Variations in Microwave Ablation Zones as a Function of Probe Spacing, Angulation, and Geometry

Despite advancements in precision and effectiveness of microwave ablation for tumor management, accurately predicting ablation zone geometry and minimum ablation margin remains a major challenge. This pilot study aimed to elucidate the influence of probe configuration on the morphometry of resulting ablation zones using tissue-mimicking thermochromic phantoms. In vitro results from 12 ablations were analyzed: (a) a single-probe ablation (n = 1) and (b) dual-probe ablations (n = 11). Angles and separations greatly influenced ablation zone morphometry. In dual-probe ablations, probe tip separation and angle of offset were positively correlated with ablation zone volume, length, and cross-sectional circularity. Interventional radiology ablation planning is currently suboptimal as it often relies on cognitive registration. Even treatment planning software creates virtual composite ablation volumes based on data from theoretical ablations in single, idealized configurations and settings. These findings draw attention to a need for improved ablation zone prediction and planning, which might impact efficiency, safety, cost, and outcomes.