Gamma Knife

In medicine, the Leksell Gamma Knife is a neurosurgical device used to treat brain tumors with radiation therapy. The device was invented by Lars Leksell, a Swedish neurosurgeon, in 1967 at the Karolinska Institute in Sweden.

The Leksell 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. A killing dose of radiation is thereby sent through the tumor in one treatment session, while all surrounding brain tissues receive less than a killing dose.

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Efficacy and risk

The Gamma Knife has proved effective for thousands of patients with benign or malignant brain tumors, vascular malformations such as an arteriovenous malformation (AVM), pain or other functional problems. 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. Leksell Gamma Knife has been reviewed in over 2,000 publications with long-term follow-up studies on patients all demonstrating high clinical success rates.^{[citation needed]}

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, neurosurgeons 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), hemorrhage, infection from the placement of the stereotactic headframe, paralysis and death.

Performance

Leksell Gamma Knife guarantees accuracy to better than 0.5mm and has found the actual achievable accuracy to be 0.15mm.^{[citation needed]} The new Leksell Gamma Knife Perfexion system provides a larger treatment volume, allowing more sites of treatment.

• Nearly half a million patients treated over 30+ years[1]
• As a form of radiosurgery, Gamma Knife is covered by most insurance providers[2]

Leksell Gamma Knife is the gold standard for stereotactic neurosurgery against which all other systems are compared.^{[citation needed]}[3]

See also

• Brain Tumor
• External beam radiotherapy
• Horsley-Clarke apparatus
• Minimally invasive procedure
• Neurosurgery
• Radiosurgery
• Radiation therapy
• Robotic surgery
• Stereotactic surgery
• Elekta, manufacturer of the Leksell Gamma Knife

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.