Role of Gamma Knife Radiosurgery in Neurosurgery: Past and Future Perspectives

Abstract

The gamma knife was the first radiosurgical device developed at the Karolinska Institute in 1967. Stereotactic radiosurgery using the gamma knife has been widely accepted in clinical practice and has contributed to the development of neurosurgery. More than 500,000 patients have been treated by gamma knife stereotactic radiosurgery so far, and the method is now an indispensable neurosurgical tool. Here we review long-term outcomes and development of stereotactic radiosurgery using the gamma knife and discuss its future perspectives. The primary role of stereotactic radiosurgery is to control small well-demarcated lesions such as metastatic brain tumors, meningiomas, schwannomas, and pituitary adenomas while preserving the function of surrounding brain tissue. The gamma knife has been used as a primary treatment or in combination with surgery, and some applications have been accepted as standard treatment in the field of neurosurgery. Treatment of cerebral arteriovenous malformations has also been drastically changed after emergence of this technology. Controlling functional disorders is another role of stereotactic radiosurgery. There is a risk of radiation-induced adverse events, which are usually mild and less frequent. However, especially in large or invasive lesions, those risks are not negligible and pose limitations. Advancement of irradiation technology and dose planning software have enabled more sophisticated and safer treatment, and further progress will contribute to better treatment outcomes not only for brain lesions but also for cervical lesions with less invasive treatment.

TSH-secreting pituitary adenomas treated by gamma knife radiosurgery: our case experience and a review of the literature

“…Its accuracy is comparable to a surgical blade, though it should not be employed for targets bigger than 4 cm since they need larger irradiation beams, producing more damage to surrounding structures. Although GK has to date been used successfully in the treatment of pituitary tumors for almost 50 years (a review by Koga et al 20 reports the sizeable number of 38,553 pituitary adenomas treated by gamma knife up to 2008), to our best knowledge only 14 cases of TSHomas treated by GK have been reported in the literature. [7][8][9][21][22][23][24][25] Due to the small number of reported cases and their scant follow-up, few data are available on the long-term efficacy and safety of this technique in the treatment of TSHomas.…”

Efficacy and Limitations of Stereotactic Radiosurgery in the Treatment of Glioblastoma

“…13) Stereotactic radiosurgery has been accepted as another option of salvage treatment for recurrent glioblastoma. 21) However, the highly invasive nature of glioblastoma makes this disease uncontrollable by stereotactic radiosurgery, because this targeted irradiation spares viable cells surrounding the target. 19) Therefore, considerable advances are needed to effectively utilize stereotactic radiosurgery for the treatment of this challenging disease.…”

Image-Guided Neurosurgery

“…Linear accelerators (linacs), CyberKnife, Gamma Knife (Figure 2), and MRIdian are devices that generate mega electron volt electrons, gamma rays, or x-rays to target lesions. These systems use either real-time optical, electromagnetic, CT, cone beam CT, portal imaging, or MRI to direct and guide the surgery [55][56][57]. Linear accelerators (linacs) rotate around the patient while multileaf collimators adjust the electron or x-ray beam width to conform to the treatment plan.…”

“…The focused gamma rays deliver enough radiation dose in one session to adequately treat tumours. If the tumour is too large, then multiple sessions can be accommodated [56]. Advantages of this type of system include lower maintenance costs and the ability to deliver a highly focused dose to a target sites.…”