Local recurrence risk factors and outcomes in minimally invasive thermal ablation for liver tumors: a single-institution analysis

Background: Minimally Invasive thermal ablation (MITA) of liver tumors is a commonly performed procedure, alone or in combination with liver resection. Despite being a first-option strategy for small lesions, it is technically demanding, and many concerns still exist about local disease control. Methods: Consecutive patients undergoing MITA from 1-2019 to 12-2022 were retrospectively enrolled. Risk factors of local recurrence were investigated through univariate and multivariable cox regression analysis. Results: At the multivariable analysis of the 207 nodules undergoing MITA, RFA was associated with worse local Recurrence Free Survival (lRFS) than MWA (HR 2.87 [95 % CI 0.96–8.66], p = 0.05), as well as a concomitant surgical resection (HR 3.89 [95 % CI 1.06–9.77], p = 0.02). A concomitant surgical resection showed worse lRFS in the subgroup analysis of both HCC (HR 3.98 [95 % CI 1.16–13.62], p = 0.02) and CRLM patients (HR 2.68 [95 % CI 0.66–5.92], p = 0.04). Interestingly, a tumor size between 30 and 40 mm was not associated to worse lRFS. Conclusion: MWA may reduce the risk of local recurrence in comparison to RFA, while MITA associated to liver resection may face an increased risk of local recurrence. Further prospective studies are needed to confirm such results.