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

Abstract

There is limited information regarding the oncological benefits of microwave ablation using ThermosphereTM technology for hepatocellular carcinoma. This study compared the overall survival and recurrence-free survival outcomes among patients with hepatocellular carcinoma after microwave ablation using ThermosphereTM 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.

An Analysis of Microwave Ablation Parameters for Treatment of Liver Tumors from the 3D-IRCADb-01 Database

“…A key element in MWA treatments is the microwave antenna (MW), which delivers energy and provides lethal temperature rise, resulting in cell death in the ablation zone [ 36 ]. Advanced antenna designs are based on three different mechanisms: thermal, field, and wavelength control [ 37 ]. Recently, a compact, multi-slot coaxial antenna was developed to achieve the required ablation zone and suitable impedance matching to the target tumoral tissue without damaging the surrounding healthy tissues [ 38 ].…”

Computational Modeling of Microwave Tumor Ablation

“…Finely tuned impedance matching minimizes damage to the surrounding healthy tissues. In one of the most sophisticated antenna designs, the required ablation zones are achieved using three different mechanisms: Thermal, field, and wavelength controls [ 32 , 33 ].…”

“…[ 30 , 31 ]. Some commercial MWA systems based on “thermosphere technology” can produce spherical ablation patterns by adding small saline irrigation channels to the antennas [ 32 , 33 ]. Novel compact multislot coaxial antennas ensure the formation of spherical ablation zones that are suitable for the interstitial MWA process [ 34 , 35 ].…”

Microwave thermosphere versus radiofrequency ablation for hepatocellular carcinoma: Are we approaching the time to end the debate?

“…Therefore, the comparison should have been performed after matching of important characteristics. Interestingly, a similar study that was based on a propensity score-matched analysis found no significant differences in recurrence free survival and overall survival between the Emprint ablation system and RFA for small HCC 2 .…”