title: High-powered microwave ablation of larger hepatocellular carcinoma: evaluation of recurrence rate and factors related to recurrence.
abstract: OBJECTIVE
  To evaluate the safety and efficacy of high-powered (80-100 W) percutaneous microwave ablation (MWA) at a frequency of 2450±10 MHz for treating larger hepatocellular carcinoma (HCC) and to predict the risk factors of local recurrence after high-powered MWA.
  
  
  METHODS
  The study was approved by the Institutional Review Board, and informed consent was waived because of the retrospective study design. Forty-five patients with a total of 60 lesions received high-power (80-100 W) MWA at a frequency of 2450±10 MHz through a percutaneous approach that was guided by ultrasound. Of the 60 lesions with a maximum tumour measuring 3-8 cm, 46 lesions were 3-5 cm and 14 were 5-8 cm. The complete ablation rates, local recurrence rates, complications, and short-term survival were analysed. Ten possible risk factors for local recurrence were analysed.
  
  
  RESULTS
  The complete ablation rates were 82.61% for the first ablation and 100% for the second ablation for 3-5 cm lesions. The complete ablation rates were 64.29% (82.61% versus 64.29%, p=0.037) for the first ablation and 85.71% (100% versus 85.71%, p=0.055) for the second ablation for 5-8 cm lesions. Local recurrence was observed in 11 out of the 45 (24.44%) successfully treated patients. The 1-year and 2-year survival rates were 95.56% (43/45) and 86.67% (39/45), respectively. No procedure-related mortality was observed and no major bleeding, liver rupture, or liver abscesses occurred. Univariate analysis showed that a positive correlation existed between the number of lesions (p=0.022), proximity to the risk area (p=0.001), pre-ablation alpha-fetoprotein (AFP) levels (p=0.025), hepatitis B virus (HBV)-DNA replication (p=0.027) and local recurrence. Multivariate analysis identified HBV-DNA (p=0.031) and proximity to the risk area (p=0.039) as the independent prognosis factors causing postoperative HCC local recurrence.
  
  
  CONCLUSIONS
  High-powered MWA of larger hepatocellular carcinomas appears to be a safe and effective treatment. HBV-DNA and proximity to the risk area appear to be independent predictors of local tumour recurrence.
authors.affiliation: Tianjin Second People's Hospital, 7 Sudi Road, Tianjin 300192, China; Tianjin Institute of Hepatology, 7 Sudi Road, Tianjin 300192, China.
authors.forename: N N
authors.initials: NN
authors.lastname: Zhang
authors.affiliation: Tianjin Second People's Hospital, 7 Sudi Road, Tianjin 300192, China; Tianjin Institute of Hepatology, 7 Sudi Road, Tianjin 300192, China. Electronic address: mail4luwei@163.com.
authors.forename: W
authors.initials: W
authors.lastname: Lu
authors.affiliation: Tianjin Second People's Hospital, 7 Sudi Road, Tianjin 300192, China; Tianjin Institute of Hepatology, 7 Sudi Road, Tianjin 300192, China.
authors.forename: X J
authors.initials: XJ
authors.lastname: Cheng
authors.affiliation: Tianjin Second People's Hospital, 7 Sudi Road, Tianjin 300192, China; Tianjin Institute of Hepatology, 7 Sudi Road, Tianjin 300192, China.
authors.forename: J Y
authors.initials: JY
authors.lastname: Liu
authors.affiliation: Tianjin Second People's Hospital, 7 Sudi Road, Tianjin 300192, China; Tianjin Institute of Hepatology, 7 Sudi Road, Tianjin 300192, China.
authors.forename: Y H
authors.initials: YH
authors.lastname: Zhou
authors.affiliation: Tianjin Second People's Hospital, 7 Sudi Road, Tianjin 300192, China; Tianjin Institute of Hepatology, 7 Sudi Road, Tianjin 300192, China.
authors.forename: F
authors.initials: F
authors.lastname: Li
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods* / Q000401:mortality; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology* / Q000401:mortality; D011183:Postoperative Complications / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional