Single-needle electroporation and interstitial electrochemotherapy: in vivo safety and efficacy evaluation of a new system.

ABSTRACT

OBJECTIVES: We conducted an in vivo trial to investigate the safety and efficacy of a newly developed system for the application of a combined therapy consisting of irreversible electroporation (IRE) and electrochemotherapy (IRECT) in the liver. The system is conceived as a single-needle multitined applicator with expandable electrodes that allow interstitial injection of fluids, e.g., chemotherapy. METHODS: Experiments were conducted in ten domestic pigs. The applicator was placed in different liver lobes under CT guidance. In one lobe, the applicator was used for conventional IRE (1500 V, 120 pulses, pulse length 100 µs). In the other lobe, the same procedure was performed preceded by the injection of a doxorubicin mixture through the expandable electrodes (IRECT). Contrast-enhanced CT and MRI were performed on days 1, 3, and 7 after the procedure. Accordingly, three animals were sacrificed on days 1, 3, and 7 after the imaging and ablation volumes were evaluated histopathologically. Related t test was used to compare the groups. RESULTS: Technical success was achieved in 9/10 experiments. One animal deceased during the intervention because of ventricular fibrillation. Follow-up CT 1 and 3 days after intervention showed a significant (p < 0.05) difference in the ablation volumes of IRECT vs IRE, respectively, of 4.47 ± 1.78 ml vs 2.51 ± 0.93 ml and of 3.39 ± 1.05 vs 1.53 ± 0.78 ml. CONCLUSIONS: IRECT using the newly developed system proved to be effective and provided significantly larger ablation volumes compared with IRE alone. However, ECG triggering is a necessary prerequisite to allow a safe application of the system. KEY POINTS • Working on the geometry of the IRE applicator in terms of expandable electrodes may overcome the current limitations of IRE resulting from the placement of multiple electrodes. • Efficacy of IRE ablations can be enhanced by the interstitial application of chemotherapy in the periphery of ablation areas.