Radiotherapy for metastatic prostate cancer

Radiotherapy for metastatic prostate cancer aims to control the cancer and relieve symptoms, such as pain. It may also be used to treat your prostate cancer if you have low volume disease

There are two types of radiotherapy that can be used for metastatic prostate cancer: 

• External radiotherapy
  High-energy X-rays are aimed at the cancer.
• Radioactive injections
  Radioactive liquid injections to help with prostate cancer that has spread to the bones.

Planning external radiotherapy

The radiation oncologist will plan how best to give your treatment. The radiation oncologist will decide how much radiotherapy is needed to treat your cancer while limiting any damage to normal cells.

An important part of the planning process is simulation. This involves using a CT scanner to pinpoint the area to be treated. The treatment field or area will be marked on your skin, usually using tiny tattoo dots.

How much radiotherapy will I need?

The amount of radiotherapy delivered depends on the site being treated and the reason for treatment. Usually you will only need a short course of radiotherapy. You may have a single dose or a dose divided into a few sessions. Radiotherapy to the prostate gland involves a longer course of treatment.

Possible side-effects include: 

• Urinary problems
• Bowel problems
• Discomfort at back passage
• Skin changes in the treated area
• Fatigue

With a short course of radiotherapy any side-effects are usually mild and reversible. Longer term (chronic) side-effects are much less common. 

Read more about radiotherapy and its side-effects.

Radioactive injections can help with symptoms of prostate cancer that has spread to the bones. They can shrink any areas of cancer in the bone by killing the cancer cells, which can relieve pain and improve your overall prognosis. Radioactive injections will not lower your PSA. Examples of radioactive injections are strontium 89 and radium-223 (Alpharadin® / Xofigo® (“zo-fee-go”). 

Getting your treatment

You will normally have the injection every month in the radiotherapy department as an outpatient, so you shouldn’t need to stay in hospital overnight.

Will I get side-effects?

Because the radiation is targeted at cancer cells, side-effects are mild and may include diarrhoea and sickness, and sometimes reduced levels of blood cells. Bone pain may get a little worse before it gets better.

Will I be radioactive?

After the injection, a small amount of radiation remains in your urine, poo (stools) and blood. It is best to use flush toilets instead of urinals afterwards. This will reduce the risk of others being exposed to the radiation. Do flush the toilet a couple of times after passing urine as well. Be careful of any spills of urine or blood, but it is quite safe to be around people and pets. The radiation usually lasts about 7 days. Your doctor or nurse will discuss any special precautions with you before you go home.