Resection of deep-seated gliomas using neuroimaging for stereotactic placement of guidance catheters.
ABSTRACT A simple computed tomography- (CT) or magnetic resonance (MR) imaging-guided stereotactic method for guided microsurgical resection of either deep-seated gliomas or tumors adjacent to an eloquent area is described. The technique employs the Brown-Roberts-Wells stereotactic system and twist drills, 2.7 mm in diameter, for the stereotactic placement of 2.4 mm diameter scaled guidance catheters through the calvaria. In a patient with a deep-seated small glioma, less than 2 cm diameter, one catheter was implanted into the center of the enhanced mass through the cerebral cortex. In the other 14 patients, three to six catheters were used which made the tumor border clearer. After implantation of the guidance catheters, the stereotactic frame was removed and a standard open craniotomy performed. Target localization is not affected by brain movement, which is inevitable during open surgery. The tumor involved the frontal lobe in eight patients, the parietal lobe in two, and the thalamus in five. In all cases the lesion was quickly localized and radical removal was achieved. Neurological complications occurred in only one patient who suffered transient hemiparesis after the resection of a lesion in the pyramidal tract. The results demonstrate that microsurgery combined with CT- or MR imaging-guided stereotactic placement of guidance catheters is a new option for surgery of deep-seated gliomas or tumors adjacent to an eloquent area.
Article: Management of deep-seated gliomas.[Show abstract] [Hide abstract]
ABSTRACT: The management of thalamic and brain stem astrocytomas remains controversial. Treatment options are: (a) clinical observation, (b) radiotherapy without biopsy, (c) stereotactic biopsy followed by radio and/or chemotherapy, and (d) surgical removal with or without adjuvant therapy. Stereotactic surgical techniques have improved the morbidity and mortality rates of biopsies and surgical resection of deep-seated gliomas. The biologic behavior of these lesions is not well known and proliferation cell index tests may help in the choice of therapy. In this review, seven recent papers on the management of deep-seated gliomas are presented. Radical removal of thalamic pilocytic astrocytoma may cure the patient. In cases of low-grade astrocytomas, stereotactic guided surgical removal has low morbidity. Adjuvant radiotherapy should be used only in selected cases. Sterotactic biopsy followed by radio- and/or chemotherapy is the best option for thalamic or brain stem anaplastic astrocytomas and glioblastomas.Critical Reviews in Neurosurgery 02/1999; 9(1):34-40. DOI:10.1007/s003290050106
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ABSTRACT: Deep-seated astrocytomas within the basal ganglia and the thalamus are considered unfavourable for microsurgical removal since the circumferential neighbourhood of critical structures limits radical resection. On closer assessment, the thalamus has a unique configuration within the basal ganglia. Its tetrahedric shape has 3 free surfaces and only the ventrolateral border is in contact with vital and critical functional structures, e.g. the subthalamic nuclei and the internal capsule. The purpose of the present study was to investigate the feasibility of maximum microsurgical removal in a series of intrinsic thalamic astrocytomas. 14 patients with intrathalamic astrocytomas grades I to 4 as diagnosed by previous stereotactic biopsy or intra-operative frozen section were selected for maximum microsurgical removal. The infratentorial supracerebellar approach from the contralateral side was used for 4 limited neoplasms of the pulvinar. For the other 10 larger and more extensive processes a parieto-occipital transventricular approach was chosen. Final histology gave the result of astrocytoma grade 1 or 2 in 4 patients, and of astrocytoma grade 3 or 4 in 10 patients. Postoperative MRI confirmed reduction of the tumor mass by 80 to 100% in 11 of 14 cases. Regional ancillary radiotherapy with 60 Gy was administered postoperatively for astrocytomas grades 3 and 4. Two patients operated on via the posterior transventricular approach had new postoperative partial hemianopia. Five of the 14 patients finally needed a ventriculo-peritoneal shunt. During the follow-up time of 6 to 52 months, tumor progression/recurrence was observed in 6 of the 10 high grade and none of the low grade neoplasms. The present pilot series demonstrates the feasibility of the microsurgical concept. Comparison with other treatment modalities, such as brachytherapy, requires future consideration.Acta Neurochirurgica 02/2000; 142(12):1327-36; discussion 1336-7. DOI:10.1007/s007010070001 · 1.79 Impact Factor
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ABSTRACT: INTRODUCTION: Thalamic tumors are typical deep brain tumors; their incidence is not precisely known because of the different definition criteria. However, taking only lesions arising in the thalami into consideration (and excluding those secondarily involving the thalami from adjacent structures) approximately 40% of thalamic tumors affect patients under 18 years of age and thalamic neoplasms account for 2-5% of all intracranial tumors in children. MATERIALS AND METHODS: In the present paper we have focused attention on the neuroimaging features of thalamic tumors in a pediatric population; based upon personal experience, we suggest a rational neuroradiological approach to the diagnostic evaluation, describe CT and MRI findings of the most common tumors, and attempt to define basic patterns in order to provide the most reliable "pathological" diagnosis.Child s Nervous System 09/2002; 18(8):426-39. DOI:10.1007/s00381-002-0607-y · 1.16 Impact Factor