Stereotactic radiosurgery (SRS) is a form of radiation therapy that focuses high-power energy on a small area of the body.
Despite its name, radiosurgery is a treatment, not a surgical procedure. Incisions (cuts) are not made on your body.
More than one system is used to perform radiosurgery. This article is about Gamma Knife radiosurgery.
Gamma Knife radiosurgery is done only for tumors and other medical problems of the head. For tumors and problems elsewhere in the body, other radiosurgery systems may be used.
Before treatment, you are fitted with a head frame. The frame is attached to your scalp. This is done using 4 small pins or anchors that go through your skin to the surface of your skull. Medicine is first given to numb the areas where the pins or anchors attach.
The frame keeps your head steady during treatment. It also helps your doctors ensure the energy beams are aimed at the exact spot in your head that needs treatment.
After the frame is attached to your head, imaging tests such as CT, MRI, or angiogram are done. The images show the exact location, size, and shape of your tumor or problem area.
Each treatment takes a few minutes to 2 hours. You may receive more than one treatment session. Most often, no more than five sessions are needed.
SRS targets and treats an abnormal area without damaging nearby healthy tissue.
Gamma Knife radiosurgery is used to treat the following types of brain tumors:
Gamma Knife is also used to treat other problems of the brain:
Radiosurgery may damage tissue around the area being treated. As compared to other types of radiation therapy, Gamma Knife treatment is much less likely to damage nearby healthy tissue.
Brain swelling may occur. Swelling usually goes away without treatment. Some people need medicine to control this swelling. In rare cases, surgery with incisions (open surgery) is needed to treat the brain swelling caused by the radiation.
The spots where the head frame is attached to your scalp may be red and sensitive after treatment. This should go away with time.
Often, you will be able to go home about 1 hour after the treatment. Arrange ahead of time for someone to drive you home. You can go back to your regular activities the next day if there are no complications such as swelling. If you have complications, you may need to stay in the hospital overnight for monitoring.
The effects of Gamma Knife radiosurgery may take weeks or months to be seen. The prognosis depends on the condition being treated. Your health care provider will monitor your progress using imaging tests such as MRI and CT scans.
The day before your procedure:
The day of your procedure:
Stereotactic radiotherapy; stereotactic radiosurgery; SRT; Fractionated stereotactic radiotherapy; SRS
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;74:165-172.
Ewend MG, Morris DE, Carey LA, et al. 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.
Welling DB, Packer MD. Stereotactic radiation treatment of benign tumors of the cranial basae. In: Flint PW, Haughey BH, Lund VJ, et al., eds. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, PA: Elsevier Mosby; 2010:chap 179.
Updated by: Luc Jasmin, MD, PhD, Department of Neurosurgery, Cedars Sinai Medical Center, Los Angeles and Department of Anatomy, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.
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