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Biopsy of pineal region neoplasms is frequently accomplished by way of endoscopic transventricular access or using an image-guided, computer-assisted stereotactic approach. We evaluated a nonorthogonal lateral temporal approach for stereotactic biopsy of pineal region tumors as a variation of previously described stereotactic methods. Magnetic resonance imaging–guided frameless stereotaxy was used to plan and perform biopsies of pineal region tumors using a nonorthogonal trajectory extending from the superior or middle temporal gyri through the temporal stem, anterior to the atrium of the lateral ventricle, and posterior to the corticospinal tract. All patients had an uncomplicated postoperative course and remained at neurologic baseline. No parenchymal or ventricular hemorrhage was present on postoperative scans. A tissue diagnosis was obtained in all patients. This method appears to be a safe alternative to stereotactic biopsy using other trajectories and provides adequate tissue for definitive diagnosis. [ABSTRACT FROM AUTHOR]

Background: Stereotactic brain biopsy techniques have been a focus of rapid technological innovation. The recent advent of frameless stereotaxy has invited the question of whether it can provide the same diagnostic yield as frame-based techniques, without increasing risk of harm to patients. The goal of this meta-analysis was to compare each of these techniques in terms of yield and safety. Methods: We independently searched four databases for English studies comparing frameless and framebased stereotactic brain biopsies. Our primary outcome was biopsy diagnostic yield. Our secondary outcomes included mortality, morbidity (e.g., symptomatic postbiopsy intracranial hemorrhage, asymptomatic postbiopsy intracranial hemorrhage, new postbiopsy neurological deficit, and postbiopsy seizure), and frequency of repeat biopsy. We calculated pooled estimates and relative risks for dichotomous outcomes using Review Manager 5.3, with corresponding 95% confidence intervals. Methods: We independently searched four databases for English studies comparing frameless and framebased stereotactic brain biopsies. Our primary outcome was biopsy diagnostic yield. Our secondary outcomes included mortality, morbidity (e.g., symptomatic postbiopsy intracranial hemorrhage, asymptomatic postbiopsy intracranial hemorrhage, new postbiopsy neurological deficit, and postbiopsy seizure), and frequency of repeat biopsy. We calculated pooled estimates and relative risks for dichotomous outcomes using Review Manager 5.3, with corresponding 95% confidence intervals. Methods: We independently searched four databases for English studies comparing frameless and framebased stereotactic brain biopsies. Our primary outcome was biopsy diagnostic yield. Our secondary outcomes included mortality, morbidity (e.g., symptomatic postbiopsy intracranial hemorrhage, asymptomatic postbiopsy intracranial hemorrhage, new postbiopsy neurological deficit, and postbiopsy seizure), and frequency of repeat biopsy. We calculated pooled estimates and relative risks for dichotomous outcomes using Review Manager 5.3, with corresponding 95% confidence intervals. [ABSTRACT FROM AUTHOR]

Purpose: To describe a case series of children with thalamic tumors treated at our institution in a 5-year period. Method: A retrospective and observational study was performed. The records of 15 patients between 2013 and 2018 were analyzed. Results: From 2013 to 2018, 15 patients were treated at our institution. The male to female index was 1.5, and the median age was 8.9 (IQR 4.75–13). Seven (46%) tumors were left-sided, seven (46%) were right-sided, and one (6%) was bilateral. All patients were symptomatic at the time of treatment. Motor deficit was the most common form of presentation (73%). Gross-total resection was performed in two (13.3%) patients, subtotal resection was performed in two other patients (13.3%), and for the rest of the patients (73.3%), the chosen surgical approach was a stereotactic-guided biopsy. The average of procedures was 3.4, mostly related to the treatment for hydrocephalus. Twelve patients (80%) received treatment for hydrocephalus. Nine patients (75%) were treated with ventriculoperitoneal shunts, and four patients (33%) underwent endoscopic third ventriculostomy. High-grade tumors predominated. Grade IV tumors were diagnosed in six patients (40%), followed by grade III in four patients (26.6%), grade II in three (20%) patients, and grade I in two (13.3%) patients. Chemotherapy was given in 93% of the cases, being temozolomide, the most used drug. Conclusion: The clinical and surgical approaches for thalamic tumors in children have changed over time. At our institution, the lesser invasive surgical procedures are now being used more frequently. [ABSTRACT FROM AUTHOR]

Introduction: The use of intraoperative imaging has been a critical tool in the neurosurgeon's armamentarium and is of particular benefit during tumor surgery. This article summarizes the history of its development, implementation, clinical experience and future directions. Methods: We reviewed the literature focusing on the development and clinical experience with intraoperative MRI. Utilizing the authors' personal experience as well as evidence from the literature, we present an overview of the utility of MRI during neurosurgery. Results: In the 1990s, the first description of using a low field MRI in the operating room was published describing the additional benefit provided by improved resolution of MRI as compared to ultrasound. Since then, implementation has varied in magnetic field strength and in configuration from floor mounted to ceiling mounted units as well as those that are accessible to the operating room for use during surgery and via an outpatient entrance to use for diagnostic imaging. The experience shows utility of this technique for increasing extent of resection for low and high grade tumors as well as preventing injury to important structures while incorporating techniques such as intraoperative monitoring. Conclusion: This article reviews the history of intraoperative MRI and presents a review of the literature revealing the successful implementation of this technology and benefits noted for the patient and the surgeon. [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 MRI alone has limited accuracy for delineating tumor margins and poorly predicts the aggressiveness of gliomas, especially when tumors do not enhance. This study evaluated simultaneous 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (FDOPA)-PET/MRI to define tumor volumes compared to MRI alone more accurately, assessed its role in patient management, and correlated PET findings with histopathology. Methods Ten patients with known or suspected gliomas underwent standard of care surgical resection and/or stereotactic biopsy. FDOPA-PET/MRI was performed prior to surgery, allowing for precise co-registration of PET, MR, and biopsies. The biopsy sites were modeled as 5-mm spheres, and the local FDOPA uptake at each site was determined. Correlations were performed between measures of tumor histopathology, and static and dynamic PET values: standardized uptake values (SUVs), tumor to brain ratios, metabolic tumor volumes, and tracer kinetics at volumes of interest (VOIs) and biopsy sites. Results Tumor FDOPA-PET uptake was visualized in 8 patients. In 2 patients, tracer uptake was similar to normal brain reference with no histological findings of malignancy. Eight biopsy sites confirmed for glioma had FDOPA uptake without T1 contrast enhancement. The PET parameters were highly correlated only with the cell proliferation marker, Ki-67 (SUVmax: r = 0.985, P  = .002). In this study, no statistically significant difference between high-grade and low-grade tumors was demonstrated. The dynamic PET analysis of VOIs and biopsy sites showed decreasing time-activity curves patterns. FDOPA-PET imaging directly influenced patient management. Conclusions Simultaneous FDOPA-PET/MRI allowed for more accurate visualization and delineation of gliomas, enabling more appropriate patient management and simplified validation of PET findings with histopathology. [ABSTRACT FROM AUTHOR]

Intravascular lymphoma (IVL) is a rare and clinically devastating subtype of extranodal diffuse large B-cell lymphoma with a distinct presentation. Diagnostic difficulty derives from marked variability in clinical presentations and nonspecific laboratory and radiological findings, especially when central nervous system (CNS) symptoms are the only manifestation. Establishing the diagnosis premortem thus remains a major challenge. We describe a 70-year-old male with CNS IVL. He presented with acute onset of neurocognitive impairments. Diffusion-weighted magnetic resonance imaging (MRI) showed multiple high-intensity areas suggesting occlusive cerebrovascular disease due to emboli, but extensive investigations detected no embolic sources. Intracranial neoplasm was included in a differential diagnosis based on elevated serum lactate dehydrogenase and interleukin 2 receptor levels. Gadolinium-enhanced MRI or 18-fluorodeoxyglucose positron emission tomography (PET) failed to demonstrate specific findings leading to a definite diagnosis, while 11C-methionine PET (MET-PET) distinctively demonstrated an area of focally increased MET uptake in the frontal cortex, suggesting the extent of tumor infiltration. Stereotactic biopsy was conducted under MET-PET imaging guidance and immunohistological examinations confirmed the proliferation and aggregation of CD20-positive lymphoma cells within the lumina of small blood vessels. The findings of the present case first suggest that MET-PET may provide important information on the diagnosis of CNS IVL and on the selection of the optimal site for brain biopsy. Further investigation is necessary to clarify whether positive findings on MET-PET are truly specific and pathognomonic for CNS IVL.

The abilities of the optical probe for fluorescence-guided stereotactic biopsy were investigated by means of a multifiber probe under 532 or 632.8 nm excitation. The set of multilayered phantoms representing a border between normal brain-tissue and a tumor with photosensitizer and gold nanoparticles (spheres or stars) in different concentrations were made to investigate the macroscopic parameters observed during the neurosurgical biopsy sample collection by means of the optical probe. These investigantions will allow to define the border of a brain tumor and control the type of tissue being collected by a stereotactic cannula during surgery. The impact of gold nanospheres and gold nanostars added in different concentrations to the bottom-layer of phantom was analyzed by fluorescence quenching or enhancement due to energy transfer between nanoparticles and fluorescent molecules. The results allow determining the tumor border and to make the biopsy uptake more efficient by observing the character of signal change while penetrating a tumor and while going out of it.

Introduction: Neuroendoscopic biopsy represents the procedure of choice for pure intraventricular lesions. Instead, in case of deep-seated paraventricular tumors, with intact ependyma, the advantage of neuroendoscopy over stereotactic biopsy is not so evident, because the lesion is not under direct vision; the tissue sample may be limited to more superficial ependymal layer, and bleeding may obscurate vision. Also, stereotactic biopsy may reserve additional problems for these lesions: inaccuracy caused by leak of cerebrospinal fluid and increased risk of severe hemorrhage due to damage of the ependymal vessels. Case reports: We report two cases of young children affected by thalamic tumors that were biopsied using a modification of a recently proposed technique: endoscopic visual control, neuronavigated needle biopsy. Conclusion: This technique may combine the accuracy of a stereotactic needle biopsy with the advantage of visual control on site of ependymal puncture and possibility of immediate bleeding control. [ABSTRACT FROM AUTHOR]

Background: Stereotactic biopsy is a well-established procedure in neurosurgery. Our objective is to define the clinical, radiological, and technical factors that can condition the emergence of postbiopsy symptomatic intracranial hemorrhage. Based on our findings, we suggest recommendations to improve its usual clinical practice. Methods: We made a retrospective study of 429 cases with stereotactic biopsies performed in the past 37 years. The surgical procedure-was adapted in terms of the stereotactic frames (Todd-Wells, CRW, Leksell), neuroimaging tests, and planning programs available in the hospital. Fifty-three variables were analyzed for each patient (SPSS.23). Results: The diagnostic yield was 90.7%. Forty-one patients (9.5%) suffered a symptomatic postbiopsy hemorrhage; only 17 (3.9%) had permanent morbidity. The mortality was 0.93% (n = 4). A postsurgical CT scan was requested only in 99 patients (23%) of our series. Lesion mass effect, cystic component, contrast enhancement, histological nature, or number of targets were not associated with a greater risk of symptomatic postbiopsy hemorrhage (P > 0.05). On the other hand, the biopsies made by nonexpert neurosurgeons (P = 0.01) or under general anesthesia (P = 0.02) resulted in a greater risk of symptomatic postbiopsy hemorrhage. Anesthetic type was the clearest predictive factor of bleeding with this technique (OR: 0.24). Conclusion: Stereotactic biopsy is a very valuable tool. To optimize its safety and minimize the risk of intracranial bleeding, it requires both a knowledge of stereotactic techniques and very careful surgical planning. While the patient's stay in intensive vigilance units after the procedure is a useful strategy, the request for control CT scans should be conditioned by the clinical evolution of each patient. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To evaluate retrospectively the positive predictive value of suspicious microcalcifications diagnosed on full-field digital mammography (FFDM) and establish the likelihood of malignancy using stereotactic biopsy results as gold standard. STUDY DURATION AND SETTINGS: Retrospective study was conducted at the department of Diagnostic Radiology, Dallah hospital, Riyadh, Saudi Arabia. Study duration was 2.3 year (January 2018-March 2020). MATERIAL AND METHODS: The study included 60 female patients with microcalcification on mammogram who underwent stereotactic guided biopsy between January 2018 and March 2020. The sample size was calculated using the WHO calculator. Non probability consecutive sampling was used for selection of patients. Ethical approval was taken. Patients underwent digital mammography with tomosynthesis and stereotactic biopsy. The morphology and distribution of microcalcifications was assessed on mammogram and subsequently BI-RADS (Breast Imaging-Reporting and Data System) descriptors were recorded. Finally, correlation with histopathology was performed. Data was analysed using SPSS version 24. Chi-square and Pearsons correlation was applied. P value < 0.05 was considered significant. RESULTS: Total 60 biopsies were included in this study. Mean age of women was 50 years - 30.1SD. There were 30 (50%) women in the age group 30-40 years and 30 (50%) women in the age group of 40-50 years. In mammography, microcalcification is seen in the right breast in 20 (33.3%) cases and in the left breast in 38 (63.3%) cases. Of the 60 microcalcification lesions biopsied, 33 were benign and 27 were malignant, representing an overall positive predictive value of 45% for the microcalcification on mammogram The morphologic characteristics of the suspicious microcalcifications were as follows: amorphous in 13 (22.0%) of the 60 cases, coarse heterogeneous in 14 (23.3%), Pleomorphic in 25(41.6%) and linear microcalcifications in 8 (13%). Among the 60 cases, the distribution of the suspicious microcalcifications was classified as grouped in 51 (85%), as segmental in 8 (13.3%), and as regional in 1 (1.6%). The 22 malignant lesions consisted of 2 cases of DCIS (9.1%) and 20 (90%) cases of invasive ductal carcinoma. In our study 63% of patients with a BIRADS score of 4 to 5 had microcalcifications associated with benign tissue. CONCLUSION: Suspicious microcalcifications (BIRADS category 4 and 5) on digital mammography had high positive correlation with histopathological findings. Appropriate screening for high risk patients leads to early diagnosis and lowers the disease progression. [ABSTRACT FROM AUTHOR]

Introduction  The role of frame-based stereotactic biopsy in brainstem lesions has been well established in literature. Transfrontal, transtentorial, and transcerebellar routes are used to access various targets within the brainstem. While the transfrontal approach is preferable in midbrain lesions, a transcerebellar approach via the middle cerebellar peduncle forms the shortest possible trajectory for pontine and medullary lesions. Objective  Authors to describe the technical nuances of frame-based stereotactic biopsy of lower brainstem lesions to increase the procedural safety and efficacy. Materials and Methods  Technical modifications in frame fixation were done to acheive the desired trajectory to the target. In adult cases biopsy was performed with patient awake during the procedure. Results  Total of five patients underwent biopsy with the technical modifications. Three patients were adults and two were in pediatric age group. Their age ranged from 12 to 50 years. No complications were encountered. Two of the biopsies showed demyelination and the other three turned out to be low-grade glioma, pilocytic astrocytoma, and lymphoma, respectively. Conclusion  Despite obvious inherent risks, the transcerebellar biopsy in semi-sitting position is a well-tolerated and effective method of obtaining a diagnostic tissue sample in brainstem lesions. We have noted that adoption of the technical modifications described in this article has aided in improving the safety and ease of the procedure. [ABSTRACT FROM AUTHOR]

Purpose: Glioma treatment planning requires precise tumor delineation, which is typically performed with contrast-enhanced (CE) MRI. However, CE MRI fails to reflect the entire extent of glioma. O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) PET may detect tumor volumes missed by CE MRI. We investigated the clinical value of simultaneous FET-PET and CE MRI in delineating tumor extent before treatment planning. Guided stereotactic biopsy was used to validate the findings. Methods: Conventional MRI and 18F-FET PET were performed simultaneously on a hybrid PET/MR in 33 patients with histopathologically confirmed glioma. Tumor volumes were quantified using a tumor-to-brain ratio ≥ 1.6 (VPET) and a visual threshold (VCE). We visually assessed abnormal areas on FLAIR images and calculated Dice's coefficient (DSC), overlap volume (OV), discrepancy-PET, and discrepancy-CE. Additionally, several stereotactic biopsy samples were taken from "matched" or "mismatched" FET-PET and CE MRI regions. Results: Among 31 patients (93.94%), FET-PET delineated significantly larger tumor volumes than CE MRI (77.84 ± 51.74 cm3 vs. 34.59 ± 27.07 cm3, P < 0.05). Of the 21 biopsy samples obtained from regions with increased FET uptake, all were histopathologically confirmed as glioma tissue or tumor infiltration, whereas only 13 showed enhancement on CE MRI. Among all patients, the spatial similarity between VPET and VCE was low (average DSC 0.56 ± 0.22), while the overlap was high (average OV 0.95 ± 0.08). The discrepancy-CE and discrepancy-PET were lower than 10% in 28 and 0 patients, respectively. Eleven patients showed VPET partially beyond abnormal signal areas on FLAIR images. Conclusion: The metabolically active biodistribution of gliomas delineated with FET-PET significantly exceeds tumor volume on CE MRI, and histopathology confirms these findings. Our preliminary results indicate that combining the anatomic and molecular information obtained from conventional MRI and FET-PET would reveal a more accurate glioma extent, which is critical for individualized treatment planning. [ABSTRACT FROM AUTHOR]

Purpose: Brainstem lesions comprise 10–20% of all pediatric brain tumors. Over the past years, the benefits of stereotactic biopsy versus the use alone of MRI features to guide treatment have been controversial. Methods: Retrospective study with pediatric patients submitted to stereotactic brainstem biopsies between 2008 and 2018. Demographic, clinical, imaging, and surgical characteristics were recorded, as well as the histological diagnosis, complications, and survival. Predictors of survival were evaluated through Cox regression models after multivariate adjustment. Results: Twenty-six patients (mean age of 8.8 ± 4.3 years and 14 female). Diagnosis was reached on 84.6% (95% CI 65.1–95.6%) of the patients. Glioma was diagnosed on 20 cases (11 high-grade and 9 low-grade lesions). There was no association between age and gender and the dichotomized histological diagnosis. Contrast enhancement, diffuse distribution, invasion of adjacent structures, and remote injury were present on 62.5%, 75.0%, 62.5%, and 25.0% of the cases. Hydrocephalus at admission was present on almost half of the patients (46.2%). Only radiological invasion of adjacent structures had a possible association with high-grade lesions (p = 0.057). Surgical trajectory was trans-cerebellar in most of the cases (79.9%). There were no major complications and only two minor/transitory complications. Poorer survival was independently associated with high-grade lesions (HR 32.14, 95% CI 1.40–735.98, p = 0.030) and contrast enhancement at MRI (HR 36.54, 95% CI 1.40–952.26, p = 0.031). Conclusions: Stereotactic biopsy was safe and allows successful tissue sampling for a definite diagnosis. Poorer survival was independently associated with high-grade and contrast-enhancing lesions. [ABSTRACT FROM AUTHOR]

Tissue diagnosis for lesions in the posterior fossa, such as the brainstem, cerebellar peduncle, and cerebellum, is an important determinant of the next treatment option. Herein, we present our 10-year experience with magnetic resonance imaging (MRI)–guided frame–based stereotactic biopsy for 39 patients with posterior fossa lesions, the largest case series in this matter. We performed a retrospective cross-sectional study on all patients with posterior fossa lesion admitted to 2 referral centers between 2006 and 2016. We used Leksell Frame G for stereotactic biopsy of all patients. MRI systems of both hospitals were 1.5 T. We performed analysis on the 39 cases (21 men and 18 women). Age of the patients ranged between 9 and 73 years (mean, 35.4 ± 15.7 years). Localization success rate was 100%. For 38 patients (97.4%), tissue sample size was enough for tissue diagnosis. For 1 case, it was insufficient and nondiagnostic. In this series, we had no surgery-related complications. We present the largest reported series of MRI-guided frame-based stereotactic biopsy of the posterior fossa lesions via a transcerebellar route. We prefer oblique positioning of the frame on the skull and use a transcerebellar route to reduce surgical complications and achieve a greater localization success rate. [ABSTRACT FROM AUTHOR]

Introduction: The prognosis of diffuse intrinsic pontine glioma (DIPG) is poor. The role of biopsy in DIPG remains controversial since the diagnosis may be established with imaging alone. Recent advances in understanding molecular biology and targeting of brain tumors have created a renewed interest in biopsy for DIPG. The Neurosurgery Working Group (NWG) of the SIOP-Europe Brain Tumor Group (BTG) undertook a survey among international pediatric neurosurgeons to define their current perceptions and practice regarding DIPG biopsy. Methods: The NWG developed a 20-question survey which was emailed to neurosurgeons in the International Society for Pediatric Neurosurgery (ISPN). The questionnaire included questions on diagnosis, indications, and techniques for biopsy, clinical trials, and healthcare infrastructure. Results: The survey was sent to 202 neurosurgeons and 73 (36%) responded. Consensus of > 75% agreement was reached for 12/20 questions, which included (1) radiological diagnosis of DIPG is sufficient outside a trial, (2) clinical trial–based DIPG biopsy is justified if molecular targets are investigated and may be used for treatment, and (3) morbidity/mortality data must be collected to define the risk:benefit ratio. The remaining 8/20 questions proved controversial and failed to reach consensus. Conclusions: Routine DIPG biopsy continues to be debated. Most neurosurgeons agreed that DIPG biopsy within a clinical trial should be supported, with the aims of defining the procedure risks, improving understanding of tumor biology, and evaluating new treatment targets. Careful family counseling and consent remain important. [ABSTRACT FROM AUTHOR]

• DIPG. • Stereotactic biopsy. • Convection enhanced delivery. • Targeted therapies. Diffuse intrinsic pontine gliomas (DIPG) are high grade gliomas of the brainstem with fatal outcomes. Radiation is known to be partially effective to control the immediate flare but relapse is frequent. There has been ongoing research to study the role of molecular subgroups and identification of specific targets but this is not possible with histopathological diagnosis alone. The authors' objective is to highlight the need for and discuss ongoing molecular research. There is an inherent need for the availability of tumor tissue to be able to conduct research studies. The authors advocate the use of neuronavigation assisted stereotactic technique for tumor biopsy. The technique is feasible with a predefined surgical trajectory. After obtaining tissue diagnosis further work can be performed to isolate and identify histone protein genetic mutations and methylation changes responsible for DIPG molecular subgrouping. Moreover, convection enhanced delivery of therapeutic agents is being developed for better instillation of future drug agents. Despite identification of genetic/epigenetic mutations, growth factors, receptors, and tissue biomarkers, the oncogenesis of DIPG remains elusive. The authors' effort to provide a comprehensive review on DIPG to better understand the disease, need for tissue diagnosis, described surgical technique, and need for pre-clinical and clinical future research is novel. [ABSTRACT FROM AUTHOR]

Primer santral sinir sistemi lenfoması, beyin ve zarlarını, göz veya spinal kordu tutabilen nadir görülen bir Non-Hodgkin lenfoma türüdür. Primer santral sinir sistemi lenfoması çoğunlukla diffüz büyük B hücreli lenfoma grubundadır ve agresif seyirlidir. Hastalığı düşündüren klinik, görüntüleme ve beyin omurilik sıvısı bulguları olmasına rağmen kesin tanı ve tedavi planlaması için biyopsi gereklidir. Yetmiş üç yaşında erkek hasta, bir aydır ilerleyici başağrısı ve sağ kolda güçsüzlük yakınmaları ile başvurdu. Hasta ileri tetkik ve tedavi için kliniğimize yatırıldı. Manyetik rezonans görüntüleme sonuçları ile santral sinir sistemi lenfoması düşünülen hastaya lomber ponksiyon yapıldı. Lomber ponksiyon incelemelerinde lenfoma lehine bulgu saptanmayan hastaya stereotaktik beyin biyopsisi yapıldı ve patolojik inceleme sonucu ile CD 20 + B hücreli lenfoma tanısı konuldu. Primer santral sinir sistemi lenfoması için MR bulguları tipik olgularda zaman kaybetmeden histopatolojik tanı konulmalı ve tedaviye başlanmalıdır.

Abnormal tissue in stereotactic brain biopsies (SBB) is traditionally identified intraoperatively via pathological frozen section (FS), a time-consuming and error-prone process. The objective of this study was to assess the efficacy of 5-aminolevulinic acid (5-ALA) administration on SBB operation time, diagnostic yield, and the associated complication rate. We retrospectively evaluated all consecutive patients undergoing SBB with preoperative 5-ALA administration and intraoperative assessment of fluorescence (5-ALA group) between 2010 and 2017 in a single center. They were compared to all consecutive patients who underwent traditional brain biopsy with FS (control group). Demographics, clinical data, diagnostic yield of biopsies, and complication rates were documented. In all, 376 patients underwent SBB for suspected oncological pathology during the study period. All 34 of the 5-ALA-assisted SBB were diagnostic compared to 96.8% of the control group. The mean operative time was the same for both groups, but it was significantly shorter for the 5-ALA patients with florescent samples compared to patients with negative fluorescence (61 ± 25 min vs. 136 ± 54 min, P = 0.003) and compared to the control group (74 ± 34 min vs. 61 ± 25 min, P = 0.03). Symptomatic bleed was absent in the 5-ALA group and present in 5.4% of the controls. No adverse events were associated with preoperative 5-ALA administration. Preoperative administration of 5-ALA may improve the diagnostic yield of SBB and shortens operation time in cases of fluorescent pathological tissue. In addition, it may reduce the risk for associated postoperative symptomatic bleed. 5-ALA-assisted SBB is a viable alternative to traditional biopsies with FS. [ABSTRACT FROM AUTHOR]

Objective: To determine the false negative and underestimation rates of stereotactic 14-gauge automated core needle breast biopsy (CNB) in Phramongkutklao Hospital. Materials and Methods: A retrospective review of 124 breast lesions receiving stereotactic 14-gauge automated CNB, with either subsequent surgical excision or complete 2-year mammographic follow-up to confirm benignity was performed. The false negative rate and underestimation rate of both high-risk lesions and ductal carcinoma in situ (DCIS) were calculated. Results: The 124 lesions presented as microcalcifications. CNB revealed 80 benign, 13 high risk (seven papillomas, five atypical ductal hyperplasia, and one atypical gland proliferation), and 31 malignant lesions. One of the 37 lesions that had a final diagnosis of carcinoma was benign at CNB, a false negative rate of 2.7%. Three of the five atypical ductal hyperplasia (60%) and two of the seven papillomas (28.6%) turned out to be cancer at surgical excision, while two of the 20 DCIS (10%) had invasive component at final diagnosis. Conclusion: The false negative rate of stereotactic 14-gauge automated CNB of microcalcifications in Phramongkutklao Hospital was 2.7%. The underestimation rates of atypical ductal hyperplasia, papilloma, and DCIS were 60%, 28.6%, and 10%, respectively. [ABSTRACT FROM AUTHOR]

Stereotactic biopsy of posterior fossa lesions is often regarded as hazardous due to the critical structures in that area. Therefore, the aim of the study was to evaluate the diagnostic accuracy and safety of infratentorial stereotactic biopsy of brainstem or cerebellar lesions and its associations with other clinical, laboratory, and radiological parameters. From January 2000 to May 2021, 190 infratentorial stereotactic biopsies of posterior fossa tumors, including 108 biopsies of brainstem lesions, were performed. Moreover, 63 supratentorial biopsies of cerebral peduncle lesions were analyzed to compare the safety and efficacy of both approaches. Additionally, the presence of antibodies against Toxoplasma gondii and Epstein–Barr Virus (EBV) were documented in 67 and 66 patients, respectively, and magnetic resonance imaging (MRI) scans were evaluated in 114 patients. Only 4% of patients had minor complications and 1.5% had major complications, including one patient who died from intracranial bleeding. Nine (4.7%) biopsies were non-diagnostic. Isocitrate dehydrogenase 1 (IDH1) mutation, 1p/19q codeletion, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status were assessed in 29 patients, and were non-diagnostic in only 3 (10.3%) cases. Patients with high-grade gliomas (HGG) were more frequently seropositive for T. gondii than individuals with low-grade gliomas (LGG; p < 0.001). A total of 27% of HGG and 41% of LGG were non-enhancing on MRI. The infratentorial approach is generally safe and reliable for biopsy of brainstem and cerebellar lesions. In our study, the safety and efficacy of supratentorial biopsy of the cerebral peduncle and infratentorial biopsy of lesions below the cerebral peduncle were comparably high. Moreover, patients with HGG were more frequently seropositive for T. gondii than patients with LGG, and the relationship between toxoplasmosis and gliomagenesis requires further investigation.

Background: Treatment effectiveness and overall prognosis for glioma patients depend heavily on the genetic and epigenetic factors in each individual tumor. However, intra-tumoral genetic heterogeneity is known to exist and needs to be managed. Currently, evidence for genetic changes varying spatially within the tumor is qualitative, and quantitative data is lacking. We hypothesized that a greater genetic diversity or “genetic distance” would be observed for distinct tumor samples taken with larger physical distances between them.Methods: Stereotactic biopsies were obtained from untreated primary glioma patients as part of a clinical trial between 2011 and 2016, with at least one biopsy pair collected in each case. The physical (Euclidean) distance between biopsy sites was determined using coordinates from imaging studies. The tissue samples underwent whole exome DNA sequencing and epigenetic methylation profiling and genomic distances were defined in three separate ways derived from differences in number of genes, copy number variations (CNV), and methylation profiles.Results: Of the 31 patients recruited to the trial, 23 were included in DNA methylation analysis, for a total of 71 tissue samples (14 female, 9 male patients, age range 21–80). Samples from an 8 patient subset of the 23 evaluated patients were further included in whole exome and copy number variation analysis. Physical and genomic distances were found to be independently and positively correlated for each of the three genomic distance measures. The correlation coefficients were 0.63, 0.65, and 0.35, respectively for (a) gene level mutations, (b) copy number variation, and (c) methylation status. We also derived quantitative linear relationships between physical and genomic distances.Conclusion: Primary brain tumors are genetically heterogeneous, and the physical distance within a given glioma correlates to genomic distance using multiple orthogonal genomic assessments. These data should be helpful in the clinical diagnostic and therapeutic management of glioma, for example by: managing sampling error, and estimating genetic heterogeneity using simple imaging inputs.

Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Contrast-enhanced MRI is the method of choice for brain tumor diagnostics, despite its low specificity for tumor tissue. This study compared the contribution of MR spectroscopic imaging (MRSI) and amino acid PET to improve the detection of tumor tissue. Methods: In 30 untreated patients with suspected glioma, O -(2-[ 18 F]fluoroethyl)-l-tyrosine ( 18 F-FET) PET; 3-T MRSI with a short echo time; and fluid-attenuated inversion recovery, T2-weighted, and contrast-enhanced T1-weighted MRI were performed for stereotactic biopsy planning. Serial samples were taken along the needle trajectory, and their masks were projected to the preoperative imaging data. Each sample was individually evaluated neuropathologically. 18 F-FET uptake and the MRSI signals choline (Cho), N -acetyl-aspartate (NAA), creatine, myoinositol, and derived ratios were evaluated for each sample and classified using logistic regression. The diagnostic accuracy was evaluated by receiver operating characteristic analysis. Results: On the basis of the neuropathologic evaluation of tissue from 88 stereotactic biopsies, supplemented with 18 F-FET PET and MRSI metrics from 20 areas on the healthy-appearing contralateral hemisphere to balance the glioma/nonglioma groups, 18 F-FET PET identified glioma with the highest accuracy (area under the receiver operating characteristic curve, 0.89; 95% CI, 0.81-0.93; threshold, 1.4 × background uptake). Among the MR spectroscopic metabolites, Cho/NAA normalized to normal brain tissue showed the highest diagnostic accuracy (area under the receiver operating characteristic curve, 0.81; 95% CI, 0.71-0.88; threshold, 2.2). The combination of 18 F-FET PET and normalized Cho/NAA did not improve the diagnostic performance. Conclusion: MRI-based delineation of gliomas should preferably be supplemented by 18 F-FET PET., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

To determine the malignancy rate in women without a concurrent breast cancer diagnosis at presentation who underwent stereotactic biopsies of distinct sites of suspicious calcifications. This retrospective study included 280 women without a concurrent breast cancer diagnosis who underwent 587 stereotactic biopsies of two or more distinct sites of suspicious calcifications in one or both breasts at our institution from 2010 to 2015. The overall malignancy rate was 27.9% (78/280, 95% CI, 22.7%–33.5%) at the patient level and 18.7% (110/587, 95% CI, 15.7%–22.1%) at the lesion level. Eighteen had invasive cancers (mean [range] diameter, 0.5 cm [0.1–1.7]; six grade I, ten grade II, two grade III), one of whom had multifocal and another bilateral malignancy. Sixty had ductal carcinoma in situ. Of the 171 with all calcifications of the same morphology, 139 (81.3%) had all calcifications in the same pathology category (benign, high-risk, or malignant). The malignancy rate is substantial in women who undergo stereotactic biopsies of two or more distinct calcification sites. Given the nearly 20% rate of dissimilar histopathology between calcification sites with similar morphology, if only one site is biopsied and results in a malignant pathology, biopsy of the additional calcifications is warranted. Even if the pathology result of the one site biopsy is benign, biopsy of additional sites may perhaps still be necessary. • Malignancy rate was 27.9% in women who underwent stereotactic guided biopsies of multiple separate suspicious calcifications in the same or both breasts. • When there were multiple distinct sites of similar-appearing suspicious calcifications, the calcifications were in the same pathology category in approximately 80% of patients • In women with two or more sites of suspicious calcifications, if the pathology result of the one site biopsy is benign, additional biopsy may perhaps still be necessary for the other sites [ABSTRACT FROM AUTHOR]

Objectives: We evaluated the feasibility, safety, and diagnostic yield of frame-based stereotactic biopsies (SB) in lesions located in deep-seated and midline structures of the brain to analyze these parameters in comparison to other brain areas. Patients and methods: In a retrospective, tertiary care single-center analysis, we identified all patients who received SB for lesions localized in deep-seated and midline structures (corpus callosum, basal ganglia, pineal region, sella, thalamus, and brainstem) between January 1996 and June 2015. Study participants were between 1 and 82 years. We evaluated the feasibility, procedural complications (mortality, transient and permanent morbidity), and diagnostic yield. We further performed a risk analysis of factors influencing the latter parameters. Chi-square test, Student t test, and Mann-Whitney rank-sum test were used for statistical analysis. Results: Four hundred eighty-nine patients receiving 511 SB procedures (median age 48.5 years, range 1–82; median Karnofsky Performance Score 80%, range 50–100%, 43.8% female/56.2% male) were identified. Lesions were localized in the corpus callosum (29.5%), basal ganglia (17.0%), pineal region (11.5%), sella (7.8%), thalamus (4.3%), brainstem (28.8%), and others (1.1%). Procedure-related mortality was 0%, and permanent morbidity was 0.4%. Transient morbidity was 9.6%. Histological diagnosis was possible in 99.2% (low-grade gliomas 16.2%, high-grade gliomas 40.3%, other tumors in 27.8%, no neoplastic lesions 14.5%, no definitive histological diagnosis 0.8%). Only the pons location correlated significantly with transient morbidity (p < 0.001). Conclusion: In experienced centers, frame-based stereotactic biopsy is a safe diagnostic tool with a high diagnostic yield also for deep-seated and midline lesions. [ABSTRACT FROM AUTHOR]

Background: Treatment effectiveness and overall prognosis for glioma patients depend heavily on the genetic and epigenetic factors in each individual tumor. However, intra-tumoral genetic heterogeneity is known to exist and needs to be managed. Currently, evidence for genetic changes varying spatially within the tumor is qualitative, and quantitative data is lacking. We hypothesized that a greater genetic diversity or "genetic distance" would be observed for distinct tumor samples taken with larger physical distances between them. Methods: Stereotactic biopsies were obtained from untreated primary glioma patients as part of a clinical trial between 2011 and 2016, with at least one biopsy pair collected in each case. The physical (Euclidean) distance between biopsy sites was determined using coordinates from imaging studies. The tissue samples underwent whole exome DNA sequencing and epigenetic methylation profiling and genomic distances were defined in three separate ways derived from differences in number of genes, copy number variations (CNV), and methylation profiles. Results: Of the 31 patients recruited to the trial, 23 were included in DNA methylation analysis, for a total of 71 tissue samples (14 female, 9 male patients, age range 21–80). Samples from an 8 patient subset of the 23 evaluated patients were further included in whole exome and copy number variation analysis. Physical and genomic distances were found to be independently and positively correlated for each of the three genomic distance measures. The correlation coefficients were 0.63, 0.65, and 0.35, respectively for (a) gene level mutations, (b) copy number variation, and (c) methylation status. We also derived quantitative linear relationships between physical and genomic distances. Conclusion: Primary brain tumors are genetically heterogeneous, and the physical distance within a given glioma correlates to genomic distance using multiple orthogonal genomic assessments. These data should be helpful in the clinical diagnostic and therapeutic management of glioma, for example by: managing sampling error, and estimating genetic heterogeneity using simple imaging inputs. [ABSTRACT FROM AUTHOR]

Clearpoint Smartframe is a magnetic resonance imaging−compatible stereotactic system often used to perform magnetic resonance imaging−guided biopsies. The system is typically mounted on the scalp through screws that pierce the skin and penetrate the outer table of the cranium. However, the frame can also be configured to be mounted directly onto the skull. Here, we describe the clinical context well suited for a skull-mount Clearpoint Smartframe surgery. The patient suffered from a subcentimeter right parafourth ventricular contrast-enhancing lesion with hydrocephalus and underwent a right suboccipital needle biopsy followed by an occipital ventriculoperitoneal shunt. Although the hydrocephalus resolved with the ventriculoperitoneal shunt, the biopsy sample proved nondiagnostic. The patient underwent a second procedure during which the Clearpoint Smartframe was mounted onto the skull through space dissected free during the previous surgery. Diagnostic biopsy (H3K27 glioma) was performed followed by stereotactic laser ablation of the lesion. We describe a case in which the skull mount Clearpoint Smartframe was used to biopsy and ablate a midline H3K27 glioma. [ABSTRACT FROM AUTHOR]

Background and Study Aims Stereotactic biopsy is a versatile, minimally invasive technique to obtain tissue safely from intracranial lesions for their histologic diagnosis and therapeutic management. Our objective was to determine the anatomical, radiologic, and technical factors that can affect the diagnostic yield of this technique. We suggest recommendations to improve its use in clinical practice. Methods This retrospective study evaluated 407 patients who underwent stereotactic biopsies in the past 34 years. The surgical methodology changed through time, distinguished by three distinct periods. Different stereotactic frames (Todd-Wells, CRW, Leksell), neuroimaging tests, and planning programs were used. Using SPSS software v.23, we analyzed a total of 50 variables for each case. Results The series included 265 men (65.1%) and 142 women (34.9%) (average age 53.8 years). The diagnostic yield was 90.4%, morbidity was 5.65% (n = 17), and mortality was 0.98% (n = 4). Intraoperative biopsy improved accuracy (p = 0.024). Biopsies of deep lesions (p = 0.043), without contrast enhancement (p = 0.004), edema (p = 0.036), extensive necrosis (p = 0.028), or a large cystic component (p = 0.023) resulted in a worse diagnostic yield. Neurosurgeons inexperienced in stereotactic techniques obtained more nondiagnostic biopsies (p = 0.043). Experience was the clearest predictive factor of diagnostic yield (odds ratio: 4.049). Conclusions Increased experience in stereotactic techniques, use of the most suitable magnetic resonance imaging sequences during biopsy planning, and intraoperative evaluation of the sample before finalizing the collection are recommended features and ways to improve the diagnostic yield of this technique. [ABSTRACT FROM AUTHOR]

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Objective Stereotactic biopsy is a standard procedure in neurosurgery. In addition to or even replacing frame-based stereotaxy, some centers also use frameless imaging-based techniques and more recently robotic systems. Here we report a retrospective analysis of our experience with 102 consecutive biopsies performed in our institution using the neuromate robotic device. Methods Between March 2013 and April 2018, 102 robot-assisted frameless biopsies were performed in 100 consecutive patients (median age/range: 66/7–86 years, male: 64). Target lesions were deep-seated (insula, basal ganglia, thalamus, midbrain, cerebellar peduncle) in 29 (28.4%) and/or small (<15 mm) in 24 (23.5%) cases. We retrospectively analyzed the histopathologic results as well as complications and the duration of the procedures. Results A definite histologic diagnosis could be established in 94 of 102 procedures (92.2%; 94/100 patients = 94.0%), including 67 glial and glioneuronal tumors, 16 central nervous system lymphomas, 7 metastases, 1 primitive neuroectodermal tumor, and 5 cases with inflammatory or infectious disorders. There were no infectious complications. A total of 13 cases (12.7%) suffered from biopsy-related hemorrhages >10 mm; however, persistent surgery-related neurologic worsening was seen in only 3 (2.9%). The average operating time was 10 minutes for placement of the localizing device under local anesthesia and 30 minutes for the actual biopsy procedure. Conclusions Robot-assisted fameless stereotactic biopsies using the neuromate robot are an alternative to frame-based stereotaxy with a similar diagnostic yield and comparable complication rates. [ABSTRACT FROM AUTHOR]

Background: Cancer cells bear various metabolic alterations in order to survive and progress. Neoplastic cells rewire their metabolic pathways for fermentation of glucose and production of more lactate. Microenvironment acidification is a common feature of many neoplastic lesions. In other words, most cancer cells produce energy ineffectively, by aerobic glycolysis, considered as "Warburg effect". Mounting on previous evidence, hypoxia also induces tumor stemness, diminished apoptosis, and more invasive behavior as well as angiogenesis. In this study, we aimed to investigate whether more lactate concentration in stereotactic puncture specimen of various brain lesions can be an alarming sign of malignancy and higher grades. The current study aims at providing a rapid prognostic biomarker of higher grades for cystic brain lesions approached stereotactically before the complete pathologic grading report is prepared. Methods: We investigated the biochemical cyst content of 44 patients with astrocytomas, 8 craniopharyngiomas, 1 oligodendroglioma and 2 cases with metastatic lesions after stereotactic surgery (47 patients were enrolled in the study). Cyst fluid was analyzed for pH, total protein concentration, cytology, and lactate. The association of these parameters was explored relative to tumor behavior (e.g., tumor grade, type, and cyst progression). The current study was conducted at Firoozgar hospital, Tehran, Iran. Patients were followed for any possible progression from 2014 to 2017. Results: The analyses revealed a significant and positive correlation between grade and lactate concentration (P ≤ 0.001); as well as between grade and mean total protein concentration (P = 0.046). This suggests that more lactate and total protein concentration in stereotactic specimen can be an alarming sign of higher grades and poor outcome in astrocytoma cysts. However, craniopharyngiomas; as benign lesions; had significantly lower lactate (P ≤ 0.001) and total protein concentrations (P = 0.018) than astrocytomas. Conclusion: Higher total protein and lactate concentrations in the stereotactic biopsy specimens are alarming signs of poor outcome and higher grades in astrocytomas. Trial Ethics Registration: IR.IUMS.FMD.REC 1396.88215207. [ABSTRACT FROM AUTHOR]

Over the last decade, advances in molecular and imaging-based biomarkers have induced a more versatile diagnostic classification and prognostic evaluation of glioma patients. This, in combination with a growing therapeutic armamentarium, enables increasingly individualized, risk-benefit-optimized treatment strategies. This path to precision medicine in glioma patients requires surgical procedures to be reassessed within multidimensional management considerations. This article attempts to integrate the surgical intervention into a dynamic -network of versatile diagnostic characterization, prognostic assessment, and multimodal treatment options in the light of the latest 2016 World Health Organization (WHO) classification of diffuse brain tumors, WHO grade II, III, and IV. Special focus is set on surgical aspects such as resectability, extent of resection, and targeted surgical strategies including minimal invasive stereotactic biopsy procedures, convection enhanced delivery, and photodynamic therapy. Moreover, the influence of recent advances in radiomics/radiogenimics on the process of surgical decision-making will be touched. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to determine the relationship between the radiological and histopathological distribution of the cerebral lesions diagnosed with stereotactic biopsy (STB) procedure and its outcomes. Materials and Methods: In the current study, a retrospective analysis of 83 patients that underwent the STB in our clinic from January 2011 to December 2015 was made. T1-weighted contrast-enhanced cranial magnetic resonance imaging examinations were performed on patients on whom Leksell stereotactic frame system was installed. The histopathological and the radiological data derived from the STB procedure were classified. Results: In terms of localization, glial tumor (56.6%) was the most common lesion in all regions, except for the multifocal lesions. Contrary to the common knowledge, lymphoma (14.4%) was found to be the most common lesion among multifocal lesions. The success of obtaining positive STB samples in the current series was 95.2% and the complication rate was 3.6%. Conclusion: Had a routine computed tomography scan been performed on each patient in this series, the number of clinically insignificant small intracerebral hematomas would have probably been higher. Nevertheless, the rate of the STB sampling accuracy and the complication rate were similar to those reported in the relevant literature. [ABSTRACT FROM AUTHOR]

Abstract Background There is currently no clear consensus recommendation for the use of short-interval follow-up mammography after a benign-concordant breast biopsy (BCBB), and practice patterns vary widely. The objectives of this study were to evaluate whether a short-interval follow-up mammogram provided clinical utility after stereotactic BCBB and to examine the costs associated with this surveillance strategy. Methods A retrospective review of women who underwent a stereotactic breast biopsy yielding benign-concordant results between January 2005 and October 2014 was performed to evaluate findings on subsequent imaging, to calculate compliance with recommended short-interval imaging, and to examine whether subsequent imaging revealed an abnormality at the site of the initial stereotactic BCBB. A cost analysis was performed utilizing Medicare reimbursement rates to calculate projected and actual costs of short-interval follow-up imaging after stereotactic BCBB. Results Of the 470 stereotactic BCBB performed, a short-interval mammogram was completed in 207 (44.0%), 9 (4.3%) of which had suspicious mammographic findings at the initial biopsy site, and 6 subsequently underwent biopsy, with none resulting in malignant or high-risk pathology. The cost of short-interval mammographic follow-up (n = 207) was calculated at $28,541.16. Conclusions This study provides evidence that 6-month follow-up mammography has low clinical utility and unnecessarily increases costs after stereotactic BCBB. A safe and more cost-effective strategy may be resumption of routine mammography at 12 months post-biopsy. Highlights • Only 44% underwent planned mammogram six months after benign breast biopsy. • Short-interval mammogram follow-up identified a new lesion at the biopsy site in 4%. • Biopsy of new findings did not yield any malignant or high-risk lesions. • The significant cost of performing 6-month post-biopsy mammography was unnecessary. [ABSTRACT FROM AUTHOR]