What is radiotherapy?

Radiotherapy uses high-energy rays, such as x-rays, to treat cancer cells. For cancer of the vulva this treatment is usually given from a machine outside the body (external radiotherapy). Sometimes it is also given by putting a radioactive source inside the body (internal radiotherapy or brachytherapy).

Before your radiotherapy, your radiotherapy team will explain what your treatment involves and how it may affect you. We have more information about what happens before and after radiotherapy, and questions you may want to ask.

After your radiotherapy, there is no risk to people around you. You are not radioactive.


Radiotherapy may be given with chemotherapy. This is called chemoradiation. The chemotherapy drugs make the cancer cells more sensitive to radiotherapy. This can help make the radiotherapy work better. The chemotherapy drug most commonly used is cisplatin. You will usually have it once a week throughout your radiotherapy.

If you have chemoradiation, your side effects may be worse than they would be if you were having just one treatment type. Your doctor, nurse or radiographer will tell you how to manage and treat any side effects.

When radiotherapy is used for vulval cancer

You may have radiotherapy:

  • before surgery – to try to shrink the cancer and make a smaller operation possible
  • after surgery – to reduce the risk of the cancer coming back (this may be used if the cancer was not completely removed, or if cancer was in the lymph nodes)
  • if you cannot have surgery
  • if vulval cancer has come back or spread.

If the cancer is advanced, the aim of radiotherapy is often to improve your quality of life by shrinking the tumour and reducing symptoms. This is known as palliative radiotherapy.


Radiotherapy to the pelvis can affect your ability to get pregnant. If this is important to you, talk to your cancer doctor before treatment begins. They can refer you to a fertility specialist to talk through your fertility options.

Having external radiotherapy

External radiotherapy is given using a machine that looks like a large x-ray machine or CT scanner. There are different types of radiotherapy machine. The most commonly used machine is called a linear accelerator (LINAC).

You have treatment in the radiotherapy department at the hospital. You usually have it as an outpatient once a day from Monday to Friday, with a rest at the weekend. Each session of treatment takes a few minutes. The number of treatments you have depends on the type and size of the cancer. The course of treatment for vulval cancer usually lasts a few weeks.

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Internal radiotherapy

Internal radiotherapy (brachytherapy) uses a radioactive material that is put inside the body to treat the cancer. This gives a high dose of radiotherapy to the tumour. As the radiation does not travel far, it will not affect your nearby organs.

Brachytherapy for vulva cancer is given through thin hollow tubes that are placed inside the cancer. You will have a general anaesthetic or spinal anaesthetic (injection of painkillers into the spine) while the tubes are put in place. 

When the tubes are in position, the radiotherapy may take from 30 minutes up to a couple of days. It depends on the amount of radiation needed. Your team will explain your treatment plan and what to expect. You cannot feel the radiotherapy when you are having it, but the tubes can be uncomfortable. The nurses will give you painkillers to help with this. They will remove the tubes when treatment is finished.

When the radiotherapy is being given, your team are careful to protect people around you from radiation. This may mean you need to be alone in a single room during the treatment. Tell your team if you are worried about this so they can help. Safety measures may be slightly different in different hospitals. Your team will explain what to expect.

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. We have more information about side effects below.

Side effects do not usually happen straight away. They may develop during treatment or in the days or weeks after treatment finishes. After you finish radiotherapy, side effects can sometimes get worse before they get better. There may also be a small risk of side effects that are long-term or that only start months or years after radiotherapy.

Smoking makes the side effects of radiotherapy worse. If you smoke, stopping smoking will help. If you want help or advice on how to give up, talk to your doctor, GP or a specialist nurse.

Side effects of radiotherapy for vulval cancer may include:

  • Skin irritation

    You may find the skin around your vulva and groin gets dry and irritated.

  • Tiredness

    Radiotherapy often makes people feel tired. Tiredness may get worse as treatment goes on. If you are having radiotherapy alongside other treatments, such as surgery or chemotherapy, you may feel more tired.

  • Bladder side effects

    You may feel like you need to pass urine more often. You may also have a burning feeling when you pass urine.

  • Bowel side effects

    You may have tummy (abdominal) cramps. You may need to pass stools (poo) more often or you may have diarrhoea.

  • Changes in your blood

    External radiotherapy can reduce the number of blood cells made by your bone marrow. This is more likely to happen if you are having chemoradiation. If your white blood cells are low, you are more likely to get an infection and need antibiotics. If your red blood cell count is low, you may feel tired and you may need a blood transfusion. Your hospital team will arrange for you to have regular blood tests if needed.

  • Vaginal discharge

    You may have a light vaginal discharge after treatment has finished. If it continues or becomes heavy, tell your cancer doctor or specialist nurse.

We have more about managing these side effects in our information about pelvic radiotherapy side effects.

Possible late effects of radiotherapy for vulva cancer

Radiotherapy to the pelvic area can sometimes cause effects months or years after treatment. These are called late effects. They may be permanent. If they happen, there are lots of ways to manage and treat them.

It is always important to tell your GP or cancer doctor about any new symptoms that develop a long time after treatment. They need to check them, as they may not be caused by radiotherapy.

Late effects of radiotherapy for vulval cancer may include:

  • Early menopause

    Radiotherapy to the pelvis affects the ovaries and may cause an early menopause. If you have not already been through the menopause, this means your periods will stop and you will no longer be able to get pregnant.

  • Vaginal changes

    Radiotherapy can make your vagina narrower and less stretchy. The vaginal walls may be dry and thin, and can stick together. This can make vaginal sex and internal examinations uncomfortable.

  • Changes to the vulva

    The skin of the vulva may become permanently discoloured. It may redden or go darker. You may have some swelling in the vulva for months or sometimes years after radiotherapy. You can reduce this with gentle, upwards massage. A specialist nurse or physiotherapist can teach you how to do this.

  • Bowel or bladder changes

    If your bowel is affected, you may have:

    • more bowel movements
    • to go to the toilet more urgently than usual
    • diarrhoea.

    If the bladder is affected, you may need to urinate (pee) more often or more urgently.

    The blood vessels in the bowel and bladder can become more fragile. This can cause blood in your urine or bowel movements.

  • Lymphoedema

    Pelvic radiotherapy may increase the risk of swelling in one or both legs. This is called lymphoedema. It is not common, but the risk is higher if you have surgery to remove the lymph nodes as well as radiotherapy.

  • Changes to the pelvic bones

    Radiotherapy can cause thinning of the bones in the pelvis. This often does not have any symptoms but can be seen on scans. Sometimes it may cause fractures in the pelvis called insufficiency fractures. These can cause pain in the lower back or pelvis.

We have more about managing these side effects in our information about pelvic radiotherapy late effects.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Professor Nick Reed, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

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We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

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Date reviewed

Reviewed: 30 April 2021
Next review: 30 April 2024

This content is currently being reviewed. New information will be coming soon.

Trusted Information Creator - Patient Information Forum
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Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.