What is Stereotactic Radiosurgery?
Stereotactic Radiosurgery (SRS) is a radiation therapy procedure that uses a special system to precisely deliver a large & accurate dose of ionizing radiation or X-ray to a tumour over one to five treatment sessions. This noninvasive procedure is implemented to destroy a tumour without surgery or harming nearby healthy tissue. It is used to treat various types of cancers such as tumours in the brain, spine, lung, liver and prostate, as well as some other non-cancerous disorders.
Is it the same as Gamma Knife?
Gamma Knife, CyberKnife and Novalis TX are different devices used for radiosurgery. They vary in their application, versatility, patient comfort and cost. While Gamma Knife is the earliest system evolved, its use is limited only to brain tumours and is a painful and invasive procedure. CyberKnife and Novalis TX are non invasive and can be applied to any tumour in any part of the body as long as they are three to four cms in size.
Is that why it is called frameless radiosurgery?
Unlike in the Gamma Knife where an invasive metallic frame is screwed on to the patient’s head, Novalis TX system uses a painless non-invasive mask to position the patient and uses a set of X-rays to verify the position of the tumour upto sub mm accuracy.
What are the advantages of frameless radiosurgery?
Apart from being a completely painless procedure, this form of radiosurgery offers extreme flexibility. Depending on the tumour size and location, the patient can be treated in either one or more fractions to maximise tumour control and minimise any side effects.
How difficult or safe is the procedure?
114 It is typically a day-care procedure hospitalisation. It does not involve any anesthesia, cuts, stitches or blood loss. A multi-disciplinary team of radiation oncologists, radiation physicists, neurosurgeons and radiologists oversee the procedure. Thousands of procedures are performed all over the world adhering to its safety norms. The key to patient safety lies in proper choice of the case and training of manpower.
For what type of tumours do you advise frameless radiosurgery?
Non-cancerous tumours of brain like meningioma, tumours of pituitary gland, and tumours of nerve sheaths like acoustic neuroma are treated by frameless SRS. However, these days more and more patients with spread of cancer inside the brain (metastasis) are treated with this procedure. In fact, this condition forms the major bulk of frameless SRS patients.
What about the other parts of the body?
Cancers spreading into the spine and early cancers of lung in elderly people are often treated with this procedure. However, early cancers of prostate, metastatic cancer into liver or other parts of abdomen as well as Technological recurrent cancers where other modalities have failed are also treated using SRS.
What are the side effects?
Being frameless, the actual procedure is absolutely painless. It takes a little more than half an hour, and patients are usually free to go home by the end of the day. They may experience a little bit of dizziness, headache and vomiting sensation for a few days, which is well managed by oral medications. Long term side effects like necrosis of adjacent tissue can be avoided by adhering to safety guidelines.
Can it replace surgery?
Not quite. Surgery and SRS arecomplementary. SRS is best used when the tumour is small and deep seated, thereby making conventional surgery risky. The main advantage of SRS is that it is painless and bloodless, yet offers the same cure rates as conventional surgery.
What is the advantage of Novalis TX?
Novalis TX is a shaped-beam frameless radiosurgery system. As tumours areusually irregular in shape, the radiationbeams from the Novalis TX system can be manipulated to conform to the shape of the tumour, thereby minimiing radiation to surrounding normal tissues. Being a frameless SRS system, it is painless, flexible and convenient. Also, it is the most cost effective of all radiosurgery systems.