title: Ablative zone size created by radiofrequency ablation with and without chemoembolization in small hepatocellular carcinomas.
abstract: OBJECTIVE
  We retrospectively evaluated whether combined use of chemoembolization expands ablative zone sizes created by radiofrequency (RF) ablation in patients with small hepatocellular carcinomas (HCCs).
  
  
  METHODS
  Fifty-seven patients treated with single RF ablation for solitary HCC measuring ≤2 cm were assessed. RF ablation alone was done in nine patients and in 48 patients following chemoembolization, with an interval of 0 days in 6, 1-14 days in 27, 15-28 days in 6, and ≥4 weeks in 9. Ablative zone sizes, disappearance of tumor enhancement, and creation of sufficient ablative margins (>5 mm) were evaluated on contrast-enhanced computed tomography (CT) images.
  
  
  RESULTS
  Both mean long-axis (4.2-4.7 vs. 3.6 ± 0.4 cm, p < 0.04) and short-axis (3.3-3.8 vs. 2.3 ± 0.5 cm, p < 0.03) diameters were expanded significantly when RF ablation was done until 4 weeks after chemoembolization than with RF ablation alone. Tumor enhancement disappeared in all patients. Frequency of achieving sufficient ablative margins was significantly higher when RF ablation was done until 4 weeks after chemoembolization than with RF ablation alone (74.0-83.3 vs. 22.2 %, p < 0.05).
  
  
  CONCLUSIONS
  Ablative zones created by RF ablation with chemoembolization become larger than RF ablation alone, leading to secure ablative margins.
authors.affiliation: Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan. t-yama@clin.medic.mie-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamanaka
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yamakado
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Takaki
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Nakatsuka
authors.forename: Katsuya
authors.initials: K
authors.lastname: Shiraki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Takei
authors.forename: Kan
authors.initials: K
authors.lastname: Takeda
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000628:therapy*; D017115:Catheter Ablation / Q000379:methods*; D016461:Chemoembolization, Therapeutic / Q000379:methods*; D003131:Combined Modality Therapy; D003287:Contrast Media; D005260:Female; D006801:Humans; D008111:Liver Function Tests; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D015641:Radiography, Interventional; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media