New system for radiotherapy
Parkway’s new radiation oncology centre at Mount Elizabeth Novena Hospital features the Varian TrueBeam system. Dr Lee Kuo Ann, a Consultant Radiation Oncologist at Parkway Cancer Centre, tells us more about it.
What is the Varian TrueBeam system and how does it make a difference?
TrueBeam is a radiotherapy and radio-surgery treatment system that is capable of very fast and very precise image-guided radiotherapy.
It incorporates advanced imaging and motion management technologies so that we can monitor the delivery of radiation better.
How does it work?
The system synchronises imaging, patient positioning, motion management, beam shaping and dose delivery.
Accuracy checks are also done every ten milliseconds throughout the entire treatment.
TrueBeam’s imaging technology is very fast. It can produce three-dimensional images in 60 per cent less time than previous Varian imaging technology.
It also uses an X-ray dose that is 25 per cent less than the normal dose to create the images.
With these images, we can fine-tune a patient’s position prior to and during the treatment process.
Because TrueBeam is incredibly accurate and can take into account movement, it can be used for tumours in places such as the lungs.
It is able to monitor the patient’s breathing and compensate for movement of the tumour while the dose is being delivered.
What does it mean for patients?
TrueBeam means greater comfort for patients as well as a new treatment option for particular kinds of cancer.
The system can deliver the radiation dose very quickly. It can do in two minutes what used to take between 10 to 30 minutes.
Because of this speed, patients spend less time being treated, which means an increase in patient comfort as they no longer need to hold still for long periods of time.
By being fast, it also reduces the chance of tumour motion during treatment. This allows TrueBeam to deliver the treatment precisely while avoiding nearby healthy tissue and critical organs.
Apart from its technology, TrueBeam has also been designed with patient comfort in mind.
It has built-in music capabilities so patients can listen to music during their treatment.
Patients can also communicate with the therapist who operates the system.
In addition, the system enables the therapist to visually monitor the patient using CCTV.
What happens when a person is treated?
After their diagnosis, a medical physicist generates three-dimensional diagnostic images (usually CT or MRI) of the tumour and the area around it. They then use these images to specify the dose of radiation needed to treat the tumour. A radiation oncologist will work with a physicist to plan an individualised treatment.
After this, the patient receives individualized TrueBeam treatments according to a schedule specific to the treatment plan. The total dose of radiation is usually divided into smaller doses (called fractions) that are given daily over a specific time period.
During a TrueBeam treatment, a medical linear accelerator is used to deliver the radiation. The linear accelerator can rotate around the patient to deliver the radiation.
The radiation is shaped and reshaped as it is continuously delivered from virtually every angle in a 360-degree revolution around the patient.
Sometimes a marker block device is used to monitor breathing patterns to compensate for breathing motion during the treatment. Most treatments usually take only a few minutes a day.
By Jimmy Yap
|new ways to treat cancer, radiotherapy (radiation therapy), varian truebeam
|PUBLISHED 27 JUNE 2015