Virtual Medical Centre

Radiotherapy for Prostate Cancer

• Introduction to radiotherapy and prostate cancer
• Forms of radiotherapy
  • External beam therapy
  • Brachytherapy
  • High dose rate (HDR) brachytherapy

Introduction to radiotherapy and prostate cancer

Radiotherapy is a form of treatment that is used to treat cancer of the prostate gland. It may be used alone or in conjunction with surgery. Radiotherapy involves the use of radiation which is targeted to the cancer site in order to destroy cancerous cells. Treatment is planned meticulously in order to minimise harm to normal cells. Treatment is usually carried out as an outpatient procedure, and lasts for several weeks (depending on the nature of the tumour). There are different forms of radiotherapy for the prostate available.

Radiotherapy fights cancer by using high energy radiation to destroy cancer cells that multiply rapidly. It prevents the cancer cells from multiplying and stops the cancer from growing larger. It is a commonly recommended form of treatment as it is less invasive than surgery, and does not carry as many risks as surgery does. During radiotherapy, patients will lie on a couch under a large x-ray machine. Each treatment lasts only for a few minutes and is not painful.

Forms of radiotherapy

There is a wide range of forms of radiotherapy in treating cancer of the prostate.

External beam therapy

External beam therapy is divided into Standard External Beam Therapy and 3D Conformal Therapy. It delivers radiation beams targeted to the prostate, and is carried out as an outpatient procedure - patients do not have to stay in the hospital.

3D Conformal Therapy is a more updated method but is less widely available. It uses beams that are shaped to the outline of the prostate. Computer images are used to target the beams accurately.

Brachytherapy

Brachytherapy is a form of radiation therapy used in more localised prostate cancer, meaning cancer that is more confined to the prostate itself. In brachytherapy, the doctor implants radioactive seeds directly into the prostate. This enables the radiation to be given at a higher dose in a more concentrated manner.

Brachytherapy is a fairly short procedure. Patients are usually required to stay in the hospital for only one night.

High dose rate (HDR) brachytherapy

High dose rate (HDR) brachytherapy is usually combined with external radiotherapy. It is used to treat more advanced prostate cancer, where treatment is needed to cover the whole prostate and a margin.

In HDR brachytherapy, thin stiff plastic tubes are inserted through the perineum (the area of skin behind the scrotum) and into the prostate. This is done under anaesthesia. A radiotherapy machine inserts a radioactive wire through each plastic tube and into the prostate. These wires are left in place for a few minutes and then removed.

Patients stay in the hospital for one night. The next day the procedure of inserting and removing the radioactive wires is repeated. The procedure takes about half an hour.

Figure 1: The machine used in HDR brachytherapy to insert radioactive wires through plastic tubes into the prostate. This is often used to treat more advanced prostate cancer.