Radiation therapy for prostate cancer

Radiation therapy (also known as radiotherapy) is one of the treatments offered to men with early prostate cancer. It is generally offered as an alternative to surgery and has similar rates of success. It may also be offered if you are not well enough for surgery. Sometimes radiation therapy is used after a prostatectomy for locally advanced or more aggressive cancers, or if there are signs that not all of the cancer has been removed by surgery.

Radiation therapy can be delivered externally using external beam radiation therapy, or internally using brachytherapy. Most men who have radiation therapy as their initial treatment for more advanced prostate cancer will receive androgen deprivation therapy (ADT) beforehand and/or afterwards.

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External beam radiation therapy (EBRT)

External beam radiation therapy (EBRT) uses targeted radiation to kill cancer cells or injure them so they cannot multiply. The radiation is usually in the form of x-ray beams.

Treatment is planned to ensure there is as little damage as possible to the normal tissue and organs surrounding the prostate. The planning sometimes involves inserting small pieces of gold (marker seeds) into the prostate to allow more accurate targeting of the radiation. This is called image-guided radiation therapy (IGRT).

Usually, EBRT for prostate cancer is given every weekday for up to eight weeks, often in combination with temporary androgen deprivation therapy (ADT).

Each EBRT treatment session takes about 15 minutes. You will lie on the treatment table under the radiation machine. The machine does not touch you but may rotate around you. You will not see or feel the radiation. EBRT does not make you radioactive and there is no danger to the people around you.

Proton therapy for prostate cancer

A special type of EBRT uses protons rather than x-rays. This is
known as proton therapy and is useful when the cancer is near
sensitive areas, such as the brainstem and spinal cord. It is not  yet available in Australia, but has been used in the US to treat prostate cancer. At this stage, there is no evidence that proton therapy provides better outcomes for prostate cancer than standard radiation therapy with x-rays.

Side effects of external beam radiation therapy

You may experience some of the following side effects. Most will be temporary and there are ways to manage them.

Erection problems (impotence) – EBRT can damage the nerves that control erections. This can make it hard to get and keep an erection, especially in men who already had trouble with erections because of their age. ADT can make the problem worse. This side effect does not always occur immediately, but may develop over time and be ongoing.

Changes in ejaculation – Some men notice pain on ejaculation or find that they ejaculate less or not at all (dry orgasm) after radiation therapy. The discomfort usually eases over time, but dry orgasms may be a permanent side effect.

Infertility – Radiation therapy to the prostate usually results in infertility. If you wish to have children, speak to your doctor before treatment about sperm banking or other options.

Skin irritation – Skin in the area treated may become red and sore (like mild sunburn) during or soon after treatment. These reactions fade with time. Ask your treatment team for advice.

Tiredness – You may become very tired because your body is coping with the effects of radiation on normal cells. Fatigue may build up slowly during treatment and should go away afterwards, but can last up to six months. Talk to your radiation oncologist or call Cancer Council 13 11 20 to find out about programs that can help improve fatigue after cancer treatment.

Urinary problems – You may experience a burning sensation when urinating, or an increased urgency to urinate. These side effects usually go away after treatment, but your doctor can prescribe medicine to reduce any discomfort. Radiation is unlikely to cause incontinence, but it can damage the lining of the bladder. In rare cases, this can lead to ongoing bleeding (radiation cystitis), which can be difficult to control. Let your doctor know of any problems with urinating or bleeding.

Bowel problems – It is common to have a feeling of being unable to completely empty the bowel and/or to develop haemorrhoids. Less commonly, men may bleed when passing a bowel motion. This is caused by damage to the fine blood vessels in the lower bowel. Tell your doctor if you have any bleeding from the rectum. Some men may also have diarrhoea or difficulty holding onto their bowel motions. These side effects usually go away in time.


Brachytherapy is a type of targeted internal radiation therapy where the radiation source is placed directly within the prostate. This allows doses of radiation to be given directly inside of the prostate, and limits the effects on nearby tissues such as the rectum and bladder.

Brachytherapy can be given by inserting permanent “seeds” that are radioactive for a few months, or through temporary needle implants. Brachytherapy is not suitable for men who already have significant urinary symptoms, or a very small or very large prostate gland.

Permanent brachytherapy

This treatment is most suitable for men with a small to mediumsized prostate, few urinary symptoms, and small tumours with a low PSA level (less than 10) and a low/intermediate Grade Group or Gleason score. It can sometimes be an expensive treatment option, so check what costs are involved before making a decision. Permanent brachytherapy involves putting radioactive seeds, about the size of an uncooked grain of rice, into the prostate. It is also called low-dose-rate (LDR) brachytherapy. The seeds are inserted under a general anaesthetic through the skin between the scrotum and anus using needles. They are guided into place with the help of an ultrasound. There is no incision, only some small puncture holes that heal very quickly, allowing for a faster recovery than EBRT or surgery. The procedure takes only 1–2 hours and you can usually go home the same day.

The seeds slowly release radiation to kill cancer cells, and lose their radioactivity after about three months. They are not removed from the prostate. The level of radiation that comes from the seeds is low, but you will need to take care around pregnant women and young children for several weeks – your treatment team will explain the precautions to you. Although very uncommon, it is possible that a seed may dislodge during sexual activity. For this reason, you will be advised to use a condom or avoid sexual activity for three months. This way if a seed comes out, the condom will catch it.

Temporary brachytherapy

Also known as high-dose-rate (HDR) brachytherapy, temporary brachytherapy may be offered to men with higher PSA levels and Grade Group scores who are at risk of locally advanced cancer. It is often given with a short course of EBRT.

In temporary brachytherapy, the radiation is delivered through hollow needles that are inserted into the prostate, usually under general anaesthetic. These needle implants stay in place for several hours. During this time, you will have three brachytherapy sessions. For each session, radioactive wires will be inserted into the needles to deliver a high dose of radiation for about a minute. Once the wires are removed after each session, you will not be radioactive and there is no risk to other people. You will need to stay in hospital overnight for this treatment, and the needle implants will be removed before you go home.

To find out more about radiation therapy, call Cancer Council
13 11 20 or visit Radiation Therapy. The Prostate Cancer
Foundation of Australia have a resource called Understanding Brachytherapy for Prostate Cancer − visit prostate.org.au or call 1800 22 00 99. You can also visit targetingcancer.com.au for more information and videos explaining radiation therapy.


Side effects of brachytherapy

The side effects of brachytherapy usually start 1–2 weeks after treatment and start to resolve within a couple of months. They may include pain when urinating, blood in the urine, poor urine flow and bladder irritation. Permanent radioactive seeds have the lowest chance of causing erection problems compared with other treatments. Erection problems and changes in ejaculation (such as pain or dry orgasm) sometimes occur after temporary needle implants.

Talk to your doctor and/or treatment team about ways to manage these side effects.

Video: What is radiation therapy?

Watch this short video to learn more about radiation therapy.

This information was last reviewed in March 2018
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