Tumor-treating Fields (TTFields) are low intensity, intermediate frequency, alternating electric fields delivered through noninvasive transducer arrays placed locoregionally around the anatomic region of the tumor. TTFields selectively disrupt cell division, and preclinical research has demonstrated the antimitotic effects of TTFields in different tumor types. TTFields’ effects on dividing cells result from the multitude of charged macromolecules and organelles responsible for key processes in the mitotic process. Structural change or dislocation of those cellular components may alter their physiologic function, and ultimately disrupt normal mitosis. The effects of TTFields on various cellular processes can be explained by two fundamental physical principles: dipole alignment and dielectrophoresis. TTFields are nonuniformly distributed within the treated region based on multiple parameters, which include the geometry of the treated organ, the distance between transducer arrays applied to the patient’s skin, and the tissue’s dielectric properties. The fields do not attenuate in correlation to the distance from the array, and may therefore be used for the treatment of deeply located tumors. As electric fields do not have a half-life time, TTFields are continuously delivered during the course of treatment.
TTFields are delivered via noninvasive transducer arrays attached to the skin of patients. The field-generator may be connected to a portable battery and is intended for continuous use. No high-grade systemic toxicity has been related to TTFields, as anticipated by the mechanism of action and the regional nature of the application. The most common adverse event related to TTFields is mild-to-moderate dermatitis (of either contact or allergic etiology) at the site of the transducer array placement.