Planning irreversible electroporation in the porcine kidney: are numerical simulations reliable for predicting empiric ablation outcomes?
OBJECTIVE
Numerical simulations are used for treatment planning in clinical applications of irreversible electroporation (IRE) to determine ablation size and shape. To assess the reliability of simulations for treatment planning, we compared simulation results with empiric outcomes of renal IRE using computed tomography (CT) and histology in an animal model.


METHODS
The ablation size and shape for six different IRE parameter sets (70-90 pulses, 2,000-2,700 V, 70-100 µs) for monopolar and bipolar electrodes was simulated using a numerical model. Employing these treatment parameters, 35 CT-guided IRE ablations were created in both kidneys of six pigs and followed up with CT immediately and after 24 h. Histopathology was analyzed from postablation day 1.


RESULTS
Ablation zones on CT measured 81 ± 18 % (day 0, p ≤ 0.05) and 115 ± 18 % (day 1, p ≤ 0.09) of the simulated size for monopolar electrodes, and 190 ± 33 % (day 0, p ≤ 0.001) and 234 ± 12 % (day 1, p ≤ 0.0001) for bipolar electrodes. Histopathology indicated smaller ablation zones than simulated (71 ± 41 %, p ≤ 0.047) and measured on CT (47 ± 16 %, p ≤ 0.005) with complete ablation of kidney parenchyma within the central zone and incomplete ablation in the periphery.


CONCLUSIONS
Both numerical simulations for planning renal IRE and CT measurements may overestimate the size of ablation compared to histology, and ablation effects may be incomplete in the periphery.
Interventional Radiology Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA, thomas.wimmer@medunigraz.at.
Thomas
T
Wimmer
Govindarajan
G
Srimathveeravalli
Narendra
N
Gutta
Paula C
PC
Ezell
Sebastien
S
Monette
Majid
M
Maybody
Joseph P
JP
Erinjery
Jeremy C
JC
Durack
Jonathan A
JA
Coleman
Stephen B
SB
Solomon
D000818:Animals; D018274:Electroporation; D007668:Kidney / Q000000981:diagnostic imaging*; D023421:Models, Animal; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed