Combining amino acid PET and MRI imaging increases accuracy to define malignant areas in adult glioma

Accurate determination of the extent and grade of adult-type diffuse gliomas is critical to patient management. In clinical practice, contrast-enhancing areas of diffuse gliomas in magnetic resonance imaging (MRI) sequences are usually used to target biopsy, surgery, and radiation therapy, but there can be discrepancies between these areas and the actual tumor extent. Here we show that adding ¹⁸F-fluoro-ethyl-tyrosine positron emission tomography (FET-PET) to MRI sequences accurately locates the most malignant areas of contrast-enhancing gliomas, potentially impacting subsequent management and outcomes. We present a prospective analysis of over 300 serial biopsy specimens from 23 patients with contrast-enhancing adult-type diffuse gliomas using a hybrid PET-MRI scanner to compare T2-weighted and contrast-enhancing MRI images with FET-PET. In all cases, we observe and confirm high FET uptake in early PET acquisitions (5-15 min after ¹⁸F-FET administration) outside areas of contrast enhancement on MRI, indicative of high-grade glioma. In 30% cases, inclusion of FET-positive sites changes the biopsy result to a higher tumor grade.

Uncovering the molecular landscape of meningiomas and the impact of perioperative steroids on patient survival

BACKGROUND

The current literature on meningioma reveals a gap in knowledge regarding the impact of genetic factors on patient survival. Furthermore, there is a lack of data on the relationship between the perioperative use of corticosteroids and patient survival in meningioma patients. Our study aims to overcome these gaps by investigating the correlation between genetic factors and overall survival and the effect of postoperative corticosteroids and other clinical characteristics on patient outcomes in meningioma patients.

METHODS

A retrospective analysis of the medical records of 85 newly diagnosed meningioma patients treated from 2016 to 2017 with follow-up until December 2022 was performed.

RESULTS

NF2 mutations occurred in 60% of tumors, AKT1 mutations in 8.2%, and TRAF7 mutations in 3.6%. Most tumors in the parasagittal region had the NF2 mutation. On the other hand, almost all tumors in the sphenoid ridge area did not have the NF2 mutation. AKT-1-mutated meningiomas had more frequent peritumoral edema. Patients who received steroids perioperatively had worse overall survival (OS) than those without steroids (p = 0.034). Moreover, preoperative peri-meningioma edema also was associated with worse OS (p < 0.003). Contrarily, NF2 mutations did not influence survival.

CONCLUSIONS

The combination of clinical, pathomorphological, and genetic data allows us to characterize the tumor better and assess its prognosis. Corticosteroids perioperatively and peri-meningioma edema were associated with shorter OS, according to our study. Glucocorticoids should be used judiciously for the shortest time required to achieve symptomatic relief.

Functional State and Rehabilitation of Patients after Primary Brain Tumor Surgery for Malignant and Nonmalignant Tumors: A Prospective Observational Study

The aim of this study was to compare the pre- and postoperative function of patients qualifying for resection of malignant and nonmalignant primary brain tumors to determine the relationship among tumor type, function, and the course of rehabilitation after surgery. This single-center, prospective, observational study recruited 92 patients requiring prolonged postoperative rehabilitation during their inpatient stay, who were divided into a nonmalignant tumor group (n = 66) and a malignant tumor group (n = 26). Functional status and gait efficiency were assessed using a battery of instruments. Motor skills, postoperative complications, and length of hospital stay (LoS) were recorded and compared between groups. The frequency and severity of postoperative complications, the time needed to attain individual motor skills, and the proportion of patients losing independent gait (~30%) were similar between groups. However, paralysis and paresis were more frequent in the malignant tumor group before surgery (p < 0.001). While nonmalignant tumor patients deteriorated more according to all scales after surgery, patients with malignant tumors were still characterized by worse ADL, independence, and performance at discharge. Worse functional outcomes in the malignant tumor group did not affect LoS or rehabilitation. Patients with malignant and nonmalignant tumors have similar rehabilitation needs, and patient expectation-especially those with nonmalignant tumors-should be appropriately managed.

Relevance of Routine Postoperative CT Scans Following Aneurysm Clipping-A Retrospective Multicenter Analysis of 423 Cases

AIM

Postoperative head computed tomography (POCT) is routinely performed in numerous medical institutions, mainly to identify possible postsurgical complications. This study sought to assess the clinical appropriateness of POCT in asymptomatic and symptomatic patients after ruptured or unruptured aneurysm clipping.

METHODS

This is a retrospective multicenter study involving microsurgical procedures of ruptured (RA) and unruptured intracranial aneurysm (UA) surgeries performed in the Centers associated with the Pomeranian Department of the Polish Society of Neurosurgeons. A database of surgical procedures of intracranial aneurysms from 2017 to 2020 was created. Only patients after a CT scan within 24 h were included.

RESULTS

A total of 423 cases met the inclusion criteria for the analysis. Age was the only significant factor associated with postoperative blood occurrence on POCT. A total of 37 (8.75%) cases of deterioration within 24 h with urgent POCT were noted, 3 (8.1%) required recraniotomy. The highest number necessary to predict (NNP) one recraniotomy based on patient deterioration was 50 in the RA group.

CONCLUSION

We do not recommend POCTs in asymptomatic patients after planned clipping. New symptom onset requires radiological evaluation. Simultaneous practice of POCT after ruptured aneurysm treatment within 24 h is recommended.

NIMG-39. AMINO ACID PET-MRI OF HIGH-GRADE GLIOMA

OBJECTIVE

MRI is gold standard for the diagnosis, surgery and radiation therapy of patients with high-grade glioma. Amino acid PET is useful in gliomas without contrast enhancement in MRI but it is unknown whether PET better identifies high-grade foci than T1-sequence with contrast enhancement or improve definition of high grade glioma infiltration related to T2/Flair images.

METHODS

More than 400 biopsy specimens from twenty-three patients with suspected high-grade glioma were examined in this prospective study. Patients meeting the inclusion criteria were referred for hybrid 18F-FET-PET-MRI before stereotactic biopsy. Biopsies were planned based on early FET-PET acquisition 5-15 minutes post injection and MRI. The following biopsy sites were determined in each case: (i) site of contrast enhancement and increased FET uptake; (ii) contrast enhancement but no increase in FET uptake; (iii) increased FET uptake but without contrast enhancement; and (iv) peripheral areas hyperintense in T2 FLAIR without increased FET uptake and contrast enhancement.

RESULTS

In 35% cases, the biopsy result was changed to a higher tumor grade after the inclusion of FET-positive sites. In all cases, high FET uptake was visualized and confirmed outside areas of contrast enhancement on MRI, indicative of high-grade glioma. Results from biopsies based on the FLAIR sequences corresponded to neoplastic lesions in 13 cases (57%), most often with a lower grade than in areas of high FET uptake.

CONCLUSIONS

FET-PET can be used to locate the most malignant areas of contrast-enhancing gliomas and impact the biopsy results. Surgery or radiotherapy planned solely on MRI images may miss parts of tumor presenting highest malignancy. Brain areas hyperintense in T2 FLAIR without increased amino acid uptake are not specific for malignancy in high grade gliomas.

Meningovertebral ligaments could be a barrier for migration of a herniated intervertebral disc: An anatomical study

Purpose

Intervertebral disc degeneration can manifest as sequestration. In most cases, the material could be found ipsilateral to the annular tear; however, a contralateral migration is also possible. We present an anatomical description of anterior meningovertebral ligaments (MVLs) as a possible barrier for disc migration.

Methods

Anatomical dissection of 20 fresh human cadavers was carried out. Complete lumbar laminectomies with facetectomies were performed. All lumbar segments were exposed. Morphologic and morphometric descriptions of anterior MVLs were presented, with special attention to possible routes of herniated disc migration.

Results

Anterior MVLs were present in all cases. They were divided in three separate groups: medial, lateral, and attached to the nerve roots. The medial group was the thickest, its mean length was 26.2 ± 1.2 mm, and it had no attachment to the disc in 51% of cases. The lateral group was less firm than the medial group, its mean length was 26.9 ± 1.0 mm, and it had no relation with the disc in 47% of cases. Ligaments related to the nerve root were the most delicate and always attached to the intervertebral disc. Their mean length was 14.9 ± 1.8 mm.

Conclusions

The medial group of anterior MVLs are strong connective tissue bands dividing the anterior epidural space. The lateral group is more delicate, and in most cases, lateral MVLs lack annular attachment. MVLs could be an anatomical barrier for disc migration in particular cases.

Current and promising treatment strategies in glioma

Gliomas are the most common primary central nervous system tumors; despite recent advances in diagnosis and treatment, glioma patients generally have a poor prognosis. Hence there is a clear need for improved therapeutic options. In recent years, significant effort has been made to investigate immunotherapy and precision oncology approaches. The review covers well-established strategies such as surgery, temozolomide, PCV, and mTOR inhibitors. Furthermore, it summarizes promising therapies: tumor treating fields, immune therapies, tyrosine kinases inhibitors, IDH(Isocitrate dehydrogenase)-targeted approaches, and others. While there are many promising treatment strategies, none fundamentally changed the management of glioma patients. However, we are still awaiting the outcome of ongoing trials, which have the potential to revolutionize the treatment of glioma.

Rehabilitation Outcomes for Patients with Motor Deficits after Initial and Repeat Brain Tumor Surgery

Repeat surgery is often required to treat brain tumor recurrences. Here, we compared the functional state and rehabilitation of patients undergoing initial and repeat surgery for brain tumors to establish their individual risks that might impact management. In total, 835 patients underwent operations, and 139 (16.6%) required rehabilitation during the inpatient stay. The Karnofsky performance status, Barthel index, and the modified Rankin scale were used to assess functional status, and the gait index was used to assess gait efficiency. Motor skills, postoperative complications, and length of hospital stay were recorded. Patients were classified into two groups: first surgery (n = 103) and repeat surgery (n = 30). Eighteen percent of patients required reoperations, and these patients required prolonged postoperative rehabilitation as often as those operated on for the first time. Rehabilitation was more often complicated in the repeat surgery group (p = 0.047), and the complications were more severe and persistent. Reoperated patients had significantly worse motor function and independence in activities of daily living before surgery and at discharge, but the deterioration after surgery affected patients in the first surgery group to a greater extent according to all metrics (p < 0.001). The length of hospital stay was similar in both groups. These results will be useful for tailoring postoperative rehabilitation during a hospital stay on the neurosurgical ward as well as planning discharge requirements after leaving the hospital.

Investigating the Potential Use of Chemical Biopsy Devices to Characterize Brain Tumor Lipidomes

The development of a fast and accurate intraoperative method that enables the differentiation and stratification of cancerous lesions is still a challenging problem in laboratory medicine. Therefore, it is important to find and optimize a simple and effective analytical method of enabling the selection of distinctive metabolites. This study aims to assess the usefulness of solid-phase microextraction (SPME) probes as a sampling method for the lipidomic analysis of brain tumors. To this end, SPME was applied to sample brain tumors immediately after excision, followed by lipidomic analysis via liquid chromatography-high resolution mass spectrometry (LC-HRMS). The results showed that long fibers were a good option for extracting analytes from an entire lesion to obtain an average lipidomic profile. Moreover, significant differences between tumors of different histological origin were observed. In-depth investigation of the glioma samples revealed that malignancy grade and isocitrate dehydrogenase (IDH) mutation status impact the lipidomic composition of the tumor, whereas 1p/19q co-deletion did not appear to alter the lipid profile. This first on-site lipidomic analysis of intact tumors proved that chemical biopsy with SPME is a promising tool for the simple and fast extraction of lipid markers in neurooncology.

Comparison of the Functional State and Motor Skills of Patients after Cerebral Hemisphere, Ventricular System, and Cerebellopontine Angle Tumor Surgery

Brain tumor location is an important factor determining the functional state after brain tumor surgery. We assessed the functional state and course of rehabilitation of patients undergoing surgery for brain tumors and assessed the location-dependent risk of loss of basic motor skills and the time needed for improvement after surgery. There were 835 patients who underwent operations, and 139 (16.6%) required rehabilitation during the inpatient stay. Karnofsky Performance Scale, Barthel Index, and the modified Rankin scale were used to assess functional status, whereas Gait Index was used to assess gait efficiency. Motor skills, overall length of stay (LOS) in hospital, and LOS after surgery were recorded. Patients were classified into four groups: cerebral hemisphere (CH), ventricular system (VS), and cerebellopontine angle (CPA) tumors; and a control group not requiring rehabilitation. VS tumor patients had the lowest scores in all domains compared with the other groups before surgery (p < 0.001). Their performance further deteriorated after surgery and by the day of discharge. They most often required long-lasting postoperative rehabilitation and had the longest LOS (35 days). Operation was most often required for CH tumors (77.7%), and all metrics and LOS parameters were better in these patients (p < 0.001). Patients with CPA tumors had the best outcomes (p < 0.001). Most patients (83.4%) with brain tumors did not require specialized rehabilitation, and LOS after surgery in the control group was on average 5.1 days after surgery. VS tumor patients represent a rehabilitation challenge. Postoperative rehabilitation planning must take the tumor site and preoperative condition into account.

Dural sinus thrombosis after resection of vestibular schwannoma using suboccipital retrosigmoid approach-thrombosis classification and management proposal

Dural sinus thrombosis is one of the complications after posterior fossa surgery. However, that topic is not described well with regard to vestibular schwannoma surgery using the unique suboccipital retrosigmoid approach. We analyzed retrospectively medical records and radiological investigations of 116 patients. The including criteria were histopathologically confirmed vestibular schwannoma operated on using the retrosigmoid approach, preoperative and postoperative contrast-enhanced MRI, and at least 1-year follow-up. The patient group included 36% males and 64% females. The average age was 47.3 ± 13.9 years. Sixty percent of the tumors were classified as T4b according to the Hannover scale and their mean volume was 13.73 ± 10.28 cm³. There were no signs of thrombosis preoperatively. Postoperative changes in the dural sinuses were found in 26 (22%) cases. In 7 (27%) cases, there was an external compression by the hemostatic agent, and in 19 (73%) cases, a thrombus was visualized in the sinus lumen. The size of the sinus, age, and the tumor size were not risk factors for thrombosis, whereas an intraoperative sinus injury was a statistically significant risk factor (p = 0.0012). All of the patients diagnosed with thrombosis were in good clinical condition in long-term follow-up, except one fatal case. Complete recanalization was observed in 58% of cases after 1-year follow-up. Postoperative changes in the dural venous sinuses are a frequent finding after vestibular schwannoma surgery using the suboccipital retrosigmoid approach. Intraoperative dural injury is a risk factor for thrombosis. Thrombosis in that group of patients is usually asymptomatic and does not influence the prognosis.

RADT-21. DUAL FET PET-GUIDED SIB IN RADIOTHERAPY OF NEWLY DIAGNOSED GLIOBLASTOMA - A PILOT STUDY

BACKGROUND

PET using FET is a valuable tool to determine the actual glioblastoma infiltration.The FET-PET examination can be performed using the dual-time point acquisition of FET . Infiltration defined in dual FET PET corresponds to the location and shape of the recurrence. The aim of this study was to evaluate safety and efficacy of simultaneous integrated boost based on dual FET PET combined with temozolomide TMZ for the postoperative treatment of GBM.

METHODS AND MATERIALS

In a prospective pilot study, 17 patients were enrolled. All patient presented an active tumor in postoperative PET imaging. The radiotherapy was performed as an FET-PET-based integrated-boost IMRT. The prescribed dose was 78 and 60 Gy (single dose 2.6 and 2.0 Gy, respectively). The progression-free survival (PFS) and overall survival (OS), toxicities and radiation necrosis rate were evaluated.

RESULTS

The median follow up was 37 months.Two patients were found to have uncontrolled seizures during radiation treatment and were not able to received treatment per protocol. Patients treated per protocol presented new or increased neurological deficits in 7/15 cases in a month after irradiation. In 4 patients radiation necrosis was confirmed in pathological report after re-surgery. Three patients were still alive after 26,28 and 38 months of follow up without progression and any signs of treatment related late toxicity. The 2-year survival rate was 43% in all patients treated per protocol. Median overall survival (OS) and disease-free survival (DFS) were 20 and 12 months, respectively. In a subgroup of MGMT methylated and unmethylated the median survival was 25 and 12 months.

CONCLUSIONS

Our dose escalation concept with a total dose of 78 Gy, based on FET-PET, have lead to promising survival results even within MGMT unmethylated subgroup. However rate of early toxicity and radiation necrosis is high.

Treating Aggression and Self-destructive Behaviors by Stimulating the Nucleus Accumbens: A Case Series

Self-destructive and aggressive behaviors can have a significant impact on the quality of life of affected individuals and their carrers. While deep brain stimulation (DBS) has been applied to the treatment of self-destructive and aggressive behaviors in isolated cases, clinical data on this treatment modality are still lacking. We therefore assessed responses to treatment with bilateral DBS of the nucleus accumbens in six patients with severe self-destructive and aggressive behaviors. Three patients had Tourette syndrome and three had other underlying predispositions including obsessive compulsive disorder, cerebral palsy, encephalitis, and epilepsy. Patients were followed up for between 2 and 7 years, and patients were assessed using the Modified Overt Aggression Scale (six patients) and the Buss-Perry Aggression Questionnaire (three patients able to complete the questionnaire on their own). DBS reduced self-destructive and aggressive behaviors by 30–100% and by an average of 74.5%. Patients with Tourette syndrome responded better to DBS and improved by 27.3% according to the Buss-Perry Aggression Questionnaire. These results suggest that nuclei accumbens stimulation may be an effective treatment for aggressive and self-destructive behaviors regardless of etiology.

Prognostic and Predictive Biomarkers in Gliomas

Gliomas are the most common central nervous system tumors. New technologies, including genetic research and advanced statistical methods, revolutionize the therapeutic approach to the patient and reveal new points of treatment options. Moreover, the 2021 World Health Organization Classification of Tumors of the Central Nervous System has fundamentally changed the classification of gliomas and incorporated many molecular biomarkers. Given the rapid progress in neuro-oncology, here we compile the latest research on prognostic and predictive biomarkers in gliomas. In adult patients, IDH mutations are positive prognostic markers and have the greatest prognostic significance. However, CDKN2A deletion, in IDH-mutant astrocytomas, is a marker of the highest malignancy grade. Moreover, the presence of TERT promoter mutations, EGFR alterations, or a combination of chromosome 7 gain and 10 loss upgrade IDH-wildtype astrocytoma to glioblastoma. In pediatric patients, H3F3A alterations are the most important markers which predict the worse outcome. MGMT promoter methylation has the greatest clinical significance in predicting responses to temozolomide (TMZ). Conversely, mismatch repair defects cause hypermutation phenotype predicting poor response to TMZ. Finally, we discussed liquid biopsies, which are promising diagnostic, prognostic, and predictive techniques, but further work is needed to implement these novel technologies in clinical practice.

Quality of YouTube Videos on Meningioma Treatment Using the DISCERN Instrument

OBJECTIVE

To assess the quality of YouTube videos on meningioma treatment.

METHODS

A search was performed on YouTube using the keywords "meningioma treatment," "meningeal tumor treatment," "meningioma brain tumor treatment," "meningioma cure," and "meningioma therapy." Sixty-one videos were independently evaluated by 2 fifth-year medical students using the DISCERN scoring system for quality analysis. Quantitative data such as video length, source of upload, and popularity and their associations with DISCERN scores were also evaluated.

RESULTS

The mean total DISCERN score was 36.4. Approximately a third of YouTube videos were classified as very poor, 32.8% as poor, 11.5% as fair, 16.4% as good, and 4.9% as excellent. The question "Does the video refer to areas of uncertainty?" obtained the lowest score (2.0), and the question "Does the video describe how each treatment works?" obtained the highest score (3.0). Videos authored by a health information channel had the highest mean total DISCERN score (46.7, standard deviation = 14.6). Videos had significantly higher DISCERN scores if they included information about the symptoms of meningioma, risk factors during treatment, prognosis, or included animations and diagrams. DISCERN scores were moderately positively correlated with duration of videos and referrers and moderately negatively correlated with number of channel subscribers, video power index, and average daily views.

CONCLUSION

The information content on meningioma treatment in YouTube videos was generally poor. The impact of inaccurate YouTube videos on patients' understanding of meningioma treatment must be recognized by health care professionals.

Influence of Epilepsy on the Quality of Life of Patients with Brain Tumors

Epilepsy is a common consequence of brain tumors, occurring in 35 to 75% of cases. Here we evaluated the influence of epilepsy on the quality of life (QoL) of patients with malignant brain tumors (primary and metastatic) and assessed which areas of function are most affected by epilepsy and brain tumors. Sixty patients undergoing brain tumor surgery at the Neurosurgery Clinic of the 10th Military Research Hospital, Bydgoszcz, Poland (30 with epilepsy and 30 without epilepsy) were studied. Relationships between categorical variables were determined with Pearson’s chi-squared test, while continuous data were analyzed with the Mann-Whitney U-test. A p value < 0.05 was considered statistically significant. A multiple regression model was used for multivariate analysis of QoL. Patients with epilepsy more frequently reported memory disorders as a problem in their daily life. There were trends towards greater impairments in social, professional, and family life, sports and recreational activities, and daily physical activities in brain tumor patients with epilepsy rather than those without epilepsy. Higher frequency and generalized seizures significantly and adversely influenced the ability of patients to leave home and drive vehicles, but a proportion of patients with frequent, generalized seizures continued to drive regardless. Patients with generalized seizures considered the adverse effects of taking medicines as significantly disruptive. Memory disorders significantly affect the QoL of patients with epilepsy, and the importance of stopping driving must be emphasized by all healthcare professionals.

Glioma Biopsy Based on Hybrid Dual Time-Point FET-PET/MRI-A Proof of Concept Study

Neuroimaging based on O-[2-(18F)fluoroethyl]-l-tyrosine (FET)-PET provides additional information on tumor grade and extent compared with MRI. Dynamic PET for biopsy target selection further improves results but is often clinically impractical. Static FET-PET performed at two time-points may be a good compromise, but data on this approach are limited. The aim of this study was to compare the histology of lesions obtained from two challenging glioma patients with targets selected based on hybrid dual time-point FET-PET/MRI. Five neuronavigated tumor biopsies were performed in two difficult cases of suspected glioma. Lesions with (T1-CE) and without contrast enhancement (T1 and T2-FLAIR) on MRI were selected. Dual time-point FET-PET imaging was performed 5–15 min (PET10) and 45–60 min (PET60) after radionuclide injection. The most informative FET-PET/MRI images were coregistered with MRI in time of biopsy planning. Five biopsy targets (three from high uptake and two from moderate uptake FET areas) thought to represent the most malignant sites and tumor extent were selected. Histopathological findings were compared with FET-PET and MRI images. Increased FET uptake in the area of non-CE locations on MRI correlated well with high-grade gliomas localized as far as 3 cm from T1-CE foci. Selecting a target in the motor cortex based on FET kinetics defined by dual time-point PET resulted in a grade IV diagnosis after previous negative biopsies based on MRI. An additional grade III diagnosis was obtained from an area of glioma infiltration with moderate FET uptake (between 1 and 1.25 SUV). These findings seem to show that dual time-point FET-PET-based biopsies can provide additional and clinically useful information for glioma diagnosis. Selection of targets based on dual time-point images may be useful for determining the most malignant tumor areas and may therefore be useful for resection and radiotherapy planning.

Endoscopic versus stereotactic biopsies of intracranial lesions involving the ventricles

Stereotactic biopsies of ventricular lesions may be less safe and less accurate than biopsies of superficial lesions. Accordingly, endoscopic biopsies have been increasingly used for these lesions. Except for pineal tumors, the literature lacks clear, reliable comparisons of these two methods. All 1581 adults undergoing brain tumor biopsy from 2007 to 2018 were retrospectively assessed. We selected 119 patients with intraventricular or paraventricular lesions considered suitable for both stereotactic and endoscopic biopsies. A total of 85 stereotactic and 38 endoscopic biopsies were performed. Extra procedures, including endoscopic third ventriculostomy and tumor cyst aspiration, were performed simultaneously in 5 stereotactic and 35 endoscopic cases. In 9 cases (5 stereotactic, 4 endoscopic), the biopsies were nondiagnostic (samples were nondiagnostic or the results differed from those obtained from the resected lesions). Three people died: 2 (1 stereotactic, 1 endoscopic) from delayed intraventricular bleeding and 1 (stereotactic) from brain edema. No permanent morbidity occurred. In 6 cases (all stereotactic), additional surgery was required for hydrocephalus within the first month postbiopsy. Rates of nondiagnostic biopsies, serious complications, and additional operations were not significantly different between groups. Mortality was higher after biopsy of lesions involving the ventricles, compared with intracranial lesions in any location (2.4% vs 0.3%, p = 0.016). Rates of nondiagnostic biopsies and complications were similar after endoscopic or stereotactic biopsies. Ventricular area biopsies were associated with higher mortality than biopsies in any brain area.

On-Site Sampling and Extraction of Brain Tumors for Metabolomics and Lipidomics Analysis

Despite the variety of tools available for cancer diagnosis and classification, methods that enable fast and simple characterization of tumors are still in need. In recent years, mass spectrometry has become a method of choice for untargeted profiling of discriminatory compound as potential biomarkers of a disease. Biofluids are generally considered as preferable matrices given their accessibility and easier sample processing while direct tissue profiling provides more selective information about a given cancer. Preparation of tissues for the analysis via traditional methods is much more complex and time-consuming, and, therefore, not suitable for fast on-site analysis. The current work presents a protocol combining sample preparation and extraction of small molecules on-site, immediately after tumor resection. The sampling device, which is of the size of an acupuncture needle, can be inserted directly into the tissue and then transported to the nearby laboratory for instrumental analysis. The results of metabolomics and lipidomics analyses demonstrate the capability of the approach for the establishment of phenotypes of tumors related to the histological origin of the tumor, malignancy, and genetic mutations, as well as for the selection of discriminating compounds or potential biomarkers. The non-destructive nature of the technique permits subsequent performance of routinely used tests e.g., histological tests, on the same samples used for SPME analysis, thus enabling attainment of more comprehensive information to support personalized diagnostics.

Biomarker concordance between molecular stereotactic biopsy and open surgical specimens in gliomas

AIMS

To compare 1p/19q codeletion, MGMT promoter methylation, and IDH mutation status in stereotactic biopsy and open craniotomy specimens.

CLINICAL RATIONALE

The latest WHO classification of gliomas requires assessment of the expression of molecular markers. Samples can be obtained for molecular assays via open craniotomy or molecular stereotactic biopsy (MSB). However, there is uncertainty as to whether MSB is representative of the entire tumour, and therefore how reliable it is for treatment planning.

PATIENTS AND METHODS

We examined 11 patients diagnosed with brain tumours suspicious of glioma who underwent open craniotomy after stereotactic biopsy and in whom multiple biomarkers were assessed in both sets of samples by methylation-specific multiplex ligation-dependent probe amplification. Institutional Review Board ethical approval was granted (KB 694/2018).

RESULTS

The initial histopathological grade as determined by stereotactic biopsy was the same as in the samples obtained by open surgery. Further, the marker profile used here was valid in both high- and low-grade gliomas.

CONCLUSION AND CLINICAL IMPLICATION

MSB is a reliable way to obtain material for precision medicine approaches.

P13.05 Chemical Biopsy as an Alternative Sampling Method in Neurooncology

BACKGROUND

Histopathology is a gold standard for diagnostics of brain tumors but it is time consuming, demands removal of the part of the tissue what makes it highly invasive. That is why it seems to be relevant to develop new diagnostic methods addressing the abovementioned drawbacks. Ideal tool should be easy to use, as low invasive as possible and of high clinical value.

The aim of the study was to assess the usefulness of chemical biopsy based on solid phase microextraction as a sampling method for lipidomic analysis of brain tumors.

MATERIAL AND METHODS

The experiment was carried out on 38 brain tumors. Sampling was performed ex vivo, directly after removal of brain tumors. SPME fibers (coated with biocompatible extraction phase, length and diameter of the coating 7mm and 200um, respectively) were inserted into the sample without prior preparation of the tissue. Desorption of lipids was performed in isopropanol-methanol mixture. Analysis of extracts was carried out using liquid chromatography coupled to high resolution mass spectrometry.

RESULTS

Wide range of tentative lipid species was obtained in the studies. Two histologically different types of brain tumors: gliomas and meningiomas were subjected to the chemical biopsy. The results showed very good separation between the tumor types in unsupervised chemometric tests. The lipid species responsible for this separation were previously reported in the literature as cancer biomarkers. With regards to malignancy grading of gliomas the separation was notable but not as clear as between the tumor types, what is probably related to high heterogeneity of this cancerous tissue and subjectivity of histopathological analysis which were a referring point in methods comparison. Very good agreement was noted for changes in lipidome obtained by chemical biopsy and histological subtypes of gliomas. However, the most promising results showed impact of IDH1 R132H mutation on lipidome of gliomas.

CONCLUSION

Chemical biopsy seems to be useful method in lipidomics studies and for differentiation of brain tumors according their histological origin and malignancy. It also enables to find a relation between IDH1 mutation and lipidomic profile.

ACKNOWLEDGMENTS

The work was supported by the grant 2015/18/M/ST4/00059 funded by National Science Centre, Poland. The authors want to acknowledge Supelco/MilliporeSigma for the SPME probes, Thermo Fisher Scientific for the access to Q-Exactive Focus mass spectrometer, Anchem for the technical support and Shim-Pol for the access to LCMS-8060 mass spectrometer and technical support.

Large In-mask Motion during Frameless Radiosurgery of a Brain Metastasis

Frameless radiosurgery is now a common alternative to traditional in-frame treatment. Several dosimetric studies have reported small in-mask positioning inaccuracies during frameless radiosurgery. We present a case of an uncommonly large deviation in in-mask motion detected offline in a patient undergoing linear accelerator-based frameless radiosurgery. Our case illustrates how the use of a thermoplastic mask can lead to unacceptable setup errors for passive image-guided radiosurgery. The case underlines the need for correct patient preparation, adequate time between mask molding and computed tomography, and routine intrafraction imaging. Image-guided positioning is recommended to achieve clinically acceptable setup accuracy (< 1 mm) for stereotactic radiosurgery.

The Sum of Tumour-to-Brain Ratios Improves the Accuracy of Diagnosing Gliomas Using 18F-FET PET

Gliomas are common brain tumours, but obtaining tissue for definitive diagnosis can be difficult. There is, therefore, interest in the use of non-invasive methods to diagnose and grade the disease. Although positron emission tomography (PET) with 18F-fluorethyltyrosine (18F-FET) can be used to differentiate between low-grade (LGG) and high-grade (HGG) gliomas, the optimal parameters to measure and their cut-points have yet to be established. We therefore assessed the value of single and dual time-point acquisition of 18F-FET PET parameters to differentiate between primary LGGs (n = 22) and HGGs (n = 24). PET examination was considered positive for glioma if the metabolic activity was 1.6-times higher than that of background (contralateral) brain, and maximum tissue-brain ratios (TBR_max) were calculated 10 and 60 min after isotope administration with their sums and differences calculated from individual time-point values. Using a threshold-based method, the overall sensitivity of PET was 97%. Several analysed parameters were significantly different between LGGs and HGGs. However, in a receiver operating characteristics analysis, TBR sum had the best diagnostic accuracy of 87% and sensitivity, specificity, and positive and negative predictive values of 100%, 72.7%, 80%, and 100%, respectively. 18F-FET PET is valuable for the non-invasive determination of glioma grade, especially when dual time-point metrics are used. TBR sum shows the greatest accuracy, sensitivity, and negative predictive value for tumour grade differentiation and is a simple method to implement. However, the cut-off may differ between institutions and calibration strategies would be useful.

Motor cortex stimulation in patients with chronic central pain

BACKGROUND

Motor cortex stimulation is one of the neuromodulation methods of treating refractory central neurogenic pain.

OBJECTIVES

The aim of this study was to retrospectively evaluate the effects of motor cortex stimulation.

MATERIAL AND METHODS

The study group consisted of 14 consecutive patients with thalamic pain, atypical facial pain, post-brachial plexus avulsion injury pain, phantom pain and pain in syringomyelia who were treated with motor cortex stimulation at the Department of Neurosurgery of the Military Research Hospital in Bydgoszcz, Poland, from 2005 to 2013. The procedures were conducted with the use of neurosurgical navigation and intraoperative neurophysiological monitoring. The outcomes were assessed in terms of visual analog scale scores. The long-term follow-up ranged from one to six years.

RESULTS

A statistically significant reduction in the intensity of pain was noted in patients treated with motor cortex stimulation (pre-surgery median visual analog scale=9, short-term result median visual analog scale=3, p=0.0009; long-term result median visual analog scale=5, p=0.0036). Over the long term, with follow-ups ranging from one to six years, the results were excellent (over 80% reduction in pain) in 31% of the patients and satisfactory (50-80% reduction in pain) in 23% of the patients. Unsatisfactory pain control (less than 50%) was noted in 31% of the patients and no improvement was noted in 15%. Significantly better relief of pain was observed in the early postoperative period. In this series of patients, the highest efficacy of motor cortex stimulation was observed in post-stroke or post-hemorrhagic thalamic pain (5/7 patients-71%). Long-term outcomes were not related to the age or sex of the patient, the preoperative duration of the pain, or to the position or number of implanted electrodes.

CONCLUSIONS

MCS significantly reduces the intensity of neurogenic pain. The best long-term results in the present study were achieved in patients with thalamic syndrome. No significant predictors were found for a successful final outcome. The authors consider appropriate selection of patients, accurate placement of the electrodes and frequent adjusting of the stimulation parameters to be important factors increasing the efficacy of MCS.

An analysis of the prognostic value of IDH1 (isocitrate dehydrogenase 1) mutation in Polish glioma patients

Background and Objective

IDH1 (isocitrate dehydrogenase 1) is a potential biomarker and drug target. Genomic and epigenetic data on astrocytoma have demonstrated that the IDH1 mutation is sufficient to establish the glioma hypermethylator phenotype. Furthermore, recent studies have also indicated that a mutant IDH1 inhibitor induced demethylation of histone H3K9me3 and expression of genes associated with gliogenic differentiation. As the presence of the p.R132H mutation in the IDH1 gene seems to be a more powerful prognostic marker than O⁶-methylguanine-DNA methyltransferase promoter status, we evaluated the presence of IDH1 mutation in Polish patients with astrocytoma, glioblastoma, oligoastrocytoma, ganglioglioma, oligodendroglioma, and ependymoma.

Methods

The IDH1 mutation status at codon 132 was determined using a mouse monoclonal antibody specific for the R132H mutation, direct sequencing, and Co-amplification at Lower Denaturation Temperature (COLD) polymerase chain reaction (PCR) high-resolution melting-curve analysis (HRM).

Results

Wild-type (WT) IDH1 was detected in cases with a World Health Organization (WHO) grade I astrocytoma. The IDH1 c.G395A; p.R132H mutation was observed in 56 and 94 % of grade II and grade III astrocytoma cases, respectively. Significant differences in the median overall survival were observed in astrocytoma patients grouped on the basis of the presence of IDH1 mutation: survival was 24 months longer in grade II astrocytoma and 12 months longer in glioblastoma. Overall survival was compared between grade II astrocytoma patients with low or high expression of the mutant protein. Interestingly, lower R132H expression correlated with better overall survival.

Conclusion

Our results indicate the usefulness of assessing the R132H IDH1 mutation in glioma patients: the presence or absence of the R132H mutation can help pathologists to distinguish pilocytic astrocytomas (IDH1 WT) from diffuse ones (R132H IDH1/WT). Moreover, low IDH1 p.R132H expression was related to better prognosis. This clinical implication appears to be important for personalization of prognosis and treatment by oncologists.

Ultrasonic Studies of Ferroelectric Phase Transition in Gly-H3PO3 Crystals

The temperature behaviour of the longitudinal and transverse ultrasound wave velocities and attenuation in the region of the ferroelectric phase transition (Tc = 225 K) of the glycine phosphite (Gly-H3PO3) crystals is studied. The obtained results are considered within the framework of phenomenological theory.

Influence of intraoperative neurophysiologic monitoring on the development of surgical dissection techniques

Intraoperative neurophysiologic monitoring (IONM) is essential in the preservation of function of nervous system. IONM is thus becoming the gold-standard method in nerve-sparing surgical procedures. Apart from spine and brain surgery, IONM is essential in significantly reducing morbidity in colorectal surgery, prostate and thyroid surgery, as well as in hip replacement, to name a few. IONM measures weak electric nerve potentials and, therefore, it is easily disturbed by other electromagnetic sources. Surgical dissection techniques and devices interfering with IONM make this technique useless because this is dissection that mainly endangers nerve structures. Therefore, there is a need to take into consideration the influence of various dissection techniques on IONM, and to develop or modify inert techniques that are currently not widely used.

[Stereotactic biopsy of polylmorphic tumors and brain tumors invisible in CT image]

The authors present the possibilities of obtaining tissue samples with stereotactic biopsy basing on three examples of intracranial polymorphic and invisible in CT tumours. CT scans of these tumours make a serious problem with proper targeting and tissue sampling from proper sites. Stereotactic serial biopsy directed by CT/MRI fusion is the best way of obtaining tissue material in order to establish correct diagnosis.

[Pathomorphological evaluation in stereotactic brain tumor biopsy]

The method is described of multistep pathomorphological examination of biopsy material obtained by stereotactic procedures from brain tumours. In the analysis of 260 biopsies the possibility was assessed of intraoperative cytological examinations confronting the results of these examinations with those of final histological and immunohistochemical investigations. Attention is called to the difficulties in the evaluation of material derived from stereotactic biopsies and to the cause of possible diagnostic errors. It is concluded that the combination of the results of cytological examination of smears and histological examination of paraffin slides makes possible establishing of full pathomorphological diagnosis with determination of tumour type and its malignancy degree in 90.7% of cases. On most cases cytological intraoperative examination had the greatest influence on therapeutic management. In the confrontation of these examinations with histological examinations a high proportion of correct cytological examinations was found (76.6%). Owing to the possibility of application of all techniques of morphological diagnosis, stereotactic biopsy is a reliable method in the diagnosis of brain tumours.

[The significance of stereotactic biopsy in the diagnosis and treatment of central nervous system lymphomas]

The paper presents seven cases of central nervous system lymphomas diagnosed in Department of Neurosurgery of Military Clinical Hospital in Bydgoszcz. The role of stereotactic biopsy in the management of this entity is underlined. Clinical, radiological and pathological symptoms met in PCNSL (Primary Central Nervous System Lymphoma) are briefly described.

[The role of stereotactic biopsy in diagnosis of pineal region tumors]

The anatomy, pathophysiology nad treatment of the pineal region tumors are presented. The authors stress the role of stereotactic biopsy in the diagnosis and correct management. Based on the literature and their experiences the risk of complications and incorrect diagnosis is discussed.

[Additional studies in the assessment of brain concussion]

Following minor head traumas nervous system injuries develop at cellular level. In these cases only multidirectional analysis using various techniques can contribute to easier detection of focal lesions. The importance of neurophysiological methods, including electroencephalography (EEG), polysomnography, neuroimaging methods, such as cerebral tomography (CT), magnetic resonance (MRI), single photon emission computerised tomography (SPECT) and positron emission tomography (PET) in cases of minor head trauma. A brief review of the diagnostic methods applicable in the assessment of brain commotion shows that the dynamic development of new diagnostic techniques such as SPECT and MRI made possible a better insight into the processes taking place after minor trauma to the head. Together with traditional methods it can contribute to more objective demonstration of the symptoms, dynamics of the pathological process and more exact expertise of late sequelae of the trauma.

[Current views on brain concussion]

Modern views on brain concussion are reviewed by the authors who present also the evolution of the views on this problem in the last five decades. Owing to devising of an experimental model of light craniocerebral injuries the presence of structural changes in the central nervous system developing after concussion has been demonstrated. Using the modern diagnostic imaging techniques (SPECT) in clinical practice persistent disturbances of regional cerebral blood flow were found following such head injuries. The mechanism, which could explain the development of cerebral perfusion changes, could produce also axonal disorders, breakdown of the blood-brain barrier, atrophy of hippocampal neurons which lesions had been noted previously in experiments. The results of SPECT investigations put in doubt the presence of a "pure" functional brain damage following slight craniocerebral injury and provide evidence for the existence will aim at correlating of electrophysiological phenomena, vascular changes and biochemical disturbances with lesions leading to disorders of behaviour observed in the so called postconcussion syndromes.

[Complications after surgery of the anterior cervical spine]

Every year several thousands of operations on the cervical spine from anterior approach are performed in the world for decompression of spinal cord and nerve roots. It is estimated that in 0.2 to 12% of the operations serious intraoperative and postoperative complications occur. Such cases have been reported in the world literature but in scant numbers. The authors discuss early and late complications after operations on the cervical spine connected with the surgical method.

[Epidemiology, diagnosis and prognosis in the clinical syndrome of brain concussion]

The paper is a continuation of the preliminary communication in Neurologia i Neurochirurgia Polska No 3/1995. The study in 1993-1995 included a group of 50 patients who had clinical symptom complex of brain concussion. After preliminary neurological assessment within 3 days in all cases brain CT and cerebral perfusion determination (SPECT M-PAO) were obtained. Focal reduction of blood flow was demonstrated in 47 cases, mostly in the temporal area (78%). In 30 cases EEG was done finding in 18 disturbances of cerebral electric activity. In 9 cases neuropsychological examination was done. After 3 months control study of cerebral perfusion was done in 28 cases and in 27 flow changes were found to persist. Another follow-up examination in 6 cases after a year demonstrated in all of them focal disturbances of cerebral blood flow associated with symptoms of postconcussion syndrome.

[Thoracic outlet syndrome: results of surgical treatment]

21 patients with thoracic outlet syndrome (t.o.s.) were operated on in the Department of Neurosurgery of MMA in Lódź between 1982-1991. Early and long-term results of treatment were analyzed in the group of 13 cases. In early postoperative period 5 patients were free of pain and neurologic or vascular disturbances in the upper limb. In other 6 cases pain disappeared partially and mild neurological or vascular syndromes persisted. Altogether satisfactory results of treatment were obtained in 8 patients (85%). There was some improvement in 2 patients but pain and neurological or vascular disorders were still significant after surgery. Long-term results were assessed at least 1 year after operative treatment. Recurrent pain with or without mild neurological (vascular) syndromes appeared in 6 patients (46%). Recurrent t.o.s. occurred mainly in cases of young women with low position of shoulder girdle and poorly developed musculature of this region. Only 2 patients still remained free of preoperative syndromes. Altogether only 8 patients (61%) had acceptable results of surgical treatment at long-term follow-up. The remaining 5 patients (39%) had unsatisfactory long-term results.

[Cerebral blood flow changes after mild head trauma imaging with SPECT HMPAO. Preliminary report]

The authors present 3 cases of mild head trauma diagnosed by CT, EEG and SPECT. The results showed that CT scan was negative in all cases while SPECT was positive. EEG recording showed changes which seemed to agree with the changes of regional cerebral blood flow presented by SPECT. This initial results indicate that SPECT HM-PAO within the first two-three days is more sensitive than CT scan and detects brain perfusion abnormalities.