What Does the Stereotaxic Procedure for Treating Parkinson's Disease Involve?

Stereotaxic (also known as stereotactic) procedures are radiosurgical techniques that have been used to successfully treat the tremors that are characteristic of Parkinson's disease and other brain disorders, including essential tremors. Less invasive than radiofrequency (RF) and deep brain stimulation (DBS) treatments, the stereotaxic procedures are an attractive option if you or a loved one suffers from one of those conditions and seeks tremor relief to improve the quality of life.

What Is Stereotaxic Radiosurgery?

• The International RadioSurgery Association (IRSA) explains that stereotaxic radiosurgery involves the delivery of "a single, high dose of radiation in a one-day session." Precisely focused beams of radiation are directed at a specific area of the brain in order to correct defects or dramatically shrink benign and malignant tumors. Although the procedure most often is done in a single day, it is possible to spread out this therapy over a period of days, or even weeks, in a variation that is known as fractionated stereotaxic radiation. The advantage of the fractionated approach is the reduced exposure to radiation and the potential side effects it can have.

Study Finds Procedure Effective

• A long-term study strongly supportive of stereotaxic surgery was presented at the 51st annual meeting of the American Society for Radiation Oncology in early November 2009. The study concluded that this less invasive approach to treating tremor disorders, including Parkinson's disease, was equally as effective as RF and DBS surgeries in terms of both tremor relief and absence of complications at seven years after treatment. One of the study's authors, Rufus Mark, M.D., a radiation oncologist at the Joe Arrington Cancer Center in Lubbock, Texas, said, "In view of these long-term results, this noninvasive procedure should be considered a primary treatment option for tremors that are hard to treat."

Equipment

• There are three types of equipment that can be used to perform stereotaxic radiosurgery, according to the website of RadiologyInfo.com. These are the Gamma Knife, linear accelerator and proton beam (heavy-charged particle radiosurgery), the last of which is rarely used in North America. Gamma Knife technology uses 192 to 201 narrowly focused beams of gamma radiation to target small to medium lesions. The linear accelerator delivers high-energy x-rays and is appropriate for the treatment of larger lesions. Proton beam technology uses a cyclotron or synchrotron to generate protons, and is used mainly in radiation treatment of tumors.

Procedure for Parkinson's

• At the University of Virginia Health System, which performs stereotaxic radiosurgery for the treatment of Parkinson's, the patient is usually admitted on the day of the procedure. The patient is fitted with a localizing frame that surrounds the area to be treated with radiation. A MRI scan is conducted to confirm proper placement, after which the surgical team focuses the radiation beam on the affected area for a prescribed period of time. IRSA reports that the one-session stereotaxic procedure "has such a dramatic effect in the target zone that the changes are considered 'surgical.'"