Radiotherapy treats cancer by using high-energy rays to destroy the cancer cells, while doing as little harm as possible to normal cells.  Radiotherapy can be given to the pelvic area to treat a number of different types of cancer. In men, it is mainly used to treat cancer of the prostate gland, but may also be used to treat cancer of the bladder, rectum and anus. Radiotherapy may sometimes be given to the lymph nodes in the pelvic area.

Radiotherapy can either be given externally from outside the body or from within the body as internal radiotherapy.

External radiotherapy

This is normally given as a series of short daily treatments in the radiotherapy department at the hospital, using equipment similar to a large x-ray machine. Treatment is often given over several weeks, once a day from Monday to Friday, with a rest at the weekends. Each treatment takes several minutes and is painless. It will not make you radioactive and it is safe for you to be around other people, including children. You may be able to have your treatment as an outpatient, or you may need to stay in the hospital.

Internal radiotherapy

This is also known as brachytherapy, implant therapy or seed implantation and is sometimes used to treat cancer of the prostate or anus. This involves inserting radioactive metal 'seeds' into the tumour.

Radioactive seeds are small radioactive metal implants, about the size of a grain of rice. They are most commonly used to treat prostate cancer. These are usually inserted under a general anaesthetic and left in place so that radiation is released slowly over a period of time. The radioactivity gradually fades over several months. All the radioactivity is absorbed by the prostate gland so it is safe for you to be around other people.

For about two months after the treatment, children and women who are pregnant (or who may be) should not stay very close to you for long periods of time. However, it is safe for them to be in the same room as you.

Treatment with radioactive seeds may be uncomfortable and you may need to take painkillers. You will also be given antibiotics to prevent an infection.