Comparing the Safety and Efficacy of Microwave Ablation Using Thermosphere(TM) Technology versus Radiofrequency Ablation for Hepatocellular Carcinoma: A Propensity Score-Matched Analysis

SIMPLE SUMMARY: Microwave ablation using Thermosphere(TM) technology is a novel locoregional treatment for hepatocellular carcinoma. This study compared the safety and efficacy outcomes of this microwave ablation strategy versus radiofrequency ablation using propensity score-matched analysis. Microwave ablation led to a high rate of curative ablation (94.7%) and a low rate of local recurrence (3.3%), with an overall survival rate of 99.3% at 1 year (recurrence-free survival: 81.1%) and 88.4% at 2 years (recurrence-free survival: 60.5%). There were no significant differences in survival outcomes after microwave and radiofrequency ablation. However, microwave ablation required significantly fewer insertions (1.22 ± 0.49 vs. 1.59 ± 0.94; p < 0.0001). Based on the similar survival outcomes, we recommend microwave ablation using Thermosphere(TM) technology for hepatocellular carcinoma with a diameter of >2 cm because of the lower number of insertions. ABSTRACT: There is limited information regarding the oncological benefits of microwave ablation using Thermosphere(TM) technology for hepatocellular carcinoma. This study compared the overall survival and recurrence-free survival outcomes among patients with hepatocellular carcinoma after microwave ablation using Thermosphere(TM) technology and after radiofrequency ablation. Between December 2017 and August 2020, 410 patients with hepatocellular carcinoma (a single lesion that was ≤5 cm or ≤3 lesions that were ≤3 cm) underwent ablation at our institution. Propensity score matching identified 150 matched pairs of patients with well-balanced characteristics. The microwave ablation and radiofrequency ablation groups had similar overall survival rates at 1 year (99.3% vs. 98.2%) and at 2 years (88.4% vs. 87.5%) (p = 0.728), as well as similar recurrence-free survival rates at 1 year (81.1% vs. 76.2%) and at 2 years (60.5% vs. 62.1%) (p = 0.492). However, the microwave ablation group had a significantly lower mean number of total insertions (1.22 ± 0.49 vs. 1.59 ± 0.94; p < 0.0001). This retrospective study revealed no significant differences in the overall survival and recurrence-free survival outcomes after microwave ablation or radiofrequency ablation. However, we recommend microwave ablation for hepatocellular carcinoma tumors with a diameter of >2 cm based on the lower number of insertions.