Microwave ablation (MWA) is the most recent development in the field of local ablative therapies. The aim of this study was to evaluate the variability and reproducibility of single-probe MWA versus radiofrequency ablation (RFA) of metastatic liver tumours smaller than 3 cm in patients without underlying liver disease.

Inclusion Criteria:

• Unresectable metastatic liver cancer
• No invasion of major biliary structures
• No invasion of major vascular structures
• ASA score < 4
• WHO score 0-1
• Pre-operative chemotherapy is allowed

Exclusion Criteria:

• Resectable liver metastases
• Life expectancy less than 3 months
• Patients with cardiac pacemaker, cerebral aneurysm clips, implanted electronic instruments or other metal materials
• Coagulopathy with platelet count less than 50000
• Active infectious disease
• Age below 18 years
• Pregnancy of breastfeeding