PURPOSE

To develop a computational model of microwave ablation (MWA) with a thermal accelerant gel and apply the model toward interpreting experimental observations in bovine and porcine liver.

METHODS

A 3D coupled electromagnetic-heat transfer model was implemented to characterize thermal profiles within bovine and porcine liver tissue during MWA with the HeatSYNC thermal accelerant. Measured temperature dependent dielectric and thermal properties of the HeatSYNC gel were applied within the model. Simulated extents of MWA zones and transient temperature profiles were compared against experimental measurements in bovine liver. Model predictions of thermal profiles under conditions in porcine liver were used to analyze thermal ablations observed in prior experiments in porcine liver .

RESULTS

Measured electrical conductivity of the HeatSYNC gel was ∼83% higher compared to liver at room temperature, with positive linear temperature dependency, indicating increased microwave absorption within HeatSYNC gel compared to tissue. In bovine liver, model predicted ablation zone extents of (31.5 × 36) mm with the HeatSYNC, compared to (32.9 ± 2.6 × 40.2 ± 2.3) mm in experiments (volume differences 4 ± 4.1 cm). Computational models under conditions in porcine liver suggest approximating the HeatSYNC gel spreading within liver tissue during ablations as a plausible explanation for larger ablation zones observed in prior studies.

CONCLUSION

Computational models of MWA with thermal accelerants provide insight into the impact of accelerant on MWA, and with further development, could predict ablations with a variety of gel injection sites.