Medical Encyclopedia


Medical Encyclopedia

Other encyclopedia topics:  A-Ag  Ah-Ap  Aq-Az  B-Bk  Bl-Bz  C-Cg  Ch-Co  Cp-Cz  D-Di  Dj-Dz  E-Ep  Eq-Ez  F  G  H-Hf  Hg-Hz  I-In  Io-Iz  J  K  L-Ln  Lo-Lz  M-Mf  Mg-Mz  N  O  P-Pl  Pm-Pz  Q  R  S-Sh  Si-Sp  Sq-Sz  T-Tn  To-Tz  U  V  W  X  Y  Z  0-9 

Stereotactic radiosurgery

Contents of this page:

Alternative Names   

Gamma knife; Cyberknife; Stereotactic radiotherapy; Fractionated stereotactic radiotherapy; Cyclotrons; Linear accelerator; Lineacs; Proton beam radiosurgery

Definition    Return to top

Stereotactic radiosurgery is a form of radiation therapy that focuses high-powered x-rays on a small area of the body. With regular radiation therapy treatment, healthy tissue that is nearby also receives radiation. Stereotactic radiosurgery better focuses the radiation on the abnormal area.

Despite its name, it is considered a form of radiation therapy, not a surgical procedure.

Description    Return to top

During treatment, you will lie on a table, which slides into a machine that delivers radiation beams. The machine may rotate around you while it works.

Sometimes, a head frame may be attached to your scalp to keep you very still during therapy. There are different machines used to perform stereotactic radiosurgery. Some require the use of a frame, and others do not.

At other times, a special plastic mask fitted for your face may be used.

The entire procedure, including the planning stage, takes about half a day or less. The time period when you are receiving the radiation is usually only about 30 minutes. Some patients receive therapy more than once.

Why the Procedure is Performed    Return to top

It 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 other diseases and conditions, including:

Risks    Return to top

Radiosurgery may damage tissue around the area being treated. Brain swelling may occur in people who received treatment to the brain. Swelling usually goes away, but some people may need medicine to control long-term swelling.

Before the Procedure    Return to top

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 to determine the specific treatment area.

The day before your procedure:

The day of your procedure:

After the Procedure    Return to top

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)    Return to top

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    Return to top

DeAngelis LM. Tumors of the Central Nervous System and Intracranial Hypertension and Hypotension. In: Goldman L, Ausiello D. Goldman: Cecil Medicine. 23rd ed. Philadelphia, PA: Saunders Elsevier;2007:chap 199.

Kavanagh BD, Timmerman RD. Stereotactic radiosurgery and stereotactic body radiation therapy: an overview of technical considerations and clinical applications. Hematol Oncol Clin North Am. 2006;20:87-95.

Romanelli P, Anschel DJ. Radiosurgery for epilepsy. Lancet Neurol. 2006;5:613-620.

Sneed PK, Kased N, Huang K, Rubenstein JL. Brain metastases and neoplastic meningitis. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKena WG, eds. Clinical Oncology. 4th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 52.

Zivin JA. Hemorrhagic Cerbrovascular Disease. In: Goldman L, Ausiello D. Goldman: Cecil Medicine. 23rd ed. Philadelphia, PA: Saunders Elsevier;2007:chap 432.

Update Date: 1/22/2009

Updated by: Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M. Logo

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2009, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.