Four-dimensional and gated radiation therapy

In delivering radiation therapy great care is taken to precisely treat the tumour, avoiding the surrounding healthy tissues. A key challenge in treating tumours in the chest and abdomen is internal movement that occurs when the patient breathes.

At Peter Mac, we are able to offer our patients advanced technologies to account for the movement caused by breathing.

What are four-dimensional and gated treatments used for?

Four-dimensional and gated radiation therapy treatments may be used to treat cancers that experience movement due to patient breathing. This may include:

What do these techniques mean for you?

To plan radiation therapy treatment, a computed tomography (CT) scan is required to outline the tumour and surrounding organs. Routine CT scans capture pictures of the anatomy at a moment in time, and may not fully display the movement that occurs with breathing. Four-dimensional CT (4DCT) scans use specialised equipment to monitor breathing while the scan is taken. 4DCT scans enable the radiation therapy team to assess tumour movement, taking this into consideration when designing your treatment. If your doctor believes your tumour is likely to move significantly with breathing, you will have a 4DCT scan to plan your treatment.

The 4DCT scan usually takes around 30 minutes. A device is placed on or around your abdomen to monitor your breathing during the scan. Your radiation therapist will provide any special instructions; however, in most cases we simply ask you to relax and breathe comfortably.

In cases where the tumour moves significantly, your doctor may decide that an advanced technique called respiratory gated radiation therapy will be helpful. For gated radiation therapy treatments, a device is worn on or around the abdomen to monitor your breathing during treatment. By turning on the treatment machine only at a defined point in your breathing cycle, we are able to accurately target the tumour as it moves.

The radiation therapy team

Four-dimensional and gated radiation therapy techniques are planned and delivered at all five of our Peter Mac radiation therapy sites: Melbourne, Bendigo, Box Hill, Moorabbin and Sunshine.

A team of specialists are required to plan and deliver these techniques, including radiation oncologists, radiation therapists and medical physicists. You will also be supported by a range of other professionals including nurses and allied health practitioners. The Peter Mac radiation therapy team is proud to offer these advanced technologies, and is dedicated to developing and progressing treatment options for the people of Victoria.

Please speak with your doctor to determine if these advanced techniques are the appropriate treatment choice for you.