Brachytherapy for prostate cancer

Radiotherapy for prostate cancer is sometimes given from inside the body. This is called internal radiotherapy or brachytherapy.

What is brachytherapy?

Brachytherapy (internal radiotherapy) gives high doses of radiation directly to the prostate. Areas close by, such as the rectum and the bladder, get a much lower dose.

It can be used for certain types of early prostate cancer. It is not suitable if you have difficult urinary problems. Sometimes for locally advanced prostate cancer brachytherapy may be given with external radiotherapy.

For early prostate cancer, brachytherapy can be given:

  • on its own, usually to treat low-risk prostate cancer
  • before or after external beam radiotherapy to make treatment work better, usually for medium-risk to high-risk prostate cancer
  • with hormonal therapy, or with hormonal therapy and external radiotherapy.

Brachytherapy is only given in specialist hospitals in the UK. There may be some differences in how each hospital gives brachytherapy. Your doctor or nurse will explain what will happen.

There are two ways of giving it:

  • Radioactive seed implants or low-dose rate (LDR) brachytherapy – this is the most common type of brachytherapy for early prostate cancer.
  • High-dose rate (HDR) brachytherapy - this may be used with external radiotherapy to treat early or locally advanced prostate cancer.

You usually have antibiotics before brachytherapy to help prevent infection. You may also be given tablets to help you pass urine more easily.

Radioactive seed brachytherapy

Small, radioactive metal ‘seeds’ are placed in the prostate and stay there permanently. They slowly release radiation until it has been used up. The radiation will be completely gone after 6 months.

You may need two separate hospital visits, or it may all be done on the same day.

You will have a general or a spinal anaesthetic (injection of painkillers into the spine) to have radioactive seed brachytherapy. If you have a spinal anaesthetic, you will be awake but will not feel any pain.


Your doctor passes an ultrasound probe into the back passage (rectum) to take pictures of the prostate. This helps them plan how many radioactive seeds are needed and where they should be placed.

Before the scan, you may need to have a special diet for 24 hours. You may also have a small amount of liquid passed into your rectum (enema). This makes sure your bowel is empty, so the ultrasound picture is clear.

Implanting the seeds

The doctor can place the seeds into the prostate (implanted) on the same day or a few weeks later under a general anaesthetic.

The doctor passes an ultrasound probe into the rectum to show your prostate and help guide them. They pass a special needle through the skin between the scrotum and back passage, to insert the seeds into the prostate.

You can usually go home on the same day, but someone will need to take you. You will not be able to drive, because of the anaesthetic.

After treatment

All the radioactivity from the seeds is absorbed from inside the prostate. So it is safe for you to be around other people. As a precaution, you need to avoid long periods of close contact with pregnant women and children for the first few months after treatment. It is safe for children to be in the same room as you. You can hold or cuddle them for a few minutes each day. Your doctor or nurse will give you more information about this.

After brachytherapy, you need to avoid heavy lifting or brisk physical activity for 2 to 3 days. The area between your legs can feel bruised and inflamed for a few days. Your doctor can prescribe painkillers to take.


Your doctor will advise you to use a condom during sexual activity for at least the first few weeks after the seeds have been put in. There is a slight chance of a single seed being passed in your semen when you ejaculate. Double-wrap used condoms and dispose of them in a dustbin.

If  you usually receive anal sex doctors usually advise avoiding this for several months. This is to protect your partner until most of the radiation has worn off. If you are worried talk to your doctor or nurse. 

Your semen may be coloured black or brown for a short time. This is caused by some bleeding during the procedure. It is harmless.

HDR brachytherapy

Thin tubes are placed in the prostate. They are attached to a machine that sends radioactive material into the tubes for a set time. HDR is usually given with external radiotherapy.

You will have a general or a spinal anaesthetic (injection of painkillers into your spine) to have HDR brachytherapy. With a spinal anaesthetic, you are still awake but will not feel any pain. You may need to stay in hospital overnight.

Having the tubes put in

Your doctor passes an ultrasound probe into the back passage (rectum) to take pictures of the prostate. This helps your doctor plan the number of tubes needed and where they should be placed.

Your specialist puts the tubes that deliver the brachytherapy into the prostate. They pass them into the prostate through the skin between the scrotum and back passage. Your doctor may also put a thin tube into the bladder to drain urine (catheter). This prevents any swelling of the prostate stopping you passing urine. They remove the catheter before you go home.

When the tubes are in, you have a CT scan or MRI scan. This helps your doctor plan exactly how much radiation to give the prostate.

Having HDR

The nurses take you to a treatment room that has the HDR machine. They attach the tubes to a machine which sends the radioactive material into the tubes going into the prostate. A computer monitors how long the radioactive material stays in place for. The treatment takes up to an hour.

The tubes can be uncomfortable, and you must stay in bed lying down while they are in place. The nurses will give you painkillers to take. After HDR brachytherapy is finished, the radioactive material is returned to the machine and your doctor removes the tubes.

If you need more than one treatment, the tubes are left in place in between treatments. Some men need 2 or 3 treatments over 24 hours.

After treatment

After treatment, you have no radioactive material inside you, so there is no risk in being around other people.

You need to avoid doing heavy lifting or physical activity for 2 to 3 days. The area between your legs can feel bruised and inflamed for a few days. Your doctor can prescribe painkillers to take.

Advantages and disadvantages of brachytherapy

If you have a low-risk cancer, you may be asked to decide between external beam radiotherapy and brachytherapy. They are both effective treatments for certain men with early prostate cancer.


  • You usually only need 1 or 2 visits to hospital, rather than weeks of external beam radiotherapy treatment.
  • Your recovery is quick.
  • Bowel side effects are less common than with external beam radiotherapy.


  • You need a general or a spinal anaesthetic.
  • With radioactive seeds, you need to avoid close contact with children or pregnant women for a couple of months after treatment.
  • Bladder side effects may be more severe than with external beam radiotherapy.

Side effects of brachytherapy

Brachytherapy causes similar side effects to external beam radiotherapy. Having brachytherapy with external beam radiotherapy may make some side effects more severe. Some side effects may take several weeks to develop and may last for longer.

Erection problems

Brachytherapy for prostate cancer can cause problems getting and keeping an erection. This is called erectile dysfunction (ED). Ask your cancer doctor about your risk of ED. If you develop ED, there are different treatments that can help.

Brachytherapy may also change ejaculations. You may find you ejaculate little or no semen.


Having brachytherapy on its own can still cause infertility, but the risk may be lower than with external beam radiotherapy. If you are worried about your fertility, talk to your cancer doctor. You may be able to store sperm before treatment starts.

We have more information on fertility.

Bowel problems

Brachytherapy may cause some bowel problems for a few weeks after treatment. But it is less likely than external beam radiotherapy to affect the bowel and cause late bowel effects.

Effects on the bladder

These can be a problem after brachytherapy. If you already have difficulties passing urine, you will not usually have brachytherapy, as it may make bladder problems worse.

It is normal to see some blood in your urine and semen for a few weeks after treatment. If bleeding gets worse or you have large clots, tell your doctor straight away. Drinking plenty of water helps flush your bladder and prevent blood clots.

You may also:

  • have discomfort or pain passing urine
  • need to pass urine urgently and more often.

Drinking plenty of water and avoiding caffeine and alcohol will help improve these symptoms.

Not being able to pass urine

Brachytherapy may cause swelling of the prostate. This may make it difficult to pass urine. If this happens, you may need to have a catheter put in your bladder until the swelling goes down.

Sometimes radiotherapy can narrow the urethra (called a stricture). This causes difficulties with passing urine. This may happen weeks, months or even years after treatment finishes. A stricture can be treated by passing a thin, plastic tube through the urethra to widen (dilate) it.

About our information

  • References

    Below is a sample of the sources used in our prostate cancer information. If you would like more information about the sources we use, please contact us at

    European Association of Urologists. Guidelines on Prostate Cancer. 2016.

    European Society for Medical Oncology. Cancer of the prostate: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. 2015.

    National Institute for Health and Care Excellence (NICE). Prostate cancer overview. Available from: (accessed from March 2017 to November 2017).

    National Institute for Health and Care Excellence (NICE). Surveillance report 2016. Prostate cancer: diagnosis and management (2014). NICE guideline CG175. 2016.

  • 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 Editors, Dr Jim Barber, Consultant Clinical Oncologist and Dr Lisa Pickering, Consultant Medical 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.

Content under review

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