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Stereotactic radiosurgery
Definition
Stereotactic radiosurgery is a form of radiation therapy that focuses high-powered x-rays on a small area of the body. Other types of radiation therapy are more likely to affect nearby healthy tissue. Stereotactic radiosurgery better targets the abnormal area.
Despite its name, radiosurgery is a treatment, not a surgical procedure.
Alternative Names
Gamma knife; Cyberknife; Stereotactic radiotherapy; SRT; Stereotactic body radiotherapy; SBRT; Fractionated stereotactic radiotherapy
Description
Some types of stereotactic radiosurgery require a specially fitted face mask or a frame attached to your scalp. This may be done using small pins or anchors that go through your skin, to the surface of your skull or bone.
During your treatment, you will lie on a table, which slides into a machine that delivers radiation. The machine may spin around you while it works. The nurses and doctors will be able to see you on cameras, and hear you and talk with you on microphones.
Each treatment takes about 30 minutes to 1 hour. Some patients may receive more than one treatment session, but usually no more than five sessions.
Why the Procedure Is Performed
Stereotactic radiosurgery is often used to slow down the growth of small, deep brain tumors that are hard to remove during surgery. Such therapy may also be used in patients who are unable to have surgery, such as the elderly or those who are very sick. Radiosurgery may also be used after surgery to treat any remaining abnormal tissue.
Stereotactic radiosurgery was once limited to brain tumors, but today it may be used to treat many other diseases and conditions.
Brain and nervous system tumors:
- Brain metastases
- Acoustic neuroma and other head and neck (nasopharyngeal) cancers
- Pituitary tumors
- Spinal cord tumors
- Cancer of the eye (uveal melanoma)
Other conditions:
- Blood vessel problems such as arteriovenous malformations
- Movement disorders
- Parkinson’s disease
- Some types of epilepsy
- Trigeminal neuralgia, which causes severe face pain
Other cancers for which radiosurgery is either being used or studied include:
Risks
Radiosurgery may damage tissue around the area being treated. Brain swelling may occur in people who received treatment to the brain. Swelling can go away without treatment, but some people may need medicine to control this swelling.
Before the Procedure
Before the treatment, you will have MRI or CT scans. Using these images, a computer creates a 3-D (three dimensional) map of the tumor area. This planning process helps your neurosurgeon and radiation oncologist determine the specific treatment area.
The day before your procedure:
- Do not use any hair creams or hair spray.
- Do not eat or drink anything after midnight unless told otherwise by your doctor.
The day of your procedure:
- Wear comfortable clothing.
- Bring your regular prescription medicines with you to the hospital.
- Do not wear jewelry, makeup, nail polish, or a wig or hairpiece.
- You will be asked to remove contact lenses, eyeglasses, and dentures.
- You will change into a hospital gown.
- An intravenous (lV) line will be placed into your arm to deliver contrast material, medicines, and fluids.
After the Procedure
Often, you will be able to go home about an hour after the treatment is finished. You should arrange for someone to drive you home. Most people go back to their regular activities the next day, if there are no complications such as swelling. Some patients are kept in the hospital overnight for monitoring.
Outlook (Prognosis)
The effects of radiosurgery may take weeks or months to be seen. The prognosis depends on the condition being treated. Many times, your health care provider will monitor your progress using imaging tests such as MRI and CT scans.
References
Chang EF, Quigg M, Oh MC, et al; Epilepsy Radiosurgery Study Group. Predictors of efficacy after stereotactic radiosurgery for medial temporal lobe epilepsy. Neurology. 2010 Jan 12;74(2):165-72.
Welling DB, Packer MD. Stereotactic radiation treatment of benign tumors of the cranial basae. In: Flint PW, Haughey BH, Lund VJ, Niparko JK, Richardson MA, eds. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa: Mosby Elsevier;2010:chap 179.
Ewend MG, Morris DE, Carey LA, Ladha AM, Brem S. Guidelines for the initial management of metastatic brain tumors: role of surgery, radiosurgery, and radiation therapy. J Natl Compr Canc Netw. 2008;6:505-513.
Suh JH. Stereotactic radiosurgery for the management of brain metastases. N Engl J Med. 2010;362:1119-1127.
Reviewed By: Ken Levin, MD, private practice specializing in Radiology and Nuclear Medicine, Allentown, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
