Association of hospital volume with survival but not with postoperative mortality in glioblastoma patients in Belgium.

OBJECTIVES: Standard of care treatment for glioblastoma (GBM) involves surgical resection followed by chemoradiotherapy. However, variations in treatment decisions and outcomes exist across hospitals and physicians. In Belgium, where oncological care is dispersed, the impact of hospital volume on GBM outcomes remains unexplored. This nationwide study aims to analyse interhospital variability in 30-day postoperative mortality and 1-/2-year survival for GBM patients. METHODS: Data collected from the Belgian Cancer Registry, identified GBM patients diagnosed between 2016 and 2019. Surgical resection and biopsy cases were identified, and hospital case load was determined. Associations between hospital volume and mortality and survival probabilities were analysed, considering patient characteristics. Statistical analysis included logistic regression for mortality and Cox proportional hazard models for survival. RESULTS: A total of 2269 GBM patients were identified (1665 underwent resection, 662 underwent only biopsy). Thirty-day mortality rates post-resection/post-biopsy were 5.1%/11.9% (target < 3%/<5%). Rates were higher in elderly patients and those with worse WHO-performance scores. No significant difference was found based on hospital case load. Survival probabilities at 1/2 years were 48.6% and 21.3% post-resection; 22.4% and 8.3% post-biopsy. Hazard ratio for all-cause death for low vs. high volume centres was 1.618 in first 0.7 year post-resection (p < 0.0001) and 1.411 in first 0.8 year post-biopsy (p = 0.0046). CONCLUSION: While 30-day postoperative mortality rates were above predefined targets, no association between hospital volume and mortality was found. However, survival probabilities demonstrated benefits from treatment in higher volume centres, particularly in the initial months post-surgery. These variations highlight the need for continuous improvement in neuro-oncological practice and should stimulate reflection on the neuro-oncological care organisation in Belgium.

Cancer Registration, Molecular Marker Status, and Adherence to the WHO 2016 Classification of Pathology Reports for Glioma Diagnosed during 2017-2019 in Belgium.

INTRODUCTION: The objective of this study was to cross-check and, if necessary, adjust registered ICD-O-3 topography and morphology codes with the findings in pathology reports available at the Belgian Cancer Registry (BCR) for glioma patients. Additionally, integration of molecular markers in the pathological diagnosis and concordance with WHO 2016 classification is investigated. METHODS: Since information regarding molecular tests and corresponding conclusions are not available as structured data at population level, a manual screening of all pseudonymized pathology reports available at the BCR for registered glioma patients (2017-2019) was conducted. ICD-O-3 morphology and topography codes from the BCR database (based on information as provided by hospital oncological care programmes and pathology laboratories), were, at tumour level, cross-checked with the data from the pathology reports and, if needed, specified or corrected. Relevant molecular markers (IDH1/2, 1p19q codeletion, promoter region of the MGMT gene [MGMTp]) were manually extracted from the pathology reports. RESULTS: In 95.3% of gliomas, the ICD-O-3 morphology code was correct. Non-specific topography codes were specified in 9.3%, while 3.3% of specific codes were corrected. The IDH status was known in 75.2% of astrocytic tumours. The rate of correct integrated diagnoses varied from 47.6% to 56.4% among different gliomas. MGMTp methylation status was available in 32.2% of glioblastomas. CONCLUSION: Both the integration of molecular markers in the conclusion of the pathology reports and the delivery of those reports to the BCR can be improved. The availability of distinct ICD-O-3 codes for each molecularly defined tumour entity within the WHO classification would increase the consistency of cancer registration, facilitate population level research and international benchmarking.

Quality indicators in neuro-oncology: Review of the literature and development of a new quality indicator set for glioma care through a two-round Delphi survey.

BACKGROUND: Quality Indicators (QIs) are important tools to assess the quality and variability of oncological care. However, their application in neuro-oncology is limited so far. The objective of this study was to develop a set of QIs for glioma, covering process and outcome indicators. METHODS: A systematic review was conducted to identify both QIs in the field of adult glioma care, and guidelines or recommendations that could be translated into QIs. Also reports from national and international healthcare agencies and scientific associations ("grey literature") were taken into account. After conversion of these recommendations into QIs, merging with existing QIs found in the literature and rationalization, a two-round Delphi survey was conducted to gain consensus on relevance for the proposed QIs. RESULTS: In total 240 recommendations and 30 QIs were retrieved from the literature. After conversion, merging and rationalization, 147 QIs were evaluated in the Delphi survey and eventually consensus was gained on 47 QIs in the following 7 domains: Diagnosis and Imaging, Surgery, Pathology, Radio/Chemotherapy, Recurrence, Supportive Treatments (Epilepsy, Thromboembolism, Steroid Use and Rehabilitation) and Survival. CONCLUSION: This study defined a set of 47 QIs for assessing quality of care in adult glioma patients, distributed amongst 7 crucial phases in the patient's care trajectory. These QIs are readily applicable for use in diverse health care systems, depending on the availability of population-based health care data enabling (inter)national benchmarking.

The supplementary motor area syndrome: a neurosurgical review.

The supplementary motor area (SMA) syndrome is a frequently encountered clinical phenomenon associated with surgery of the dorsomedial prefrontal lobe. The region has a known motor sequencing function and the dominant pre-SMA specifically is associated with more complex language functions; the SMA is furthermore incorporated in the negative motor network. The SMA has a rich interconnectivity with other cortical regions and subcortical structures using the frontal aslant tract (FAT) and the frontostriatal tract (FST). The development of the SMA syndrome is positively correlated with the extent of resection of the SMA region, especially its medial side. This may be due to interruption of the nearby callosal association fibres as the contralateral SMA has a particular important function in brain plasticity after SMA surgery. The syndrome is characterized by a profound decrease in interhemispheric connectivity of the motor network hubs. Clinical improvement is related to increasing connectivity between the contralateral SMA region and the ipsilateral motor hubs. Overall, most patients know a full recovery of the SMA syndrome, however a minority of patients might continue to suffer from mild motor and speech dysfunction. Rarely, no recovery of neurological function after SMA region resection is reported.

Conscious Sedation Using Dexmedetomidine During Surgical Paddle Lead Placement Improves Outcome in Spinal Cord Stimulation: A Case Series of 25 Consecutive Patients.

OBJECTIVES: Different anesthesia techniques are used for surgical implantation of paddle lead electrodes for neurostimulation through a laminectomy. We wanted to evaluate the use of dexmedetomidine as sedative for this procedure in a series of patients. Second, we wanted to verify whether the stimulation pattern and position of the electrode had to be changed during the procedure guided by the patient's feedback. MATERIAL AND METHODS: Twenty-five consecutive patients received surgical implantation of a spinal cord stimulation electrode under conscious sedation using dexmedetomidine and local anesthesia. We evaluated the effects of the administered drug, the patient comfort, and the adequacy of the stimulation pattern. RESULTS: Twenty-four patients completed the procedure with only dexmedetomidine and local anesthetic. Infusion was started on average 55 minutes (sd 29) prior to incision. The mean dose of lidocaine was 430 mg (sd 95). There were no significant hemodynamic changes. Median time to reach Modified Aldrete's score postoperative was 67 minutes (sd 38). In 46% of the patients, the position of the electrode was changed guided by the feedback of the patient. More than half of the patients remember most details of the procedure. Only four patients mentioned substantial discomfort and only three would definitely not want to undergo this procedure again. CONCLUSIONS: Implantation of spinal cord stimulation electrodes through a surgical laminectomy using dexmedetomidine is a safe and feasible procedure with adequate comfort for patient and surgeon. This way of working increases the optimal position of the electrode resulting in the most convenient stimulation pattern and avoiding revisions.

Epidemiology and survival of adult-type diffuse glioma in Belgium during the molecular era.

BACKGROUND: Survival data of diffuse adult-type glioma is mostly based on prospective clinical trials or small retrospective cohort studies. Real-world data with large patient cohorts is currently lacking. METHODS: Using the nationwide, population-based Belgian Cancer Registry, all known histological reports of patients diagnosed with an adult-type diffuse glioma in Belgium between 2017 and 2019 were reviewed. The ICD-O-3 morphology codes were matched with the histological diagnosis. The gathered data were transformed into the 2021 World Health Organization classification of CNS tumors using the IDH- and 1p/19q-mutation status. RESULTS: Between 2017 and 2019, 2233 diffuse adult-type gliomas were diagnosed in Belgium. Full molecular status was available in 67.1% of identified cases. The age-standardized incidence rate of diffuse adult-type glioma in Belgium was estimated at 8.55 per 100 000 person-years and 6.72 per 100 000 person-years for grade 4 lesions. Median overall survival time in IDH-wild-type glioblastoma was 9.3 months, significantly shorter compared to grade 4 IDH-mutant astrocytoma (median survival time: 25.9 months). The 3-year survival probability was 86.0% and 75.7% for grades 2 and 3 IDH-mutated astrocytoma. IDH-wild-type astrocytoma has a worse prognosis with a 3-year survival probability of 31.6% for grade 2 and 5.7% for grade 3 lesions. CONCLUSIONS: This registry-based study presents a large cohort of adult-type diffuse glioma with known molecular status and uses real-world survival data. It adds to the current literature which is mainly based on historical landmark trials and smaller retrospective cohort studies.

Deep brain stimulation for essential tremor in patients with ventriculomegaly.

Background: Deep brain stimulation of the nucleus ventralis intermedius (VIM-DBS) is considered a safe and effective treatment for medically intractable essential tremor (ET). However, ventriculomegaly can provide a surgical challenge, as there is an increased risk of breaching the ventricle during the procedure, with potential risk of intraventricular hemorrhage and target displacement. Case Description: In this case series, we report successful bilateral VIM-DBS in a 72-year-old and 69-year-old female ET patient with significant ventriculomegaly. VIM-DBS therapy provided an excellent tremor response. After 5 years, a ventriculoperitoneal shunt was implanted in the first patient due to an incomplete Hakim-Adams triad, with significant improvement in gait and cognition. Conclusion: To the best of our knowledge, we present the first report on VIM-DBS in ET patients with ventriculomegaly and illustrate that VIM-DBS can provide an excellent tremor response in patients with medically intractable ET, even in the context of marked ventriculomegaly.

Chiari Type I Malformation Presenting with Unilateral Hearing Loss.

INTRODUCTION: Chiari type I malformations can present in different ways, but the most frequent symptom is an occipitocervical headache. Hearing loss as the main presenting symptom is rare. CASE: A young woman with progressive left-sided unilateral hearing loss was diagnosed with a Chiari type I malformation. She underwent a suboccipital craniectomy with C1 laminectomy and duraplasty. The hearing loss had resolved postoperatively with normalization of the audiometry. CONCLUSION: Chiari type I malformation can present solely with hearing loss. Improvement after surgical decompression is possible. This phenomenon is not emphasized well enough within the neurologic community. In this report, we present a summary of the pathophysiology and management in Chiari type I malformations.

Impact of the COVID-19 Pandemic on Incidence and Observed Survival of Malignant Brain Tumors in Belgium.

(1) Background: This study evaluates the impact of the COVID-19 pandemic on the incidence, treatment, and survival of adults diagnosed with malignant brain tumors in Belgium in 2020. (2) Methods: We examined patients aged 20 and older with malignant brain tumors (2004-2020) from the Belgian Cancer Registry database, assessing incidence, WHO performance status, vital status, and treatment data. We compared 2020 incidence rates with projected rates and age-standardized rates to 2015-2019. The Kaplan-Meier method was used to assess observed survival (OS). (3) Results: In 2020, there was an 8% drop in age-specific incidence rates, particularly for those over 50. Incidence rates plunged by 37% in April 2020 during the first COVID-19 peak but partially recovered by July. For all malignant brain tumors together, the two-year OS decreased by four percentage points (p.p.) in 2020 and three p.p. in 2019, compared to that in 2015-2018. Fewer patients (-9 p.p.) with glioblastoma underwent surgery, and the proportion of patients not receiving surgery, radiotherapy, or systemic therapy increased by six percentage points in 2020. (4) Conclusions: The COVID-19 pandemic profoundly impacted the diagnosis, treatment strategies, and survival of brain tumor patients in Belgium during 2020. These findings should guide policymakers in future outbreak responses, emphasizing the need to maintain or adapt (neuro)-oncological care pathways and promote informed decision making when care capacity is limited.

Anterolateral versus posterior minimally invasive lumbar interbody fusion surgery for spondylolisthesis: comparison of outcomes from a global, multicenter study at 12-months follow-up.

BACKGROUND CONTEXT: Several minimally invasive lumbar interbody fusion techniques may be used as a treatment for spondylolisthesis to alleviate back and leg pain, improve function and provide stability to the spine. Surgeons may choose an anterolateral or posterior approach for the surgery however, there remains a lack of real-world evidence from comparative, prospective studies on effectiveness and safety with relatively large, geographically diverse samples and involving multiple surgical approaches. PURPOSE: To test the hypothesis that anterolateral and posterior minimally invasive approaches are equally effective in treating patients with spondylolisthesis affecting one or two segments at 3-months follow-up and to report and compare patient reported outcomes and safety profiles between patients at 12-months post-surgery. DESIGN: Prospective, multicenter, international, observational cohort study. PATIENT SAMPLE: Patients with degenerative or isthmic spondylolisthesis who underwent 1- or 2-level minimally invasive lumbar interbody fusion. OUTCOME MEASURES: Patient reported outcomes assessing disability (ODI), back pain (VAS), leg pain (VAS) and quality of life (EuroQol 5D-3L) at 4-weeks, 3-months and 12-months follow-up; adverse events up to 12-months; and fusion status at 12-months post-surgery using X-ray and/or CT-scan. The primary study outcome is improvement in ODI score at 3-months. METHODS: Eligible patients from 26 sites across Europe, Latin America and Asia were consecutively enrolled. Surgeons with experience in minimally invasive lumbar interbody fusion procedures used, according to clinical judgement, either an anterolateral (ie, ALIF, DLIF, OLIF) or posterior (MIDLF, PLIF, TLIF) approach. Mean improvement in disability (ODI) was compared between groups using ANCOVA with baseline ODI score used as a covariate. Paired t-tests were used to examine change from baseline in PRO for both surgical approaches at each timepoint after surgery. A secondary ANCOVA using a propensity score as a covariate was used to test the robustness of conclusions drawn from the between group comparison. RESULTS: Participants receiving an anterolateral approach (n=114) compared to those receiving a posterior approach (n=112) were younger (56.9 vs 62.0 years, p <.001), more likely to be employed (49.1% vs 25.0%, p<.001), have isthmic spondylolisthesis (38.6% vs 16.1%, p<.001) and less likely to only have central or lateral recess stenosis (44.9% vs 68.4%, p=.004). There were no statistically significant differences between the groups for gender, BMI, tobacco use, duration of conservative care, grade of spondylolisthesis, or the presence of stenosis. At 3-months follow-up there was no difference in the amount of improvement in ODI between the anterolateral and posterior groups (23.2 ± 21.3 vs 25.8 ± 19.5, p=.521). There were no clinically meaningful differences between the groups on mean improvement for back- and leg-pain, disability, or quality of life until the 12-months follow-up. Fusion rates of those assessed (n=158; 70% of the sample), were equivalent between groups (anterolateral, 72/88 [81.8%] fused vs posterior, 61/70 [87.1%] fused; p=.390). CONCLUSIONS: Patients with degenerative lumbar disease and spondylolisthesis who underwent minimally invasive lumbar interbody fusion presented statistically significant and clinically meaningful improvements from baseline up to 12-months follow-up. There were no clinically relevant differences between patients operated on using an anterolateral or posterior approach.

Hippocampal Sclerosis in Frontotemporal Dementia: When Vascular Pathology Meets Neurodegeneration.

Hippocampal sclerosis (HS) is a common neuropathological finding and has been associated with advanced age, TDP-43 proteinopathy, and cerebrovascular pathology. We analyzed neuropathological data of an autopsy cohort of early-onset frontotemporal dementia patients. The study aimed to determine whether in this cohort HS was related to TDP-43 proteinopathy and whether additional factors could be identified. We examined the relationship between HS, proteinopathies in frontotemporal cortices and hippocampus, Alzheimer disease, cerebrovascular changes, and age. We confirmed a strong association between HS and hippocampal TDP-43, whereas there was a weaker association between HS and frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP). Nearly all of the FTLD-TDP cases had TDP-43 pathology in the hippocampus. HS was present in all FTLD-TDP type D cases, in 50% of the FTLD-TDP A cohort and in 6% of the FTLD-TDP B cohort. Our data also showed a significant association between HS and vascular changes. We reviewed the literature on HS and discuss possible pathophysiological mechanisms between TDP-43 pathology, cerebrovascular disease, and HS. Additionally, we introduced a quantitative neuronal cell count in CA1 to objectify the semiquantitative visual appreciation of HS.

Intracranial dural arteriovenous fistula successfully treated by combined open-endovascular procedure.

Intracranial dural arteriovenous fistulas constitute a rare though potentially devastating disease. Because the arterial (high-pressure) blood flow drains directly into the low-pressure venous system, there is a high risk of bleeding and associated neurological deficit. The classifications by Borden and Cognard underline the correlation between bleeding risk and venous drainage pattern of the fistula. There are different treatment options for this vascular pathology, which always poses a challenge for the physicians involved to offer the optimal treatment for an individual patient. This case report illustrates how combining forces between the neurosurgical and endovascular team benefits outcome. Simultaneously, this contributes to the growing amount of evidence that a new endovascular technique with transarterial ONYX embolisation enables complete obliteration of the vascular malformation.

Treatment of cranial epidural hematoma in a neonate by needle aspiration of a communicating cephalhematoma.

A newborn presented on day 15 of life with an epidural hematoma, extending through a diastatic sutura squamosa in an external cephalhematoma. There was no skull fracture. The cephalhematoma was punctured twice with 24-h interval, reducing both the cephalhematoma and the epidural component. In the absence of neurological signs or symptoms, aspirating a cephalhematoma to evacuate the communicating epidural hematoma in a newborn infant may avoid more invasive surgical intervention.

Granular Cell Tumor of the Pituitary Presenting with Major Intraventricular Hemorrhage.

Granular cell tumors of the pituitary gland are rare, slow-growing lesions arising from the neurohypophysis or pituitary stalk. We describe an extremely rare presentation of a pituitary granular cell tumor mimicking an anterior communicating artery aneurysmal rupture with ventricular hemorrhage. The patient was admitted in a comatose state and underwent urgent bilateral external ventricular drainage. Further diagnostic investigation revealed a sellar tumoral mass with suprasellar extension. No vascular anomalies, hormonal abnormalities, or visual disturbances were observed. Macroscopic complete resection without neurologic impairment was obtained via a right pterional approach. Posthemorrhagic hydrocephalus necessitated ventriculoperitoneal shunt placement, and hormonal substitution for panhypopituitarism was provided. The 5-year follow-up examination showed no tumor recurrence. The clinical course of these benign World Health Organization grade I lesions will normally correspond to nonsecreting pituitary adenomas with an insidious development of visual disturbances, hypopituitarism, or hydrocephalus. Sudden onset with potential catastrophic intratumoral and intraventricular hemorrhage is very uncommon.

Partial resection offers an overall survival benefit over biopsy in MGMT-unmethylated IDH-wildtype glioblastoma patients.

Background Isocitrate dehydrogenase (IDH)-wildtype glioblastoma patients with O6-methylguanine-DNA-methyltransferase (MGMT)-unmethylated tumors have the worst outcome of all glioblastoma patients. The overall survival (OS) benefit of partial resection of glioblastoma compared to biopsy only remains controversial specifically in relation to molecular factors. In this report, we analyzed the effect of incomplete resection on OS compared to biopsy only in a cohort of IDH-wildtype glioblastoma patients who were uniformly treated with temozolomide-based chemoradiotherapy (TMZ-CR) after surgery. Material & Methods A retrospective study was conducted including only glioblastoma patients who were treated with TMZ-CR after surgery from two centers. Surgical groups were defined as biopsy only, partial resection (PR) or gross total resection depending on the presence of contrast-enhancing tumor on postoperative imaging. IDH-mutation was determined using next generation sequencing technique and MGMT-methylation was analyzed with semi-quantitative methylation-specific polymerase chain reaction. Next to descriptive statistics, univariate and multivariate survival analyses were performed using Kaplan-Meier estimates and Cox regression models. Results In total, 159 patients were included. 37 patients underwent biopsy only and 73 partial resections. 99 patients (62.3%) harbored unmethylated tumors. Median OS for the whole patient group was 13.4 months. In the subgroup of patients with unmethylated tumors, PR yielded a median OS of 12.2 months vs 7.6 months for biopsy patients (P = 0.003). PR proved an independent beneficial prognostic factor in multivariate Cox regression model, together with age, Karnofsky Performance Score and MGMT-methylation. Conclusion In IDH-wildtype glioblastoma patients with MGMT-unmethylated tumors, treated with chemoradiotherapy after surgery, PR yields a significant OS benefit compared to biopsy.

Migration of pump for intrathecal drug delivery into the peritoneal cavity. Case report.

BACKGROUND: We report on a patient in whom a subfascially implanted pump for the intrathecal delivery of baclofen spontaneously migrated into the peritoneal cavity. CASE DESCRIPTION: A 54-year-old male patient presented with a refilling problem of a drug pump that had been implanted 16 months earlier subfascially through a right-sided incision 10 cm below the costal margin. Because we were unable to refill the pump even under fluoroscopy, we presumed a backward turning of the pump. At exploration, we found that the deeper part of the pocket had spontaneously eroded and had caused the migration of the pump into the peritoneal cavity. The peritoneum and the abdominal wall were closed and the pump was placed in a subcutaneous pouch. We suppose that the migration of the pump was due to its particular implantation site with the lower extent of the device at or below the level of the linea semilunaris. Below this line, the aponeuroses of all 3 lateral abdominal muscles pass in front of the rectus muscle, leaving only the transversal fascia underneath the rectus, which is not a solid layer. Not considering this anatomical detail may facilitate the inward migration of implanted material. CONCLUSION: When creating a pocket for subfascial implantation, a high subcostal incision should be used so that the lower extent of the pocket will still be above the level of the linea semilunaris, hence ensuring a strong fascial layer between the pump and the peritoneum.

Cystoperitoneal shunt as alternative treatment for a giant thoracic meningocele in a patient with neurofibromatosis.

BACKGROUND: Thoracic meningoceles are associated with neurofibromatosis 1 in 60% to 85% of all cases. Usually, these meningoceles remain asymptomatic, but back pain, headache, cough, and dyspnea are possible manifestations. Often, there is an associated kyphoscoliotic deformity of the thoracic spine. CASE DESCRIPTION: A 60-year-old woman known in our department after a fossa posterior decompression for an Arnold-Chiari malformation was admitted through the emergency department because of progressive dyspnea. A giant intrathoracic meningocele was already diagnosed earlier but was left untreated because the patient was asymptomatic at that time. She now had dyspnea, and on chest x-ray and CT scan, there was an obvious shift of the mediastinum to the right. Because of the long-existing hemithoracic meningocele, we assumed that this patient actually had only 1 functional lung, and so, left-sided thoracotomy with resection of the meningocele and closure of the defect included a high operative mortality. Instead, we chose to obtain a permanent drainage of the meningocele by putting a shunt between the meningocele and the peritoneum. Postoperatively, the patient recovered well and became oxygen-independent. CONCLUSION: Treatment of giant intrathoracic meningoceles in patients with progressive dyspnea can be challenging, and different options can be found in the literature. Treatment with a cystoperýtoneal shunt, as in our case, can be a less invasive alternative in patients with a high operative mortality risk. To our knowledge, this is the first report of a patient with neurofibromatosis 1 treated in this way.

Endoscopic Treatment of Temporal Arachnoid Cysts in 34 Patients.

INTRODUCTION: Arachnoid cysts are lesions present in 1% of the population and usually found in the temporal fossa. Clinical and radiologic presentations can differ greatly. Despite intensive research, it is still debatable which patients will benefit from surgery. OBJECTIVE: This study aims to investigate the pretreatment parameters influencing the outcome after neuroendoscopic treatment of temporal arachnoid cysts. MATERIALS AND METHODS: A retrospective analysis of 34 patients who underwent an endoscopic fenestration of a temporal arachnoid cyst between July 1991 and December 2013 was performed. RESULTS: In symptomatic patients, there was a clinical improvement in 76.4% of cases. The best results were found in treating symptoms related to intracranial hypertension, acute neurologic defects, and macrocrania. Patients with temporal lobe epilepsy improved after cyst fenestration in 33.3% of cases. Behavioral problems and psychomotor retardation remained largely unchanged. Patients with a complex neurologic presentation, often from a congenital syndrome and combined with an intellectual disability, had the least benefit from endoscopic surgery. Radiologic follow-up showed a cyst volume decrease in 91.2% of cases. Complications were present in 29.4%, but were mostly minor and transient. CONCLUSION: This study demonstrates that patients with symptoms related to intracranial hypertension, acute neurologic deficits, and macrocrania have the best postoperative outcome. Also, patients with ipsilateral temporal lobe epilepsy seem to be good candidates for endoscopic arachnoid cyst fenestrations. In complex neurologic disorders without one of the previously mentioned symptoms, endoscopy remains less successful.

Treatment of cystic craniopharyngioma by endocavitary instillation of yttrium9° radioisotope--still a valuable treatment option.

Craniopharyngiomas are a challenging pathology in neurosurgery because of their anatomic localization in the (supra)sellar region and their contact with diencephalic structures around the third ventricle. Among the different treatment modalities, stereotactic intracavitary treatment by instillation of yttrium9° radioisotope is a minimally invasive technique of particular use in the treatment of cystic or partially cystic craniopharyngiomas. It can be performed under local anesthesia during a short hospitalization and has a long-lasting effect. This treatment can be repeated or used in combination with other treatment modalities such as microsurgery, endoscopy, conformal external radiation therapy, or stereotactic radiosurgery. Thus, this old and perhaps almost forgotten treatment option is still valuable in the treatment of cystic craniopharyngiomas.