Overview (What it is, why it is used and how it works)
Stereotactic radiosurgery is a specialised type of external beam radiation therapy. Stereotactic radiosurgery (SRS) makes use of precisely-focused radiation beams that target tumours in the human body. Although the name of the treatment refers to surgery, it does not involve any incisions as in the case of traditional surgery.
The treatment damages the DNA of the targeted cells and prevents them from reproducing and it causes them to shrink.
When Stereotactic Radiosurgery is used
This treatment is used to treat small tumours in delicate areas such as the brain, liver, spine, neck, lungs and other parts of the body.
Stereotactic Radiosurgery is also a good option for patients who cannot undergo anaesthesia and for those whose disease is not surgically accessible or in cases where the cancer is too advanced for neurosurgery.
Types of Stereotactic Radiosurgery
There are three technologies that are used to administer Stereotactic Radiosurgery radiation to the different parts of the body. Regardless of the type used, all radiosurgery or radiotherapy works similarly. The following types of technologies used:
- Linear accelerators which use high energy X-rays
- Gamma knife machines which use 192 or 201 small beams of gamma rays
- Proton beam therapy, which is currently only available in the United States and which uses high energy proton beams
Generally, one to five treatment sessions are administered over a one- or two-week period.
How Stereotactic Radiosurgery is administered
Before treatment an outline of the patient’s tumour is generated by an MRI and CT scan. During the procedure the patient remains awake while a radiation oncologist will use a computerised system to shape the radiation beam to match a three-dimensional model based on the outline of the tumour. Specialised equipment focuses multiple small beams on the tumour. An intense dose of radiation is delivered at the intersection point of the multiple beams but the beams do not affect the body parts through which the individual beams pass. Patients do not feel any pain or discomfort during treatment.
Side effects of Stereotactic Radiosurgery
- Temporary skin changes may occur at the site of treatment such as itchiness, dryness, redness and scaling
- Increased sensitivity to hot and cold temperatures
- Pain and infection at the site of the tumour