Percutaneous microwave ablation of HCC: comparison between 100 and 150 W technology systems

To evaluate the differences in efficacy and safety between the 100 and 150 W percutaneous microwave ablation (MWA) systems in the treatment of hepatocellular carcinoma (HCC).

We retrospectively reviewed all patients who underwent percutaneous MWA (Emprint™ HP Ablation System, Medtronic) between January 2021 and May 2023. We divided the cohort into two groups: Group 1, treated with MWA at 100 W power system, and Group 2, treated with 150 W one. Effectiveness was defined as the absence of residual disease at 1-month CT follow-up; safety was defined as the absence of grade II-VI complications.

A total of 135 HCC nodules were treated with MWA in 87 patients with a median age of 66 ± 10 years: 76 procedures in 42 patients were carried out in group 1, while 59 procedures in 45 patients in group 2. Cases treated with 150 W had a shorter ablation time (p: 0.002; mean 227.37 ± 92.5 vs 180.51 ± 75.6 s (100 vs 150 W)) and a larger ablation volume (p 0.008; mean 13,920.0 ± 10,723.2 vs 21,241.4 ± 18,374.7 mm³ (100 vs 150 W)), and a major effectiveness at 1-month CT follow-up (p: 0.013). A higher rate of complications (grade II and III) was observed in Group 2 (p < 0.001).

In conclusion, these preliminary results showed a good correlation between intended-to-treat area and ablation volume and intended-to-treat area and ablation time for both Groups. A minor ablation time, and major ablation volume, but also a higher incidence of complications was observed in 150 W Group.