A comparison of microwave thermosphere versus radiofrequency thermal ablation in the treatment of colorectal liver metastases.

ABSTRACT

BACKGROUND: Microwave thermosphere ablation (MTA) is a new generation technology. The aim of this study was to compare the efficacy of MTA and radiofrequency ablation (RFA) in achieving local tumor control in patients with colorectal liver metastasis (CRLM). METHODS: This was a retrospective study of a prospective ablation database. Fifty-four patients with 155 CRLM lesions underwent RFA and 51 patients with 121 lesions underwent MTA. Patients were managed by a multidisciplinary team. Clinical and oncologic data were analyzed. Kaplan-Meier and Cox Proportional Hazards model were used for statistical analysis. RESULTS: Demographics were similar between the two groups. Total ablation and operative times were significantly shorter in MTA group (19 vs. 37 mins, p < 0.001, 154 vs. 202 mins, p = 0.009). With a similar hospital stay (median 1), 90-day morbidity was similar (8 vs. 10%, p = 0.848), without mortality. Local recurrence (LR) rate per lesion was 20% in RFA and 10% in MTA group (p = 0.020). On Cox Proportion Hazards model, ablation modality and tumor size were independent predictors of LR. CONCLUSIONS: This is the first study comparing the efficacy of RFA and MTA on CRLM. The results suggest that compared to RFA, MTA improves local tumor control, while significantly shortening operative time.