SBRT – Stereotactic Body Radiotherapy
Stereotactic Radiotherapy is a type of external beam radiotherapy that focuses high doses of radiation within the body and may be planned to account for movement associated with breathing where necessary. This is important when treating tumour’s of the lung. The trilogy machine used alongside RPM (Varian® Real-time Position Management™) Respiratory Gating System allows the synchronized delivery of radiation with the patient’s respiratory cycle in real time, leading to increased treatment precision. This video shows respiratory gating being used to treat a lung tumour. The beam of radiation only comes on when the tumour is in line with the beam and so, spares normal tissue from irradiation. Click below to watch a video on SBRT.
As with other radiotherapy techniques a CT scan must be obtained of you in the correct position for your treatment. The radiotherapy team will use this scan to plan your treatment. This usually takes two to three visits. Your treatment may require special equipment to help you lie in the correct position. This may be one of two different types.
The first is a special mask that helps you keep your head, neck and shoulders still during treatment. The other is a special mould of your body to be made to hold your position for your treatment. You will be required to hold your arms above your head and a plastic sheet may be draped over your chest and adhered to you by vacuum. This sheet will further help you to maintain your position. If it is required, the radiotherapy team will account for your breathing motion.
To do so a plastic marker is placed on your chest and its movement is traced by a camera in the room. The therapists may assist you with your breathing, if necessary, by prompting you when to breathe in and/or breathe out. Reference dots will be placed on your skin for the scan and your therapists will advise you if these marks are to be made permanent.
The total time required to position you and acquire the scan can be up to 1-2 hours. This is similar for the treatment also. Back to Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiotherapy (SBRT) Programme – Introduction Back to Extra-Cranial Radiosurgery Programme