What to Know About Optune

Wearable Device to Treat Brain Cancer by Using Electrical Stimulation

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Optune is a newer treatment approach for taking on glioblastoma (GBM), the most common form of brain cancer. Optune is a device that delivers low-intensity electrical fields to stop cancer spread. Worn on the head and indicated for adult patients, this device emits what are called tumor treating fields (TTF) directly to affected areas.

Optune is indicated as a treatment to prevent cancerous cells from recurring following chemotherapy or radiation therapy. Mounting evidence suggests that these devices are successful in significantly improving prognosis for those with GBM.

Doctor with cancer patient
Ridofranz / Getty Images


As noted above, the Optune device is indicated to treat glioblastoma. This brain cancer is aggressive, and it has been shown to develop either from adult neural stem cells or oligodendrocyte progenitor cells.

GBM symptoms arise once tumor growth has started impacting other parts of the brain and include headache, nausea, vomiting, and fatigue, with other symptoms arising based on the specific location of the cancer.

According to the Food and Drug Administration (FDA), Optune is indicated for adult patients who have:

  • Newly-diagnosed GBM: Alongside the chemotherapy drug, Temodar (temozolomide (TMZ)), the Optune device can be employed to take on cases of this cancer that have already been treated with radiation and/or chemotherapy as well as surgery.
  • Recurrent GBM: Cases of recurrent GBM that affect the supra-tentorial region of the brain, which is responsible for planning and control of bodily motion, may also be treated by Optune alone. That said, it’s recommended as an alternative treatment to chemotherapy or radiation treatment, especially if those therapies have not yielded acceptable results.

Before Using

Proper diagnosis of GBM is required prior to starting Optune treatment. Typically, there’s a progression of tests and evaluations, which includes a physical examination, imaging, and biopsy.

Physical Evaluation

The first step of diagnosis involves physical assessment as well as a review of medical history. This allows the healthcare provider to assess reported symptoms as well as the likelihood of cancer developing in the brain.


If GBM is suspected following initial consultation, the healthcare provider will call for imaging to be performed. Two types are most frequently performed—computer tomography (CT or CAT scan) and/or magnetic resonance imaging (MRI). These allow the medical team to get a sense of the location and size of any tumors and will help guide any surgery if that is deemed necessary.

In addition, two other tests may be performed during the course of treatment: magnetic resonance spectroscopy (MRS), which can reveal the chemical profile of any tumor, and positron emission tomography (PET), which can detect any recurrence of cancerous cells.  


If a tumor is detected using imaging, the healthcare provider will need to figure out which cells are being affected and how severe the case is. This requires biopsy, in which a specialized doctor called a neuropathologist carefully analyzes a small sample harvested from the tumor(s). Such analysis also can give your practitioner a sense of how fast GBM is spreading.

Optune therapy is not usually the first line of treatment for GBM. It’s usually indicated alongside or after other approaches, such as surgery, radiation therapy, or chemotherapy.

Precautions and Contraindications

As with any cancer therapy, using the Optune device may not be the best approach for everyone. As you’re being evaluated for treatment, you’ll need to let your healthcare provider know as much as possible about your medical history, and medications or any other supplements you’re taking. What factors might preclude treatment? Here’s a quick breakdown:

  • Use of other implanted medical devices: Since Optune relies on TTF to target cancerous cells, those who use other implanted electrical medical devices, such as pacemakers, deep brain stimulators, spinal cord stimulators, defibrillators, and programmable shunts, among others, will not be good candidates. 
  • Skull defects/Implants: The safety of Optune therapy has not been established for those who have skull defects. Those with missing bone that has not been replaced or those that have fragments from bullets or other projectiles may be advised against this treatment. Implanted screws or plates may also disrupt efficacy, so in some cases, other options will need to be explored.
  • Sensitivity to conductive hydrogels: Some people have an adverse reaction to the electrically conductive hydrogels required for this therapy. These are similar to those used for other procedures, such as electrocardiogram (ECG) monitoring. Mild reactions lead to redness and itching in the affected area, though more severe allergic reactions occasionally occur.
  • Age below 22: The safety of Optune therapy has not been established for those 21 and under.
  • Pregnancy: This therapy may also produce adverse side-effects in pregnant women and/or their fetuses, and its safety for this population has not been established. As such, your healthcare provider will advise you to take birth control during the course of treatment and recommend an alternative if a patient is expecting.
  • Skin rash: If you’re experiencing a skin condition, particularly on the head or scalp, be sure to let your healthcare provider know. Severe cases may call for alternative treatments.


Unlike pharmaceutical drugs, Optune treatment relies on TTF electrical signals for its therapeutic effect, and, as such side-effects and adverse reactions are rarer with this therapy.

The device goes on the head and consists of two main components: an electric field generator (the emitting device itself) as well as the transducer arrays that deliver the TTF to the brain. In addition, a power supply, battery charger, portable battery, battery rack, connection cable, as well as carrying case are provided.

Optune devices are carefully calibrated to emit electrical signals that disrupt the division of cancer cells while leaving healthy cells unharmed. This TTF will vary in strength between 100 and 300 kilohertz (kHz) depending on the specific type of cancer cells that are being targeted.

This electricity is consistently applied as the patient wears the device, barring any adverse reactions. Be sure to let your healthcare provider know if anything feels off.

How to Use and Store

You'll receive training on how to operate, care for, and wear Optune, so be sure to listen carefully and ask any questions you have. While Optune devices are user-friendly, proper administration relies on careful adherence to these instructions. The manufacturer’s guidelines for usage are as follows:

  • Daily wear: Wear the device at least 18 hours a day, every day.
  • Duration of treatment: Unless otherwise directed, therapy should be a minimum of four weeks. Don’t stop treatment on your own; keep it up until your healthcare provider indicates otherwise.
  • Implant considerations: If you have plates or screws in your skull following surgery, take extra care when putting on the device. Make sure the circular transducer arrays don’t go directly over these implants to prevent tissue damage.
  • Damaged equipment: Immediately stop treatment and let your healthcare provider know if any part of the device is worn down or damaged. This includes any frayed wires, loose sockets or connectors, and cracks in the case of the device.
  • Battery performance: If you plan on leaving your home for more than two hours, make sure to have an extra fully charged battery or a charger with you. Note, too, that batteries will eventually wear out, and this is seen when the device isn’t able to function as long on fully-charged batteries. If the low power indicator goes off within 1.5 hours, the battery should be replaced. Make sure you have extras on hand to prevent interruption of treatment.  
  • Transducer use: Keep in mind that each set of transducers is meant for single-use. Don’t use the same set more than once.
  • Charging: You can safely sleep with this device on; however, make sure you are plugging it into the wall, so the battery doesn’t run out.
  • The right equipment: Only use the batteries, chargers, or any other equipment provided in the Optune kit. Use of outside elements can damage the device.
  • Device safety: Don’t allow any part of the Optune device to get wet, especially the transducer arrays. This can affect its functioning or may even cause it to malfunction.
  • Consistent treatment: If you miss a day of treatment, or if you’ve worn it for less than 18 hours on a day, resume wearing the device as soon as possible. It’s recommended that you have on hand at least 12 extra transducer arrays at all times so as to prevent interruptions in treatment. Be proactive and order more in a timely fashion.
  • Servicing equipment: Should anything go wrong with the device, do not try to fix it yourself. Leave this work to appropriately trained and qualified personnel.
  • Safely connecting/disconnecting: As your healthcare provider will tell you, make sure the Optune device is set to “Off” when putting on or taking it off.   

Keep in mind that the above are FDA-approved recommendations from the manufacturer; your healthcare provider's instructions for use may vary slightly from these guidelines. Make sure you understand as much as possible about what the medical team wants to do. 

Side Effects


The good news about Optune, in contrast to most cancer therapies, is that adverse effects are rarer and rarely outright dangerous. That said, it’s your job to be mindful of how you’re feeling and to keep your healthcare provider in the loop. The side effects of this therapy include:

  • Allergic reaction: Some patients report rashes or skin discomfort due to the gel used for conduction of the device.
  • Overheating: Due to malfunction, cases have been reported where one or more transducers become very hot, leading to pain and/or burns on the skin.
  • Falls: Patients undergoing Optune therapy are at a higher risk for falls and loss of balance.
  • Fatigue: Constant tiredness has been reported as a common side-effect of this therapy.
  • Infection: In rare cases, infections have been reported at the site of contact with the skin. Telltale signs are a feeling of heat in the area, swelling, redness, or even pain.
  • Tingling sensations: Some patients have reported feeling warmth and tingling in the skin during treatment.
  • Muscle twitching: Because Optune devices rely on electrical fields—which are also the way messages are sent to muscles—twitching of muscle groups in the face has been reported.
  • Skin ulcer: Ulcers in the skin have also been reported at the site of contact.

These side effects of Optune therapy alone are largely manageable, though some cases may prompt discontinuation.


Keep in mind that when chemotherapy or other treatments are indicated alongside Optune—which represents a majority of cases—there will be a much wider set of side effects and potentially adverse reactions.

That said, studies have shown that Optune use will not accelerate or worsen the effects of chemotherapy or radiation treatment. Still, these effects can become serious and lead to medical emergencies.

Here’s a quick breakdown of adverse effects when Optune therapy is co-administered with Temodar (temozolomide) as chemotherapy:

  • Lowered red and white blood cell counts: Given that chemotherapy drugs have an immunosuppressive effect (meaning they act on the immune system), co-administration can lead to lowered blood cell counts. The healthcare provider will be monitoring this throughout treatment.
  • Nausea/vomiting: A common but occasionally very dangerous reaction to this therapy when co-administered with others is nausea and vomiting. If this is disruptive and severe, seek medical help.
  • Severe infection: Something that can occur on the skin or elsewhere as a result of either Optune or other cancer drugs, infections can become very serious and require medical attention.
  • Cognitive/sensory problems: Though relatively rare, some patients undergoing this combined therapy have noticed effects on thinking or sensation. These may be the sign of worsening problems and should be reported immediately.
  • Sudden changes in behavior: Another rare adverse response, the effects of therapy can lead to unexplained and sudden changes in behavior and mood. This, too, should be reported and might indicate a more serious underlying problem.
  • Breathing problems: Slowed respiration or difficulty breathing has also been reported with this therapy. This constitutes a medical emergency, so seek help as soon as you can.
  • Heart disorders: Though largely considered safe in terms of its effect on the heart, some patients have reported irregular heart beat or other cardiac issues.
  • Blood clotting issues: The immunosuppressive effects of this therapy can also lead to easier bruising, easier bleeding, and problems with blood clotting. This can be very problematic, so be sure to report this to your healthcare provider and seek out emergency care as necessary.

Regardless of the specific treatment regimen you’re going through, be mindful of how you’re feeling, and don’t hesitate to seek medical help if you have an emergency.

Warnings and Interactions

As you’re undergoing this treatment be mindful of its effects on your body. Optune therapy will not interact with foods or drugs you’re taking, though drugs it’s co-administered with, like Temodar, very well may. Here’s what you should look out for:

  • Skin irritation: As mentioned above, skin irritation and allergic reaction commonly occur during the course of treatment. Let your healthcare provider know if there’s redness, rash, itching, or other discomfort in areas where the transducer contacts skin. You’ll be prescribed a specialized steroid topical cream to take care of the issue, and if it doesn’t work, other avenues may need to be explored.
  • Infection: Though rare, cases of infection in the skin can occur during treatment, especially if irritation isn’t dealt with appropriately. In these cases, your healthcare provider will prescribe an antibiotic cream to place onto the transducers, or, in extreme cases, may ask you to pause treatment.
  • Electrical shock: When properly applied, there’s no risk of electrical shock wearing this device. That said, if it’s malfunctioning or incorrectly worn, this can occur. If you feel anything like electrical shock during treatment, let your healthcare provider know immediately and discontinue use until the issue is resolved.
  • Ending treatment: Unless the healthcare provider instructs it, don’t stop treatment on your own. Doing so might significantly reduce efficacy.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. University of Washington Health. Optune device helps increase brain cancer patients' survival rates. 2019. 

  2. Kinzel A, Ambrogi M, Varshaver M, Kirson E. Tumor treating fields for glioblastoma treatment: patient satisfaction and compliance with the second-generation Optune® systemClin Med Insights Oncol. 2019;13:117955491882544.

  3. US Food and Drug Administration. Summary of safety and effectiveness data: Optune. 2015. 

  4. American Association of Neurological Surgeons. Glioblastoma multiforme.

  5. US Food and Drug Administration, Novocure. Instructions for use: Optune. 2015. 

Additional Reading

By Mark Gurarie
Mark Gurarie is a freelance writer, editor, and adjunct lecturer of writing composition at George Washington University.