What is SRS?
Stereotactic radiosurgery (SRS) is a non-surgical treatment for small malignant tumors in the brain and some non-cancerous (benign) brain conditions. It’s an advanced radiation therapy technique that precisely delivers multiple beams of radiation to a tumor, sometimes in one, single treatment session. The benefit of SRS is that no surgery is required, hospitalization and the side effects of surgery are avoided. No incisions, no hospital stays.
SRS uses narrower x-ray beams than conventional “whole-brain” radiation therapy where a larger area of your brain receives radiation. As a result, it can target small tumors with pinpoint accuracy, within one to two millimeters, avoiding the surrounding healthy brain tissue. Because SRS has greater accuracy, we are able to deliver higher doses of radiation to the tumor site. The reduced risk of damage to healthy tissue also means that side effects are less likely.
There are three main advantages of stereotactic radiosurgery (SRS) over conventional whole-brain radiation therapy
- Single treatment
With conventional radiation therapy you may need as many as 10 treatments. But with SRS, the radiation is far more powerful and can be delivered in three to five doses, or even a single dose. This allows you to spend more time doing what you love, without having to factor in multiple trips for treatment sessions.
- Reduced side effects
Increased accuracy means that the radiation beam is less likely to hit your healthy tissue - and less likely to cause side effects than with conventional radiation therapy. Several studies have shown that this can help to preserve everyday cognitive function and an improved quality of life after treatment in both the short and long term.
- Surgery free treatment
In many cases, SRS means you can avoid having surgery. The benefit of SRS - surgery, hospitalization and the side effects of surgery are avoided. No incisions, no hospital stays.
How does SRS work?
Before your treatment, you’ll attend a planning appointment. Here, you’ll have a custom-made flexible mask fitted which will be used to keep your head still during treatment. You’ll also need a CT (computerized tomography) or MRI scan so we can locate the exact size, shape and position of your tumor, which helps us plan your treatment.
Before your treatment begins, you may be given steroids to help minimize the risk of swelling in thearea of your brain that is being treated.
You will lie down on the treatment couch and your radiation therapist will fit your mask on. It’s important that you’re in the correct position to match your planning scans so your radiation therapist may take some time to move you into place by moving the couch. SGRT and IGRT are utilized to improve the pin point accuracy required for SRS treatments.
You can also listen to music throughout the session, which should take between 20 and 30 minutes, or longer for more complex cases. You won’t be able to feel the treatment—SRS is a painless procedure. You can go home after your treatment has finished.
SRS may be suitable for you if you have either a tumor that started in your brain (primary tumor) or a tumor that has spread from elsewhere in your body (metastatic or secondary tumor). This includes:
- If you’ve had surgery to remove brain metastases to reduce the risk of recurrence
- Small tumors such as pituitary adenomas and chordomas or meningiomas at the base of the skull
- Benign (non-cancerous) tumors such as acoustic neuromas (vestibular schwannomas)
Your physicians are very experienced in the use of SRS as well as other techniques and together you’ll decide if this is the best option for you. SRS may not be suitable for you if:
- The treatment area includes certain important nerves that could be accidentally damaged by radiation
- The tumor is larger than 4cm
What about side effects?
You can expect fewer side effects with stereotactic radiosurgery (SRS) than conventional whole-brain radiation therapy because its greater accuracy means that the risk of damage to healthy brain tissue is lower.
You may experience some of the following during your treatment course, but they’ll usually disappear within two to four weeks of completing your treatment:
- Nausea and vomiting
- Dizziness and headaches
- Hair loss
- Changes to your skin in the treatment area
- Temporary worsening of your symptoms
Around 10% of people notice side effects months, or even years, after SRS. These are related to the treatment area within the brain and may include:
- Hearing loss
- Loss of brain function
- Memory loss
- Pituitary gland damage
- Radiation damage to the normal brain
- Visual impairment
- Secondary cancer, though this is rare
Many of these side effects can be successfully treated. It’s important you attend your follow-up visits and scans so we can identify and treat any of your problems as soon as possible.