In stereotactic radiosurgery (SRS), dozens of tiny radiation beams are used to accurately target brain tumours with a single high dose of radiation. Despite its name, SRS is not a surgical procedure that requires an incision or anaesthesia. Despite this, the radiation beams are as small and precise as a scalpel.
Three-dimensional images from MRI and CT scans are used to determine the exact dimensions of the tumour. It then calculates the radiation dose that nearly 200 radiation beams will administer. The radiation therapist can target the tumour without affecting delicate structures nearby. Multiple lesions can be treated using SRS in a single procedure.
With stereotactic radiosurgery, patients do not have to undergo multiple radiation treatments and can return to their routine within a few days after the procedure.
Your oncologist may order additional SRS treatments in some cases. There are smaller doses of radiation, or fractions, within a single dose of radiation. Fractionated stereotactic radiosurgery is what is referred to as this procedure.
Using stereotactic radiosurgery effectively treats tumours in small areas of the head and neck that surgery cannot reach. The procedure may also be used on patients who cannot tolerate surgery or have previously received radiation therapy to the brain.
In addition to treating secondary cancers that have spread to the brain (brain metastasis), SRS may also be used to remove slow-growing benign tumours (such as acoustic neuromas) and occasionally to re-radiate areas that have previously been treated with radiation therapy (head and neck cancers, primary brain cancers). Also, SRS may be used to treat conditions that are not cancerous or tumourous, including arteriovenous malformations (an abnormal connection between veins and arteries) and complex cases of trigeminal neuralgia.