Decorative image


Radiotherapy uses radiation to kill cancer cells. It is used to treat many different types of cancer.

How pelvic radiotherapy might affect you

Pelvic radiotherapy can cause an early menopause by stopping your ovaries from working. This can cause symptoms such as vaginal dryness and loss of interest in sex.

External and internal radiotherapy

Radiotherapy for some types of cancer (such as cervical cancer) can be external or internal radiotherapy. 

External radiotherapy targets radiation at the cancer from a radiotherapy machine outside of the body. Internal radiotherapy (brachytherapy) gives radiation from inside the body. For cervical cancer, a radioactive source goes inside the vagina. This gives a high dose of radiotherapy both to the cervix and the vagina.

Both external and internal radiation can cause vaginal dryness fibrosis and narrowing of the vagina. 

Radiotherapy side effects and sex

The skin inside the vagina can also become thin, delicate and easily torn. This can lead to pain, discomfort or bleeding, and may make intercourse painful. Rarely, ulcers (sores) can form inside the vagina when the skin tears. These can take a few weeks (or even months) to heal.

You may not feel like having sex while you are having a course of pelvic radiotherapy. The treatment can make you feel very tired and give you bladder inflammation (cystitis) and diarrhoea. You may also find that you feel too sore to have sex comfortably.

For many people it is best to avoid intercourse altogether during this time. But you can still enjoy a sexual relationship. There are many other ways of satisfying each other. It is important to talk to each other about what you want.

It is important to avoid pregnancy during radiotherapy, as it might harm the baby. Talk to your specialist about a suitable type of reliable contraception before starting treatment. 

Narrowing of your vagina

Pelvic radiotherapy can make the tissues in the vagina less stretchy. This is called fibrosis. Fibrosis can narrow the vagina, making it uncomfortable and difficult to have sex.

Vaginal dilators after treatment might help to prevent this. Ask your radiographer, doctor or nurse about dilators if they haven't been mentioned to you.

Vaginal dilators

Dilators are cone shaped plastic objects that you put into your vagina to help stretch it.

You can can use vaginal dilators from 2 to 8 weeks after treatment to help prevent narrowing of the vagina. Ask your doctor or nurse when you should start using them. The dilators come in sets of different sizes. You begin with one of a comfortable size and use larger ones until your vagina is stretched enough for you to have sex comfortably. Some people involve their partner with this.

How to use them

There are international guidelines for using vaginal dilators and these are described below. Ask your medical team for individual advice.

You usually start with the smallest size and go up to whatever size is comfortable for you. 

For the first 6 months 

Use dilators with a water soluble lubricating gel at least twice a week and up to twice a day, for 3 to 10 minutes each time.

Between 6 and 12 months

Use dilators once a week.

After 12 months

Use your dilators occasionally as long as you are not having any difficulty.

Alternatives to vaginal dilators

Sexual intercourse also helps to keep the vagina open and is a good alternative to using dilators.

You might prefer to use your fingers or a vibrator to help stretch your vagina. If water soluble lubricants do not give enough lubrication for comfortable intercourse you may want to try a silicone based lubricant. These give more lubrication and are usually fine to use after any vaginal irritation caused by radiotherapy has settled down.

A small amount of bleeding is usual at first but contact a health professional if you have a lot of bleeding or pain.

Chemoradiotherapy for pelvic cancer

Sometimes chemotherapy is combined with radiotherapy for cancers in the pelvic area. For example, cervical cancer, rectal cancer or anal cancer. Having the two treatments together can make the vaginal area very fragile and sensitive.

Always use reliable contraception if you're having chemotherapy treatment. You should avoid becoming pregnant, as the treatment drugs could harm the baby. Women who have or have had breast cancer are usually advised not to take the pill because the hormones it contains may affect the cancer.

It is not known for sure whether cancer drugs, such as chemotherapy, can be passed on through semen or secretions from the vagina. Because of this some doctors advise people to use a barrier method (such as condoms, femidoms or dental dams) if you have sex during their treatment. This applies to vaginal, anal or oral sex.

Generally, doctors advise a barrier method only for the time a person is actually having the treatment and for about a week after treatment.

Advice like this can be worrying, but this does not mean that you have to avoid being intimate with your partner. You can still have close contact and continue to enjoy sex.

Last reviewed: 
27 Jul 2018
  • A nurse-led sexual rehabilitation intervention after radiotherapy for gynecological cancer

    R Bakker and others 

    Supportive Care in Cancer 2017 Volume 25, Number 3, Pages 729-73

  • Use of local estrogenotherapy in urology and pelviperineology: A systematic review 

    T Benoit and others (2015) 

    Progres en urologie Sep;25(11):628-35

  • Royal College of Obstetricians and Gynaecologists 

    Vaginal atrophy after breast cancer (query bank)

    Accessed 2015

  • Woman cancer sex

    A katz

    Hygeia media 2010