Comparison of simulation-based treatment planning with imaging and pathology outcomes for percutaneous CT-guided irreversible electroporation of the porcine pancreas: a pilot study.

PURPOSE: To investigate the reliability of simulations for planning pancreatic irreversible electroporation (IRE) ablations compared with computed tomography (CT) and pathology outcomes in an animal model.
MATERIALS AND METHODS: Simulations were performed varying treatment parameters, including field strength (1.5-2.5 kV/cm), pulse number (70-90 pulses), and pulse length (70-100 µs). Pancreatic IRE was performed in six pigs under CT guidance. Two animals each were sacrificed for histology after 1 day, 14 days, and 28 days. Follow-up CT scans were performed on day 0, day 1, day 14, and day 28. Biochemical markers were collected before the procedure, 1 day after the procedure, and 14 days after the procedure.
RESULTS: All ablation zones could be visualized on CT scan immediately after the procedure and on day 1 follow-up CT scan, and all animals survived until the designated endpoints. Histopathology revealed necrosis and edema on day 1 and fibrosis and glandular atrophy after 28 days. Blood vessels close to the ablation zone appeared normal. Laboratory analysis indicated mild to moderate amylasemia and lipasemia with normalization after 14 days. The ablation size on CT scan measured a mean (± SD) 146% ± 18 (day 0, P < .126) and 168% ± 18 (day 1, P < .026) of the simulation and on pathology measured 119% ± 10 (day 1, not significant) of the simulation.
CONCLUSIONS: Results from simulations for planning IRE ablations, CT, and pathology may differ from each other. Ablation zones on CT and pathology appear larger than simulated, suggesting that clinically used treatment planning may underestimate the ablation size in the pancreas. © SIR, 2013.