What is Stereotactic Radiosurgery?
Stereotactic = positioned very precisely
Radiosurgery = a form of radiation therapy that does not involve a surgical opening or incision
Stereotactic radiosurgery is a form of radiation therapy that directs powerful doses of radiation to very precise locations. It is used to shrink tumors and treat tangled blood vessels.
Radiosurgery is not considered surgery per se, since it does not require making an incision. Instead, stereotactic radiosurgery uses radiation:
- to shrink tumors by distorting or destroying the DNA of tumor cells. The destruction of their genetic material prevents the cells from reproducing and the tumor from growing. As a result, the tumors usually shrink in size over time.
- to treat blood vessel lesions in the spine, such as arteriovenous malformations (AVMs), by closing off the blood vessels.
Stereotactic radiosurgery uses many small beams of radiation that approach the tumor, lesion, or other area from many different angles. Each individual beam of radiation has very little effect on the healthy tissue it passes through. However, the beams all meet precisely at the area of treatment, delivering a large, focused dose of radiation there.
Stereotactic radiosurgery is usually performed in a single session. Occasionally, when the tumor or lesion is located within the spinal cord, the treatment may be split into two or three sessions. This minimizes the amount of radiation exposure that the spinal cord experiences at once.
When is this Procedure Performed?
Stereotactic radiosurgery is performed in patients who have small tumors or tangles of blood vessels on the spinal cord or on the surrounding areas. It may be performed when the lesion or tumor cannot be reached by standard surgical procedures. It may also be used in patients with heart conditions or other problems that make them unable to undergo an open surgical procedure. It can also be used as a follow-up if residual tumor or AVM remains after open surgery.
Stereotactic radiosurgery can be used in adult or pediatric patients, though it is rarely used in children under the age of 3.
How is this Procedure Performed?
Radiosurgery typically involves a team of health care providers that may include a neurosurgeon and/or a neuroradiologist, a radiation oncologist (a physician specializing in radiation treatment of cancer), a radiation therapist (professional who delivers radiation therapy), a registered nurse, and a medical physicist and a dosimetrist (professionals who work together to calculate the exact placement and number of radiation beams that will meet the treatment specifications).
This type of procedure does not cause any pain, and in adult patients it does not require general anesthesia (medicine that produces unconsciousness). Pediatric patients may receive general anesthesia.
The doctor or nurse starts an intravenous (lV) line that can deliver the contrast dye, medicines, and fluids needed for the procedure directly into a vein in the patient’s arm. The patient lies on a table that slides into the machine that delivers the radiation. This machine has a robotic arm that will move around and deliver the radiation to the specific area of interest.
The treatment typically takes about 30 minutes to 2 hours.
There are three types of radiosurgery systems. These are the Gamma Knife system, linear accelerator (LINAC) system, and particle beam therapy. Which system is used depends on the condition being treated.
- Gamma Knife system- This system releases highly-focused beams of radiation called gamma rays to treat small to medium size lesions and tumors, usually in the brain.
- Linear accelerator (LINAC) system- This system releases high-energy X-rays to treat a tumor or other lesion. LINAC systems differ from Gamma Knife systems in that LINAC systems use X-rays and Gamma Knife systems use gamma rays. With LINAC systems, the machinery moves around the patient during treatment and so is able to treat larger tumors and larger affected areas than the Gamma Knife system. The LINAC system is used in the brain and other areas. The Truebeam is the LINAC system used for spine procedures at Columbia University Medical Center/NewYork-Presbyterian Hospital.
- Particle beam therapy- This system uses particles like protons, neutrons, or helium or carbon ions instead of radiation like gamma rays or X-rays. This system may be used for radiosurgery procedures or for fractionated radiotherapy (therapy involving several smaller doses of radiation over a certain period of time). Proton beam therapy is the most commonly used type of particle beam therapy.
How Should I Prepare for this Procedure?
The day of your procedure, avoid using body lotion, hair creams or hair spray. In addition, avoid eating or drinking anything after midnight unless told otherwise by your doctor.
On the day of your procedure, it is recommended that you wear comfortable clothes you can change into after the procedure (you will be given a hospital gown to wear during the procedure). Be sure to remove any nail polish or acrylic nails and remove all jewelry. Do not wear any makeup or wigs/hairpiece.
During the procedure, you will need to remove contact lenses, eyeglasses, and dentures.
What Should I Expect After the Procedure?
Patients should arrange to have someone else drive them home from the treatment. Normal activities can usually be resumed the following day.
The neurosurgeon will arrange a follow-up visit about four weeks after the procedure. Imaging scans of the treated area may be performed about six weeks after the procedure.
- How long will I stay in the hospital?
Patients who do not experience complications such as swelling usually go home the day of treatment. If there is swelling, or in selected cases, patients may stay in the hospital overnight.
- Will I need to take any special medications?
No special medications are necessary.
- Will I need to wear a collar or brace?
No collar or brace is necessary.
- When can I resume exercise?
Patients can resume exercise as they feel able.
- Will I need rehabilitation or physical therapy?
Rehabilitation and physical therapy are not necessary following stereotactic radiosurgery.
- Will I have any long-term limitations due to stereotactic radiosurgery?
There are no long-term limitations due to this procedure.
Preparing for Your Appointment
Dr. Richard C. E. Anderson is an expert in pediatric stereotactic radiosurgery.