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Purpose: We aimed to present our surgical experience and the impact of a solid or cystic morphology of cerebellar pilocytic astrocytoma (cPA) on surgery and the risk for a re-resection., Methods: We retrospectively analyzed all children operated at our institution between 2009 and 2023 for cPA. Tumours were categorized into 4 groups: (i) cystic PA without cyst wall enhancement, (ii) cystic PA with cyst wall enhancement, (iii) solid tumour, (iv) and solid tumour with central necrosis., Results: Forty-two children with a median age at surgery of 7.1 years (range 0.7-14 years; male to female ratio 1.5) were identified. The median follow-up time was 3.1 years (0.6-14 years). Twenty-eight patients (66.6%) presented with cystic PA (20 without and 8 with cyst wall enhancement), 9 patients (21.4%) exhibited a solid tumour with central necrosis and 5 (11.9%) had a solid tumour without central necrosis. Gross total resection could be achieved in 31 patients (73.8%), near total resection in 6 (14.3%), and subtotal resection in 5 (11.9%). Progression occurred in 11 cases with 9 patients having a 2nd resection after a mean time of 3.4 years. The highest risk for a 2nd resection was seen in the group of solid tumours with a necrotic centre (odds ratio = 2.3), progression of enhancing cyst wall remnants was seen in one out of two patients with remnants needing reoperation., Conclusion: Surgery in cerebellar PA should aim for gross total resection of the solid-enhancing tumour., Competing Interests: Declarations. We wish to confirm that there are no conflicts of interest associated with this publication and there has been no financial support for this work that could have influenced its outcome. We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us. There are no financial or non-financial interests that are directly or indirectly related to the work submitted for publication. A positive ethics vote was obtained from the Ethics Commission of the Medical University of Vienna. No funding was received for conducting this study. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: Imaging and resection strategies for pediatric gangliogliomas (GG) and dysembryoplastic neuroepitheliomas (DNET) presenting with epilepsy were retrospectively analyzed in a consecutive institutional series of surgically treated patients., Methods: Twenty-two children (median 8 years, 3-18 years) presented with seizures for 30 months median (14-55.2 months) due to a histologically verified GG/DNET., Results: There were 20 GG and 2 DNT, 68 % located temporal, 32 % extra-temporal. Seizure history was significantly longer in temporal cases (38 versus 14 months median, p < 0.01). MRI contrast enhancement was present in 50 % and methionine (MET) positron emission tomography (PET) uptake in 70 % (standard uptake values (SUVs) 2.92 mean, from 1.6 to 6.4). 27 % had glucose PET hypometabolism. Primarily, in temporal GG, ECoG (electrocorticography) -guided lesionectomies were performed in 87 % and antero-mesial temporal lobe resections (AMTLR) in 13 %, whereas in extra-temporal GG/DNETs, lesionectomies were performed in 100 %. ILAE Class 1 seizure outcome was primarily achieved in 73 % of the temporal cases, and was increased to 93 % by performing six repeat surgeries using AMTLR. Extratemporal patients experienced ILAE Class 1 seizure outcomes in 86 % without additional surgeries, although harboring significantly more residual tumor (p < 0.005, mean follow-up 28 months)., Conclusion: In children, MET PET imaging for suspected GG is proposed preoperatively showing a high diagnostic sensitivity and an option to delineate the lesions for navigated resection, whereas MRI contrast behavior was of no differential diagnostic use. As a surgical strategy we propose primarily lesionectomies for extratemporal but AMTLR for temporal GG respecting eloquent brain areas., Competing Interests: Declaration of competing interest The authors declare, that there is no conflict of interest according to the submitted manuscript titled Seizure outcome in surgically treated pediatric gangliogliomas and dysembrioplastic neuroepitheliomas according to imaging and resection strategies., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: Temporal lobe epilepsy (TLE) is the most frequent form of focal epilepsy in adults. Because approximately half of these patients develop drug resistance, epilepsy surgery designed to remove the epileptogenic zone is an excellent option in selected patients. Histopathological analyses of hippocampal specimens in TLE patients revealed 4 types of Ammon's horn sclerosis, which are correlated with long-term epileptological outcome. The aim of this study was the correlation of noninvasive, high-resolution, morphological magnetic resonance imaging (MRI) at an ultra-high-field (7 T) of the hippocampus in TLE patients with histopathological findings., Methods: High-resolution, T2-weighted FSE MRI in 14 patients with drug-resistant temporal lobe epilepsy was performed on a 7 T Magnetom using a 32-channel coil. Four independent investigators assessed the delineation and semiquantitative evaluation of volume, signal intensity, internal architecture, and overall grading of the hippocampal subfields CA1-4, as well as the presence of the dentate granule cell layer (DGCL), on MRI scans. Results were compared with semiquantitative evaluation of neuronal loss and astrogliosis in the histological sections of the surgical specimens., Results: Seven-tesla MR examinations were evaluable in 13 cases. Volume loss and signal intensity, as well as overall grading, showed a strong correlation between MRI and histology in individual CA regions. Furthermore, sensitivity and specificity values up to 100% were found for the detection of pathology in the CA subfields. The prediction of Ammon's horn sclerosis type was correct in up to 12 of 13 cases, whereas the dentate gyrus could not be delineated on MRI., Discussion: High-resolution, ultra-high-field MRI is a promising tool for the detection of subtle changes in the hippocampus in patients with temporal lobe epilepsy. Large cohorts will be necessary to confirm the predictive value of 7 T MRI in the preoperative evaluation of TLE patients.

Focal cortical dysplasias (FCD) which represent a composite group of cortical malformations are increasingly recognized as morphological substrate for severe therapy-refractory epilepsy in children and young adults. However, presurgical evaluation remains challenging as not all FCD variants can be reliably detected by high-resolution magnetic resonance imaging (MRI). Here, we studied a cohort of 52 epilepsy patients with neuropathological evidence for FCD using the 2011 classification of the International League against Epilepsy (ILAE) and systematically analysed those histopathologic features applicable also for MRI diagnostics. Histopathologic parameters included quantitative measurements of cellular profiles, cortical thickness, heterotopic neurons in white matter, and myelination that were compared between FCD subtypes and age-/localization-matched controls (n = 36) using multivariate analysis. Dysmorphic neurons in both FCD Type II variants showed significantly increased diameter of their cell bodies and nuclei. Cortical thickness was also increased with a distinct loss of myelin content specifying FCD Type IIb from IIa. The data further suggested that myelination deficits in FCD Type IIb result from compromised oligodendroglial lineage differentiation and we concluded that the "transmantle sign" is a unique finding in FCD Type IIb. In contrast, FCD Type Ia was characterized by a smaller cortical ribbon and higher neuronal densities, but these parameters failed to reach statistical significance (considering age- and location-dependent variability in controls). All FCD variants showed abnormal grey-white matter boundaries with increased numbers of heterotopic neurons. Similar results were obtained also at deep white matter location. Thus, many FCD variants may indeed escape visual MRI inspection, but suspicious areas with increased or decreased cortical thickness as well as grey-white matter blurring may be uncovered using post-processing protocols of neuroimaging data. The systematic analysis of well-specified histopathological features could be helpful to improve sensitivity and specificity in MRI detection during pre-surgical work-up of patients with drug-resistant focal epilepsies.

Objective: In diffusely infiltrating gliomas (DIG), positron emission tomography (PET) imaging is a powerful method for detection of anaplastic foci. Recently, (1)H-magnetic resonance spectroscopy chemical shift imaging (CSI) using choline/creatine (Cho/Cr) or choline/N-acetylaspartate (Cho/NAA) ratios has emerged as a new non-invasive, widely available alternative. The authors therefore correlated CSI with (11)C-methionine (MET)-PET data in a series of DIG with non-significant contrast-enhancement (CE)., Methods: Thirty-two patients with DIG were examined with single-slice CSI on a T MRI and MET-PET. Maximum pathological intratumoural ratios of CSI (=CSI(max)) and maximum tumour-to-normal-brain PET ratios (=PET(max); T/N ratio) were determined. Coregistration of MRI with CSI and PET was performed, and the topographic overlap of CSI(max) and PET(max) was analysed. Histological criteria of anaplasia as well as cell proliferation rate were assessed in tumour samples inside and outside CSI(max)., Results: CSI showed a pathological ratio in all patients, whereas PET demonstrated a pathological T/N ratio in 21/32 patients. Topographical correlation of CSI(max) and PET(max) revealed a ≥ 50% overlap in 18/21 and <50% overlap in 3/21 patients, respectively. Cho/Cr(max) and Cho/NAA(max) showed a ≥ 50% overlap in 24/32 and a <50% overlap in 8/32 patients. Cell proliferation rate was significantly higher inside than outside the CSI(max) (13.6% vs 6.9%, p<0.001)., Conclusion: The results indicate that CSI is a promising method for detection of anaplastic foci within DIG with non-significant CE. Intraoperative use of CSI by multimodal neuronavigation may increase the reliability of detection of malignant areas in glioma surgery and therefore optimise allocation of patients to adjuvant treatments.

Background: Selective amygdalohippocampectomy (SAHE) yields 60-80% of patients with medically refractory mesial temporal lobe epilepsy seizure-free and seems to be equally effective compared to the more extended temporal lobe resections. The resection of the entire entorhinal cortex (EC) is of crucial importance to warrant complete seizure control for those patients. Thus, evidence of residual EC could be a predictor of a potentially successful reoperation in patients with recurrent seizures after SAHE. We performed an analysis of preoperative and postoperative magnetic resonance imaging (MRI) in patients who underwent a reoperation after an unsuccessful transsylvian SAHE to assess the presence of residual EC before reoperation and to determine whether certain anatomical variants may dispose patients to incomplete resection of EC., Materials and Methods: Ten patients who underwent reoperation after SAHE for the recurrence of medically refractory seizures were studied. MRI after SAHE was assessed for the presence of residual EC using T2-weighted and inversion recovery sequences perpendicularly to the main axis of the hippocampus. The results were compared with a control group of ten patients who became seizure-free after SAHE. In the nine patients of the study group, the sulcal anatomy of the basal temporal lobe was graphically outlined and analysed on MRI scans performed before SAHE to characterise the sulcal boundaries of the EC., Findings: Residual EC was found in nine of ten patients and was absent in the control group. After reoperation (median follow-up of 36.5 months), eight out of ten patients were completely seizure-free. In seven out of nine patients, a discontinuous course of the lateral sulcal boundaries of the EC was determined., Conclusions: Careful analysis of MRI verified residual mesiotemporal structures in the majority of patients who became seizure-free after reoperation. Certain temporobasal sulcal patterns might dispose for a higher risk of incomplete resection of the EC. The study confirms that reoperation is an effective treatment modality for patients with recurrent seizures after transsylvian SAHE.

Object: The aim of this study was to determine the value of high-field magnetic resonance (MR) imaging for diagnosis and surgery of sellar lesions., Methods: High-field MR images were obtained using a 3-tesla unit with emphasis on sellar and parasellar structures in 21 patients preoperatively to delineate endo-, supra-, and parasellar anatomical structures. Special attention was given to the medial border of the cavernous sinus and possible invasion of a sellar tumor therein, and to assessing the application of high-resolution images during intraoperative neuronavigation. The 3-tesla MR images were compared with the standard MR images already obtained and with intraoperative findings. Anatomical structures were studied in all 42 cavernous sinuses; in 32 of them comparisons with intraoperative findings were possible. The medial cavernous sinus border was rated intact in 53% on standard MR images, in 72% on 3-tesla MR images, and in 81% intraoperatively. With a positive correlation to surgical findings on 84% of 3-tesla MR images compared with 59% of standard MR images, a sensitivity of 83% compared with 67%, and a specificity of 84% compared with 58% (p = 0.016, McNemar test), 3-tesla MR imaging was superior for predicting tumor invasion through the medial cavernous sinus border. Although no difference was noted in delineation of the medial, superior, and inferior compartments, there was a better delineation of the lateral cavernous sinus compartment with 3-tesla MR imaging. This compartment was clearly visible on 40 sides (95%) on 3-tesla MR images compared with 34 sides (81%) on standard MR images. Identification of the cavernous sinus segments of the third, fourth, fifth (V1 and V2), and sixth cranial nerves was improved using high-resolution 3-tesla imaging compared with standard MR imaging. A mean of four cranial nerves was found as hypointense spots (range two-five spots) on 3-tesla MR imaging compared with a mean of three (range zero-four spots) on standard MR imaging. After addition of contrast agents, the anterior pituitary gland was found to be highly intense on 78% of T1-weighted three-dimensional magnetization-prepared rapid acquisition gradient-echo (MPRAGE) 3-tesla MR images compared with 73% of standard T1-weighted MR images. The optochiasmatic system displayed increased intensity on pre-contrast T1-weighted MPRAGE 3-tesla compared with standard T1-weighted MR images; it was hyperintense on 76% of 3-tesla compared with 15% of standard MR images, which was helpful for its delineation from suprasellar pituitary and tumor structures. Intraoperative navigation guided by fusion of 3-tesla MR images and computerized tomography (CT) scans was performed in seven patients. Whereas CT scanning was used during the transsphenoidal approach to depict the nasal bone structures, 3-tesla MR imaging was particularly useful for the visualization of parasellar tumor extension during microsurgical and/or endoscopic resection., Conclusions: Due to its higher resolution, 3-tesla MR imaging was found to be superior to standard MR imaging for the delineation of parasellar anatomy and tumor infiltration of the cavernous sinus, and this modality provided improved imaging for intraoperative navigation.

Object: The concept of selective amygdalohippocampectomy is based on pathophysiological insights into the epileptogenicity of the hippocampal region and the definition of the clinical syndrome of mesial temporal lobe epilepsy (TLE). High-resolution magnetic resonance (MR) imaging allows correlation of the site of histologically conspicuous tissue with anatomical structure. The highly variable sulcal pattern of the basal temporal lobe, however, definitely complicates the morphometric analysis of histomorphologically defined subdivisions of the hippocampal region. The goal of this study was to define individual variations in the sulcal anatomy on the basis of preoperative MR images obtained in patients suffering from TLE., Methods: The authors analyzed coronal MR images obtained in 50 patients for the presence of and intrinsic relationships among the rhinal, collateral, and occipitotemporal sulci. The surface relief of consecutive sections of 100 temporal lobes was graphically outlined and the resulting maps were used for visual analysis. The sulci were characterized by measurement of their depth, distance to the temporal horn, and laterality. The anatomical measurements and frequencies of sulcal patterns were assessed for statistical correlation with patients' histories and the lateralization of the seizure focus., Conclusions: Statistical assessment shows that patient sex is a significant factor in sulcal patterns. Anatomical measurements are significantly decreased on the side of the seizure origin, which relates to loss of white matter, a known morphological abnormality associated with TLE. Magnetic resonance imaging allows for accurate preoperative knowledge of individual sulcal patterns and facilitates intraoperative orientation to anatomical landmarks.

Simple Summary: In order to compare responses to different therapies among clinical trials and to differentiate between therapy-induced changes and true tumor progression, reliable response parameters are crucial. With the advent of targeted and immunologic treatments, several assessment tools have been proposed. In this post hoc analysis we compared assessment criteria according to MacDonald, RANO, mRANO, iRANO as well as Vol-RANO and Vol-mRANO in patients with newly diagnosed glioblastoma treated with standard of care (SOC) ± tumor lysate-charged autologous dendritic cells (Audencel). We found that the best correlation between progression-free survival (PFS) and overall survival (OS) was seen for mRANO and Vol-mRANO. Interestingly, iRANO was not superior for predicting OS in patients treated with Audencel. Introduction: In this post hoc analysis we compared various response-assessment criteria in newly diagnosed glioblastoma (GB) patients treated with tumor lysate-charged autologous dendritic cells (Audencel) and determined the differences in prediction of progression-free survival (PFS) and overall survival (OS). Methods: 76 patients enrolled in a multicenter phase II trial receiving standard of care (SOC, n = 40) or SOC + Audencel vaccine (n = 36) were included. MRI scans were evaluated using MacDonald, RANO, Vol-RANO, mRANO, Vol-mRANO and iRANO criteria. Tumor volumes (T1 contrast-enhancing as well as T2/FLAIR volumes) were calculated by semiautomatic segmentation. The Kruskal-Wallis-test was used to detect differences in PFS among the assessment criteria; for correlation analysis the Spearman test was used. Results: There was a significant difference in median PFS between mRANO (8.6 months) and Vol-mRANO (8.6 months) compared to MacDonald (4.0 months), RANO (4.2 months) and Vol-RANO (5.4 months). For the vaccination arm, median PFS by iRANO was 6.2 months. There was no difference in PFS between SOC and SOC + Audencel. The best correlation between PFS/OS was detected for mRANO (r = 0.65) and Vol-mRANO (r = 0.69, each p < 0.001). A total of 16/76 patients developed a pure T2/FLAIR progressing disease, and 4/36 patients treated with Audencel developed pseudoprogression. Conclusion: When comparing different response-assessment criteria in GB patients treated with dendritic cell-based immunotherapy, the best correlation between PFS and OS was observed for mRANO and Vol-mRANO. Interestingly, iRANO was not superior for predicting OS in patients treated with Audencel. [ABSTRACT FROM AUTHOR]

Background: P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) are two efflux transporters expressed at the blood–brain barrier which effectively restrict the brain distribution of the majority of currently known anticancer drugs. High-grade brain tumors often possess a disrupted blood–brain tumor barrier (BBTB) leading to enhanced accumulation of magnetic resonance imaging contrast agents, and possibly anticancer drugs, as compared to normal brain. In contrast to high-grade brain tumors, considerably less information is available with respect to BBTB integrity in lower grade brain tumors. Materials and methods: We performed positron emission tomography imaging with the radiolabeled ABCB1 inhibitor [11C]tariquidar, a prototypical ABCB1/ABCG2 substrate, in seven patients with non-contrast -enhancing brain tumors (WHO grades I–III). In addition, ABCB1 and ABCG2 levels were determined in surgically resected tumor tissue of four patients using quantitative targeted absolute proteomics. Results: Brain distribution of [11C]tariquidar was found to be very low across the whole brain and not significantly different between tumor and tumor-free brain tissue. Only one patient showed a small area of enhanced [11C]tariquidar uptake within the brain tumor. ABCG2/ABCB1 ratios in surgically resected tumor tissue (1.4 ± 0.2) were comparable to previously reported ABCG2/ABCB1 ratios in isolated human micro-vessels (1.3), which suggested that no overexpression of ABCB1 or ABCG2 occurred in the investigated tumors. Conclusions: Our data suggest that the investigated brain tumors had an intact BBTB, which is impermeable to anticancer drugs, which are dual ABCB1/ABCG2 substrates. Therefore, effective drugs for antitumor treatment should have high passive permeability and lack ABCB1/ABCG2 substrate affinity. Trial registration: European Union Drug Regulating Authorities Clinical Trials Database (EUDRACT), 2011-004189-13. Registered on 23 February 2012, https://www.clinicaltrialsregister.eu/ctr-search/search?query=2011-004189-13. [ABSTRACT FROM AUTHOR]

While it has been shown that cerebellar tumor lesions have an impact on cognitive functions, the extent to which they shape distant neuronal pathways is still largely undescribed. Thus, the present neuroimaging study was designed to investigate different aspects of cognitive function and their neuronal correlates in patients after childhood cerebellar tumor surgery. An alertness task, a working memory task and an incompatibility task were performed by 11 patients after childhood cerebellar tumor surgery and 17 healthy controls. Neuronal correlates as reflected by alterations in functional networks during tasks were assessed using group independent component analysis. We were able to identify eight networks involved during task performance: default mode network, precuneus, anterior salience network, executive control network, visual network, auditory and sensorimotor network and a cerebellar network. For the most ‘basic’ cognitive tasks, a weaker task-modulation of default mode network, left executive control network and the cerebellar network was observed in patients compared to controls. Results for higher-order tasks are in line with a partial restoration of networks responsible for higher-order task execution. Our results provide tentative evidence that the synchronicity of brain activity in patients was at least partially restored in the course of neuroplastic reorganization, particularly for networks related to higher-order cognitive processes. The complex activation patterns underline the importance of testing several cognitive functions to assess the specificity of cognitive deficits and neuronal reorganization processes after brain lesions. [ABSTRACT FROM AUTHOR]

Tuberous Sclerosis Complex (TSC) is a genetic hamartoma syndrome frequently associated with severe intractable epilepsy. In some TSC patients epilepsy surgery is a promising treatment option provided that the epileptogenic zone can be precisely delineated. TSC brain lesions (cortical tubers) contain dysmorphic neurons, brightly eosinophilic giant cells and white matter alterations in various proportions. However, a histological classification system has not been established for tubers. Therefore, the aim of this study was to define distinct histological patterns within tubers based on semi-automated histological quantification and to find clinically significant correlations. In total, we studied 28 cortical tubers and seven samples of perituberal cortex from 28 TSC patients who had undergone epilepsy surgery. We assessed mammalian target of rapamycin complex 1 (mTORC1) activation, the numbers of giant cells, dysmorphic neurons, neurons, and oligodendrocytes, and calcification, gliosis, angiogenesis, inflammation, and myelin content. Three distinct histological profiles emerged based on the proportion of calcifications, dysmorphic neurons and giant cells designated types A, B, and C. In the latter two types we were able to subsequently associate them with specific features on presurgical MRI. Therefore, these histopathological patterns provide consistent criteria for improved definition of the clinico-pathological features of cortical tubers identified by MRI and provide a basis for further exploration of the functional and molecular features of cortical tubers in TSC. [ABSTRACT FROM AUTHOR]

To study long-term postoperative course and identify predictors for postoperative seizure control in patients with medically intractable temporal lobe epilepsy (TLE) associated with hippocampal sclerosis (HS), diagnosed by magnetic resonance imaging (MRI), and ascertained histopathologically. To compare patients becoming seizure-free (i.e., cured from epilepsy) and patients experiencing prolonged seizure-free periods interposed with recurring seizures. One hundred thirty-five patients (74 women) underwent complete evaluation for epilepsy surgery. The predictive value of duration of epilepsy, age at onset, age at surgery, gender, febrile convulsion history, ictal dystonic posturing, unilateral interictal electroencephalography (EEG) discharges (IED), preoperative secondarily generalized tonic–clonic seizures (SGTCS), and preoperative seizure frequency for short- and long-term postoperative seizure control were evaluated with two classification systems: Classification 1 (seizure-freedom with or without auras during 12-months before observation points) and the stringent classification 2 [International League Against Epilepsy (ILAE) Ia; absolute absence of seizures and auras after operation]. Unilateral IED at year 1 and 2 (p = 0.037 and p = 0.034), male gender and low seizure frequency at year 2 (p = 0.013 and p = 0.046) were significant predictors for seizure freedom using classification 1. All variables (except male gender at year 2; p = 0.035) lost their predictive power, applying classification 2. The proportion of seizure-free patients remained stable between 70% to 79% with classification 1, but decreased from 64.4% at year 1 to 45.8% at year 5 with classification 2. Positive predictors of short-term outcome do not predict long-term outcome in patients with TLE associated with HS. Absolute freedom of seizures and auras cannot be predicted by conventional preoperative variables. [ABSTRACT FROM AUTHOR]

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Gliomas are the most common brain tumor type in children and adolescents. To date, diagnosis and therapy monitoring for these tumors rely on magnetic resonance imaging (MRI) and histopathological as well as molecular analyses of tumor tissue. Recently, liquid biopsies (LB) have emerged as promising tool for diagnosis and longitudinal tumor assessment potentially allowing for a more precise therapeutic management. However, the optimal strategy for monitoring gliomas by LB remains to be determined. In this study, we analyzed circulating tumor DNA (ctDNA) from 78 liquid biopsies (plasma n = 44, cerebrospinal fluid n = 34 (CSF)) of 35 glioma patients, determining H3F3A K28M (K27M) and BRAF V600E mutation allele frequency using droplet digital PCR (ddPCR). All results were correlated to clinically relevant parameters including diagnostic imaging and CSF aspiration site (ventricular vs lumbar) with respect to tumor localization. Regarding diagnostic accuracy, the calculated sensitivity score in the H3F3A K27M cohort was 84.61% for CSF and 73.68% for plasma. In the BRAF V600E cohort, we determined a sensitivity of 83.3% in plasma and 80% in CSF. The overall specificity was 100%. With respect to the CSF aspiration, the intra-operatively obtained CSF demonstrated 100% detection rate, followed by ventricular CSF obtained via Ommaya Reservoir/shunt puncture (93%) and CSF obtained via lumbar puncture (66%). Notably, this further correlated with the proximity of the CSF site to tumor localization. Longitudinal CSF monitoring demonstrated a good correlation to clinical and radiological disease evolution. Importantly, we show for the first time that monitoring BRAF V600E by ddPCR could serve as treatment response assessment in gliomas. In summary, our observation may inform recommendations with regard to location of CSF aspiration when incorporating LB into future treatment protocols. [ABSTRACT FROM AUTHOR]

To evaluate the neurosurgical and economic effectiveness of a newly launched intraoperative high-field (3T) magnetic resonance imaging (MRI) suite for pediatric tumor and epilepsy neurosurgery. Altogether, 148 procedures for 124 pediatric patients (mean age, 8.7 years; range, 0–18 years) within a 2.5-year period were undertaken in a 2-room intraoperative MRI (iopMRI) suite. Surgery was performed mainly for intractable epilepsy (n = 81; 55%) or pediatric brain tumors (n = 65; 44%) in the supine (n = 113; 76%) and prone (n = 35; 24%) positions. The mean time of iopMRI from draping to re-surgery was 50 minutes. IopMRI was applied not in all but in 64 of 148 procedures (43%); in 45 procedures (31%), iopMRI was estimated unnecessary at the end of surgery based on the leading surgeon's decision. In the remaining 39 procedures (26%), ultra-early postoperative MRI was carried out after closure with the patient still sterile in the head coil. Of the 64 procedures with iopMRI, second-look surgery was performed in 26% (in epilepsy surgery in 17%, in tumor surgery in 9%). We did not encounter any infections, wound revisions, or position-related or anesthesiology-related complications. We used iopMRI in less than half of pediatric tumor and epilepsy surgery for which it was scheduled initially. Therefore, high costs argue against its routine use in pediatric neurosurgery, although it optimized surgical results in one quarter of patients and met high safety standards. [ABSTRACT FROM AUTHOR]