title: Factors in successful radiofrequency ablation therapy for malignant liver tumors.
abstract: OBJECTIVE
  Radiofrequency ablation has become a new therapeutic method for treating malignant liver tumors. We reviewed our experience to identify the factors involved in successful radiofrequency ablation therapy.
  
  
  METHODS
  Patients who underwent this therapy between 1999 July and 2002 July were reviewed for the characteristics of their tumors, clinical data and operative techniques used.
  
  
  RESULTS
  Sixty-one patients (hepatocellular carcinoma 50 and metastatic tumors 11) were ablated. Forty-six cases (75.4%) were ablated effectively. Survival of patients with hepatocellular carcinoma was superior to those with metastases. The effective factor was the number of nodules while the survival factors were the number of nodules and the maximum tumor diameter. Recurrence factors in patients with hepatocellular carcinoma ablated effectively were poor hepatic function due to cirrhosis and higher protein induced by vitamin K absence or antagonist-II (PIVKA-II).
  
  
  CONCLUSIONS
  The survival of patients with hepatocellular carcinoma was significantly better than those with metastases. We recommend radiofrequency ablation therapy for cases having a single hepatic tumor less than 3.5 cm in diameter (4 cm for hepatocellular carcinoma requiring much care). In patients with hepatocellular carcinoma, hepatic function with cirrhosis and PIVKA-II showed a significant correlation with recurrence.
authors.affiliation: Department of Surgery II, Medical School of Nagoya University, Nagoya, Aichi, Japan. sakakima@med.nagoya-u.ac.jp
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Sakakima
authors.forename: Soichiro
authors.initials: S
authors.lastname: Inoue
authors.forename: Shin
authors.initials: S
authors.lastname: Takeda
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kaneko
authors.forename: Akimasa
authors.initials: A
authors.lastname: Nakao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D006528:Carcinoma, Hepatocellular / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D009367:Neoplasm Staging; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome