Gamma knife

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Gamma knife
Gamma knife
Leksell Gamma Knife.
Leksell Gamma Knife.

A gamma knife (or Leksell gamma knife) is a device used to treat brain tumors with a high dose of radiation therapy in one day. The device was invented by Lars Leksell, a Swedish neurosurgeon, in 1967 at the Karolinska Institute in Sweden. As of March 2008 there are 259 devices deployed worldwide.[1]

The gamma knife device contains 201 cobalt-60 sources of approximately 30 curies (1.1 TBq) each, placed in a circular array in a heavily shielded assembly. The device aims gamma radiation through a target point in the patient's brain. The patient wears a specialized helmet that is surgically fixed to their skull so that the brain tumor remains stationary at target point of the gamma rays. An ablative dose of radiation is thereby sent through the tumor in one treatment session, while surrounding brain tissues are relatively spared.

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[edit] Efficiency

Gamma knife radiosurgery has proved effective for patients with benign or malignant brain tumors, vascular malformations such as an arteriovenous malformation (AVM), pain or other functional problems.[citation needed] The procedure is less invasive than alternative surgeries such as micro-decompression. For treatment of trigeminal neuralgia the procedure may be used repeatedly on patients.

Ultimately, consideration for gamma knife radiosurgery treatment is contingent upon the patient's diagnosis, medical history and the case's overall severity upon consultation. In some instances, radiation oncologists will consider treatment for patients with metastatic disease, the elderly and whose life span will not exceed fifteen years, as well as those with inoperable lesions.

The risks of gamma knife radiosurgery treatment include but are not limited to radiation necrosis, secondary malignancy caused by the radiation (ie: formation of new tumor), bleeding, infection from the placement of the stereotactic headframe, paralysis, and death.

[edit] Operating principles

Radiosurgery uses high doses of radiation to kill cancer cells and shrink tumors, delivered with surgical precision to avoid damaging healthy brain tissue. Gamma knife radiosurgery is able to accurately focus many beams of high-intensity gamma radiation to converge on one or more tumors. Each individual beam is relatively low energy, so the radiation has little effect on intervening brain tissue.

[edit] See also

[edit] Footnotes

  1. ^ Leksell Gamma Knife 15 years later (Czech). Retrieved on 2008-03-27. “Article about the national-wide fundraising campaign in Czechoslovakia to obtain the device, written by the František Janouch, the main organizer.”

[edit] References

  • Sheehan et al. Gamma knife surgery-induced meningioma. Report of two cases and review of the literature. J Neurosurg. 2006 Aug;105(2):325-9.
  • Rowe et al. Risk of Malignancy after Gamma Knife Radiosurgery, Neurosurgery. 60(1):60-66, January 2007.
  • Sheehan et al. Gamma knife surgery for brain metastases from lung cancer, J Neurosurg, No. 102, Suppl:128-33, 2005
  • Mack et al. Quality assurance in stereotactic space. A system for verifying the accuracy of aim in radiosurgery. Medical Physics 29:4. April 2002.

[edit] External links