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Macmillan and Cancerbackup merged in 2008. Together we provide free, high quality information for people affected by cancer through our publications, website and phone service. Find out more|.
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Radiotherapy| for locally-advanced prostate cancer is usually given using a machine (external beam radiotherapy).
Radiotherapy treats cancer by using high-energy x-rays to destroy cancer cells, while doing as little harm as possible to normal cells in the surrounding area. Your doctor may suggest that you have hormonal therapy| before or after your radiotherapy.
The treatment is given in the hospital radiotherapy department, usually as daily sessions from Monday to Friday, with a rest at the weekend. For locally-advanced prostate cancer, radiotherapy will be given for 4–7 weeks.
Benefits Radiotherapy can help to control locally-advanced prostate cancer for many years and may lead to a cure in some situations. In small, slow-growing cancers the benefits are uncertain. A complete course takes up to seven weeks. Giving hormonal therapy before and during the radiotherapy may improve the results.
Risks For a small number of men external beam radiotherapy to the prostate can cause long-term bowel problems, such as occasional bleeding and discomfort. Bowel motions may become looser and more frequent. Approximately 1 in 3 men will develop erection problems (this depends on age and whether you are also being treated with hormonal therapy). Rarely, some men may have leakage or incontinence of urine. Radiotherapy to the prostate may also cause infertility|.
Planning is a very important part of radiotherapy and may take one or two visits. The treatment has to be carefully planned to make sure that it’s as effective as possible. You will be asked to have a CT scan or lie under a machine called a simulator, which takes x-rays of the area to be treated. The treatment is planned by a cancer specialist (clinical oncologist).
Marks are usually drawn on your skin to help the radiographer (who gives you your treatment) to position you accurately and show where the rays will be directed. These marks must stay in place throughout your treatment. Permanent marks (like tiny tattoos) may also be used. These are very small and will only be done with your permission. You may feel a little discomfort while they are being done.
At the beginning of each session of radiotherapy, the radiographer will position you carefully on the couch and make sure you’re comfortable. You will be left alone in the room during your treatment, but you’ll be able to talk to the radiographer, who will be watching you from the next room. Radiotherapy is not painful, but you have to lie still for a few minutes while the treatment is being given.
Conformal radiotherapy or intensity modulated radiotherapy are usually used, although these are not available at every hospital.
In conformal radiotherapy (CRT), a special attachment to the radiotherapy machine carefully shapes the radiation beams to match the shape of the prostate gland. Shaping the radiotherapy beams reduces the radiation received by the healthy cells in nearby organs such as the bladder and rectum. This reduces the side effects of radiotherapy and may allow higher doses to be given, which could be more effective.
Intensity modulated radiotherapy (IMRT) is a more complex type of conformal radiotherapy that allows the radiotherapist to vary the dose of radiation given to different parts of the tumour and surrounding tissue. It is not yet known whether IMRT is better than conformal radiotherapy.
Radiotherapy to the prostate can make it more difficult to have an erection. There are various treatments which can help. Radiotherapy may also reduce fertility and can make some men infertile. It may be possible to store sperm before treatment if you want to have children.
Radiotherapy to the prostate area may irritate the rectum, and cause discomfort and diarrhoea. It can sometimes cause soreness around the anus. Your doctor can prescribe medicines to reduce this and you may be advised to make some changes to your diet.
Radiotherapy may also cause inflammation of the bladder (cystitis), which can make you want to pass urine more often or cause a burning feeling when you pass urine. Your doctor can prescribe medicines to reduce this. These effects usually disappear gradually a few weeks after the treatment has ended.
Very occasionally, if you have difficulty in passing urine, it may be necessary to have a urinary catheter put in.
Radiotherapy can also cause general side effects (such as tiredness|), which are mild for some men and more troublesome for others. The radiographer will be able to advise you what to expect. Try to balance rest with regular, gentle exercise – especially if you have to travel a long way for treatment each day.
The radiotherapy may make some of your pubic hair fall out|. When you’ve finished the course of treatment, the hair will grow back. However, it may be thinner or finer than before.
Most side effects of radiotherapy gradually disappear once the treatment has ended. However, others may continue for some months and some may even be permanent. If you have any problems during your treatment, talk to the radiotherapy staff. They will be able to help you.
Radiotherapy doesn’t make you radioactive and it’s perfectly safe for you to be with other people, including children, throughout your treatment.
We have information about the side effects of pelvic radiotherapy during treatment|.
Radiotherapy to the prostate area can sometimes lead to long-term problems.
Radiotherapy for prostate cancer causes an inability to get an erection (impotence) in about 1 in 3 men (30%) who have this treatment. This side effect of treatment can be very difficult to deal with and can affect your sex life and your relationship with your partner, if you have one. You may find it helpful to read our information about sexuality| and cancer. Many organisations offer counselling for sexual or relationship problems - see our A-Z list of useful organisations|.
Radiotherapy to the prostate can cause permanent infertility. Some men find this very difficult to cope with, whether they have children or not. If you want to father children after your treatment it may be possible to store sperm before treatment starts. (You may find it helpful to read our separate information about fertility|.)
In a number of men, the bowel or bladder may be permanently affected by the radiotherapy. The blood vessels in the bowel and bladder can become more fragile and this can make blood appear in your urine or bowel motions. This can take many months or years to occur. If you notice any bleeding, it’s important to let your doctor know so that tests can be carried out and appropriate treatment given. Occasionally bowel movements may be more urgent after radiotherapy and very occasionally there may be some difficulty controlling the bowels (faecal incontinence).
Often, radiotherapy can improve problems with passing urine. However, for a small number of men radiotherapy can lead to leakage of urine (urinary incontinence) due to damage to the nerves that control the bladder muscles. This usually happens only if you’ve had a TURP or prostactectomy| as well. If it happens it’s important to discuss it with your doctor, who can arrange for you to see a specialist continence nurse. You may also find it helpful to contact the Bowel and Bladder Foundation|.
If radiotherapy has been given to the lymph glands in the pelvic area as well as to the prostate, it can cause some swelling of the legs, known as lymphoedema|.
You might find our information about the long-term side effects of pelvic radiotherapy| useful.
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