Tumor treating fields (TTFields) is a noninvasive, regional antimitotic 
treatment modality that has been approved for the treatment of recurrent 
glioblastoma by the U.S. FDA and has a CE mark in Europe. TTFields therapy 
delivers low-intensity (1-3 V/cm), intermediate-frequency (100-300 kHz), 
alternating electric fields to the tumor using transducer arrays placed on the 
skin around the region of the body containing the tumor. TTFields therapy 
affects metaphase, by disrupting mitotic spindle formation, and anaphase, by 
dielectrophoretic dislocation of intracellular constituents, resulting in 
apoptosis. TTFields therapy is frequency tuned to specific cancer cell types. 
The antimitotic effect of TTFields therapy has been demonstrated in multiple 
cell lines when the appropriate frequency was utilized. A phase III trial of 
TTFields monotherapy compared to active chemotherapy in recurrent glioblastoma 
patients established that TTFields therapy is associated with minimal toxicity, 
better quality of life, and comparable efficacy to chemotherapy. Ongoing and 
future trials will evaluate TTFields in newly diagnosed glioblastoma, solid 
tumor brain metastases, nonsmall cell lung cancer, and ovarian and pancreatic 
cancers.