Analysis of microwave ablation antenna optimization techniques

摘要

Microwave ablation is a minimally invasive treatment modality for malignant andrnbenign tumors in several organs. While many microwave ablation antennas havernbeen described in the literature, most have been designed assuming normal ambientrntissue and have not accounted for tissue property changes that occur during intensernheating. We analyzed three optimization approaches for canonical monopole andrndual-slot antennas: minimal reflection, spherical specific absorption rate (SAR) pattern,rnand spherical ablation zone. Simulated ablations with each optimal design werernalso validated in ex vivo liver tissue. Optimized designs for minimal reflectionrnmatched previously published results, while designs optimized for spherical SAR andrnspherical ablation yielded novel geometries. Surprisingly, optimization for sphericalrnSAR rendered the most spherical ablation zones in ex vivo tissue. Optimizations forrnminimal reflection and spherical ablation zone did not achieve the most sphericalrnablation zones in experiments. These results point to the need for greater accuracy inrndielectric and thermal tissue models to improve simulation-aided design, and to thernpotential for continued refinement in microwave ablation antenna design.