What is radiation therapy?

After surgery your doctors may recommend radiation therapy to help improve your outcome.

Radiation therapy uses x-rays to kill cancer cells by damaging their DNA. Normal cells can repair damage to their DNA, but cancer cells  are less able to do this  and therefore die. The dead cancer cells are then broken down and eliminated by the body’s natural processes. 

Since radiation therapy damages normal cells as well as cancer cells, treatment must be carefully planned to allow the normal cells to repair themselves and minimise side effects.

The total dose of radiation and the number of treatments you need will depend on the size and location of your melanoma, your general health and other medical treatments you’re receiving.

The radiation used for cancer treatment can come from a machine outside your body or it might come from radioactive material placed in your body near the cancer cells.

Types of radiation therapy

These are three of types of radiation therapy used at Melanoma Institute Australia:

Stereotactic Radiosurgery/Radiotherapy

  • Uses an extremely accurate beam to deliver a high-dose of radiation to a small area of cancer without excess damage to surrounding normal tissue.
  • Can only be used to treat small cancers with well-defined edges.
  • Most commonly used in the treatment of cancer in the brain, liver and lungs.
  • Requires an immobilisation device to ensure treatment is delivered accurately.

Volumetric Modulated Arc Therapy

  • Uses three-dimensional volume imaging to maximise the dose the tumour receives while minimising exposure of the surrounding healthy tissue.
  • Takes much less time to deliver treatment.
  • A new radiotherapy method first performed in the Sydney at Mater Hospital, North Sydney.


  • Uses radioactive sources placed inside the body.
  • Requires an operation with anaesthesia.
  • May require a hospital stay.
  • Can deliver treatment to otherwise inaccessible areas.

Side Effects

  • Temporary or permanent loss of hair in the area being treated
  • Skin irritation
  • Temporary change in skin colour in the treated area
  • tiredness

Other side effects might be experienced depending on the area of the body treated. Your radiation oncologist will discuss these with you.

External radiation therapy does not cause your body to become radioactive. There’s no need to avoid being with other people because you are undergoing treatment. Even hugging, kissing or having sex create no risk of radiation exposure.