Tumor treating fields (TTFs) using uninsulated electrodes induce cell death in human non-small cell lung carcinoma (NSCLC) cells

Tumor Treating Fields (TTFs) is a new tumor electric therapy that has success with many tumor types. This modality is very low-intensity alternating current (AC) fields (1–3 V/cm) and intermediate frequency (100–300 kHz). The delivery of TTFs was applied only through completely insulated electrodes by using external high voltage to avoid any reactions that may occur through using conductive electrodes, specially the generation of oxidative reactions. In order to achieve the required effect, the patient can be exposed to the technique for continuous three days, which may lead to long-term side effects. The adoption of the idea that TTFs should be applied through insulated electrodes did not give the chance to evaluate the uninsulated electrodes to conduct TTFs. This study aims to evaluate the possibility of using uninsulated electrodes, find the optimum exposure time, and determine the accompanying oxidative stress on human non-small cell lung carcinoma (NSCLC) cells. Here we found that applying TTFs through uninsulated electrodes produced 18–29% tumor growth inhibition for exposure time of 2.5 min to 40 min without significant oxidative stress. These findings will lead to the possibility of using the uninsulated electrodes TTFs in simple technology. The treatment quality will be improved by highly decreasing the exposure time.