What is radiotherapy?

Radiotherapy uses high-energy rays, such as x-rays, to treat cancer. It destroys cancer cells in the area where it is given.

Some normal cells in the area can also be damaged by radiotherapy. This can cause side effects. These normal cells can usually repair themselves, but cancer cells cannot. As the normal cells recover, the side effects usually get better.

Radiotherapy is always carefully planned by a team of experts and is continuing to become even more accurate. This means it can be used to treat the cancer more effectively, while doing as little harm as possible to normal cells.

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Some people may have chemotherapy at the same time as radiotherapy. This is called chemoradiation or chemoradiotherapy. Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. The chemotherapy drugs can make cancer cells more sensitive to radiotherapy. This can help the radiotherapy work better. This is only helpful for certain types of cancer, so it is not suitable for everyone.

Having chemotherapy and radiotherapy together can make the side effects of treatment worse. Your doctor, radiographer or specialist nurse can give you more information about chemoradiation and the possible side effects.

Why am I having radiotherapy?

You may have radiotherapy for different reasons:

  • Radiotherapy to destroy a tumour and cure the cancer (sometimes called radical treatment)

    You may have radiotherapy on its own, or you may have it combined with chemotherapy (chemoradiation). For some types of cancer, you have radiotherapy after surgery (adjuvant radiotherapy), to lower the risk of it coming back. Some people may have radiotherapy before surgery (neo-adjuvant radiotherapy) to shrink the cancer and make it easier to remove.

  • Radiotherapy to treat symptoms (palliative radiotherapy)

    This is when radiotherapy is given to shrink the cancer and help with symptoms such as pain or coughing. Doctors may suggest this treatment to help control the cancer for longer when it is not possible to cure it.

How will I have radiotherapy?

You usually have radiotherapy in a hospital that has a major cancer treatment centre. This means you may have some treatment at your local hospital, such as surgery or chemotherapy. But you may have radiotherapy at a different hospital.

There are two ways of having radiotherapy:

  • External beam radiotherapy is given from outside the body (externally) by a radiotherapy machine.
  • Internal radiotherapy is when a radioactive material is placed inside the body. It is sometimes called brachytherapy or radioisotope therapy.

How you have radiotherapy will depend on the type of cancer you have and where it is in the body. Some cancers are treated with both external and internal radiotherapy.

Even if you know someone with the same type of cancer as you, their radiotherapy treatment may be different.

You usually have external beam radiotherapy as an outpatient. If you are unwell, or are having chemotherapy at the same time, you may need to stay in hospital. In this case, you will go to the radiotherapy department each day from the ward.

If you are having some types of internal radiotherapy, you may have to stay in hospital for a few days.

Radiotherapy masks

For most types of radiotherapy to your brain, head or neck area, you wear a mask during each treatment. The mask helps keep you in position so your treatment is as accurate and effective as possible.

Before you have radiotherapy

Before you start your treatment, it needs to be planned carefully by your radiotherapy team. This is to make sure the radiotherapy is aimed precisely at the cancer, causing as little damage as possible to surrounding tissue.

Your team will explain what the treatment involves and will ask you to sign a consent form. This gives your team permission to give you treatment.

There are some things you should consider before having radiotherapy:

  • Avoiding pregnancy or making someone pregnant

    It is important that you do not get pregnant or make someone pregnant during your treatment. This is because radiotherapy could harm a developing baby. Before treatment, you need to confirm you are not pregnant and may need to give a urine sample for a pregnancy test.

    You also need to confirm that you understand you should use contraception during treatment, to avoid pregnancy. You may have questions about your ability to have children in the future (your fertility). You should talk to your doctor or specialist nurse about this before you start treatment. We have more information about fertility for men and women.

  • Tell your doctor if you have a pacemaker, implantable cardiac device (ICD) or cochlea implant

    If you have a pacemaker, ICD or cochlea implant (a hearing implant in your ear), you must tell your doctor or radiographer before or during your first planning appointment. Radiotherapy can affect how these devices work, so your treatment has to be planned to allow for them.

  • Skin care

    Before treatment starts, your radiotherapy team advise you about looking after your skin. This is because you will need to take extra care of the skin in the area being treated, to avoid a skin reaction. How you take care of your skin will depend on the type of treatment you are having.

  • Arranging help at home and getting to appointments

    Feeling tired is a common side effect of radiotherapy. It may be useful for you to think about help with day-to-day tasks before you start treatment. It may also be helpful to plan how you will travel to the hospital. If you are worried about this, let the staff in the radiotherapy department know.

  • Stopping smoking

    Research shows that stopping smoking may make radiotherapy treatment more effective. It can also reduce the side effects of treatment. If you smoke, try to stop. Many hospitals provide help or advice on how to quit smoking. Ask your clinical oncologist, radiographer, or specialist nurse if your hospital provides this service.

  • Talking to employers or tutors

    If you are working or you are a student, it is a good idea to talk to your employer or tutors. They can make arrangements to support you and organise your time off during treatment.

If you would like to talk about your treatment or how you are feeling, Macmillan is here to support you. You can do the following:

Planning your radiotherapy

Your first planning session usually lasts 30 to 60 minutes, but it may take longer or need more than one visit. Your session will usually involve the following:

  • A discussion with your team

    Your team will tell you what to expect and if there is anything you need to do to prepare. For example, you may be asked to follow a special diet or drink plenty of water. You should ask them any questions you have about your treatment.

  • Having a CT scan of the area to be treated

    A CT scan takes lots of pictures from different angles to build up a 3D picture of the inside of your body. This helps plan the precise area for your radiotherapy. Before your scan, the radiographer may ask you to change into a hospital gown.

Some people may also have an MRI scan or PET scan. MRI scans use magnets to give a detailed picture of the area that needs treating. PET scans use low-dose radioactive glucose (a type of sugar) to measure the activity of cells in different parts of the body.

If you have a mould or mask, it will be carefully fitted to help you lie still during your scan.

If you feel uncomfortable while having any of these scans, tell the radiographers so they can make you more comfortable. It is important you lie still, so your position can be recorded. This is because you need to be in exactly the same position when you have the radiotherapy treatment. The information from the scan then goes to a planning computer, which works out the precise dose and area for your treatment.

Skin markings

You may have markings made on your skin to help the radiographers position you accurately for treatment. Usually, tiny permanent markings are made in the same way as a tattoo. The marks are the size of a pinpoint and are only made with your permission. If you have a mould or mask, the marks may be made on this. If you are concerned about having permanent marks, let your radiographers know. They can discuss other options with you.

Side effects of radiotherapy

Your team plans your treatment carefully to reduce your risk of side effects. However, most people have a few side effects during or after radiotherapy.

The side effects you have will depend on:

  • the area of your body being treated - you may find it helpful to read information about the cancer type you have
  • the type of radiotherapy you have
  • other treatments you are also having, such as chemotherapy.

We have more information on the side effects of radiotherapy.

Your follow-up after radiotherapy

After your radiotherapy has finished, your oncologist or radiographer will explain your follow-up. This depends on the type of cancer and the type of radiotherapy you had.

Your follow-up care may involve any of the following:

  • You may not need follow-up appointments

    Instead, you might get advice about problems you should look out for. You will also get details of someone to contact if you need to.

  • You might have regular follow-up appointments at the radiotherapy department or your original hospital

    These may be with the specialist who recommended the radiotherapy. The first appointment is usually 4 to 8 weeks after treatment has finished.

  • A nurse or radiographer may follow-up by telephone

    They will check how you are by asking you questions. If needed, they will arrange for you to have an appointment at the clinic.

  • You may do patient-led follow-up

    This means you do not have set appointments but can contact the team and arrange one if you are worried. This may not be suitable for everyone. You still have any tests or scans you need as normal.

Follow-up appointments are a good opportunity to discuss any problems or worries you have. It may help to make a list of questions beforehand, so you do not forget anything important. If you feel anxious, it can help to have a friend or family member with you.

You will be told who to contact if you have any problems or notice any new symptoms after treatment. This may be your specialist nurse or cancer doctor. Do not wait until your next appointment, just ask for an earlier one.

Late and long-term side effects of radiotherapy

After having radiotherapy, there is a small risk you will have side effects that:

  • do not get better after treatment – these are called long‑term side effects
  • only start months or years later – these are called late side effects.

This risk may be higher if you are also having other treatments, such as chemotherapy.

Before you decide to have cancer treatment, your team will explain your risk of developing these side effects. Even if it is not very likely, it is important that you understand and think about these long-term risks.

Radiotherapy and your sex life

During and after external radiotherapy, it is usually safe for you and a partner to have sex. For some types of internal radiotherapy, there may be times during and after treatment when you should avoid having sex or close physical contact. If you have any questions or concerns, talk to your healthcare team.

If you have any type of radiotherapy, you should use contraception to:

  • prevent pregnancy during radiotherapy and for a time after
  • protect yourself from infection.

Side effects of radiotherapy can change how you feel about having sex. It is normal to be less interested in sex if you are tired, unwell or anxious.

Changes caused by radiotherapy may change how you feel about your body or make you feel less confident. For a time, men may find it difficult to get or keep an erection.

Remember that most of these side effects are usually short-term and get better after you finish treatment. Some people feel embarrassed talking about their sex life. But if you find a side effect difficult to cope with, try talking to your healthcare team. They will be able to help if you have any concerns during or after treatment.

Radiotherapy and your fertility

Radiotherapy to most areas of the body does not affect your ability to get pregnant or make someone pregnant (your fertility).

However, your fertility may be affected if you have treatment to:

  • the pelvic area – the area between the hips in the lower part of the tummy
  • the pituitary gland – a small gland at the base of the brain.

Before you decide to have treatment, your team will explain any risks to your fertility. For some people, radiotherapy causes changes that get better with time. For others, the treatment they have to the pelvic area or pituitary gland causes permanent infertility. Your team may talk to you about fertility preservation, if this is possible for you.

We have more information about pelvic radiotherapy and fertility for men and women.

Beginning to recover from radiotherapy

You may have mixed emotions when you get to the end of your radiotherapy and begin to recover. You will probably feel relieved, but you may also feel anxious and uncertain.

You may feel ready to get on with your life after radiotherapy, but sometimes you may feel less positive.

It can take time to recover and you may feel tired for a while. You may also have new challenges to cope with, such as physical effects caused by the cancer or its treatment. It usually takes time to adjust to these and find out what is now normal for you. Complementary therapies may help you feel better and reduce any stress and anxiety.

When your treatment is over, you may want to think about making some positive changes to your lifestyle. Many people find that over time they settle back into their usual routines. But it is important to remember that support is available to help you with any physical or emotional problems you have.

Information about coronavirus

We understand that people are worried about coronavirus (COVID-19). You may have questions about the different vaccines, or you may be worried about how the pandemic will affect your cancer treatment. We have detailed information about coronavirus and cancer treatment here.

Talk to an expert

We know cancer throws a lot your way, and right now, the coronavirus pandemic is making it even tougher. If you're worried about something, and you need to talk to someone, whatever is on your mind, we're here to listen.

To speak to our experts, you can:

Find out more about the Macmillan teams that are here to support you.