Tissue Shrinkage in Microwave Ablation: Ex Vivo Predictive Model Validation

Aim of the present study was to test and validate an ex vivo predictive model for the evaluation of the shrinkage occurring in hepatic tissue during a microwave thermal ablation procedure. Microwave ablation $(\text{N}=134)$ was conducted with three different commercial devices on cubes of ex vivo liver $(15-40\pm 2\text{mm}/\text{side})$ embedded in agar phantoms. 50-60W was applied for 1–10 min duration. Pre-and post-ablation dimensions of the samples, as well as the extent of carbonization and coagulation were measured. The model results able to estimate the occurred contraction in presence of carbonization with good accuracy (>80% of the studied cases). The estimated error range resulted within the accuracy of the clinical practice.