Irreversible electroporation in eradication of rabbit VX2 liver tumor.

PURPOSE: To show the effectiveness and safety of irreversible electroporation (IRE) in treating large tumor models.
MATERIALS AND METHODS: VX2 liver tumor implantation was performed in 35 New Zealand White Rabbits. The rabbits were divided into three groups 1 week after implantation. The control group included 15 rabbits; the remaining 20 rabbits were divided into two IRE treatment groups. For the treatment groups, 10 rabbits underwent ablation with a single IRE application (IRE-S group), and 10 rabbits underwent ablation with multiple IRE applications (IRE-M group). Treatments and outcomes were analyzed using ultrasound, contrast-enhanced computed tomography (CT), and immunohistologic staining (hematoxylin and eosin [H&E], P-53, Ki-67, CD30, and vascular endothelial growth factor receptor [VEGFR] staining, and terminal deoxynucleotidyl-transferase-mediated 2'-deoxyuridine 5'-triphosphate [dUTP]-biotin nick-end labeling [TUNEL] assay).
RESULTS: Multiple IRE ablations consistently produced complete cell death in all the animals in the IRE-M group (n = 10, IRE ablation time 2.45 minutes ± 0.3). The results were validated with ultrasound, CT, H&E, Ki-67, P53, and TUNEL assay. A high level of CD30-positive cells were identified in the IRE groups. A sharply demarcated ablation zone with no damage to surrounding vital structures was observed in all IRE-treated tissues. No complications during or after ablation were observed in any of the animals.
CONCLUSIONS: The effects of IRE were shown in a large tumor model with single and multiple IRE ablations (IRE-S and IRE-M treatment groups); complete ablation of the tumor was seen in the IRE-M group. These findings successfully show the beneficial effects and safety of IRE in the treatment of tumors and validate its potential as a clinically translatable treatment.