Tumor Treating Fields (TTF)
Tumor treating fields (known as TTFields or TTF) are a type of cancer therapy that use low-energy electrical fields to disrupt cancer cells’ ability to grow and divide. TTFs may also be called alternating electric fields.
How are TTFs used to treat tumors?
TTFs are delivered through a special portable device with electrodes that are placed on your skin near the tumor. These electrodes are connected to a portable battery that you can carry in a backpack. The device sends mild electrical currents that target cancer cells while sparing most nearby healthy cells. The TTF device usually needs to be worn for at least 18 hours each day, but people can continue most of their daily activities while wearing it.
TTFs may be used alone or along with other treatments, such as chemo. TTFs tend to have few side effects (see below), so they may be used if other treatments have already been tried.
Two tumor treating fields devices are FDA-approved to treat cancer:
- Optune Gio is approved for new or recurrent glioblastoma (GBM)
- Optune Lua is approved for pleural mesothelioma that can’t be removed with surgery
Research studies are also looking at using TTFs for other types of cancers, such as pancreatic, non-small cell lung, ovarian, and breast cancer.
Do TTFs use radiation?
TTFs do use radiation, but it’s a different type of radiation than traditional radiation therapy. The electrical fields created in TTFs are a type of non-ionizing radiation. Other types of non-ionizing radiation include radio waves, microwaves, and visible and infrared light.
Non-ionizing radiation doesn’t have as much energy as ionizing radiation does. Traditional radiation therapy uses high-energy ionizing radiation to kill cancer cells. Ionizing radiation can damage healthy cells nearby, which can cause side effects.
What are the side effects of TTFs?
Since TTFs use low energy, non-ionizing radiation, side effects tend to be mild. The most common side effect is skin irritation in the area where the electrodes are worn.
Other side effects are also possible, depending on where the electrodes are placed on the body. For example, TTF devices worn on the scalp can cause:
- Headaches
- Sleep problems
- Mood changes
- Increased risk of seizures
Some people might not be good candidates for treatment with TTFs, because of other health issues they have. Talk to your doctor to learn more about whether this type of treatment might be right for you.
For more information on TTFs
Learn more about how TTFs are used to treat glioblastoma and mesothelioma.
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- References
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.
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Last Revised: July 25, 2024
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