Radiotherapy treats cancer by using high-energy X-rays to destroy the cancer cells while doing as little harm as possible to normal cells.

Radiotherapy for prostate cancer is usually given from an external machine (external beam radiotherapy). Still, for some men with early prostate cancer, it can be provided by inserting tiny radioactive seeds into the tumour (brachytherapy).

External Radiotherapy and brachytherapy both appear to be equally effective in curing prostate cancer. In many cases, your doctor may suggest that you have hormonal therapy before or after your Radiotherapy.

When Radiotherapy is used

In early prostate cancer, Radiotherapy is given to the prostate gland. The aim is to destroy the cancer cells while doing as little harm as possible to normal tissues in the surrounding area, such as the bladder or back passage (rectum). This is known as radical Radiotherapy.

As with all treatments, there can be side effects. If you are worried, make sure your doctor has explained everything, or call the Cancerbackup helpline on 0808 808 00 00 for more information.

See this link for a more recent explanation of Radiotherapy…

Also, see PC UK.