OBJECTIVES: To perform the cost-effectiveness analysis of thermoablation versus surgery for liver metastasis treatment (lesions smaller than 3.5 cm).

METHODS: In the present economic evaluation, overall survival and progression-free survival probabilities for surgery and thermoablation were based on a systematic review. The model considered as horizon the Brazilian’s population average lifetime (75 years old), while the initial study population age was set at 50 years. In the health state transition model, following health states were considered: stable disease, progression and death. The costs included: thermoablation = US$ 3,328.89; surgery = US$ 7,043.22; post-procedure follow-up = US$ 190.84; thermoablation adverse events = US$ 40.26; surgery adverse events = US$ 202.11; pre-progression monitoring after thermoablation = US$ 1,120.86; pre-progression monitoring after surgery = US$ 2,666.87; palliative care after thermoablation = US$ 8,036.85; palliative care after surgery = US$ 4,0598.58.

RESULTS: Thermoablation was superior to surgery (dominated) and presented a cost reduction of US$ 10,804.32 and incremental effectiveness of 1% when compared to surgery. The multivariate probabilistic sensitivity analysis showed that after 100,000 iterations, thermoablation had the lowest ICER regardless of the willingness to pay threshold.

CONCLUSIONS: In the studied scenario, thermoablation was considered dominant over surgery and should be considered for the treatment of liver metastasis in Brazil.