Search Results

You are looking at 1 - 10 of 29 items for :

  • By Author: Levivier, Marc x
Clear All
Restricted access

György T. Szeifert, Nicolas Massager, Jacques Brotchi and Marc Levivier

possible treatment modalities is radiosurgery, either as a primary intervention for circumscribed, small-volume, deep-seated lesions with difficult surgical access, or as a complementary treatment to other therapy. 10, 19, 20 Astrocytic tumors usually present with histologically more malignant characteristics at the time of recurrence, even if the original picture was relatively benign. 9 Postirradiation recurrent tumors may demonstrate alterations in gene expression, 7 which generally results in a dedifferentiated phenotypic appearance. We describe a patient with

Restricted access

Nicolas Massager, Jean Régis, Douglas Kondziolka, Théodore Njee and Marc Levivier

Grade III, 13 were Grade IV, and 34 were Grade VI. TABLE 1 Location of AVM in 87 patients Location No. of Patients (%) thalamopeduncular region 24 (28) tectopineal area 2 (2) cerebral peduncle 26 (30) pons 22 (25) middle cerebellar peduncle 7 (8) medulla oblongata 6 (7) Dose planning was based either on the results of angiography and MR imaging and/or computerized tomography studies. The mean treated volume was 1.3 cm 3 (range 1.4 mm 3 –14.2 cm 3 ). The median number of

Free access

Marc Levivier, Rafael E. Carrillo, Rémi Charrier, André Martin and Jean-Philippe Thiran

T he Leksell Gamma Knife (LGK, Elekta AB) is a dedicated device for cranial radiosurgery using concomitant gamma rays emitted from 60 Co radiation sources focusing at an isocenter. This design provides unique dosimetry characteristics with a very steep gradient. 10 , 13 , 17 , 18 Usually, multiple isocenters are used to shape the desired irradiation to the target volume with a high conformity and selectivity. Manual forward planning (i.e., the user places each isocenter at specific stereotactic coordinates) is currently the standard, most frequent way to plan

Restricted access

Nicolas Massager, José Lorenzoni, Daniel Devriendt, Françoise Desmedt, Jacques Brotchi and Marc Levivier

mild intravenous sedative had been administered in a standard manner. The frame was applied as close as possible to the plane of the intracisternal trigeminal nerve root. In all patients, we obtained stereotactic axial T 1 -weighted MR images, without and with Gd-contrast enhancement, and three-dimensional T 2 -weighted volume acquisitions divided in 1-mm slices, followed by CT densitometric imaging acquisition. Treatment planning was performed using Leksell GammaPlan (Version 5.31; Elekta Instruments AB). Fusion of the MR and CT images was performed to visualize the

Free access

Daniele Starnoni, Roy Thomas Daniel, Constantin Tuleasca, Mercy George, Marc Levivier and Mahmoud Messerer

to perform an intracapsular debulking focusing on reducing tumor size to render the tumor volume compatible for treatment with SRS. With increasing interest generated in this strategy at several centers worldwide, this article attempts to analyze the existing literature through a systematic review of this novel trend in the treatment of large VSs. Experience with this treatment paradigm is limited, and therefore functional and surgical outcomes should be updated through a meta-analysis approach of published data. Methods Search Strategy and Selection Criteria

Full access

Constantin Tuleasca, Laura Negretti, Mohamed Faouzi, Vera Magaddino, Thierry Gevaert, Erik von Elm and Marc Levivier

R adiosurgery was invented by the Swedish neurosurgeon Lars Leksell at the beginning of the 1950s 19 and defined as the “delivery of a single, high dose of ionizing radiation to a small and critically located intracranial volume through the intact skull.” 19 The main principle is that the radiation dose is concentrated within the target (conformity) while minimizing the irradiating of the surrounding healthy tissue, due to a very steep gradient (selectivity). Originally, Leksell conceived radiosurgery as a primary tool for functional disorders. 18 , 19 In the

Full access

Jean Régis, Constantin Tuleasca, Noémie Resseguier, Romain Carron, Anne Donnet, Jean Gaudart and Marc Levivier

may involve a mechanism of action that is more subtle than a purely destructive one. The technical nuances of GKS have a major impact on the clinical outcome of radiosurgery for TN. 33 Pain control increases according to the dose prescription, but a larger volume of nerve treated has been reported to dramatically increase the toxicity (i.e., the risk of bothersome hypesthesia) without increasing the rate of pain relief. 8 Also, a target placed close to the brainstem at the level of the root entry zone 26 seems to be associated with a higher risk of numbness and

Restricted access

effects are dependent not only on distance, but also on the dose, rate of administration, and the volume injected. 6 A dose administered as a bolus is more likely to produce central side effects than the same dose given as a slow continuous infusion. The efficacy and safety of intrathecal baclofen for long-term control of spasticity are well established. Interest in functional outcome and quality of life issues in patients with spasticity or other neurological disabilities has exposed the limitations of the currently available objective scales. There is a need for

Restricted access

Benoit Pirotte, Nicolay Gabrovsky, Nicolas Massager, Marc Levivier, Philippe David and Jacques Brotchi

microscopic variations were present between synovial cysts and pseudosynovial cysts. Clinical Presentation In this series, acute or subacute radicular pain was the most frequent synovial cyst—related symptom and was associated with intermittent neurogenic claudication in 25% of the patients. Indeed, the clinical presentation of synovial cysts depend on their volume, anatomical level, and mechanical relationship to neural structures. Once a critical size is reached, the cyst determines a cystoradicular conflict and generates acute or progressive sciatica. The

Restricted access

Benoit J. M. Pirotte, Alphonse Lubansu, Nicolas Massager, David Wikler, Serge Goldman and Marc Levivier

emission tomography with [ 18 F]fluoro-2-deoxy-D-glucose in the low-grade glioma . Neurosurgery 39 : 470 – 476 , 1996 6 Fisher BJ , Bauman GS , Leighton CE , Stitt L , Cairncross JG , Macdonald DR : Low-grade gliomas in children: tumor volume response to radiation . J Neurosurg 88 : 969 – 974 , 1998 7 Fisher PG , Fisher PG , Breiter SN , Carson BS , Wharam MD , Williams JA , : A clinicopathologic reappraisal of brain stem tumor classification. Identification of pilocystic astrocytoma and fibrillary astrocytoma as distinct