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November 05, 2018

Surface Guided Radiation Therapy

Surface Guided Radiation Therapy

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GenesisCare answer all our SGRT questions—one of the most revolutionary technologies that increases the efficacy of radiotherapy.

Why is it imperative that radiotherapy is accurately administered?

Radiotherapy uses ionizing radiation to control or kill cancer cells.  It is an extremely effective treatment for cancer and in many cases can be a key part of a cure for the disease. Tumours are often located near sensitive normal tissues and critical organs, so while we want to get the prescribed dose to the tumour or tumour bed, we need to minimise dose to healthy tissue. Radiotherapy techniques are highly complex and any error in accuracy—either at planning or during set up and delivery—can lead to a geographic miss of the target, or healthy tissue being irradiated, which can lead to harmful consequences for the patient.

What is Surface Guided Radiation Therapy?

Surface Guided Radiation Therapy (SGRT) is a technique that tracks the exact position of the surface of the patient in real time, and compares this to the ‘ideal’ position from the treatment plan. Firstly, this gives very clear directions to accurately position the patient before treatment. Secondly, during treatment, if the patient moves away from the correct position, SGRT can automatically pause the treatment, protecting healthy tissue

How does SGRT work?      

SGRT systems use stereo cameras to project a patterned or speckled light onto the patient, which is then registered within the SGRT system, and a computer turns this into a 3D view. This is rather like using your two eyes to build up a 3D view of the world. The SGRT system then compares this to the patient’s individual treatment plan in 3D, and checks that the surface in this plan is matched by the surface in real life. During positioning, this gives directions for how to set the patient up accurately. During treatment, it automatically pauses treatment if the patient moves from the ideal position.

Who can benefit from using SGRT?

SGRT can be used to position ANY patient. SGRT is at least as effective as the historical technique of setting up with tattoos and lasers. It offers the benefit of not requiring us to tattoo or mark our patients and being able to monitor them with sub-millimetric accuracy through the entire procedure, without any extra dose.  It is also highly advantageous for those patients whose treatment area is close to important organs that are at risk from radiation exposure, such as the breast, brain, lungs or liver.

What are the advantages of using SGRT?

  • SGRT has been shown in a study to reduce to zero the heart toxicity typically found in treating left-breast cancer, so these patients clearly gain a huge benefit
  • For patients with cancer in the brain, SGRT has been shown to give the same long-term outcomes as more invasive, slower treatments that are less comfortable for the patient
  • No requirement for tattoos for radiotherapy
  • Easier to re-align patient if they move during treatment, correcting rotations
  • Less imaging = Less radiation 
  • Faster treatment time
  • Reducing repeat imaging

What can a patient expect to experience when planning and receiving SGRT? 

The first stage within the treatment cycle is a CT scan, where the patient will be positioned in the same way as for the treatment. This CT scan is then used to produce an individualised treatment plan and the patient contours are sent to the SGRT system.

The patient will be treated on a linear accelerator.  To get the patient into the same position as the CT scan, the SGRT system is switched on during set up and the patient will see a light pattern on their skin which is the SGRT system monitoring their position.

The radiographers will use SGRT system to position the patient in exactly the same position as during the CT scan.  During delivery of the treatment fields the SGRT system will constantly track the patients position, ensuring that even accidental movements do not lead to inaccurate treatment.

How do you find that radiation tattooing affects patients?

Some patients don’t mind tattoos, and some see tattoos as the most dreaded aspect of radiotherapy. A lot of people might think it’s a small thing to deal with while being treated for cancer. However, so many patients now survive cancer, and permanent tattoos, especially in highly visible places, can be a permanent reminder of a really bad time in a patient’s life and have a negative impact on body image.

Is it true that SGRT can make treatment tattoo-less?

Yes—100 percent with the introduction of SGRT.

Is SGRT available in the U.K?

At GenesisCare we provide SGRT in all our U.K. centers.

Are there any other treatments that can help to increase the effectiveness of conventional radiotherapy?

Currently SGRT is one of the most revolutionary technologies that helps increase the speed, accuracy and safety of radiotherapy.

GenesisCare are constantly working to implement the latest treatments and technologies for patients, by designing better care for better life outcomes.

For more information, visit: https://www.genesiscare.co.uk/