Assessment of a new 150 W single‐antenna microwave ablation system in the treatment of malignant liver tumors: The first worldwide experience

Abstract

Background and Objectives: Data in literature regarding liver microwave ablation pertain to systems delivering 100 W of maximum power. Our aim is to assess a new 150 W microwave system for liver tumor ablation.Methods: This was an institutional review board-approved study of patients undergoing ablation of malignant liver tumors using a 150 W microwave system. Feasibility, safety, ablation algorithm, perioperative outcomes, and efficacy were analyzed. Comparison was made to historical patients undergoing ablation using a 100 W microwave system.Results: There were 33 patients with 76 malignant liver lesions who underwent ablation with the 150 W system. Using a step-wise algorithm, ablations without intraoperative complications were performed for tumors ranging in size from 0.3 to 6.7 cm. Ninety-day morbidity was 5%, with no mortality. Compared to the 100 W system, the 150 W system shortened ablation time and created larger ablation zones with a single stick. Conclusion:This first worldwide experience showed that surgical ablations could be safely created at 150 W using a step-wise algorithm with complete tumor destruction achieved at short-term follow-up. Advantages versus 100 W systems include reduction in ablation time and creation of larger ablation zones with a single stick.

Percutaneous Application of High Power Microwave Ablation With 150 W for the Treatment of Tumors in Lung, Liver, and Kidney: A Preliminary Experience

“…In 10 of 16 patients, pre-treatment imaging consisted of contrast enhanced CT, instead in 6 of 16 patients the pre-treatment imaging consisted of contrast enhanced MRI. The lesions treated were the follows: hepatocellular carcinoma (HCC) (10), liver metastasis from colon cancer (1), liver metastasis from pancreas cancer (1), squamous cell lung carcinoma (2), renal cell carcinoma (1) and renal oncocytoma (1). (Table 1) (Figures 1-4) Pre-intervention biopsy was performed for all 2 renal lesions, for all 2 lung lesions and for 2 hepatic lesions.…”

“…6,7 Although RFA is still the most widely used ablation technique worldwide, throughout the years MWA has gained a lot of interest proving to be an effective technique, equal or even superior to RFA in some cases. [5][6][7][8][9][10][11][12] Among advantages of MWA over RFA there are: shorter time of treatment, higher intra-tumoral temperatures, larger area of necrosis and less effectiveness by the heat-sink effect. 8,10,13,14 The basic microwave system consists of three components: a generator, a power distribution system and antennas.…”

“…[5][6][7][8][9][10][11][12] Among advantages of MWA over RFA there are: shorter time of treatment, higher intra-tumoral temperatures, larger area of necrosis and less effectiveness by the heat-sink effect. 8,10,13,14 The basic microwave system consists of three components: a generator, a power distribution system and antennas. [15][16][17][18] The generator operates in the 915 MHz and 2.45 GHz frequency bands to directly heat tissue to lethal temperatures greater than 150 °C through dielectric hysteresis.…”

“…Although RFA is still the most widely used ablation technique worldwide, throughout the years MWA has gained a lot of interest proving to be an effective technique, equal or even superior to RFA in some cases. 5 – 12 …”

“…Among advantages of MWA over RFA there are: shorter time of treatment, higher intra-tumoral temperatures, larger area of necrosis and less effectiveness by the heat-sink effect. 8 , 10 , 13 , 14 …”