Microwave ablation of liver metastases to overcome the limitations of radiofrequency ablation.

Ierardi, Anna Maria; Floridi, Chiara; Fontana, Federico; Chini, Claudio; Giorlando, Francesca; Piacentino, Filippo; Brunese, Luca; Pinotti, Graziella; Bacuzzi, Alessandro; Carrafiello, Gianpaolo

PURPOSE The purpose of our study was to evaluate technical success, effectiveness and safety of microwave ablation (MWA) in patients with unresectable liver metastases, where radiofrequency ablation (RFA) presents some limits. MATERIALS AND METHODS Twenty-five patients (17 men, 8 women) with 31 liver metastases >3 cm or located near vessels (>3 mm) were treated in a total of 29 sessions. Tumours were subdivided as follows: colorectal metastases (n=21) and no colorectal metastases (n=10). All procedures were performed percutaneously under ultrasound (US) guidance. Follow-up was performed with computed tomography (CT) scan at 1, 3, 6 and 12 months after treatment; mean follow-up period was 12.04 (range, 3-36) months. Technical success, mean disease-free survival, effectiveness and safety were evaluated. RESULTS Technical success was obtained in all cases. Mean disease-free survival was of 20.5 months. Local recurrence was recorded in 12.9% of metastases treated (4/31). No major complications were recorded. The rate of minor complications was 44.8% (13/29 sessions). Mortality at 30 days was 0%. CONCLUSIONS Percutaneous MWA of liver metastases >3 cm or located near vessels (>3 mm) can be considered a valid and safe option, probably preferable to RFA. Further studies are required to confirm these encouraging initial results.