Four-dimensional and gated radiation therapy

In delivering radiation therapy we take great care to treat only the tumour. This avoids the surrounding healthy tissues. A key challenge in treating tumours in the chest and abdomen is internal movement. This movement occurs when the patient breathes. We offer patients advanced technologies to account for the movement caused by breathing

We can use four-dimensional and gated radiation therapy treatments to treat cancers. More exactly, these are cancers that experience movement due to patient breathing. This may include: 

What four-dimensional and gated radiation therapy techniques mean for you

We need a computed tomography (CT) scan to outline the tumour and surrounding organs. This allows us to plan radiation therapy treatment. Routine CT scans capture pictures of the anatomy at a moment in time. They may not display the movement that occurs with breathing. Four-dimensional CT (4DCT) scans use specialised equipment. This equipment watches breathing while we take the scan. 4DCT scans let the radiation therapy team assess tumour movement. They can then consider this movement when designing your treatment. Your doctor may believe your tumour is likely to move a lot with breathing. You will have a 4DCT scan to plan your treatment if this is the case. 

The 4DCT scan usually takes around 30 minutes. We place a device on or around your abdomen to check your breathing during the scan. Your radiation therapist will supply any special instructions. In most cases we only ask you to relax and breathe as you like. 

Respiratory gated radiation therapy might help in cases where the tumour moves a lot.  Your doctor may decide that this advanced technique is useful. If so, you will wear a device on or around the abdomen. This device will check your breathing during treatment for gated radiation therapy treatments. We can then target the tumour as it moves. We do this by turning on the treatment machine only at a defined point in your breathing cycle. 

The radiation therapy team

We plan and deliver four-dimensional and gated radiation therapy techniques. This takes place at our five radiation therapy sites. These are in Melbourne, Bendigo, Box Hill, Moorabbin, and Sunshine.  

A team of specialists to plan and deliver these techniques. This team includes radiation oncologists, radiation therapists and medical physicists. A range of other professionals will also support you. These professionals include nurses and allied health practitioners. Our radiation therapy team is proud to offer these advanced technologies. We continue to develop and progress treatment options for the people of Victoria.  

Speak with your doctor to find out if these techniques are the right choice for you. 

Related links

Benefits of four-dimensional (4D) imaging on radiation therapy