title: Local Tumor Progression of Hepatocellular Carcinoma After Microwave Percutaneous Ablation: A Preliminary Report.
abstract: BACKGROUND
  Microwaves (MW) technology is an ablative treatment alternative to radiofrequency (RF) for early stages of hepatocellular carcinoma (HCC) in cirrhotic patients not suitable for surgical resection. It is well known that HCC lesions ≥ 30 mm treated by RF show a high rate of local tumor progression because of residual of unablated neoplastic tissue.
  
  
  METHODS
  Aim of this study was to describe a limited experience of MW ablation (9 cirrhotic patients with medium size HCC: 11 lesions, 31 - 50 mm in diameter) treated from June 2009 to May 2010 by one of currently marketed western MW ablation systems and followed up for 2 years. Primary end-point was the probability of local tumor progression at 24 months; secondary end-point was the safety of the procedure.
  
  
  RESULTS
  Radiological response after a single session and re-evaluation of local tumor progression along the time were performed by contrast enhanced computed-tomography at months 1-8-12-24. Early effectiveness rate was 90.1 %. The cumulative incidence of local tumor progression at 1 and 2 years were 36.4% (95% CI 11.2 - 62.7) and 57.6% (95% CI 23.6 - 81.0). We observed a single minor complication of the procedure.
  
  
  CONCLUSIONS
  In conclusion, MW ablation system "Amica" has a high rate of primary effectiveness rate but residual of unablated neoplastic tissue induce local tumor progression in about half of the cases during the following 2 years.
authors: Department of Gastro-Hepatology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Franco
authors: F
authors: Brunello
authors: Department of Gastro-Hepatology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Patrizia
authors: P
authors: Carucci
authors: Department of Gastro-Hepatology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Silvia
authors: S
authors: Gaia
authors: Department of Gastro-Hepatology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Emanuela
authors: E
authors: Rolle
authors: Department of Gastro-Hepatology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Paola Rita
authors: PR
authors: Brunocilla
authors: Departement of Tumor Epidemiology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Anna
authors: A
authors: Castiglione
authors: Departement of Tumor Epidemiology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Giovannino
authors: G
authors: Ciccone
authors: Department of Gastro-Hepatology, Azienda Ospedaliera San Giovanni Battista della Citta di Torino, corso Bramante, 88 Turin, Italy.
authors: Mario
authors: M
authors: Rizzetto
keywords: Hepatocellular carcinoma; Microwave percutaneous ablation; Progression; Tumor