Brachytherapy
Before treatment, your doctor will explain the risk of you getting side effects. But they won’t be able to tell you whether any of these side effects will definitely happen to you. Some side effects are more likely in some people.
Your risk of side effects is higher if you have brachytherapy as well as external radiotherapy.
Find out more about external radiotherapy for prostate cancer
You might have problems passing urine after the radiotherapy ends. It might be more difficult to pass urine at first. And then it might gradually get easier over some months or years. This is due to the treatment causing a narrowing of the . The narrowing is called a urethral stricture.
You can have an operation to stretch it. This short operation is 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 or .
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. You need to go to your local accident and emergency (A and E) department if:
your tummy (abdomen) feels swollen and uncomfortable
you can’t pass urine
The staff there will put in a to drain your bladder.
You may have some problems with leaking urine after treatment with brachytherapy.
There is specialist incontinence clinic if urine leakage becomes a long term problem. Your nurse or doctor can refer you. 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.
Read more about managing bladder problems after prostate cancer treatment
Radiotherapy can damage the nerves that control getting an erection.
Whether you have problems getting and keeping an erection depends on several factors. These include:
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) might help you to get and keep erections. If you continue to have problems, they can refer you to a specialist to help with this.
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.
Inflammation of the back passage (rectum) is called proctitis. This is a possible long term side effect. Proctitis can cause:
a feeling of wanting to strain whether or not you actually need to pass a bowel movement
bleeding from your rectum
a slimy mucous discharge from your rectum
Talk to your doctor or specialist nurse if you have any of these side effects. They will be able to refer you to a specialist team to check the cause. They can help you to find ways of controlling the effects.
Read more about treating diarrhoea during and after radiotherapy treatment
A small number of men develop bladder cancer or cancer of the lower bowel (rectum) after radiotherapy for prostate cancer. This can happen many years after treatment.
It is important that you contact your GP if you notice blood in the urine or poo or a change in your bowel habits.
Coping with the side effects of prostate cancer radiotherapy can be difficult. There are things you can do, and people who can help you and your family to cope.
Find out more about coping and support when you have prostate cancer
Last reviewed: 02 Jul 2025
Next review due: 02 Jul 2028
Permanent seed brachytherapy is when your doctor puts very small radioactive metal seeds into your prostate gland. Over a few months, the seeds slowly release a low level of radiation into the area of the prostate.
Temporary brachytherapy is when your doctor puts radioactive pellets in your prostate gland. They take them out at the end of the treatment. It is also called high dose rate (HDR) brachytherapy.
Prostate cancer usually depends on testosterone to grow. Hormone therapy blocks or lowers the amount of testosterone in the body.
After treatment for prostate cancer, you have regular check ups. This includes tests to check your PSA level.
Prostate cancer is cancer of the prostate gland. The prostate gland is part of the male reproductive system, and is at the base of the bladder.
Prostate cancer is cancer that starts in the prostate gland. The prostate gland is found at the base of the bladder and is about the size of a walnut.
About Cancer generously supported by Dangoor Education since 2010. Learn more about Dangoor Education
Search our clinical trials database for all cancer trials and studies recruiting in the UK.
Meet and chat to other cancer people affected by cancer.
Questions about cancer? Call freephone 0808 800 40 40 from 9 to 5 - Monday to Friday. Alternatively, you can email us.
