Tumor treating fields: living with the device you wear

A device worn on a shaved head for at least eighteen hours a day, used for glioblastoma. What wearing it is like, and what it does to your scalp. How other people react, and what it asks of the person helping you. Why doctors do not all agree about it.

The short version

This is a treatment you wear on your head, for glioblastomaglioblastoma: A glioma that is given grade 4. Grade 4 is the highest grade there is. The tumor grows fast. Treatment usually starts soon after it is found. It often means surgery, and then radiation and chemotherapy. See the glossary. Sticky pads on your shaved scalp are wired to a small machine in a bag, which sends weak electric fields through them. It is called tumor treating fields. It is only expected to work while it is switched on, which is why you wear it at least eighteen hours a day. Doctors do not all agree about how much it adds. So the choice is about two things at once: what it might do, and what living with it asks of you.

What is it?

It is a treatment that uses weak electric fields to get in the way of tumor cells as they divide.

Four sets of sticky pads go on your scalp once your head has been shaved. Wires run from the pads to a small machine that runs on batteries.

The fields are thought to affect tumor cells more than healthy brain cells. It is not the kind of radiation used in radiation therapy. The American Cancer Society puts it in the same family as radio waves.

The device you will hear named is Optune Gio, often just called Optune.

Why would I be offered it?

It is approved for some people with glioblastoma, and it is used at two different points. What it has been shown to do is different at each one.

• After surgery and radiation, alongside chemotherapy. Here it is added to temozolomidetemozolomide: A chemotherapy taken as a capsule, used for some brain tumors. Your team checks your blood counts while you are on it. See the glossary, not used instead of it. The American Cancer Society says it may help people live longer than temozolomide on its own.
• If glioblastoma comes back. Here it can be used instead of chemotherapy. The American Cancer Society says that at this point it has not been shown to help people live longer than chemotherapy, but its side effects tend to be much milder.

Those are two different claims, so check which one applies to you. Glioblastoma covers who the device suits and when it usually starts.

Do doctors agree about it?

No, and it is fair to know that before you decide.

The European guideline calls its role controversial and says it is not widely available there. In the United States, the main cancer guidelines list it as a standard option for newly diagnosed glioblastoma.

Here is what the doubts are about. Reviewers in England and Canada raised concerns about the main trial. It was an open trial, so people knew whether they had the device. The people in it were a chosen group, which makes it less clear how well the results fit everyone else. The European guideline also questions whether it is practical, and whether it is worth what it costs. It is very expensive, and in the United Kingdom it is only available privately or in trials.

In one study in Chicago, all the doctors asked called it a good option, and some said it may not suit every patient. Ask your own team where they stand on it for you, and what makes them think so.

What happens, step by step

1. You talk it through with your team. They check whether it suits you.
2. You, and anyone helping you, are taught how to use it. That means putting the pads on, taking them off, swapping batteries, and what to do when the machine beeps.
3. Your head is shaved close. Hair stops the pads from sticking, so all of it has to come off.
4. The pads go on in planned places. Where each one sits is worked out for your tumor.
5. You switch it on and take it home. From then on, you wear it at home and when you go out.
6. Every few days the pads come off. Your scalp is washed and checked, shaved again, and a new set goes on.

How long does it take?

At least eighteen hours a day, every day, for as long as you and your team keep going with it.

• The hours are the treatment. Unlike a pill, it is only expected to act while it is on. The trial that found a benefit asked people to wear it at least eighteen hours a day. How much it helps is thought to depend on the hours.
• The pads are changed about twice a week.
• A change takes a while. In one small study in Germany, a change took about half an hour for a typical person, and much longer for some.
• Getting used to it takes time. In that study it often took about two weeks, and for some people it took a few months. Life felt hardest in the first month, and for most it had settled by the end of the second.
• How many months it goes on is decided with your doctor. Ask what would make them suggest stopping.

What does it feel like?

Mostly like having something on your head, and a bag to carry.

The pads can feel warm. Some people feel warmth or tingling under them. The machine checks how warm the pads get, and switches itself off with an alarm if they get too warm. If you wear a hat, choose one that lets air through, so your head does not get too hot.

It beeps. Alarms go off when something needs attention, at night as well as in the day. In the German study, most people said the alarms bothered them a fair amount or a lot.

The cap and the bag have their own downsides. In the Chicago study, people named the heat on their head, the discomfort of the cap, and carrying the bag as real downsides. They also said sleeping and showering were harder. Tell your team which of these is hardest for you, because several can be made easier.

Carrying it, sleeping, and washing

It comes with you when you go out, so the ordinary parts of the day need a plan.

Carrying it. The machine rides in a shoulder bag or a backpack. Each battery lasts a few hours, so you carry spares and swap them. When you are sitting still, you can plug it into the wall instead. One person in the German study got back pain from carrying it on one shoulder, so ask whether a backpack would suit you.

Sleeping. You wear it while you sleep, too. If you are not sleeping well, tell your team rather than putting up with it.

Washing. Pads that get wet or start to lift need changing sooner, so a shower takes planning. On the day you change them, the shower helps: wetting the old pads first lets them come off more gently.

Work, hobbies, and closeness. In the German study, most people said it got in the way of work or hobbies, of washing and looking after themselves, and of sex and closeness with a partner. Most said they would choose it again. These are known problems, and you can raise any of them with your team.

The shaved head, and other people

Your head stays shaved for as long as you wear it, and the pads and wires can be seen.

For some people that is the hardest part. In the Chicago study, shaving their head was the reason people who said no gave most often. Some did not want to look sick. One person had not told people at work what was going on, and the device would have told them.

For others it matters less. In the Chicago study, one person said shaving was easy, because most of their hair had already gone. Another went back to work the day after being fitted, and said it was awkward at first but started some good conversations.

In the German study, about half said the shaved head bothered them little or not at all, and most said the same about how the pads looked.

Both reactions are ordinary. One person in the Chicago study said others might think it silly to mind about hair with cancer, and that it had still been really hard. If the look of it is what is holding you back, say that to your team plainly. It is a real reason, and it belongs in the conversation.

You decide what to share. It can help to have a short answer ready for strangers, and to decide ahead of time who you want to tell more.

Your scalp, and other side effects

Skin trouble under the pads is the most common side effect, and many people get some. It can be:

• redness and soreness,
• itching,
• a sweaty scalp that stops the pads sticking well,
• dry, flaky skin,
• and, less often, broken skin, open sores or an infection.

What helps:

• Shave with a clean electric razor, to avoid nicks.
• Wash your scalp with a mild shampoo that has no perfume in it.
• Move the pads a little at each change, in the way your team shows you.
• Keep the pads off scars, and off any screws under the skin.
• Ask your team before you put anything on your scalp. If they say yes, water-based lotions are better than greasy ones, which get in the way of the pads.

Tell your team about skin changes as soon as you notice them, not at your next visit. A sore scalp is one of the main reasons people lose hours, and early care can help you keep wearing it.

Other side effects. Headaches, trouble sleeping, mood changes and muscle twitching. It can also slightly raise the chance of a seizure. Read What to do when someone has a seizure now, and share it with anyone who spends time with you.

If you are also taking temozolomide, some of what you feel may be that drug. In the main trial, adding the device made little or no difference to serious side effects. An upset stomach, tiredness and changes in your blood counts are known effects of that drug. Chemotherapy covers those. If something new starts, ask your team which one it is likely to be.

What you need first

• A talk about any metal or implants from surgery. Your team plans where the pads go around them.
• Someone to help change the pads. If there is nobody, ask about a visiting nurse before you start.
• Answers about cost. Ask who pays for it and what you will owe, before you start rather than after.
• A number for the machine. Ask who you call when it keeps alarming, or a pad comes loose at night. That may not be the same number as your care team. For anything about your health, call your care team.

For the person alongside them

If you are the one driving to the appointments, keeping track of the pills, and lying awake at night worrying about them, this part is for you.

You are allowed to ask questions. In one study, families said they were afraid of annoying the doctor by asking too much. One of them was told by a doctor to stop playing doctor. Ask anyway. Write your questions down before you go, and bring a notepad. Two people in the room hear more than one.

Ask who your first call is. Care comes from a lot of people at once, and it is easy to end up as the only one holding it together. Ask the team: who do I call first? Some teams have one person whose job this is, often a nurse. Get the name and the number.

Get two numbers, and know which one to use. One for work hours, one for nights and weekends. Then ask what counts as "call us today" and what counts as "call an ambulance" for this tumor, and write the answer down where you can see it. If you are not sure which it is, call. Nobody on that team will mind.

If they have seizures, read about them before you need to. What to do when someone has a seizure is the one to know by heart. Living with seizures is about the rest of the time: what is safe, what to change, and driving.

Ask to be shown anything you are sent home to do. In that same study, families were sent home to change dressings and give medicines with no training at all. That is not fair to you. Before you leave the hospital, ask someone to show you. Then do it once while they watch.

Say what you notice. You may see a change before they do. Changes in thinking, mood and behavior can show up to the people close by first. Telling the team is not going behind their back. It is something the team cannot learn any other way.

Look after yourself, and let people help. Eat, sleep, and keep your own appointments. Take a little of the day back for yourself. When someone asks what they can do, give them a real job: a meal, a ride, an hour with the kids. Most people want to help and do not know how to offer.

You can talk to somebody about all of this today. See where to get help.

This treatment happens at home, every day, and a lot of it can land on you.

You may be the one changing the pads. It is a real job, and it does not stop. If you cannot do every change, say so to the team.

You can see the parts of the scalp the person you care for cannot. Look at the skin each time the pads come off. Redness, broken skin, pus, or a sore that is not healing are worth telling the team about early.

If the hours are slipping, talk about it together, and then with the team. Tell the team what is getting in the way, rather than letting it slide.

Night alarms can wake the whole house. Decide together who gets up, so it is not always the same person.

If the tumor grows while you are wearing it

Growth is not the only reason a scan can look worse. Treatment can change how a scan looks for a while. Follow-up scans, and what the results mean covers how teams tell the difference.

If it is growth, going on with the device is not automatic. The European guideline advises against staying on it once the tumor has clearly grown while you are wearing it, because no benefit from doing that has been shown. Ask your team what they suggest next, and whether a trial fits. Clinical trials: is this for me? goes through that question.

Who decides whether to keep going?

You do, with your team.

Your team says what they suggest, and why. You decide whether the hours, the shaved head and the pads are a trade you want to make. People weigh that differently, and you can raise it again later.

Your scans are how your team keeps watch on the tumor. Ask how and when you will be told each result.

What to ask your team

• Is this right for me, and why do you think so?
• Would it be added to my other treatment, or used instead of it?
• What do you make of the European guideline calling it controversial?
• Who will teach us to change the pads, and who helps if I have nobody?
• Who do I call when the machine alarms at night?
• What should I do about a sore scalp, and what is safe to put on it?
• Do I have any screws or implants that change where the pads go?
• What will it cost me, and who pays for it?
• What happens if I cannot manage the hours?
• How will we decide whether to keep going?

Where to go next

• Glioblastoma for who the device suits and when it usually starts.
• High-grade glioma for where it sits among the other treatments.
• Chemotherapy: the drugs, your blood counts, and the fever rule for temozolomide, if you take it alongside the device.
• Radiation therapy for the treatment that comes before it.
• Follow-up scans, and what the results mean for what a changed scan does and does not settle.
• What to do when someone has a seizure for the seizure risk.
• Get help now if you need to talk to a person today.