Burst and continuous high frequency irreversible electroporation protocols evaluated in a 3D tumor model.

Burst and continuous high frequency irreversible electroporation protocols evaluated in a 3D tumor model. Phys Med Biol. 2018 Jul 06;63(13):135022 Authors: Sano MB, Fesmire CC, DeWitt MR, Xing L Abstract High frequency irreversible electroporation (H-FIRE) is an emerging cancer therapy which uses bursts of alternating polarity pulses to target and destroy the membranes of cells within a predictable volume. Typically, 2 µs pulses are rapidly repeated 24-50 times to create a 48-100 µs long energy burst. Bursts are repeated 100×  at 1 Hz, resulting in an integrated energized time of 0.01 s per treatment. A 3D in vitro tumor model was used to investigate H-FIRE parameters in search of optimal energy timing protocols. Monopolar IRE treatments (100  ×  100 µs positive polarity pulses) resulted in a lethal electric field threshold of 423 V cm-1. Baseline H-FIRE treatments (100  ×  100 µs bursts of 2 µs pulses) resulted in a lethal threshold of 818 V cm-1. Increasing the number of H-FIRE bursts from 100×  to 1000×  reduced the lethal threshold to 535 V cm-1. An alternative diffuse H-FIRE protocol, which delivers 4 µs pulse cycles (one positive and one negative 2 µs pulse) continuously at 100 Hz, resulted in the lowest H-FIRE lethal threshold of 476 V cm-1. Finite element simulations using 5 kV pulses predict an IRE ablation volume of 3.9 cm3 (1.7 cm diameter) and a maximum H-FIRE ablation volum...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research