Understanding Radiation Therapy

What is radiation therapy?

Radiation therapy is a treatment that uses x-rays to kill cancer cells.  Radiation treatment only affects the part of the body where beams are aimed.  You do not feel radiation as it is being delivered.

Why is radiation therapy used?

  • To cure cancers.
    Radiation therapy is often in addition to other cancer treatment (surgery, chemotherapy(external link), and/or hormone therapy).  
  • To shrink a tumour so that surgery is more effective. 
  • To treat any cancer cells remaining after surgery.
  • To control cancers – slow cancer progression. 
  • To relieve cancer symptoms such as pain or a persistent cough.  This is called palliative care. 

How is radiation therapy delivered?

Radiation treatment can be given in two ways: from outside the body (external beam) or inside the body (internal).

External beam radiation therapy

Linear accelerator

Linear accelerator

This is the most common method.  Radiation beams from a treatment unit (linear accelerator) are focused from outside the body into the area affected by cancer. 
External beam radiation therapy is typically given over a number of days or weeks.  Treatments are usually given Monday to Friday with a rest at the weekend to help normal cells recover.
Almost everyone is treated as an outpatient.

Internal radiation therapy (Brachytherapy)

Brachytherapy involves placing a radioactive source inside your body, on or near the cancer.  This procedure may or may not require a general anaesthetic.
In some cases, a combination of both external and internal radiation therapy is used.

For further information on radiation therapy see the Cancer Society website section on Radiation Treatment(external link) 

For information on specific types of cancer click here(external link)