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O De Witte

Publications and source records attributed to O De Witte.

At least 19 recordsLinked to original sources
PubMed2005

[Transsphenoidal approach with low field MRI for pituitary adenoma].

INTRODUCTION: Appropriate evaluation of resection remains one of the major difficulties of surgical treatment of pituitary adenoma. The transsphenoidal approach does not allow direct visual control. Endoscopy provides useful information but may no distinguish well residual adenoma from the pituitary gland. Intraoperative MRI offers new perspectives for assessing the quality of resection. We report our experience with low field intraoperative MRI in surgical treatment of pituitary adenoma. POPULATION: Intraoperative MRI (Polestar N10, 30 patients and Polestar N20, 17 patients) was performed in 45 consecutive patients undergoing surgery for pituitary adenoma. Thirty-seven patients had a macroadenoma. Patients were in the prone position with the head fixed with a three-pin MRI-compatible headholder. METHOD: Coronal T1 MRI scans with enhancement were acquired pre and per operatively. We compared scans and surgical filling (complete removal). If there was a difference, a surgical control was undertaken. RESULTS: Intraoperative images were unavailable for two patients due to small size of the neck and the pituitary glands which were not in the middle in the field of view. For the others, the pituitary glands were in the field of view and the intraoperative scans could be used for comparison. For four patients, there was a discrepancy between surgeon filling and the intraoperative MRI. A control showed no residual adenoma but hemostatic tissue. CONCLUSION: Low field intraoperative MRI is an excellent technique for controlling the size of pituitary adenoma resection.

Adenoma↗
PubMed2004

[Contribution of PET to the management of patients with low-grade glioma].

BACKGROUND AND PURPOSE: Management of patients with low-grade glioma is a major challenge for the neurosurgeon. When is neurosurgery indicated? Should chemotherapy or radiotherapy be used? Many questions without an answer. We reviewed our experience with 65 patients treated for low-grade glioma who had preoperative PET images (FDG or/and MET). We examined the prognostic value of PET and also determined the sensitivity and the specificity of PET images to predict outcome. METHODS: Sixty-five patients with a FDG or MET PET images were analyzed. We used two visual scales and had complete follow-up data for 63 patients. The free interval was the principal criterion for statistical analysis. The sensitivity and the specificity of PET images was determined. RESULTS: Strong FDG uptake was correlated with a short free interval (p=0.001). Similar results were found with the MET analysis (p=0.0076). We had a PET with MET and FDG for 36 patients. The sensitivity was 66% and the specificity 94% for FDG PET. Sensitivity was 100% and specificity 53% for MET PET. CONCLUSIONS: PET imaging provides a prognostic factor independent from histology. MET PET is the best exam for the follow-up of patients with low-grade glioma and is helpful for separating aggressive from low-grade glioma.

Adult↗
PubMed2004

S100A5: a marker of recurrence in WHO grade I meningiomas.

Some WHO grade I intracranial meningiomas resected from the same sites and with the same quality of resection (Simpson's grading scale) recur, while others do not. The reasons for this variability in occurrence of recurrence have not yet been determined. We therefore investigated the prognostic recurrence value of seven biological markers on a series of completely resected WHO grade I meningiomas. For this purpose, we analysed a series of 33 WHO grade I meningiomas totally resected between 1980 and 1990 (a follow-up of 10 years), including 14 cases of recurrence. The fixed tumour material from each meningioma was submitted to histochemical analyses targeting galectin-3 and its binding sites, the S100A5, S100A6 and S100B proteins, and cathepsin-B and -D. The levels of expression were assessed semi-quantitatively (in terms of the staining intensity and the labelling index) and submitted to uni- and multivariate analyses. Of all the markers investigated, only S100A5 expression can be associated with any significant prognostic value in the matter of recurrence. More particularly, the meningiomas with high levels of S100A5 staining intensity either did not recur, or recurred later than those with a low immunopositive S100A5 intensity (P = 0.004). Cox regression analyses demonstrated that this latter marker was associated with significant prognostic values independent of the patients' ages. Furthermore, the combination of the patients' ages and S100A5 staining intensity permitted the identification of a group with a particularly high risk of recurrence, that is, the patients younger than 55 and with meningiomas exhibiting low S100A5 intensities (P = 0.001). In conclusion, the S100A5 protein could play a role in the recurrence of totally resected WHO grade I meningiomas.

Adolescent↗
PubMed2002

[Pineal region surgery. Experience in 22 patients].

BACKGROUND AND PURPOSE: Different approaches to the pineal region are described in the literature with high mortality and morbidity. We report our experience with two different approaches (occipitoparietal or infratentorial supracerebellar approaches) for pineal region. METHODS: Between 1986 and 1997, 25 operations were performed in 22 patients. Preoperative work-up included a CT-scan with conventional angiography (for older patients), magnetic resonance imaging with angiographic study (angio-MRI) for the others. Two different approaches, the occipitoparietal (n=14) or the infratentorial supracerebellar (n=8) ones, were used. Three patients had a stereotactic biopsy, followed by a total resection for one of them. RESULTS: The mortality and morbidity induced by the approaches were low compared to the series of the literature. Only 2 patients were worsened by the surgery: Patient 4 developed hemianopsia after an occipitoparietal approach and patient 21 temporary Parinaud syndrome after resection of a teratoma by supracerebellar infratentorial approach. One patient improved his neurological status but died on the 10th postoperative day from pulmonary embolism. CONCLUSIONS: Total or partial resection of well-defined pineal region lesions by direct neurosurgical approaches can be achieved in most cases with low morbidity. The choice among the two surgical occipitoparietal or infratentorial supracerebellar approaches depends on the size and the location of the lesion in the pineal area, its relation to the ventricular system, the median line and the splenium. Angiographic sequences in magnetic resonance with study of the deep veins are helpful in this respect.

Adolescent↗
PubMed2002

[The neurosurgery department].

Opened on November 1st, 2001, the Department of Neurosurgery has progressively grown to become worldwide renown in a few years. All the pathologies are covered, from lumbar disc hernia to intracranial tumors and vascular malformations. But the originality stays into the exceptional environment by the concentration of logistic resources and the ability of clinician and researchers who daily collaborate with the neurosurgical team. The Department of Neurosurgery has a strong reputation in several fields like intraspinal cord tumors or Pet-guided Neurosurgery in stereotactic biopsies, neuronavigation and Gamma Knife and, generally speaking, in the original approach of the treatment and follow-up of brain tumors. Neurodegenerative diseases also benefit of modern approaches trough the Gamma Knife, deep brain stimulation or fetal cell grafting into the brain in Parkinson and soon in Huntington diseases. Last but not least, the arrival for the 25th anniversary of Erasme Hospital of an interventional MRI will allow to follow in real-time the resection of brain tumors with an obvious benefit for the surgical performances and the quality of life of the patients. It will also open a new window for neurosurgical research through combination with functional MRI and Pet-Scan, reinforcing the reputation of Erasme Neurosurgical Department who has been distinguished in 1997 by the World Health Organisation as "WHO Collaborating Center for Research and Training in Neurosurgery" and nominated again in 2002 for a new 4-year period, which is unique in the Neurosurgical World.

Belgium↗
PubMed2001

Positron emission tomography with injection of methionine as a prognostic factor in glioma.

OBJECT: Positron emission tomography with L-[methyl-11C]methionine (MET-PET) provides information on the metabolism of gliomas. The aim of this study was to determine the predictive value of MET-PET in the treatment of patients with gliomas. METHODS: Since 1992, 85 patients with a World Health Organization (WHO) classification-verified glioma underwent PET studies in which MET was injected before (74 cases) or after treatment (11 cases). Analysis of PET data was conducted by the same investigator using two scales: a qualitative visual grading scale and a quantitative scale (ratio between tumor uptake and normal brain uptake, classified on a seven-level scale). Uptake of MET was present in 98% of gliomas. The investigator judged this uptake to be moderate to very high based on visual inspection (qualitative scale). For all grades of gliomas, a visual grade of 3 was statistically associated with a shorter patient survival period (p < 0.005). The tumor/normal brain uptake ratio was significantly influenced by the histological grade of the tumor. A statistically poor outcome was demonstrated when this ratio was higher than a threshold of 2.2 for a WHO Grade II tumor and 2.8 for WHO Grade III tumor. For Grade II and III tumors, oligodendrogliomas had a higher uptake of MET than astrocytomas. CONCLUSIONS: Uptake of MET was present in 98% of the gliomas studied. A high uptake is statistically associated with a poor survival time. The intensity of MET uptake represents a prognostic factor for WHO Grade II and III tumors considered separately.

Adult↗
PubMed2000

FDG-PET as a prognostic factor in high-grade astrocytoma.

BACKGROUND: The prognostic value of the metabolic status of cerebral gliomas determined by positron emission tomography with [18F]-fluoro-deoxy-D-glucose (FDG-PET) has been established in populations with a mixture of grades 2, 3 and 4 gliomas, but remains uncertain when only malignant gliomas are considered (grade 3 and 4). METHODS: FDG-PET performed in 30 patients with anaplastic astrocytoma (grade III) and 61 patients with glioblastoma (grade 4) were classified according to a metabolic grading. The uptake of FDG was lower in the tumor compared to white matter (WM) in grade 1 (4 glioblastoma, 4 anaplastic astrocytoma), it was intermediate between WM and cortex in grade 2 (20 glioblastoma, 22 anaplastic astrocytoma), and it was superior to cortex in grade 3 (38 glioblastoma, 4 anaplastic astrocytoma). RESULTS: Kaplan-Meier survival curves were similar in patient with grades 1 and 2, but were significantly worse (p = 0.007) in grade 3. In multivariate analysis considering age, pathological grade (anaplastic astrocytoma versus glioblastoma), and metabolic grades, the metabolic grade did not appear to be an independent prognostic factor. When anaplastic astrocytomas and glioblastomas were considered separately, metabolic grade is of predictive value only in the group of glioblastomas. CONCLUSION: In malignant gliomas, metabolic grading determined by FDG-PET was not superior to the pathological grading for survival prediction. Still, it remains of predictive value when applied to malignant gliomas histologically classified as glioblastoma.

Adolescent↗
PubMed2000

[Cerebellar hemorrhage complicating a supratentorial craniotomy. A case report and review of the literature].

Postoperative cerebellar hemorrhage after a supratentorial craniotomy represents a rare event. We report a case of a patient with a meningioma of the jugum who developed suddenly after surgery a neurological deterioration due to a cerebellar hemorrhage detected on the CT scan. An occipital craniectomy and an external ventricular drainage were performed in emergency. A complete neurological recovery was observed after surgery. Nineteen similar other cases are found in the literature. Pre- and postoperative high blood pressure, lowered intracranial pressure and mispositioning of the head during surgery could be at the origin of the hemorrhage. Size of the hemorrhage, time between diagnosis and treatment represent two prognostic factors. All patients, who present a neurological deterioration in postoperative course, must have CT scan including posterior fossa.

Cerebellar Diseases↗
PubMed1999

Prevention of epidural fibrosis in a prospective series of 100 primary lumbo-sacral discectomy patients: follow-up and assessment at re-operation.

An implantable device (ADCON-L), which acts as a resorbable barrier to epidural fibrosis following lumbar discectomy, has been shown to minimize the formation of peridural fibrotic scar and to improve the post-operative outcome, in two large controlled and multi-center clinical trials. In this prospective study, 100 patients were treated with the device during their first-time lumbo-sacral discectomy surgeries and monitored for 12 months. During this time interval, four of these patients required re-operation. In these cases, epidural scar and ease of dissection were systematically evaluated and recorded. At the time of re-operation, in all four patients, absent or minimal soft scar tissue was found where ADCON-L had been placed, no adhesions to the involved root were observed, and the dissection was easier than expected; the healing of the surgical wound was excellent , and no residual implant material was found. These observations indicate that the use of ADCON-L at the time of the first lumbar disc surgery minimizes the hazards and difficulty that can be encountered in a subsequent revision surgery due to the presence of epidural fibrosis, and may therefore improve the chances of satisfactory outcome following re-operation.

Adolescent↗
PubMed1999

Traumatic epidural hematoma of the cervical spine: magnetic resonance imaging diagnosis and spontaneous resolution: case report.

OBJECTIVE AND IMPORTANCE: Demonstration of interest of medical treatment of cervical epidural hematomas. CLINICAL PRESENTATION: A young patient developed cervical pain after experiencing cervical trauma. Computed tomography and magnetic resonance imaging demonstrated an epidural cervical hematoma. A spontaneous resolution of the clinical symptoms and the radiological abnormalities was observed. CONCLUSION: Although surgical decompression is generally regarded as mandatory in selected patients with incomplete and nonprogressing deficits, conservative management may be possible.

Adult↗
PubMed1999

Arnold Chiari Type I malformation presenting as a trigeminal neuralgia: case report.

OBJECTIVE AND IMPORTANCE: Arnold Chiari Type I malformation usually presents as headache, arm numbness, dysesthesia, upper weakness, or gait difficulty. We report a case of Chiari malformation presenting as a left trigeminal neuralgia. CLINICAL PRESENTATION: A patient with a history of 29 years of trigeminal neuralgia was admitted. He was treated with three thermocoagulations. Microvascular decompression was planified. Magnetic resonance imaging was performed, and it demonstrated an Arnold Chiari malformation. After surgery, the patient was asymptomatic. INTERVENTION: Posterior fossa decompression by enlarging the foramen magnum and aspiration of the cerebellar tonsils was performed. CONCLUSION: The trigeminal neuralgia could be attributable to a compression of the trigeminal nucleus. The compression of the nucleus could explain both the pain and the regression after surgery. This is the second reported case of pure trigeminal neuralgia in Arnold Chiari malformation.

Aged↗
PubMed1999

[Malignant rhabdoid tumors of the central nervous system. Report of a case].

Primitive malignant rhabdoid tumor of the central nervous system are extremely rare. Less than 70 cases are reported in the literature. This tumor grows during the first months of life and prognosis is very poor. We report a case of primitive malignant rhabdoid tumor in a 17-year-old young adult. To our knowledge it is the first such case reported in the literature. We review the clinical feature, the neuradiological and therapeutical aspects.

Adolescent↗
PubMed1998

Response of recurrent glioblastoma and anaplastic astrocytoma to dibromodulcitol, BCNU and procarbazine--a phase-II study.

Twenty six (17 males) patients with glioblastoma (GBL), median age 55 years, median Karnofsky Index (KI) 70/100, and 11 patients (9 males) with anaplastic astrocytoma (AA), median age 56 years, median KI 70/100 were treated at recurrence with dibromodulcitol (DBD) 1400 mg/m2 on day 1, BCNU 150 mg/m2 on day 2, and procarbazine (PCZ) 150 mg/day on days 1 to 15. The course was repeated every 4 weeks, but was delayed or decreased by 25% according to hematological toxicity. Response to treatment was evaluated by the criteria of MacDonald et al. (J Clin Oncol 1990; 8: 1277-1280). All GBL-patients were followed until death. One patient with complete response (CR) survived one year, and 2 patients with partial response (PR) survived 1 and 3 years. Ten patients who stabilized (SD) survived 7.5 months, and 13 patients who progressed under chemotherapy had a median survival of 3.5 months. In AA-group 3 patients were alive at the time of the analyses. Six patients: 1 CR and 5 PR survived 6 to 40+ months. Two patients with SD survived 4 and 14 months. Three patients with progressive disease had a mean survived of less than 3 months. The response rate of 55% in AA was significantly higher (p = 0.011) than the 12% response rate seen in GBL. We conclude that the regimen tested appears particularly promising in AA. The results in GBL are comparable to those obtained with a single nitrosourea, despite an increased but reversible toxicity.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Treatment of tumours.

Technical progress made in neuroradiology, and focal external and internal radiation therapy, have allowed the development of a series of local therapeutic modalities both in primary and in metastatic brain tumours. Eligibility criteria and results obtained with these new techniques are compared. Experimental studies with implications for radiation therapy, particularly boron neutron capture therapy, and for chemotherapy are reviewed. The possible use of chemotherapy as first-line treatment in non-Hodgkins lymphomas of central nervous system is stressed.

Animals↗
PubMed1997

Positron emission tomography and brain tumours.

The first applications of positron emission tomography (PET) for the study of brain tumours appeared early in the development of this technology. New trends in these particular PET applications tend to take into account the histological heterogeneity of these tumours and the necessity to integrate PET data in their surgical management. Better knowledge on PET tracers behavior in brain tumours should lead to new clinical uses, in particular in the promising field of cancer treatment evaluation.

Brain Neoplasms↗
PubMed1997

[Multiple and de novo aneurysms in Ehlers-Danlos syndrome].

BACKGROUND AND PURPOSE: In 1964, the first case of "de novo" aneurysm has been reported by Graf and Hamby. The risk of late formation of aneurysm is unknown. Some factors could influence risk: history of hypertension, oral contraceptives, cigarette smoking. We report a rare case of "de novo" aneurysm associated with Ehlers-Danlos syndrome. RESULTS: A 35-year-old female developed a subarachnoid hemorrhage (SAH). Angiography demonstrated 4 aneurysms. Five years before, she presented a SAH. At that time, four vessels angiography demonstrated only one PICA aneurysm. A Ehlers-Danlos syndrome was suspected, which was demonstrated on skin biopsies. CONCLUSION: At our knowledge, this is the first case of "de novo" aneurysm associated with a Ehlers-Danlos syndrome.

Adult↗