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Introduction: Stereotactic brain biopsies are essential for obtaining tissue samples from brain lesions, crucial for comprehensive histological analysis and subsequent adjuvant therapies. While most biopsies target supratentorial lesions, those involving the posterior fossa are less frequent but pose significant technical and surgical challenges, necessitating careful patient management. Methods: We present our experience with stereotactic biopsies of the posterior fossa using the Leksell Vantage frame (Elekta, Stockholm, Sweden) and the ZD Inomed frame (Inomed Medizintechnik GmbH, Emmendingen, Germany). For the ZD frame, we either mounted it upside down or employed a frontal approach, while for the Leksell Vantage frame, we utilized a reverse x-axis orientation. Planning was based on 3-T MRI scans and preoperative MRI merged with stereotactic CT for coordinate generation. Results: From 2006 to 2023, we performed 25 stereotactic biopsies of the posterior fossa in our department—9 with the ZD Inomed frame and 16 with the Leksell Vantage frame. The cohort included 14 male and 11 female patients, with an average age of 60.6 years (range 36—80 years). The average surgery duration was shorter with the Leksell Vantage frame (32.6 min vs. 44.8 min, p = 0.05). The average length of the planned trajectory was 41.7 mm for the Leksell Vantage frame and 52.2 mm for the ZD Inomed frame. Postoperativ bleeding occurred in two cases—one managed conservatively, the other required surgical intervention. Additionally, two other cases presented new postoperative focal neurological deficit. The overall mortality rate was 34.8% and a 40-day postoperative mortality rate of 13.0%. Conclusion: Our experience demonstrates that stereotactic biopsies of lesions in the posterior fossa can be effectively managed with different frame systems, though they present a higher degree of complexity. Notably, the Leksell Vantage frame was associated with a significantly shorter surgery duration. This technical note provides valuable insights and detailed technical guidance for neurosurgeons facing similar challenges. [ABSTRACT FROM AUTHOR]

Both the transfrontal and the suboccipital-transcerebellar approach are frequently used trajectories for frame-based stereotactic biopsies of brainstem lesions. Nevertheless, it remains unclear which approach is more favorable in terms of complications, diagnostic success and outcome, especially considering the location of the lesion within the brainstem. This study compared the safety and diagnostic yield of these two approaches. Furthermore, a brainstem zone model was created to answer the question, whether there is a favorable approach depending on the location of the lesion in the brainstem. A retrospective analysis of 84 consecutive cases of frame-based stereotactic biopsies for brainstem lesions via either transfrontal or suboccipital-transcerebellar approaches over a 16-year period was performed. Clinical and surgical data regarding trajectories, histopathology, complications and outcome was collected. The brainstem was divided in anatomical zones to compare the use of the two approaches depending on the location of the lesions. A total of n = 84 cases of stereotactic biopsies for brainstem lesions were performed. In 36 cases the suboccipital-transcerebellar approach was used, while in 48 cases surgery was performed via the transfrontal approach. The patient's demographic data were comparable between the two approaches. Overall diagnostic yield was 90.5% (93.8% transfrontal vs. 86.1% suboccipital, p = 0.21, Risk Difference (RD) 0.077, CI [-0.0550, 0.2090]). Complications occurred in 11 cases (total complication rate: 13.1%; 12.5% transfrontal vs. 13.9% suboccipital, p = 0.55, RD 0.014, CI [-0.1607, 0.1327]). The brainstem model showed a more frequent use of the suboccipital approach in lesions of the dorsal pons. The transfrontal approach was used more frequently in mesencephalic targets. No significant differences in terms of complications and diagnostic yield were observed, even though complications in medullary lesions appeared higher using the transfrontal approach. This study showed, that if the approaches are used for their intended target locations there are no significant differences between the transfrontal and the suboccipital-transcerebellar approach for frame-based stereotactic biopsies of brainstem lesions in terms of diagnostic yield and safety. Therefore, our data suggests that both approaches should be considered for stereotactic biopsy of brainstem lesions. [ABSTRACT FROM AUTHOR]

Background: Stereotactic approaches to diffuse intrinsic pontine gliomas (DIPGs) remain essential due to advances in molecular biology and management, necessitating tissue sampling. Here we present an effective technique with a biopsy by robot-assisted transcerebellar approach. Method: Our procedure was performed using the ROSA robotic system and the OARM CT scan, which provided stereotactic conditions for this transcerebellar approach to brainstem lesions. Conclusion: The robot-assisted transcerebellar stereotactic approach remains essential to provide complications for biopsy of brainstem lesions. [ABSTRACT FROM AUTHOR]

Purpose of the study. Development of a method for preventing hemorrhages during stereotactic biopsy of a brain tumor using liquid hemostatic matrices on the example of the drug "Floseal®".Patients and methods. The target of the biopsy is the most representative area of tumor tissue according to the data of various modalities of MRI neuroimaging, including contrast-enhanced ones. Out of 133 patients, 60 patients with signs of intraoperative bleeding along the biopsy needle cannula were included in the study group. Further, patients with signs of intraoperative bleeding along the cannula of the biopsy needle were divided into 2 subgroups by independent sequential randomization. Control subgroup (n = 45): cases with signs of intraoperative bleeding of varying severity were operated on, according to the standard technique, without the use of the liquid hemostatic drug Floseal®. The main subgroup (n = 15): in case of intraoperative signs of bleeding, the hemostatic fluid drug Floseal® was injected into the area of tumor material removal.Results. In 6.7 % of patients of the control subgroup, the formation of massive intracerebral hemorrhages was noted in the postoperative period. In 53.3 % of the observations of the control subgroup according to X-ray computer examinations of the brain, there were signs of minor hemorrhages at the point of tumor material collection, which did not require repeated surgical interventions. Postoperative hemorrhages after injection of the Floseal® liquid hemostatic matrix into the biopsy needle in the study subgroup were not detected according to neuroimaging X-ray CT.Conclusion. A method of hemostasis has been developed to prevent hemorrhages using liquid hemostatic matrices. If signs of bleeding from the biopsy needle appeare, the introduction of a hemostatic matrix in the volume of 2 ml helps to manage bleeding intraoperatively, as well as to prevent the occurrence of hemorrhage in the early postoperative period.

To summarize the preliminary application experience of intraoperative ultrasound with burr hole probe in minimally invasive neurosurgery and to explore its application value. Thirty-one patients who underwent intraoperative ultrasound guided puncture with burr hole probe in our center from August 2018 to May 2024 were collected, including 16 cases of ventriculoperitoneal shunt operation, 6 cases of assisted stereotactic needle biopsy, 3 cases of intracranial pressure probe implantation in lateral ventricle, 3 cases of brain abscess puncture for external drainage, and 3 cases of intracranial cyst puncture and peritoneal drainage. During the procedures, the burr hole probe was used to locate the intracranial targets and guide the puncture. The postoperative computed tomography (CT) scans or combined postoperative pathological results could verify the accuracy of puncture. In addition, the intervention effect and recovery status of patients were also recorded. The intraoperative ultrasound with burr hole probe could clearly display all the purposed targets and accurately guide the puncture procedures in all cases. All patients achieved satisfactory diagnostic and therapeutic results without new neurological dysfunction and serious complications. The intraoperative ultrasound with burr hole probe is an effective device for demonstrating intracranial structures. It not only enables minimally invasive and precise diagnosis or treatment of many neurosurgical diseases, but also is simple and safe to operate, which has important promotional value in the neurosurgery. [ABSTRACT FROM AUTHOR]

Diffuse intrinsic pontine gliomas are aggressive tumors that carry a poor prognosis with a 2-year survival rate of <10%. The imaging appearance is often pathognomonic, and surgical biopsy is not mandatory to initiate treatment in children. Studies of biopsy samples provide insight into the disease's molecular pathobiology and open prospects for targeted therapy. This study was conducted to determine the diagnostic yield and safety of stereotactic biopsies. This is a prospective observational study from a single tertiary health care center. All patients with clinical and radiological features diagnostic of diffuse intrinsic pontine gliomas (DIPGs) who underwent biopsy from July 2018 to June 2023 were included. Biopsies were performed using either stereotactic frame-based, frameless, or endoscopic techniques. A total of 165 patients with DIPGs were evaluated in the study period. The option of biopsy with its associated risks and benefits was offered to all patients. A total of 76 biopsies were performed in 74 patients (40 children and 34 adults, including 2 repeat biopsies). The median age was 15 years. Diffuse midline gliomas, H3K27M altered, was the most common histopathological diagnosis (85% pediatric and 55.9% adults). The diagnostic efficacy of the procedure was 94.7%. The complication rate was 10.8%, with no permanent neurological deficits due to surgery. There was no procedure-related mortality. Establishing the safety of the procedure could be an important step toward popularizing the concept, which might offer a better understanding of the disease. Brainstem eloquence and a lack of direct benefit to patients are the primary obstacles to brainstem biopsy. [ABSTRACT FROM AUTHOR]

Purpose: To explore imaging biomarkers predictive of intratumoral haemorrhage for lesions intended for elective stereotactic biopsy. Method: This study included a retrospective cohort of 143 patients with 175 intracranial lesions intended for stereotactic biopsy. All the lesions were randomly split into a training dataset (n=121) and a test dataset (n=54) at a ratio of 7:3. Thirty-four lesions were defined as "hemorrhage-prone tumors" as haemorrhage occurred between initial diagnostic MRI acquisition and the scheduled biopsy procedure. Radiomics features were extracted from the contrast-enhanced T1 Weighted Imaging and T2 Weighted Imaging images. Features informative of haemorrhage were then selected by the LASSO algorithm, and an Support Vector Machine model was built with selected features. The Support Vector Machine model was further simplified by discarding features with low importance and calculating them using a "permutation importance" method. The model's performance was evaluated with confusion matrix-derived metrics and area under curve (AUC) values on the independent test dataset. Results: Nine radiomics features were selected as haemorrhage-related features of intracranial tumours by the LASSO algorithm. The simplified model's sensitivity, specificity, accuracy, and AUC reached 0.909, 0.930, 0.926, and 0.949 (95% CI: 0.865-1.000) on the test dataset in the discrimination of "hemorrhage-prone tumors". The permutation method rated feature "T2_gradient_firstorder_10Percentile" as the most important, the absence of which decreased the model's accuracy by 10.9%. Conclusion: Radiomics features extracted on contrast-enhanced T1 Weighted Imaging and T2 Weighted Imaging sequences were predictive of future haemorrhage of intracranial tumours with favourable accuracy. This model may assist in the arrangement of biopsy procedures and the selection of target lesions in patients with multiple lesions. [ABSTRACT FROM AUTHOR]

Purpose: The gold standard for diagnostics in primary central nervous system lymphoma (PCNSL) is histopathological diagnosis after stereotactic biopsy. Yet, PCNSL has a multidisciplinary diagnostic work up, which associated with diagnostic delay and could result in treatment delay. This article offers recommendations to neurosurgeons involved in clinical decision-making regarding (novel) diagnostics and care for patients with PCNSL with the aim to improve uniformity and timeliness of the diagnostic process for patients with PCNSL. Methods: We present a mini review to discuss the role of stereotactic biopsy in the context of novel developments in diagnostics for PCNSL, as well as the role for cytoreductive surgery. Results: Cerebrospinal fluid-based diagnostics are supplementary and cannot replace stereotactic biopsy-based diagnostics. Conclusion: Histopathological diagnosis after stereotactic biopsy of the brain remains the gold standard for diagnosis. Additional diagnostics should not be a cause of diagnostic delay. There is currently no sufficient evidence supporting cytoreductive surgery in PCNSL, with recent studies showing contradictive data and suboptimal study designs. [ABSTRACT FROM AUTHOR]

Objective: To assess the effectiveness of stereotactic biopsy in individuals with brain lesions and describe the surgical procedure utilized during this to analyze the features of pathologies linked to the application of this surgical approach. Study Design: Descriptive study. Setting: Neurospinal Cancer Care Institute in Karachi. Period: January 2019 and June 2022. Methods: This study had approval from the ethics committee and patients provided written informed permission Under general anaesthesia the biopsy was performed. The definitive diagnosis based on histopathological report were considered positive. Results: We had of 61 patients, gender wise males were 37 (55.73%) and females were 24(39.34%), with calculated mean age was 41.01years (range between 15-67 years). Majority of patients were between the age of 33 and 66 years (67.21%). Pre and post procedure, patients had to go brain MRI brain or CT scan brain for helping in localization. The lesion was supratentorial as observed in 56 patients (91.80%) and 5(8.19%) were infratentorial. The post contrast enhancements were observed in 35 patients (57.37%). Conclusion: The study presented compelling evidence supporting the ease and accuracy of the stereotactic procedure in targeting the lesion, Stereotactic intervention for lesions has been shown to be both effective and safe. [ABSTRACT FROM AUTHOR]

Background and objectives: Robot-assisted biopsies have gained popularity in the last years. Most robotic procedures are performed with a floor-based robotic arm. Recently, Medtronic Stealth Autoguide, a miniaturized robotic arm that work together with an optical neuronavigation system, was launched. Its application in pediatric cases is relatively unexplored. In this study, we retrospectively report our experience using the Stealth Autoguide, for frameless stereotactic biopsies in pediatric patients. Methods: Pediatric patients who underwent stereotactic biopsy using the Stealth Autoguide cranial robotic platform from July 2020 to May 2023 were included in this study. Clinical, neuroradiological, surgical, and histological data were collected and analyzed. Results: Nineteen patients underwent 20 procedures (mean age was 9-year-old, range 1–17). In four patients, biopsy was part of a more complex surgical procedure (laser interstitial thermal therapy — LITT). The most common indication was diffuse intrinsic brain stem tumor, followed by diffuse supratentorial tumor. Nine procedures were performed in prone position, eight in supine position, and three in lateral position. Facial surface registration was adopted in six procedures, skull-fixed fiducials in 14. The biopsy diagnostic tissue acquisition rate was 100% in the patients who underwent only biopsy, while in the biopsy/LITT group, one case was not diagnostic. No patients developed clinically relevant postoperative complications. Conclusion: The Stealth Autoguide system has proven to be safe, diagnostic, and highly accurate in performing stereotactic biopsies for both supratentorial and infratentorial lesions in the pediatric population. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Intracranial RDD is rare medical event mimicking different diagnoses. Although the surgical resection is the best treatment option, but radiation therapy can also achieves long‐term suboptimal outcomes. An 83‐year‐old male with a history of tension‐type headaches was evaluated. He was conscious with no focal neurological deficits. His brain MRI revealed an enhancable bifrontal tumor originating from falx cerebri and superior sagittal sinus dura. Due to the patient's preference and decline for gross total resection, she underwent a stereotactic biopsy. The pathology was positive for Rosai–Dorfman diseases. He received definitive targeted radiation with a total dose of 4500 cGy administered in 200 cGy daily fractions. His 4‐year follow‐up showed regional tumor control with excellent neurological outcome. [ABSTRACT FROM AUTHOR]

Intratumoral heterogeneity (ITH) complicates the diagnosis and treatment of glioma, partly due to the diverse metabolic profiles driven by underlying genomic alterations. While multiparametric imaging enhances the characterization of ITH by capturing both spatial and functional variations, it falls short in directly assessing the metabolic activities that underpin these phenotypic differences. This gap stems from the challenge of integrating easily accessible, colocated pathology and detailed genomic data with metabolic insights. This study presents a multifaceted approach combining stereotactic biopsy with standard clinical open-craniotomy for sample collection, voxel-wise analysis of MR images, regression-based GAM, and whole-exome sequencing. This work aims to demonstrate the potential of machine learning algorithms to predict variations in cellular and molecular tumor characteristics. This retrospective study enrolled ten treatment-naïve patients with radiologically confirmed glioma. Each patient underwent a multiparametric MR scan (T1W, T1W-CE, T2W, T2W-FLAIR, DWI) prior to surgery. During standard craniotomy, at least 1 stereotactic biopsy was collected from each patient, with screenshots of the sample locations saved for spatial registration to pre-surgical MR data. Whole-exome sequencing was performed on flash-frozen tumor samples, prioritizing the signatures of five glioma-related genes: IDH1, TP53, EGFR, PIK3CA, and NF1. Regression was implemented with a GAM using a univariate shape function for each predictor. Standard receiver operating characteristic (ROC) analyses were used to evaluate detection, with AUC (area under curve) calculated for each gene target and MR contrast combination. Mean AUC for five gene targets and 31 MR contrast combinations was 0.75 ± 0.11; individual AUCs were as high as 0.96 for both IDH1 and TP53 with T2W-FLAIR and ADC, and 0.99 for EGFR with T2W and ADC. These results suggest the possibility of predicting exome-wide mutation events from noninvasive, in vivo imaging by combining stereotactic localization of glioma samples and a semi-parametric deep learning method. The genomic alterations identified, particularly in IDH1, TP53, EGFR, PIK3CA, and NF1, are known to play pivotal roles in metabolic pathways driving glioma heterogeneity. Our methodology, therefore, indirectly sheds light on the metabolic landscape of glioma through the lens of these critical genomic markers, suggesting a complex interplay between tumor genomics and metabolism. This approach holds potential for refining targeted therapy by better addressing the genomic heterogeneity of glioma tumors. [ABSTRACT FROM AUTHOR]

Current diagnostic and therapeutic approaches for gliomas have limitations hindering survival outcomes. We propose spectroscopic magnetic resonance imaging as an adjunct to standard MRI to bridge these gaps. Spectroscopic MRI is a volumetric MRI technique capable of identifying tumor infiltration based on its elevated choline (Cho) and decreased N-acetylaspartate (NAA). We present the clinical translatability of spectroscopic imaging with a Cho/NAA ≥ 5x threshold for delineating a biopsy target in a patient diagnosed with non-enhancing glioma. Then, we describe the relationship between the undertreated tumor detected with metabolite imaging and overall survival (OS) from a pilot study of newly diagnosed GBM patients treated with belinostat and chemoradiation. Each cohort (control and belinostat) were split into subgroups using the median difference between pre-radiotherapy Cho/NAA ≥ 2x and the treated T1-weighted contrast-enhanced (T1w-CE) volume. We used the Kaplan–Meier estimator to calculate median OS for each subgroup. The median OS was 14.4 months when the difference between Cho/NAA ≥ 2x and T1w-CE volumes was higher than the median compared with 34.3 months when this difference was lower than the median. The T1w-CE volumes were similar in both subgroups. We find that patients who had lower volumes of undertreated tumors detected via spectroscopy had better survival outcomes.

Background and Objectives: Stereotactic biopsies are a relatively safe and reliable way of tissue diagnosis and characterization of eloquent area lesions/neoplasm. However, predicting the accuracy of the site of biopsy with the desired/planned site is not always possible. We describe a technique to identify the precise location of the biopsy site in the post-operative computed tomography (CT) scan using the injection of a low volume of air into the biopsy cannula. Methods: Hundred consecutive biopsies were performed in 80 adults/20 children (59 males/41 females, median age 51 years) over 3 years, consisting of 75 frameless and 25 frame-based stereotactic biopsies. After the biopsy specimens had been collected, a small volume of air (median 1 cc) was injected into the site. Post-operative CT was done within 4 hours of the biopsy to see the site of the air bubble, and the same was correlated with the histopathological accuracy. Results: Intra-cranial air in the selected target was present in 95 patients (Grade 1 and 2), while the air was seen in the track (Grade 3) in 3% and at an unrelated site (Grade 4) in 2% of cases. Both Grade 4 biopsies were negative on histopathology (diagnostic yield = 98%). Two negative biopsies were reported, which were both predicted with the Grade 4 biopsy. The grading allowed uniform reporting across series and eliminated the chance of upgrading/downgrading the report due to wrong site sampling within the lesion/neoplasm. Conclusion: The air-injection manoeuvre proposed for use in stereotactic biopsies of intra-cranial mass lesions is a safe and reliable technique that allows the exact biopsy site to be located without any related complications. [ABSTRACT FROM AUTHOR]

The factors on which the accuracy of stereotactic brain biopsy depends are the competence of the neurosurgeon in obtaining a representative sample and the ability of the neuropathologist to make a histological diagnosis from a minuscule sample. Over the years intraoperative frozen section has enhanced the diagnostic yield of this minimally invasive procedure. Use of fluorescence in achieving a greater extent of resection is well-established in contemporary neurosurgical practice. This ability of brain tumors to take up the fluorescein sodium dye and glow under the YELLOW 560-nm filter has been utilized in a handful of studies to increase the diagnostic accuracy of stereotactic biopsy. We performed a prospective study where the fluorescein sodium dye was injected at a low dose and fluorescence of the biopsied core was compared with that of a tissue obtained from the normal parenchyma. Sample was labeled 'truly fluorescent' only when the glow was more than that of the tissue from normal parenchyma. On cross-tabulating the index test (true fluorescence status) and the reference standard test (final histopathological report) the sensitivity of acquiring a representative sample was found to be 94.74%, specificity was 100%. The positive predictive value and negative predictive value were calculated to be 100% and 50% respectively. The diagnostic yield was comparable to that of the intraoperative frozen section. The use of the YELLOW 560-nm filter can make stereotactic biopsy faster, safer, less cumbersome, and more cost-effective, and can be used as a substitute for the frozen section in resource-constrained centers. [ABSTRACT FROM AUTHOR]

Stereotactic needle biopsy (SNB) may be performed to collect tissue samples from lesions not amenable to open surgery. Integration of tractography, intraoperative imaging and fluorescence has been applied to reduce risk of complications and confirm the adequacy of bioptic specimens. Clinical and radiological data from patients who underwent stereotactic needle biopsy with the use of intraoperative CT, tractography and 5-aminolevulinic acid (5-ALA) fluorescence in a single Hospital were retrospectively reviewed to evaluate the accuracy and safety of the procedure. Seven patients were included in the study, and all the collected specimens showed red fluorescence. In six of them, the final histopathological diagnosis was grade 4 glioblastoma IDH-wt and in the other case it was Diffuse large B-Cell Lymphoma. The integration of tractography, intraoperative CT and 5-ALA as an intraoperative marker of diagnostic samples may be suggested in biopsies of suspect gliomas and lymphomas. The cost-effectiveness of the procedure should be evaluated in future studies. [ABSTRACT FROM AUTHOR]

Objective: Lesions of the posterior fossa (brainstem and cerebellum) are challenging in diagnosis and treatment due to the fact that they are often located eloquently and total resection is rarely possible. Therefore, frame-based stereotactic biopsies are commonly used to asservate tissue for neuropathological diagnosis and further treatment determination. The aim of our study was to assess the safety and diagnostic success rate of frame-based stereotactic biopsies for lesions in the posterior fossa via the suboccipital-transcerebellar approach. Methods: We performed a retrospective database analysis of all frame-based stereotactic biopsy cases at our institution since 2007. The aim was to identify all surgical cases for infratentorial lesion biopsies via the suboccipital-transcerebellar approach. We collected clinical data regarding outcomes, complications, diagnostic success, radiological appearances, and stereotactic trajectories. Results: A total of n = 79 cases of stereotactic biopsies for posterior fossa lesions via the suboccipital-transcerebellar approach (41 female and 38 male) utilizing the Zamorano-Duchovny stereotactic system were identified. The mean age at the time of surgery was 42.5 years (± 23.3; range, 1–87 years). All patients were operated with intraoperative stereotactic imaging (n = 62 MRI, n = 17 CT). The absolute diagnostic success rate was 87.3%. The most common diagnoses were glioma, lymphoma, and inflammatory disease. The overall complication rate was 8.7% (seven cases). All patients with complications showed new neurological deficits; of those, three were permanent. Hemorrhage was detected in five of the cases having complications. The 30-day mortality rate was 7.6%, and 1-year survival rate was 70%. Conclusions: Our data suggests that frame-based stereotactic biopsies with the Zamorano-Duchovny stereotactic system via the suboccipital-transcerebellar approach are safe and reliable for infratentorial lesions bearing a high diagnostic yield and an acceptable complication rate. Further research should focus on the planning of safe trajectories and a careful case selection with the goal of minimizing complications and maximizing diagnostic success. [ABSTRACT FROM AUTHOR]

Simple Summary: In most cases, it is impossible to differentiate primary central nervous system lymphoma (PCNSL) from other brain tumors or neuroinflammatory diseases without histological confirmation. In most differential diagnoses of PCNSL, preoperative treatment with glucocorticoids is administered. This treatment reduces the symptoms of PCNSL but can also disguise the histological diagnosis, which can lead to an incorrect or delayed diagnosis of PCNSL and postponed therapy. To obtain a broader database for evidence-based decisions in the management of patients with PCNSL, we retrospectively evaluated all patients biopsied and diagnosed with PCNSL at our institution over the last 16 years. Particular focus was placed on the influence of preoperative glucocorticoid therapy and the effect of anticoagulation and dual antiplatelet therapy on the validity of histological diagnosis. In patients with primary central nervous system lymphoma (PCNSL), the choice of surgical strategy for histopathologic assessments is still controversial, particularly in terms of preoperative corticosteroid (CS) therapy. To provide further evidence for clinical decision-making, we retrospectively analyzed data from 148 consecutive patients who underwent surgery at our institution. Although patients treated with corticosteroids preoperatively were significantly more likely to require a second or third biopsy (p = 0.049), it was only necessary in less than 10% of the cases with preoperative (but discontinued) corticosteroid treatment. Surprisingly, diagnostic accuracy was significantly lower when patients were treated with anticoagulation or dual antiplatelet therapy (p = 0.015). Preoperative CSF sampling did not provide additional information but was associated with delayed surgery (p = 0.02). In conclusion, preoperative CS therapy can challenge the histological diagnosis of PCNSL. At the same time, our data suggest that preoperative CS treatment only presents a relative contraindication for early surgical intervention. If a definitive diagnosis cannot be made after the first surgical intervention, the timing of a repeat biopsy after the discontinuation of CS remains a case-by-case decision. The effect of anticoagulation and dual antiplatelet therapy on diagnostic accuracy might have been underestimated and should be examined closely in future investigations. [ABSTRACT FROM AUTHOR]

Image-guided stereotactic techniques can display the locations of surgical instruments and biopsy targets in real time, allowing minimally invasive brain biopsies with reduced risk. This study aimed to assess the accuracy of an optical frameless neuronavigation system in feline cadavers and describe potential influencing factors. Phantom lesions were created in different brain regions and depths in 15 feline cadavers. After installing eight fiducial markers in the frontal bone and zygomatic arches, magnetic resonance imaging (MRI) was performed, and the images were imported into the neuronavigation system. Following patient and instrument registration, diluted gadolinium was injected into the phantom lesion (target), guided by the neuronavigation system. The coordinates of the target and contrast points were determined on repeated MRI scans and the distance between them was defined as the targeting error. The time from target selection to the completion of gadolinium injection was recorded as the required time. The targeting error and required time were compared between the initial 30% and final 30% of the collected data to assess the influence of operator experience. Among 76 lesions, the mean targeting error was 2. 9 6 ± 0. 8 6 mm (95% confidence interval 2.76–3.15 mm). Lesion location, lesion depth, and operator experience did not affect the accuracy; however, operator experience reduced the required time. This frameless optical neuronavigation system is potentially feasible for feline brain biopsy. The demonstrated accuracy substantiates its clinical utility for feline brain lesions > 3. 1 5 mm, and is comparable to that of other neuronavigation systems described in dogs. [ABSTRACT FROM AUTHOR]

Simple Summary: This report aims to demonstrate the value of spectroscopic MRI in glioma diagnostics and therapeutics planning. We first demonstrate clinical translatability by showing a biopsy case of a lower-grade glioma patient. The biopsy target was delineated via spectroscopy. Then, we conducted a secondary analysis of our clinical trial treating newly diagnosed glioblastoma (GBM) patients with belinostat by investigating the relationship between under-radiated tumor areas identified via spectroscopy and overall survival. Our results revealed that patients with a lower volume of undertreated tumors detected via spectroscopy had improved survival outcomes, highlighting the potential benefits of integrating metabolite information with treatment planning. Finally, we establish the utility of spectroscopic MRI for treating areas of future recurrence in patients with GBM. The report highlights the potential of advanced imaging techniques in improving the diagnostic and treatment strategies for this challenging disease. Current diagnostic and therapeutic approaches for gliomas have limitations hindering survival outcomes. We propose spectroscopic magnetic resonance imaging as an adjunct to standard MRI to bridge these gaps. Spectroscopic MRI is a volumetric MRI technique capable of identifying tumor infiltration based on its elevated choline (Cho) and decreased N-acetylaspartate (NAA). We present the clinical translatability of spectroscopic imaging with a Cho/NAA ≥ 5x threshold for delineating a biopsy target in a patient diagnosed with non-enhancing glioma. Then, we describe the relationship between the undertreated tumor detected with metabolite imaging and overall survival (OS) from a pilot study of newly diagnosed GBM patients treated with belinostat and chemoradiation. Each cohort (control and belinostat) were split into subgroups using the median difference between pre-radiotherapy Cho/NAA ≥ 2x and the treated T1-weighted contrast-enhanced (T1w-CE) volume. We used the Kaplan–Meier estimator to calculate median OS for each subgroup. The median OS was 14.4 months when the difference between Cho/NAA ≥ 2x and T1w-CE volumes was higher than the median compared with 34.3 months when this difference was lower than the median. The T1w-CE volumes were similar in both subgroups. We find that patients who had lower volumes of undertreated tumors detected via spectroscopy had better survival outcomes. [ABSTRACT FROM AUTHOR]

Key Clinical Message Intracranial RDD is rare medical event mimicking different diagnoses. Although the surgical resection is the best treatment option, but radiation therapy can also achieves long‐term suboptimal outcomes. Abstract An 83‐year‐old male with a history of tension‐type headaches was evaluated. He was conscious with no focal neurological deficits. His brain MRI revealed an enhancable bifrontal tumor originating from falx cerebri and superior sagittal sinus dura. Due to the patient's preference and decline for gross total resection, she underwent a stereotactic biopsy. The pathology was positive for Rosai–Dorfman diseases. He received definitive targeted radiation with a total dose of 4500 cGy administered in 200 cGy daily fractions. His 4‐year follow‐up showed regional tumor control with excellent neurological outcome.

Aim of the Study: Multiple ring-enhancing lesions are commonly experienced group of brain pathologies which we come across in day-to-day practice. Clinical symptoms in these lesions are quite non-specific, and hence, it is difficult to reach a final diagnosis. However, these lesions have a varied group of differential diagnosis and it is sometimes difficult to have an accurate diagnosis on conventional MRI. This article was written with the objective of discussing the demographical study and etiology, clinical diagnosis and management for these patients. Materials and Methods: It is a prospective study carried out at the Department of Neurosurgery, Dr. D Y Patil Medical College and Hospital, Pune, from September 2019 to August 2022 and included 50 patients who presented to us multiple ring-enhancing brain lesions. Results: In our study, 50 patients between age (1-70 years) with multiple ring-enhancing lesions were analyzed. Majority of the patients were between age group 30-39 years. Males (76%) were majority in our study than females (24%). Most common pathology was primary neoplasm (glioma) and metastasis, followed by nine patients of pyogenic abscess and tuberculosis each. Neurocysticercosis was seen in eight patients and three patients were diagnosed with CNS lymphoma. Most of our patients presented with headache (38 patients) and a subset of patients had associated seizures (28 patients). Two patients with primary neoplasm were diagnosed to have WHO grade 3 glioma and seven patients were diagnosed to have WHO grade 4 glioma. Glioblastoma multiforme presented as multifocal and multicentric lesions. Among the patients with primary neoplasm, three patients underwent stereotactic biopsy for diagnosis and the rest of seven patients underwent maximum safe resection followed by chemotherapy and radiotherapy. Ten patients were diagnosed with metastatic lesions, among them six patients underwent stereotactic biopsy for histopathological diagnosis and immunohistochemistry, and rest of the patients were managed on the basis of the primary lesion. Five patients were immune-compromised, among them two patients presented with abscess and three patients presented with primary neoplastic lesion. Thirty-six patients underwent biopsy, among them seven patients underwent frameless, seven patients underwent frame stereotactic biopsy, and the rest 22 patients underwent excision biopsy. Conclusion: Multiple ring-enhancing lesions of brain pose a challenge in terms of achieving an accurate diagnosis and planning further treatment. It is of utmost importance to have a diagnosis in mind based on radiological investigations, so that surgical intervention can be planned accordingly be it by invasive or minimal invasive techniques. An idea toward the diagnosis also helps in prognosticating these patients which could avoid costly whole-body scans and unnecessary surgical intervention. [ABSTRACT FROM AUTHOR]

Objectives: Stereotactic biopsy (STB) is a potential diagnostic tool considering its minimal invasiveness, high diagnostic yield, and minimal associated complications. Over the years, various frame-based instrument systems and frameless stereotactic biopsy systems have emerged to be employed in clinical use. With this study, we intend to get more by doing less in the form of STB for the patients of doubtful intracranial lesions treated over the past 5 years. We also want to highlight the technique of performing the procedure under scalp block, which can be used as a versatile tool in many clinical scenarios. Stereotactic biopsies may be planned even in rural district-level health facilities. One-time investment to procure instruments and avail existing imaging can lead to establishing definitive diagnoses in many doubtful cases. This will result in lesser cost and early establishment of treatment. Independent risk factors determining the outcome, such as deep-seated lesions, associated edema, and intraoperative hypertension, were studied. Establishing the diagnosis helped in prognosticating the disease, explaining the natural progression of symptoms, and starting adjuvant therapy. This tissue biopsy would also help secure samples for research and molecular analysis. Materials and Methods: Twenty patients underwent STBs at our institution between January 2018 and December 2022. We retrospectively analyzed patient characteristics, tumor pathology, surgical procedures, and outcomes, including the diagnostic value and surgery-related complications. These patients were followed up, and their progression-free and overall survival were analyzed. The need for adjuvant treatment was noted and analyzed. All procedures were performed using Cosman Roberts Wells® stereotactic frame. Pre-procedure magnetic resonance scans were performed at the time of admission. Contrast-enhanced computerized tomography (CT) scan after frame application was performed to identify targets and calculate the coordinates. A post-procedure CT scan was done to confirm the accessibility of the targeted lesion. Results: The most common location of the tumor was a deep-seated thalamic lesion. A definitive diagnosis was established in 19 patients (95%) at the first STB. The diagnoses were glioma in 55% of cases, primary central nervous system lymphoma, tuberculosis, and demyelinating disorders in 10% of each, and a metastatic brain tumor in 1 (5%). The post-operative complications were all transient except in one patient with deterioration of motor weakness. The follow-up was noted, and modes of adjuvant treatment needed in these patients were recorded. Conclusion: Stereotactic biopsy is a useful and effective method for achieving a definitive diagnosis and aiding in treating multifocal or small deep-seated lesions in or around eloquent regions. [ABSTRACT FROM AUTHOR]

Introduction: B3-lesions of the breast are a heterogeneous group of neoplasms, associated with a higher risk of breast cancer. Recent studies show a low upgrade rate into malignancy after subsequent open surgical excision (OE) of most B3-lesions when proven by vacuum-assisted biopsy (VAB). However, there is a lack of long-term follow-up data after VAB of high-risk lesions. The primary aim of this study was to demonstrate whether follow-up of B3 lesions is a beneficial and reliable alternative to OE in terms of long-term outcome. The secondary aim was to identify patient and lesion characteristics of B3 lesions for which OE is still necessary. Methods: This retrospective multicenter study was conducted at 8 Swiss breast centers between 2010 and 2019. A total of 278 women (mean age: 53.5 ± 10.7 years) with 286 B3-lesions who had observation only and who had at least 24 months of follow-up were included. Any event during follow-up (ductal carcinoma in situ [DCIS], invasive cancer, new B3-lesion) was systematically recorded. Data from women who had an event during follow-up were compared with those who did not. The results for the different B3 lesions were analyzed using the t test and Fisher's exact test. A p value of <0.05 was considered statistically significant. Results: The median follow-up interval was 59 months (range: 24–143 months) with 52% (148/286) having a follow-up of more than 5 years. During follow-up, in 42 women, 44 suspicious lesions occurred, with 36.4% (16/44) being invasive cancer and 6.8% (3/44) being DCIS. Thus, 6.6% (19/286) of all women developed malignancy during follow-up after a median follow-up interval of 6.5 years (range: 31–119 months). The initial histology of the B3 lesion influenced the subsequent occurrence of a malignant lesion during follow-up (p < 0.038). The highest malignancy-developing rate was observed in atypical ductal hyperplasia (ADH) (24%, 19/79), while all other B3-lesions had malignant findings ipsi- and contralateral between 0% and 6%. The results were not influenced by the VAB method (Mx-, US-, magnetic resonance imaging-guided), the radiological characteristics of the lesion, or the age or menopausal status of the patient (p > 0.12). Conclusion: With a low risk of <6% of developing malignancy, VAB followed by long-term follow-up is a safe alternative to OE for most B3-lesions. A higher malignancy rate only occurred in ADH (24%). Based on our results, radiological follow-up should be bilateral, preferable using the technique of initial diagnosis. As we observed a late peak (6–7 years) of breast malignancies after B3-lesions, follow-up should be continued for a longer period (>10 years). Knowledge of these long-term outcome results will be helpful in making treatment decisions and determining the optimal radiological follow-up interval. [ABSTRACT FROM AUTHOR]

Intratumoral heterogeneity (ITH) complicates the diagnosis and treatment of glioma, partly due to the diverse metabolic profiles driven by underlying genomic alterations. While multiparametric imaging enhances the characterization of ITH by capturing both spatial and functional variations, it falls short in directly assessing the metabolic activities that underpin these phenotypic differences. This gap stems from the challenge of integrating easily accessible, colocated pathology and detailed genomic data with metabolic insights. This study presents a multifaceted approach combining stereotactic biopsy with standard clinical open-craniotomy for sample collection, voxel-wise analysis of MR images, regression-based GAM, and whole-exome sequencing. This work aims to demonstrate the potential of machine learning algorithms to predict variations in cellular and molecular tumor characteristics. This retrospective study enrolled ten treatment-naïve patients with radiologically confirmed glioma. Each patient underwent a multiparametric MR scan (T1W, T1W-CE, T2W, T2W-FLAIR, DWI) prior to surgery. During standard craniotomy, at least 1 stereotactic biopsy was collected from each patient, with screenshots of the sample locations saved for spatial registration to pre-surgical MR data. Whole-exome sequencing was performed on flash-frozen tumor samples, prioritizing the signatures of five glioma-related genes: IDH1, TP53, EGFR, PIK3CA, and NF1. Regression was implemented with a GAM using a univariate shape function for each predictor. Standard receiver operating characteristic (ROC) analyses were used to evaluate detection, with AUC (area under curve) calculated for each gene target and MR contrast combination. Mean AUC for five gene targets and 31 MR contrast combinations was 0.75 ± 0.11; individual AUCs were as high as 0.96 for both IDH1 and TP53 with T2W-FLAIR and ADC, and 0.99 for EGFR with T2W and ADC. These results suggest the possibility of predicting exome-wide mutation events from noninvasive, in vivo imaging by combining stereotactic localization of glioma samples and a semi-parametric deep learning method. The genomic alterations identified, particularly in IDH1, TP53, EGFR, PIK3CA, and NF1, are known to play pivotal roles in metabolic pathways driving glioma heterogeneity. Our methodology, therefore, indirectly sheds light on the metabolic landscape of glioma through the lens of these critical genomic markers, suggesting a complex interplay between tumor genomics and metabolism. This approach holds potential for refining targeted therapy by better addressing the genomic heterogeneity of glioma tumors.

Introduction: Central nervous system lymphoma poses significant diagnostic challenges, with stereotactic biopsy being the gold standard for diagnosis. Intraoperative magnetic resonance imaging and intraoperative histological examination are utilized to enhance biopsy yield, yet their comparative efficacy remains unclear. Research question: This study aims to compare the diagnostic yield of intraoperative magnetic resonance imaging and intraoperative histological examination in stereotactic brain biopsies for central nervous system lymphoma. Materials and methods: A retrospective analysis was conducted on 115 patients who underwent stereotactic brain biopsies for central nervous system lymphoma. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of intraoperative magnetic resonance imaging and intraoperative histological examination were assessed and compared. Results: Out of 125 surgeries, frameless biopsies were the most common, accounting for 74.4 percent. Intraoperative magnetic resonance imaging demonstrated a sensitivity of 80.00 percent and a specificity of 98.51 percent (AUC = 0.893, p = 0.004), whereas intraoperative histological examination showed a sensitivity of 66.67 percent and a specificity of 59.09 percent (AUC = 0.629, p = 0.459). Discussion and conclusions: The study emphasizes the critical role of intraoperative examinations, thus improving precision and diagnostic yield in the surgical management of central nervous system lymphoma. Intraoperative magnetic resonance imaging outperforms intraoperative histological examination in terms of sensitivity and specificity for confirming positive biopsy yields in central nervous system lymphoma, thereby reducing the need for additional surgeries. These findings support the routine use of intraoperative magnetic resonance imaging in the surgical strategy for central nervous system lymphoma to improve diagnostic accuracy and patient outcomes.

Abstract Objective Methods Results Conclusions The cytolytic effect of corticosteroids on primary central nervous system lymphoma (PCNSL) has established the clinical dogma of avoiding steroid therapy prior to surgery for diagnostic purposes. However, since steroids are very useful during the initial management of intracranial lesions with vasogenic oedema, it was our aim to determine whether they cause a drawback in the diagnosis and prognosis of PCNSL.A retrospective cohort study of patients diagnosed with PCNSL between 2000 and 2020 in our tertiary neurosurgical centre. Data on steroid administration, surgery type and complications, haematopathological findings and prognostic factors were compiled. A second cohort was used as a control group to compare the ratio of non-diagnostic biopsies; this series comprised patients who underwent stereotactic brain biopsy for any reason between 2019 and 2020.Forty patients with PCNSL were included in the study, of which 28 (70%) had received steroids before surgery. The use of steroids was more prevalent in patients with poorer performance status at diagnosis. No relevant differences were found in the diagnostic accuracy regardless of steroid exposure (93% under steroids vs 100% without steroids) or type of surgery performed. Furthermore, steroid withdrawal did not seem to augment the diagnostic ratio. The notable diagnostic delay was not influenced by the use of steroids.Novel imaging and surgical techniques might obviate the need to withhold corticosteroids from patients suffering from PCNSL prior to biopsy. Moreover, when steroids have been given, tapering them and delaying the surgery might not be justified. This could hold relevant therapeutic implications in the early clinical stages. [ABSTRACT FROM AUTHOR]

The role of surgical resection in primary central nervous system lymphoma (PCNSL) was not recognized until recently. However, prognostic factors for surgically treated PCNSL remain unclear. In the present study, we aimed to identify and compare the prognostic value of comorbidity indices and immunohistochemical markers in patients with surgically and non-surgically treated PCNSL. This retrospective single-center study analyzed patients who underwent either surgical resection or stereotactic biopsy for newly diagnosed PCNSL between January 2012 and December 2021. Clinical demographics, comorbidity indices, and immunohistochemical markers were analyzed. We included 23 and 18 patients who underwent stereotactic biopsy and surgical resection, respectively. The median overall survival (OS) was 11.05 months. Using multivariate Cox regression, we identified pretreatment prognostic nutritional index (PNI) (p = 0.009), positive BCL2 staining (p = 0.026), and infratentorial involvement (p = 0.004) as independent prognostic factors of OS. Predictors of progression-free survival (PFS) included PNI (p = 0.040), infratentorial involvement (p = 0.021), and surgical resection for PCNSL (p = 0.048). Subgroup analyses revealed that positive BCL2 (p = 0.048) and PD-L1 (p = 0.037) staining were associated with worse OS in the biopsy group. PNI and infratentorial involvement could significantly impact both OS and PFS in patients with PCNSL. Surgical resection could predict favorable PFS but not OS. Moreover, BCL2 and PD-L1 expression can be employed as prognostic markers in these patients. [ABSTRACT FROM AUTHOR]

Purpose: With the increasing role of molecular genetics in the diagnostics of intracranial tumors, delivering sufficient representative tissue for such analyses is of paramount importance. This study explored the rate of successful diagnosis after frame-based stereotactic biopsies of intracranial lesions. Methods: Consecutive patients undergoing frame-based stereotactic biopsies in 2020 and 2021 were included in this retrospective analysis. Cases were classified into three groups: conclusive, diagnosis with missing molecular genetics (MG) data, and inconclusive neuropathological diagnosis. Results: Of 145 patients, a conclusive diagnosis was possible in n = 137 cases (94.5%). For 3 cases (2.0%), diagnosis was established with missing MG data. In 5 cases (3.5%), an inconclusive (tumor) diagnosis was met. Diagnoses comprised mainly WHO 4 glioblastomas (n = 73, 56%), CNS lymphomas (n = 23, 16%), inflammatory diseases (n = 14, 10%), and metastases (n = 5, 3%). Methylomics were applied in 49% (n = 44) of tumor cases (panel sequencing in n = 28, 30% of tumors). The average number of specimens used for MG diagnostics was 5, while the average number of specimens provided was 15. In a univariate analysis, insufficient DNA was associated with an inconclusive diagnosis or a diagnosis with missing MG data (p < 0.001). Analyses of planned and implemented trajectories of cases with diagnosis with missing MG data or inconclusive diagnosis (n = 8) revealed that regions of interest were reached in almost all cases (n = 7). Conclusion: Although stereotactic frame-based biopsies deliver a limited amount of tissue, they bear high histopathological and molecular genetic diagnostic yields. Given the proven surgical precision of the planned biopsy trajectories, optimizing surveyed lesion regions could help improve the rate of conclusive diagnoses. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Information evaluating the efficacy of 2D synthesized mammography (2Ds) reconstructions in microcalcification detection is limited. This study used stereotactic biopsy data for microcalcifications to evaluate the stepwise implementation of 2Ds in screening mammography. The study aim was to identify whether 2Ds + digital breast tomosynthesis (DBT) is non-inferior to 2D digital mammography (2DM) + 2Ds + DBT, 2DM + DBT, and 2DM in identifying microcalcifications undergoing further diagnostic imaging and stereotactic biopsy. Materials and Methods: Retrospective stereotactic biopsy data were extracted following 151,736 screening mammograms of healthy women (average age, 56.3 years; range, 30–89 years), performed between 2012 and 2019. The stereotactic biopsy data were separated into 2DM, 2DM + DBT, 2DM + 2Ds + DBT, and 2Ds + DBT arms and examined using Fisher's exact test to compare the detection rates of all cancers, invasive cancers, DCIS, and ADH between modalities for patients undergoing stereotactic biopsy of microcalcifications. Results: No statistical significance in cancer detection was seen for 2Ds + DBT among those calcifications that underwent stereotactic biopsy when comparing the 2Ds + DBT to 2DM, 2DM + DBT, and 2DM + 2Ds + DBT imaging combinations. Conclusion: These data suggest that 2Ds + DBT is non-inferior to 2DM + DBT in detecting microcalcifications that will undergo stereotactic biopsy. [ABSTRACT FROM AUTHOR]

Stereotactic biopsy and open biopsy represent useful diagnostic tools of breast lesions. However, both affect the Quality of Life (QoL) in various degrees. We conducted this prospective longitudinal comparative study in order, first to access the impact of these techniques on short-term QoL and second to compare and critically discuss our results with those of literature review. Group A (58 patients) underwent vacuum-assisted stereotactic biopsy and Group B (46 patients) underwent open biopsy. The Health-Related Quality of Life (HRQol) was estimated using the European Quality of Life scale (EuroQol) and the SF-36 (The 36-Item Short-Form Health Status Survey) questionnaires. The stereotactic breast biopsy seems to be more accepted from the patients as it affects quality of life to a lesser extent than open breast biopsy. This difference is mainly attributable to a reduction of physical discomfort and pain. [ABSTRACT FROM AUTHOR]

Abstract Background and objectives Multiple brain lesions represent a serious challenge in which biopsy is commonly the first step to help overcome patients' mental anxiety and decide the following treatment step. This study presents an effective decisional algorithm that could guide in dealing with such a challenge. We evaluate the feasibility and safety of frame-based stereotactic biopsy to obtain the histopathologic diagnosis of the multiple intra-axial brain lesions and to decide the further treatment. Patients and methods Thirty-two patients with multiple intracerebral lesions underwent stereotactic serial biopsies for brain lesions at the Neurosurgery Department, Tanta University Hospital. All the stereotactic biopsies were obtained under local anesthesia using Riechert–Mundinger (RM) system or Cosman–Roberts–Wells (CRW) system. Results The histopathological diagnosis revealed multifocal malignant gliomas in 43.75% of patients (18.75% anaplastic astrocytoma and 25% multiform glioblastoma) and metastatic tumor in 37.5% of patients (all were adenocarcinoma). In addition, 12.5% had multiple brain abscesses, and 6.25% had malignant lymphoma. We reported no mortality secondary to the surgical procedure. Conclusions Stereotactic biopsy is considered the best choice to allow histopathologic diagnosis of multiple brain lesions with minimal morbidity and no mortality. Histopathologic findings gained with stereotactic procedures guided the choice of proper treatment thus eliminating the hazards associated with blind treatments.

Abstract Background The purpose of this study was to evaluate the clinical performance of Digital Breast Tomosynthesis guided vacuum-assisted biopsy (DBT-VAB) for microcalcifications in the breast. Methods Retrospective review of 131 mammography-guided VABs at our institution were performed. All of the targets were calcification lesion suspicious for cancer. 45 consecutive stereotactic vacuum-assisted biopsies (ST-VABs) and 86 consecutive DBT-VABs were compared. Written informed consent was obtained. Tissue sampling methods and materials were the same with both systems. Student’s t-test was used to compare procedure time and the Fisher’s exact test was used to compare success rate, complications, and histopathologic findings for the 2 methods. Results The tissue sampling success rate was 95.6% for ST-VAB (43/45) and 97.7% (84/86) for DBT-VAB. Time for positioning (10.6 ± 6.4 vs. 6.7 ± 5.3 min), time for biopsy (33.4 ± 13.1 vs. 22.5 ± 13.1 min), and overall procedure time (66.6 ± 16.6 min vs. 54.5 ± 13.0 min) were substantially shorter with DBT-VAB (P

Acute disseminated encephalomyelitis (ADEM) is an immune demyelinating central nervous system (CNS) disorder, characterized by monophasic new onset neurological symptoms including encephalopathy, combined with neuroradiological evidence of multifocal demyelination. ADEM is extremely rarely diagnosed and is much more common in children and adolescents than in adults. The aim of this study is to present an extremely rare case of ADEM in a heroin-addicted patient with a very difficult diagnostic course. The results of the magnetic resonance imaging (MRI) examination in this patient were inconclusive. Fungal abscesses or inflammatory lesions of an unclear nature were suspected especially in a patient with impaired immunodeficiency. In view of the constantly deteriorating condition of the patient with disturbed consciousness and the unclear aetiology, the lack of effective treatment, a decision was made to perform a bilateral stereotactic biopsy and aspiration of brain abnormalities in order to obtain a neuropathological specimen and begin with the causal treatment. Neuropathological examination revealed the presence of Creutzfeldt-Peters cells characteristic of ADEM. Treatment with methylprednisolone significantly improved the patient’s general and neurological condition. To our knowledge, the above case is the first in the world literature in which ADEM has been confirmed by bilateral stereotaxic aspiration for the treatment of symptoms of increased intracranial pressure as a lifesaving procedure. Neuropathological confirmation allowed for the implementation of appropriate treatment, which resulted in complete recovery. Moreover, this case is interesting because ADEM was diagnosed in a patient addicted to heroin, where opportunistic inflammation of a fungal aetiology was considered in the first place.

Objective To explore the application value of intraoperative frozen section analysis in stereotactic biopsy of brain lesions. Methods The clinical data of 44 patients with brain lesions from June 2015 to October 2021 were analyzed retrospectively. Intraoperative frozen pathology analysis was applied in all 46 procedures, immunohistochemical examination was applied if necessary. Regular pathological results were used as the gold standard for diagnosis, and the diagnostic rate, delayed diagnostic rate and misdiagnosis rate of frozen results were judged. The diagnostic positive rate, diagnostic coincidence rate and influencing factors of frozen pathology during operation were analyzed. Results Of the 44 patients who underwent 46 biopsies, 9 patients had negative results in the first intraoperative freezing, and 7 of them had positive results after adjusting the depth of puncture and re-biopsy. 23 patients were diagnosed by intraoperative immunohistochemistry. In the end, 44 patients (96.65%) had positive intraoperative freezing results, and the diagnostic accuracy rate was 91.3% （35 cases were confirmed+7 cases were delayed). The results of puncture biopsy included 27 cases of glioma (6 cases of WHO grade Ⅰ-Ⅱ, 21 cases of WHO grade Ⅲ-Ⅳ12cases of lymphoma, 4 cases of germinoma, and 1 case of amyloidosis. Conclusions Although intraoperative frozen pathology leads to more operation time consuming, it can quickly uncover the pathology of biopsy specimens, avoid excessive sampling improve operation efficiency and reduce surgical complications. Intraoperative frozen pathology can be applied in robot-assisted stereotactic brain lesion biopsy. [ABSTRACT FROM AUTHOR]

Safe Trajectory planning for navigation guided biopsy (nBx) of motor eloquent tumours (METs) is important to minimise neurological morbidity. Preliminary clinical data suggest that visualisation of the corticospinal tract (CST) and its relation to the tumour may aid in planning a safe trajectory. In this article we assess the impact of tractography in nBx planning in a simulation-based exercise. This single centre cross-sectional study was performed in March 2021 including 10 patients with METs divided into 2 groups: (1) tractography enhanced group (T-nBx; n = 5; CST merged with volumetric MRI); (2) anatomy-based group (A-nBx; n = 5; volumetric MRI only). A biopsy target was chosen on each tumour. Volunteer neurosurgical trainees had to plan a suitable biopsy trajectory on a Stealth S8® workstation for all patients in a single session. A trajectory safety index (TSI) was devised for each trajectory. Data collection and analysis included a comparison of trajectory planning time, trajectory/lobe changes and TSI. A total of 190 trajectories were analysed based on participation from 19 trainees. Mean trajectory planning time for the entire cohort was 225.1 ± 21.97 s. T-nBx required shorter time for planning (p = 0.01). Mean trajectory changes and lobe changes made per biopsy were 3.28 ± 0.29 and 0.45 ± 0.08, respectively. T-nBx required fewer trajectory/lobe changes (p = 0.01). TSI was better in the presence of tractography than A-nBx (p = 0.04). Neurosurgical experience of trainees had no significant impact on the measured parameters despite adjusted analysis. Irrespective of the level of neurosurgical training, surgical planning of navigation guided biopsy for METs may be achieved in less time with a safer trajectory if tractography imaging is available. [ABSTRACT FROM AUTHOR]

Stereotactic frame-based brain tumor biopsy (SFB) is a potent diagnostic tool considering its minimal invasiveness, though its diagnostic power and safety for brainstem lesions remain to be discussed. Here, we aimed to examine the usefulness of SFB for brainstem tumors. Twenty-two patients with brainstem tumors underwent 23 SFBs at our institution during 2002–2021. We retrospectively analyzed patient characteristics, tumor pathology, surgical procedures, and outcomes, including surgery-related complications and the diagnostic value. Seven (32%) tumors were located from the midbrain to the pons, eleven (50%) in the pons only, and four (18%) from the pons to the medulla oblongata. The target lesions were in the middle cerebellar peduncles in sixteen procedures (70%), the cerebellum in four (17%), the inferior cerebellar peduncles in two (9%), and the superior cerebellar peduncles in one (4%). A definitive diagnosis was made in 21 patients (95%) at the first SFB. The diagnoses were glioma in seventeen (77%) cases, primary central nervous system lymphoma in four (18%), and a metastatic brain tumor in one (5%). The postoperative complications (cranial nerve palsy in three [13%] cases, ataxia in one [4%]) were all transient. SFB for brainstem tumors yields a high diagnostic rate with a low risk of morbidity.

Background and objectives: Multiple brain lesions represent a serious challenge in which biopsy is commonly the first step to help overcome patients' mental anxiety and decide the following treatment step. This study presents an effective decisional algorithm that could guide in dealing with such a challenge. We evaluate the feasibility and safety of frame-based stereotactic biopsy to obtain the histopathologic diagnosis of the multiple intra-axial brain lesions and to decide the further treatment. Patients and methods: Thirty-two patients with multiple intracerebral lesions underwent stereotactic serial biopsies for brain lesions at the Neurosurgery Department, Tanta University Hospital. All the stereotactic biopsies were obtained under local anesthesia using Riechert–Mundinger (RM) system or Cosman–Roberts–Wells (CRW) system. Results: The histopathological diagnosis revealed multifocal malignant gliomas in 43.75% of patients (18.75% anaplastic astrocytoma and 25% multiform glioblastoma) and metastatic tumor in 37.5% of patients (all were adenocarcinoma). In addition, 12.5% had multiple brain abscesses, and 6.25% had malignant lymphoma. We reported no mortality secondary to the surgical procedure. Conclusions: Stereotactic biopsy is considered the best choice to allow histopathologic diagnosis of multiple brain lesions with minimal morbidity and no mortality. Histopathologic findings gained with stereotactic procedures guided the choice of proper treatment thus eliminating the hazards associated with blind treatments. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate the clinical performance of Digital Breast Tomosynthesis guided vacuum-assisted biopsy (DBT-VAB) for microcalcifications in the breast. Methods: Retrospective review of 131 mammography-guided VABs at our institution were performed. All of the targets were calcification lesion suspicious for cancer. 45 consecutive stereotactic vacuum-assisted biopsies (ST-VABs) and 86 consecutive DBT-VABs were compared. Written informed consent was obtained. Tissue sampling methods and materials were the same with both systems. Student's t-test was used to compare procedure time and the Fisher's exact test was used to compare success rate, complications, and histopathologic findings for the 2 methods. Results: The tissue sampling success rate was 95.6% for ST-VAB (43/45) and 97.7% (84/86) for DBT-VAB. Time for positioning (10.6 ± 6.4 vs. 6.7 ± 5.3 min), time for biopsy (33.4 ± 13.1 vs. 22.5 ± 13.1 min), and overall procedure time (66.6 ± 16.6 min vs. 54.5 ± 13.0 min) were substantially shorter with DBT-VAB (P < 0.0001). There were no differences in the distribution of pathological findings between the 2 groups. Conclusion: Depth information and stable visibility of the target provided by DBT images led to quick decisions about target coordinates and improved the clinical performance of microcalcification biopsies. [ABSTRACT FROM AUTHOR]

Background: Cerebral toxoplasmosis is a relatively rare disorder that usually affects immunocompromised patients. The most common scenario occurs among human immunodeficiency virus (HIV)-positive patients. In those patients, toxoplasmosis is the most frequent cause of expansive brain lesion and continues to cause elevated morbidity and mortality. In typical cases of toxoplasmosis, both computed tomography and magnetic resonance imaging reveal single/multiple nodular or ring-enhancing lesions with surrounding edema. Nevertheless, cases of cerebral toxoplasmosis with atypical radiological features have been reported. Diagnosis can be obtained by finding organisms in the cerebrospinal fluid or in stereotactic biopsy samples of the brain lesion. If untreated, cerebral toxoplasmosis is uniformly fatal, so prompt diagnosis is mandatory. A prompt diagnosis is necessary, as untreated cerebral toxoplasmosis is uniformly fatal. Case Description: We discuss imaging and clinical findings of a patient - not aware of being HIV-positive - with a solitary atypical brain localization of toxoplasmosis mimicking a brain tumor. Conclusion: Although relatively uncommon, neurosurgeons should be aware of the potential occurrence of cerebral toxoplasmosis. High index of suspicion is needed for timely diagnosis and prompt initiation of therapy. [ABSTRACT FROM AUTHOR]

The open-face design of the Leksell Vantage frame provides many advantages. However, its more rigid, contoured design offers less flexibility than other frames. This is especially true for posterior fossa approaches. This study explores whether these limitations can be overcome by tailored frame placement using a virtual planning approach. The posterior fossa was accessed in ten patients using the Leksell Vantage frame. Frame placement was planned with the Brainlab Elements software, including a phantom-based (virtual) pre-operative planning approach. A biopsy was performed in all patients; in four, additional laser ablation surgery was performed. The accuracy of virtual frame placement was compared to actual frame placement. The posterior approach was feasible in all patients. In one case, the trajectory had to be adjusted; in another, the trajectory was switched from a right- to a left-sided approach. Both cases showed large deviations from the initially planned frame placement. A histopathological diagnosis was achieved in all patients. The new Leksell Vantage frame can be used to safely target the posterior fossa with a high diagnostic success rate and accuracy. Frame placement needs to be well-planned and executed. This can be facilitated using specific software solutions as demonstrated. [ABSTRACT FROM AUTHOR]

Background. Even in the 21st century, infections of the central nervous system and their secondary damage still represents a high mortality condition. Furthermore, brain abscesses (BA) are huge public health issues due to their high mortality and morbidity with high financial implications for the health care system. Material and methods. In this article, we want to present our clinic's experience in the management of brain abscesses between 2012 and 2021. A 10 years retrospective study was performed in the 4th Neurosurgery Department of "Bagdasar-Arseni" Clinical Emergency Hospital in Bucharest Results. In the last 10 years, our clinic admitted 46 patients, 10 women and 36 men. The mean age was 47 years old. The most common symptom was headache (42 cases). In 39 cases, patients had solitary abscesses while seven patients presented multiple abscesses. The therapeutic approach was classic surgery in 37 cases. In four cases abscess drainage was performed and in five cases conservative treatment was used. At discharge, 31 patients were healed and seven patients died. Discussions. In BA management, antimicrobial therapy is crucial. Thus, identifying the pathogen is crucial for accurate antimicrobial treatment. Unfortunately, in too many cases, the agent remains unknown and empiric treatment is required. Aspiration of the abscesses proved to be safe and with similar results compared to classic surgery. Conclusions. Brain abscesses remain a high challenge to manage even in the 21st century. Broad-spectrum antibiotic treatment should be applied as soon as possible until the pathogen is identified and specific treatment will be used. [ABSTRACT FROM AUTHOR]

Butterfly glioblastoma (bGBM) is a grade 4 glioma with a poor prognosis. Surgical treatment of these cancers has been reviewed in the literature with some recent studies supporting resection as a safe and effective treatment instead of biopsy and adjuvant therapy. This meta-analysis was designed to determine whether there are significant differences in overall survival (OS) and postoperative neurologic deficits (motor, speech, and cranial nerve) following intervention in patients who underwent tumor resection as part of their treatment, compared to patients who underwent biopsy without surgical resection. A literature search was conducted using PubMed (National Library of Medicine) and Embase (Elsevier) to identify articles from each database's earliest records to May 25, 2021, that directly compared the outcomes of biopsy and resection in bGBM patients and met predetermined inclusion criteria. A meta-analysis was conducted to compare the effects of the two management strategies on OS and postoperative neurologic deficits. Six articles met our study inclusion criteria. OS was found to be significantly longer for the resection group at 6 months (odds ratio [OR] 2.94, 95% confidence interval [CI] 1.23–7.05) and 12 months (OR 3.75, 95% CI 1.10–12.76) than for the biopsy group. No statistically significant differences were found in OS at 18 and 24 months. Resection was associated with an increased rate of postoperative neurologic deficit (OR 2.05, 95% CI 1.02–4.09). Resection offers greater OS up to 1 year postintervention than biopsy alone; however, this comes at the cost of higher rates of postoperative neurologic deficits. [ABSTRACT FROM AUTHOR]

• Our data suggests a potential benefit of cytoreductive surgery for selected patients with PCNSL. • Although not statistically significant, there was a trend towards improved OS, reduced TTR, greater RIC, and reduced WBRT requirement. Cytoreductive surgery for Primary Central Nervous System Lymphoma (PCNSL) is controversial and is not routinely practiced. Cumulative literature in recent years, however, suggests a potential survival benefit associated with a greater extent of resection. A retrospective single institution cohort analysis of 58 consecutive patients with PCNSL was conducted between January 2011 and December 2020. Demographic, clinical, and radiographic characteristics were compared between patients with and without cytoreductive surgery following diagnosis of PCNSL. The primary outcome measures were progression-free survival (PFS) and overall survival (OS). Secondary outcome measures included time to remission (TTR), time to chemotherapy (TTC) and response to initial chemotherapy (RIC). Forty-six patients (79.3 %) received stereotactic biopsy and 12 (20.6 %) underwent cytoreductive surgery. There was a trend towards longer OS (29.8 vs 22.3 months, p = 0.672), shorter TTR (4.0 vs 4.7 months, p = 0.362), and greater complete or near-complete radiographic RIC (81.8 % vs 67.6 %, p = 0.367) for patients undergoing cytoreductive surgery. This correlated with a lesser need for whole brain radiotherapy (WBRT) (8.3 % vs 19.6 %, p = 0.359). Our data suggests a potential benefit of cytoreductive surgery for selected patients diagnosed with PCNSL. Although not statistically significant, there was a trend towards improved OS, reduced TTR, greater RIC, and reduced WBRT requirement. Further studies with better randomization and statistical power are needed to validate this correlation. [ABSTRACT FROM AUTHOR]