging. The primary technique effectiveness rate was 96% (44/46) based on one-month follow-up CT imaging. Local tumor progression was noted in six (14%) of 44 completely ablated tumors during the follow-up period. The direction of electrode insertion (perpendicular), tumor size (>or=3 cm) and tumor location (a tumor that abutted the gallbladder) were associated with an increased risk of early incomplete treatment. No variable was significantly associated with local tumor progression.
  
  
  CONCLUSIONS
  Percutaneous RF ablation of HCCs adjacent to the gallbladder using an internally cooled electrode is a safe and effective treatment. Significant risk factors that lead to early incomplete treatment include tumor size, tumor location and electrode direction.
authors: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Sang Won
authors: SW
authors: Kim
authors: Hyunchul
authors: H
authors: Rhim
authors: Mihyun
authors: M
authors: Park
authors: Heejung
authors: H
authors: Kim
authors: Young-sun
authors: YS
authors: Kim
authors: Dongil
authors: D
authors: Choi
authors: Hyo K
authors: HK
authors: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D002765:Cholecystography; D004566:Electrodes; D005260:Female; D005500:Follow-Up Studies; D005704:Gallbladder; D006801:Humans; D008113:Liver Neoplasms / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed