Journal of neurosurgery
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Journal of neurosurgery · Jan 2005
Tolerance dose in gamma knife surgery of lesions extending to the anterior visual pathway.
The authors performed a retrospective analysis of the radiation dose to the anterior visual pathway (AVP) to assess its tolerance to gamma knife surgery. ⋯ The tolerance dose of the AVP is considered to be less than 8 to 10 Gy; however, although the delivered dose to the AVP definitely exceeded the tolerance dose in all five cases, no visual disturbance has been identified. Longer follow up is required before any final conclusions may be drawn. Nonetheless, it is suggested that a visual disturbance may be avoided by using careful accurate dose planning even if the dose delivered to the AVP is higher than currently believed to be acceptable.
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Journal of neurosurgery · Jan 2005
Case ReportsGamma knife surgery of the pituitary: new treatment for thalamic pain syndrome.
Although reports in the literature indicate that thalamic pain syndrome can be controlled with chemical hypophysectomy, this procedure is associated with transient diabetes insipidus. It was considered reasonable to attempt gamma knife surgery (GKS) to the pituitary gland to control thalamic pain. ⋯ An initial significant pain reduction was observed in 13 (76.5%) of 17 patients. Some patients experienced pain reduction within 48 hours of treatment. Persistent pain relief for more than 1 year was observed in five (38.5%) of 13 patients. Rapid recurrence of pain in fewer than 3 months was observed in four (30.8%) of 13 patients. The only complication was transient diabetes insipidus in one patient. It would seem that GKS of the pituitary might have a role to play in thalamic pain arising after a stroke.
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The authors analyzed tumor control rates and complications in patients with superficially located meningiomas after gamma knife surgery (GKS). ⋯ There was a good tumor control rate with a high complication rate. Longer follow up of more patients is needed. Adjusting the dose-volume relationship should be considered to reduce complications.
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The authors conducted a study to evaluate the safety and efficacy of gamma knife surgery (GKS) for the treatment of brain metastases from lung cancer. ⋯ The risk-benefit ratio of GKS in this series was satisfactory. There was no difference in response rates of the two tumor types, and WBRT did not improve the duration of survival.
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Journal of neurosurgery · Jan 2005
Does new magnetic resonance imaging technology provide better geometrical accuracy during stereotactic imaging?
The authors sought to compare the accuracy of stereotactic target imaging using the Siemens 1T EXPERT and 1.5T SYMPHONY magnetic resonance (MR) units. ⋯ Larger distortions were observed when using the SYMPHONY 1.5T unit than those with the EXPERT 1T unit. Typical average distortion in EXPERT 1T was not more than 0.6 mm and 0.9 mm for axial and coronal images, respectively. Typical mean distortion for SYMPHONY 1.5T was not more than 1 mm and 1.3 mm for axial and coronal images, respectively. The image sequence affected the distortions in both units. Coronal T2-weighted spin-echo images performed in subthalamic imaging produced the largest distortions of 2.6 mm and 3 mm in the EXPERT 1T and SYMPHONY 1.5T, respectively. Larger distortions were observed in coronal slices than in axial slices in both units, and this effect was more pronounced in SYMPHONY 1.5T. Noncentrally located slice positions in the investigated volume of the phantom were associated with larger distortions.