Tumour Treating Fields (TTF) or Optune® for brain tumours

What does using tumour treating fields involve?

Using TTF, or TT Fields, involves a set of adhesive patches or bandages that hold insulated ceramic discs, called ‘transducer arrays’, onto your shaved head, forming what looks like a skull cap. The arrays are attached by wires to a portable battery-powered device that is carried in a shoulder bag or backpack.

The battery-powered device, also known as Optune and which can alternatively be attached to a static power supply, creates alternating electrical fields. These are called Tumour Treating Fields or TTF.

These fields are low intensity and disrupt the cell division process in rapidly dividing cells, such as tumour cells. The TTF are applied at a frequency which specifically targets glioblastoma cells. Normal adult brain cells divide slowly, if at all, so are thought not to be affected by TTF.

To get the best response to treatment, Optune has to be worn continuously, and for at least 18 hours per day. This is because, unlike a drug, the effects of TTF on glioblastoma cells are only expected to occur when treatment is active. The total length of treatment will be determined by the doctor.

The arrays have to be changed, and the scalp re-shaved, one to two times per week, to make sure a good contact is maintained with the skull.

Can I use tumour treating fields?

Optune is only available privately or through clinical trials in the UK.  Speak to your medical team if you are interested in accessing Optune. You will need to be referred for an outpatient consultation to discuss the suitability.

Optune is designed for use with adults aged 18 years or older with:

Newly diagnosed glioblastoma

• alongside the chemotherapy drug, temozolomide
• after surgery and radiotherapy have been given

or recurrent glioblastoma.

Unfortunately, TTF is quite expensive at this point. However, some private healthcare insurance providers might cover this cost.

Imperial Private Healthcare offers an Optune clinic and a support group, where they can help patients to reduce and manage side-effects from treatment, while also giving patients the opportunity to share tips on using the device. This support group is open to all brain tumour Optune® users with a brain tumour in the UK.

How has tumour treating fields performed in clinical trials?

There have been some clinical trials of Optune in newly diagnosed and recurrent glioblastoma. The results show prolonged survival in newly diagnosed patients with glioblastoma treated alongside temozolomide (TMZ). These patients have a 5-year survival rate of 13% compared to control patients, not using Optune, who have a rate of 5%.

The average (median) overall survival, from the start of treatment, was 20.9 months in patients treated with Optune plus TMZ, compared to 16 months in patients treated with TMZ only.

Is TTF treatment approved?

The Optune device is FDA (Food & Drug Administration) approved in the USA; and CE marked in the European Union. This means it has proved itself to be “safe and effective” in the US, and fits the essential requirements for health and safety in the EU.

Novocure, the company that produces Optune, is hoping, in the future, to get the treatment through a review by NICE (National Institute for Health and Care Excellence) in the UK. NICE provides guidance and sets quality standards for health, public health and social care.

What are the side-effects of tumour treating fields?

The most common side-effects of using Optune are mild to moderate skin irritation on the scalp and headaches. When used with chemotherapy, TT Fields can cause low blood platelet count, nausea, constipation, vomiting, tiredness, seizure, and depression. Other side-effects that may be due to using the device include muscle-twitching, skin ulcers and malaise (general feeling of being unwell).

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