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Tumor Treating Fields (TTFields) and Mesothelioma

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Tumor Treating Fields, also known as TTFields, is a new cancer therapy approved by the U.S. Food and Drug Administration to treat pleural mesothelioma. It works in combination with chemotherapy to limit cancer growth and improve survival.

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How Is Tumor Treating Fields Used to Treat Mesothelioma?

Tumor Treating Fields is a new type of anti-cancer therapy that uses alternating electrical fields to limit cancer growth. It is combined with chemotherapy to control the growth of pleural mesothelioma.

In May 2019, TTFields became the second pleural mesothelioma treatment to be approved by the U.S. Food and Drug Administration.

The first mesothelioma treatment approved by the FDA was a chemotherapy regimen combining Alimta (pemetrexed) with cisplatin or carboplatin, which was approved in 2004. TTFields is administered in combination with this chemotherapy regimen.

A company called Novocure invented the noninvasive technology and has been developing Tumor Treating Fields since 2000. TTFields received its first approval from the FDA in 2011 to treat a type of brain cancer called glioblastoma.

The clinical trial that led the FDA to approve TTFields for pleural mesothelioma reported an overall survival of 18.2 months.

Patients in the trial who received only chemotherapy lived 12.1 months. The addition of TTFields helped patients live an average of six months longer.

TTFields doesn’t offer a cure for mesothelioma, but it can significantly improve survival with a low risk of side effects.

“Tumor Treating Fields is a novel therapy different from chemotherapy or radiation therapy. Basically, low-voltage electrical fields are safely applied through the skin to disrupt the microelectrical currents inside cells required for their division. It ‘jams up’ those fields inside tumor cells, not allowing them to divide, multiply or grow.”

Jacques Fontaine, Moffitt Cancer Center
Dr. Jacques Fontaine
Thoracic Surgeon for Mesothelioma

How Does TTFields Work?

Tumor Treating Fields applies alternating electrical fields of an intermediate frequency that are low in intensity.

The electrical fields are delivered through insulated pads that adhere to skin. The electrical field frequency is 100 to 300 kilohertz, and the intensity is delivered at 1 to 3 volts per centimeter.

Research shows that applying this range of alternating frequencies to cancer cells has the power to disrupt certain proteins that are essential to cell division.

When the electrical fields enter a cancer cell, they prevent these proteins from functioning properly. This stops cancer cells from multiplying, which limits tumor growth and may kill some cancer cells.

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How Is TTFields Administered?

Novocure’s TTFields delivery system for mesothelioma, branded under the name Optune Lua (previously known as the NovoTTF-100L System), is a portable device that can be used anywhere.

The system comes with a TTFields-generating device, battery charger and rechargeable batteries, power supply, insulated pads and a carrying bag.

The components of Novocure's NovoTTF-100L Tumor Treating Fields System.
The components of Novocure's NovoTTF-100L Tumor Treating Fields System. Credit: ©2019 Novocure.

The treatment is designed for continual use at home or on-the-go. The carrying bag can be worn as a backpack or held in your hand.

The therapy is applied with four pads attached to the front and back of a patient’s chest. The pads are changed every two to three days, and the area must be shaved. It involves no skin incisions or insertion of any medical devices into the body.

Patients are advised to wear NovoTTF-100L for 18 to 20 hours a day until their cancer progresses.

Patients can carry on with their lives while receiving treatment. They can run errands, take walks and do house chores while the therapy is administered.

However, keeping the device charged may present some logistical challenges for active people. NovoTTF-100L is plugged into a power supply or uses a large rechargeable battery pack that must be carried to power the device.

Every three weeks, patients will receive chemotherapy with Alimta and cisplatin or carboplatin for six cycles. Research shows that using NovoTTF-100L does not increase the toxicity of chemotherapy.

NovoTTF-100L is only prescribed with chemotherapy. That means patients must take chemotherapy to use the device.

Side Effects of TTFields for Mesothelioma

The most common side effects of TTFields plus chemotherapy in pleural mesothelioma patients include:

  • Device skin reaction

  • Itchy skin

  • Constipation

  • Nausea

  • Fatigue

  • Cough

  • Chest pain

  • Anemia

Mesothelioma patient using the NovoTTF-100L System.
Mesothelioma patient using the NovoTTF-100L System. Credit: ©2019 Novocure.

Less common side effects include:

  • Treatment-related skin toxicity

  • Allergic reaction to transducing patches

  • Pain or skin burns from patches that overheat

  • Skin infections

  • Skin breakdown or skin ulcers

  • Tingling sensation beneath the patches

  • Muscle twitching

Skin irritation is reported in nearly half of patients who receive the therapy, but only 4% of patients report a severe level of irritation.

Contraindications, Warnings and Precautions

Do not use TTFields if:

  • You have an active implanted medical device such as a pacemaker

  • You have a sensitivity to conductive hydrogels (severe allergic reactions are possible)

  • You are pregnant or trying to get pregnant

The NovoTTF-100L System can only be prescribed by a mesothelioma doctor that has completed required certification training.

Patients with an underlying serious skin condition on the chest may not be able to receive Novocure’s mesothelioma treatment.

Research on Mesothelioma and TTFields

The clinical trial that led the FDA to approve NovoTTF-100L for pleural mesothelioma reported the following:

  • Patients lived an average of six months longer with the addition of NovoTTF-100L (18.2 months) compared to those only receiving chemotherapy (12.1 months).

  • More than 97% of patients responded to the therapy with tumor shrinkage or no new tumor growth.

  • Patients with epithelial mesothelioma, which responds best to treatment, lived 21.2 months.

  • Participants using NovoTTF-100L had no new cancer growth for an average of 7.6 months. Those only receiving chemotherapy had no new cancer growth for 5.7 months.

Availability of TTFields for Mesothelioma

In October 2019, a patient at West Cancer Center in Memphis, Tennessee, became the first pleural mesothelioma patient outside of a clinical trial to use NovoTTF-100L since it was approved by the FDA.

Since February 2020, over 40 cancer centers across the U.S. have become certified to prescribe TTFields to patients with pleural mesothelioma. Many more centers are also seeking approval to offer the device.

“We are always looking for treatments to improve the survival, quality of life and options for patients,” said thoracic surgeon Dr. Taylor Ripley, director of the Mesothelioma Treatment Center at Baylor College of Medicine. “This provides another therapeutic option that may be valuable.”

Find a Top Mesothelioma Cancer Center
Treatment Centers Certified for Tumor Treating Fields
Treatment Center Doctors

Allegheny General Hospital

Dr. Zachary Horne

Dr. Tom Colonias

Baylor College of Medicine

Dr. Pavan Jhaveri

Beaumont Hospital

Dr. Craig Stevens

Dr. Zachary Seymour

Cleveland Clinic

Dr. Gregory Videtic

Frye Regional Medical Center

Dr. John O. DelCharco

Loyola University Medical Center

Dr. Tamer Abdelrhman

Dr. Raymond Wynn

Miami Cancer Institute

Dr. Rupesh Kotecha

Ochsner Medical Center

Dr. Rockne Hymel

Dr. Clayton Smith

Oregon Health and Science University

Dr. John Holland

Dr. Josh Walker

Sylvester Comprehensive Cancer Center

Dr. Alan Dal Pra

Dr. Derek Isrow

West Cancer Clinic

Dr. Matthew Ballo

Dr. Cilla Edmonston

Dr. Wes Garner

Dr. Yuefeng Wang

Novocure’s other TTFields device, called Optune, is specially designed to treat glioblastoma. It cannot be used to treat mesothelioma.

If you are interested in TTFields, ask your doctor if they are certified to prescribe the NovoTTF-100L System, and ask if you qualify for the therapy. The FDA has approved it only for pleural mesothelioma patients with inoperable tumors.

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Registered Nurse and Patient Advocate

Karen Selby joined in 2009. She is a registered nurse with a background in oncology and thoracic surgery and was the regional director of a tissue bank before becoming a Patient Advocate at The Mesothelioma Center. Karen has assisted surgeons with thoracic surgeries such as lung resections, lung transplants, pneumonectomies, pleurectomies and wedge resections. She is also a member of the Academy of Oncology Nurse & Patient Navigators.

Walter Pacheco, Managing Editor at
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5 Cited Article Sources

The sources on all content featured in The Mesothelioma Center at include medical and scientific studies, peer-reviewed studies and other research documents from reputable organizations.

  1. BioSpace. (2019, October 16). Results from STELLAR Trial of Tumor Treating Fields with Chemotherapy in Malignant Pleural Mesothelioma Published in The Lancet Oncology.
    Retrieved from:
  2. Novocure. (2019, May 23). FDA Approves the NovoTTF-100L™ System in Combination with Chemotherapy for the Treatment of Malignant Pleural Mesothelioma.
    Retrieved from:
  3. Novocure. (2019, January). Optune: Instructions for Use.
    Retrieved from:
  4. Novocure. (2019). Our Therapy.
    Retrieved from:
  5. Mun, E.J. et al. (2017). Tumor-Treating Fields: A Fourth Modality in Cancer Treatment. Retrieved from:

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Last Modified August 21, 2020

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