title: Radiofrequency ablation of problematically located hepatocellular carcinoma: tailored approach.
abstract: BACKGROUND
  The challenge for radiofrequency ablation (RFA) of hepatocellular carcinomas (HCC) in problematic locations is that the outcome is limited due to insufficient ablation or injury of nearby structures. This study aimed to evaluate effective strategy and treatment results of RFA in these cases.
  
  
  METHODS
  Ultrasound guided percutaneous RFA was performed in 326 HCC patients. Among them, 249 tumors in 215 patients located at liver periphery, including 54 adjacent to GI tract, 110 close to the diaphragm, 49 close to the gallbladder, and 36 tumors close to liver surface. The sizes of the tumors ranged 1.2-7.0 cm (average 3.7 +/- 1.3 cm). Individualized treatment strategy was established for tumors in various locations, including "artificial ascites", "lift-expand" electrode placement, "draw-expand" electrode placement, "Supplementary ablation", and "accumulative multiple ablations" techniques. Treatment outcome was compared with another 64 central-located tumors (control group) in the same patients. One-month post-RFA contrast CT was used to evaluate early necrosis rate of the treated tumors.
  
  
  RESULTS
  Early tumor necrosis were obtained in 91.6% (228/249) of the problematically located HCC, including 90.7% (49/54) of the tumors adjacent to GI tract, 90.9% (100/110) near the diaphragm, 91.8% (45/49) by the gallbladder, and 94.4% (34/36) close to liver surface. The necrosis rate of control group was 98.4% (63/64), which was higher than the tumors close to diaphragm (P = 0.049). Local tumor recurrence was 8.4% (21/249), comparing with 3.1% (2/64) of the control group (P > 0.05). The 1-, 2- and 3-year survival rate of this group were 81.6%, 63.8%, and 53.6%, respectively. Major complications occurred in 3.2% (11/343) of the treatment sessions, including hemorrhage in two, nearby structure injury in five, and needle tract seeding in four patients.
  
  
  CONCLUSIONS
  Individualized treatment strategy for problematically located HCC is helpful in improving RFA outcome and expanding the application range of the therapy.
authors.affiliation: Department of Ultrasound, Peking University School of Oncology, Beijing Cancer Hospital & Institute, Beijing, 100036, China. minhuachen@bjcancer.org
authors.forename: Min-Hua
authors.initials: MH
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Kun
authors.initials: K
authors.lastname: Yan
authors.forename: Yi-Bin
authors.initials: YB
authors.lastname: Hou
authors.forename: Ying
authors.initials: Y
authors.lastname: Dai
authors.forename: Wen
authors.initials: W
authors.lastname: Gao
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D016009:Chi-Square Distribution; D002985:Clinical Protocols; D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D015996:Survival Rate; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D003287:Contrast Media