Journal of neurosurgery
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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.
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Journal of neurosurgery · Jan 2005
Does gamma knife surgery stimulate cellular immune response to metastatic brain tumors? A histopathological and immunohistochemical study.
The aim of this study was to analyze the cellular immune response and histopathological changes in secondary brain tumors after gamma knife surgery (GKS). ⋯ Histopathological findings of the present study are consistent with a cellular immune response of natural killer cells against metastatic brain tumors, presumably stimulated by the ionizing energy of focused radiation.
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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
Comparative StudyStereotactic noninvasive volume measurement compared with geometric measurement for indications and evaluation of gamma knife treatment.
Volume estimation is one of the most important criteria in the evaluation and follow up of radiosurgical treatments and outcomes; however, several limitations are involved in the calculation estimation of target volumes. ⋯ The use of stereotactic volume calculation is highly recommended in planning, follow up, and determination of the outcome in patients participating in radiosurgical treatment and should lead to more uniform reports of the response to treatment.
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Journal of neurosurgery · Jan 2005
Long-term outcomes in patients with vestibular schwannomas treated using gamma knife surgery: 10-year follow up.
Gamma knife surgery (GKS) has been a safe and effective treatment for vestibular schwannomas in both the short and long term, although less is known about long-term outcomes in the past 10 years. The aim of this study was to clarify long-term outcomes in patients with vestibular schwannomas treated using GKS based on techniques in place in the early 1990s. ⋯ Gamma knife surgery remained an effective treatment for vestibular schwannomas for longer than 10 years. Although treatment failures usually occurred within 3 years after GKS, it is necessary to continue follow up in patients to reveal delayed tumor recurrence.