Stereotactic radiosurgery is a medical procedure which is used to treat brain tumors as well as certain other brain abnormalities. Stereotactic radiosurgery is not actually a type of surgery; it is a type of radiation therapy which involves the delivery of high-dose radiation. This radiation is very specifically targeted to a brain tumor or other abnormality. This procedure is the preferred alternative to open surgery, as it is much less invasive and avoids the possible complications of brain surgery.
Stereotactic radiosurgery is mainly used to treat benign and malignant brain tumors. In addition, the procedure can treat defects in blood vessels, and functional brain disorders such as trigeminal neuralgia, which causes severe trigeminal nerve pain. In the future, this procedure may also be useful for the treatment of brain disorders such as Parkinson’s disease and epilepsy.
The primary piece of equipment used in this procedure is a tool called a Gamma Knife®. This tool is used to focus approximately 200 beams of gamma rays at the targeted region of the brain. The Gamma Knife® focuses beams of radiation on the target area in three dimensions, allowing the use of high-energy radiation which is so specifically targeted that it leaves surrounding areas of healthy tissue almost completely untouched. This piece of equipment is operated by a radiation therapist, typically with the aid of a neurosurgeon or oncologist.
As with other types of radiation therapy, the objective of stereotactic radiosurgery is to shrink a tumor, rather than remove it as in true surgery. Radiation therapy damages tumor cell DNA, causing the cells to stop reproducing. Eventually the tumor begins to shrink. In most cases, malignant tumors shrink more quickly than benign tumors; a malignant brain tumor may shrink within just a few months, whereas a benign tumor may shrink over one to two years.
Stereotactic radiosurgery is an outpatient procedure which generally requires a hospital stay of around twelve hours. The entire procedure involves an MRI scan and CT scan to determine the exact location and size of the tumor, followed by the radiation treatment. During the treatment, the patient wears an aluminum head frame which ensures the head is held immobile and that the radiation beams are focused accurately on the tumor. The Gamma Knife® stereotactic procedure is completely painless, and lasts between one and four hours.
After the procedure is over, the head frame is removed, and the patient may have a rest period before leaving the hospital. A minor headache is normal following this procedure and can be managed with pain medication. Over the next several weeks, certain side effects are likely to be experienced. These include dry, itchy, sensitive skin over the site of the treatment, hair loss in the area of treatment, and fatigue. Other possible short-term side effects are problems with eating, swallowing, or digesting food, headaches, nausea, vomiting, and diarrhea.