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Jason Sheehan, Douglas Kondziolka, John Flickinger and L. Dade Lunsford

.5-tesla magnet are obtained for each patient. The sequences used are 1-, 2-, or 3-mm axial slice thickness volume acquisitions with intravenous Gd contrast. If patients were unable to undergo MR imaging, a contrast-enhanced CT scan was obtained using 1-, 2-, or 3-mm contiguous axial slices through the patient's entire brain. Patients were initially treated with fractionated radiation therapy. Patients were then eligible for radiosurgery if the tumor recurred or there was evidence of new tumors after radiation therapy, and if they harbored between one to six metastases

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Jason Sheehan, Douglas Kondziolka, John Flickinger and L. Dade Lunsford

had residual, recurrent, or unresectable tumor demonstrable on MR imaging or computerized tomography In addition, the maximal tumor size in any dimension had to be less than 4 cm. We ensured that all female patients were not pregnant at the time of GKS. All procedures were performed using model U, model B, or model C Gamma Knife units (Elekta Instruments, Norcross, GA). Currently, an MR image performed on a 1.5-tesla magnet is obtained in each patient. The sequence used is a 1-mm axial slice thickness, T 1 -weighted volume acquisition with intravenous Gd contrast

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Jason P. Sheehan, Douglas Kondziolka, John Flickinger and L. Dade Lunsford

Instruments, Atlanta, GA). The GKS methodology used to treat pituitary lesions is described in detail elsewhere. 36 An MR image of the sellar region was obtained for each patient by using a 1.5-tesla imager. One-millimeter-thick axial slices with volume acquisition, fat suppression, and intravenous gadolinium contrast were obtained. In all cases prior to 1989 or when a patient could not undergo MR imaging (for example, because of a non—MR imaging compatible aneurysm clip or a pacemaker), high-resolution 1-mm-thick axial CT scans with intravenous contrast were obtained

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Jason P. Sheehan, Ming-Hsi Sun, Douglas Kondziolka, John Flickinger and L. Dade Lunsford

, model B, or model C Leksell gamma knife units (Elekta Instruments, Atlanta, GA). Currently, MR imaging performed with a 1.5-tesla magnet is obtained in each patient. The sequences used are gadolinium-enhanced 1-, 2-, or 3-mm axial slice thickness volume acquisitions. If a patient was unable to undergo MR imaging, a contrast-enhanced CT scan was obtained using 1-, 2-, or 3-mm contiguous axial slices through the patient's entire brain. Patients were eligible to undergo GKS if they had between one and four metastases at presentation or one to six that progressed after

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Jason P. Sheehan, Ming-Hsi Sun, Douglas Kondziolka, John Flickinger and L. Dade Lunsford

, systemic disease and distant metastasis are not uncommon. Because of this, aggressive intervention combined with a low morbidity rate is desirable. Stereotactic radiosurgery provides, in a single session, a high dose of radiation to a localized brain tumor volume. Brain metastases are frequently easily identifiable as well-demarcated lesions on either CT scans or MR images, and this shape usually makes them amenable to stereotactic radiosurgery. 1, 4, 10, 11, 14, 15, 17, 27, 31 In this study we detail the efficacy of radiosurgery for treatment of renal cell carcinoma

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Greg Bowden, Hideyuki Kano, Daniel Tonetti, Ajay Niranjan, John Flickinger and L. Dade Lunsford

presented on the day of treatment and intravenous sedation was administered; in the case of children, general anesthesia with endotracheal intubation was used. The Leksell stereotactic frame was applied with local anesthetic applied to the pin sites. High-resolution axial imaging (MRI after 1991) was then performed, followed by biplanar stereotactic angiography. Radiosurgery planning was calculated with a margin dose covering the entire nidus volume. This study spans the use of several Leksell Gamma Knife units (models U, B, C, and 4C). At the conclusion of treatment all

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Greg Bowden, Hideyuki Kano, Ellen Caparosa, Seong-Hyun Park, Ajay Niranjan, John Flickinger and L. Dade Lunsford

publications. 14 , 22 Briefly, SRS was conducted as an outpatient procedure and intravenous conscious sedation was used. The Leksell stereotactic frame was applied after a local anesthetic agent was administered to the pin sites. High-resolution axial imaging (MRI unless contraindicated) was then conducted. Radiosurgery planning was calculated using a 3D conformal plan enveloping the entire enhancing tumor volume. This study spans the use of Leksell Gamma Knife models C, 4C, and Perfexion (Elekta AB). Clinical and imaging follow-up were requested at 3-month intervals

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Greg Bowden, Hideyuki Kano, Daniel Tonetti, Ajay Niranjan, John Flickinger, Yoshio Arai and L. Dade Lunsford

the entire nidus volume. This study spans the use of several Leksell Gamma Knife units (Elekta AB): models U, B, C, 4C, and Perfexion. After treatment, all patients received 20–40 mg of methylprednisolone intravenously. Patients were discharged from the hospital 2–24 hours after the procedure. Expanded technical elements of this technique have been detailed in previous publications. 27 , 28 The median AVM target volume was 3.85 cm 3 (range 0.1–17.7 cm 3 ), and the median maximum AVM nidus diameter was 2.3 cm (range 0.6–4.8 cm). The median marginal dose of

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Greg Bowden, Hideyuki Kano, Huai-che Yang, Ajay Niranjan, John Flickinger and L. Dade Lunsford

that corresponded to the 3D nidus volume. This study spans the use of Leksell Gamma Knife (Elekta AB) models U, B, C, 4C, and Perfexion. At the conclusion of treatment all patients received 20–40 mg of intravenous methylprednisolone. Patients were discharged within 2–24 hours after the procedure. Expanded technical elements of this technique have been detailed in our previous publications. 19 , 27 The median target volume was 4.6 cm 3 (range 0.1–22 cm 3 ), which was associated with a median maximum AVM nidus diameter of 2.6 cm (range 0.6–5.2 cm). The median

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Greg Bowden, Hideyuki Kano, Ellen Caparosa, Daniel Tonetti, Ajay Niranjan, Edward A. Monaco III, John Flickinger, Yoshio Arai and L. Dade Lunsford

GammaPlan software version 10 ( Fig. 1 ). The selected margin dose was based on the volume and location of the AVM. In this study, we used Leksell Gamma Knife Models U, B, C, 4C, and Perfexion units (Elekta AB). FIG. 1. Stereotactic radiosurgery planning using GammaPlan version 10 for optic radiation AVM. The AVM nidus was treated with 19 Gy at the 50% isodose line. Anteroposterior angiogram (A) , lateral angiogram (B) , sagittal T1-weighted MR image (C) , coronal T1-weighted MR image (D) , and axial T1-weighted MR image (E) . Figure is available in color