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Long term side effects of internal radiotherapy

Find out about the possible long term side effects of internal radiotherapy for prostate cancer and what you can do about them.

About side effects

Your doctor won’t be able to tell before your treatment whether any of these long term effects will happen to you. But some side effects are more likely in some people. You have a higher risk of side effects if you have internal radiotherapy as well as external radiotherapy.

You might have problems passing urine after the radiotherapy ends. It might be more difficult to pass urine at first and then gradually get easier over some months or years. This is due to the treatment causing a narrowing of the tube from the bladder to the penis (the urethra). The narrowing is called a urethral stricture.

Tell your doctor if you find it harder to pass urine.

Up to 1 in 10 men (10%) need treatment to help them pass urine more easily again.

A doctor stretches the narrow area during a short operation called urethral dilatation. They might slide a thin rod into the urethra to widen it. Or they may use a thin flexible tube with a light and camera on the end. They can see the narrowed area and put a tiny knife down the tube to cut away tissue and open up the urethra. You have these operations under local or general anaesthetic.

You might need to have this operation repeated if the urethra gets narrower again.

A small number of men find they can’t pass urine at all. This is called urine retention. If your tummy (abdomen) feels swollen and uncomfortable but you can’t pass urine, go to your local accident and emergency department. The staff there will put in a catheter to drain your bladder.

You might feel that you have to pass urine more often than usual. And you may have a burning feeling when you do. Or you might feel that you can’t wait then you need to go. This is called radiation cystitis.

The radiotherapy inflames the lining of your bladder. This might get worse as you go through your course of treatment. But it should get better within a few weeks or months of finishing. 

It helps to drink plenty of fluids. Some people think that cranberry juice can help but others feel it makes the soreness worse. Research studies haven’t found that it helps.

You might find that some drinks increase the soreness, such as tea and coffee. You can experiment for yourself and see what works for you. Don’t take potassium citrate, which is an old fashioned remedy for cystitis. You might hear it called mist pot cit for short. This drug can be very harmful if taken in large amounts.

Tell your doctor or nurse if you have soreness. They can prescribe medicines to help.

You might notice blood in the urine. It usually stops after a few days or weeks. Let your doctor know if there is any blood in your urine. In some men it may last for months or years.

'Just can’t wait' card

You can get a card to show to staff in shops or pubs etc. It allows you to use their toilets, without them asking awkward questions. You can get the cards from Disability Rights UK or the Bladder and Bowel Foundation. They also have a map of all the public toilets in the UK.

Disability Rights UK can also give you a key for disabled access toilets so that you don't have to ask for a key when you are out.

Leakage of urine (urinary incontinence) is uncommon. But it is more likely if you have previously had a TURP operation. Radiation damage can cause slight leaking. Between 1 and 14 men out of every 100 (1 to 14%) have some problem with leaking urine. It happens within 3 to 5 years of the treatment.

Your doctor or nurse can refer you to a specialist incontinence clinic if urine leakage becomes a long term problem. Staff at the clinic can help you with muscle exercises, bladder training and medicines.

Some men find that they can’t control their urine at all. This is very uncommon. If it happens you need to have a tube called a catheter into your bladder. The tube drains the urine into a bag.

Radiotherapy can damage the nerves that control getting an erection. Different studies give different statistics. But between 40 to 70 out of every 100 men (40 to 70%) can’t get or keep an erection after treatment. The problem usually comes on gradually after a year or more.

Whether you have problems getting and keeping an erection depends on:
  • your age (impotence is less likely if you are under 65)
  • whether you have other health conditions
  • whether you had erection problems before the treatment
  • if you have hormone therapy before or after the radiotherapy
  • whether you have internal radiotherapy as well as external radiotherapy

Tell your doctor or specialist nurse as soon as possible if you have erection problems. Early treatment with medicines such as sildenafil (Viagra) or apomorphine hydrochloride might help you to get and keep erections.

Your bowel movements might be looser or more frequent than before your treatment.

You might need to take anti diarrhoea medicines, such as loperamide (Imodium). Bulking agents, such as Fybogel might also help. Your doctor or nurse can prescribe these for you, talk to your doctor before taking these.

You might find that you need to avoid high fibre foods. Although we normally think that a high fibre diet is the most healthy, it might make long term diarrhoea worse. Some people find it best to avoid high fibre vegetables, beans and pulses (such as lentils).

Let your doctor know if you have ongoing problems with frequent bowel movements or bleeding. They can refer you to a specialist team. The team includes cancer doctors, digestive system specialists, bowel surgeons, dietitians and specialist nurses.

Inflammation of the back passage (rectum) is the most common long term side effect. Proctitis can cause a feeling of wanting to strain whether or not you actually need to pass a bowel movement. You might also have bleeding from your back passage or a slimy mucous discharge.

Bleeding is usually slight but can be more severe for some people. Talk to your radiographer or nurse if you have proctitis. They might suggest you use treatments such as steroid suppositories for a short time. This might reduce the inflammation. 

You might get swelling in the legs or the sack of skin around the testicles (the scrotum). The swelling is called lymphoedema (pronounced lim-fo-dee-ma). It happens when the lymph channels that drain fluid from the legs are damaged by the radiotherapy. The swelling can be uncomfortable.

You can do various things to lower your risk of getting lymphoedema.

Early treatment for lymphoedema can reduce the swelling and stop it getting worse.

A small number of men develop bladder cancer or cancer of the lower bowel (rectum) after radiotherapy for prostate cancer.

The risk of rectal cancer is small.

Around 5 to 6 men out of 100 (5 to 6%) develop bladder cancer a few years or more after treatment.

Your doctor will discuss this with you and you will have regular checks after your treatment ends. The checks aim to pick up cancer early when the chance of successful treatment is high.

Radiotherapy can damage the bone cells in the pelvic area, and also lower the blood supply to the bones. The bones can become weaker. This is called avascular necrosis. Damage to the bones can cause pain and sometimes makes it hard to walk or climb stairs.

Your doctor will monitor you carefully, including checking your bone strength with a DEXA scan. They might suggest treatment with painkillers and walking aids to help you get around, such as a stick. You might also need to take medicines to strengthen the bones called bisphosphonates. These drugs can help to control pain and reduce the risk of fractures.

Sometimes, tiny cracks can appear in the pelvic bones some years after treatment. They are called pelvic insufficiency fractures. This is more likely to happen in people who have general weakening of their bones as they get older (osteoporosis). It is also more likely in people who are taking hormone therapies or steroids.

The pain, in this case, can be quite bad. It usually gets worse if you move around or do exercise and gets better when you sit still or rest. This type of pain normally goes away overnight. It doesn't stop you from sleeping well. Your doctor might ask you to have x-rays, a CT scan or an MRI scan (or a combination of these) to see if there are any fractures in the bones.

Let your doctor know if you have bone pain
Last reviewed: 
05 Jul 2016
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    RK Nam and others
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