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Purpose: This review aimed to summarize the available literature on the clinical application of [18F] FLT PET imaging in primary brain tumours. Methods: A comprehensive search strategy based on Pubmed/Medline, Scopus, Web of Science, Cochrane Library, Google Scholar, and the Embase databases was carried on using the following search string: ('3` Fluorothymidine'/exp OR 'FLT' OR '[18F]-FLT' OR '[18F] Fluorothymidine') AND ('pet'/exp OR 'pet' OR 'positron emission tomography') AND ('glioma'/exp OR 'glioma' OR 'brain tumour'/exp OR 'brain tumour’). The search was updated till March 2021 and only articles in English and studies investigating the clinical applications of [18F] FLT PET and PET/CT in primary brain tumours were considered eligible for inclusion. Results: The literature search ultimately yielded 52 studies included in the systematic review, with main results as follows: a) the uptake of [18F] FLT may guide stereotactic biopsy but does not discriminate between grade II and III glioma. b) [18F] FLT uptake and texture parameters correlate with overall survival (OS) in newly diagnosed gliomas. c) In patients with recurrent glioma, proliferative volume (PV) and tumour-to-normal brain (T/N) uptake ratio are independent predictors of survival. d) Patients demonstrating response to therapy at [18F] FLT PET scan show longer OS compared to non-responders. e) [18F] FLT PET demonstrated good performance in discriminating tumour recurrence from radionecrosis. However, controversial results exist in comparative literature examining the performance of [18F] FLT vs. other radiotracers in the assessment of recurrence. Conclusion: [18F] FLT PET imaging has demonstrated potential benefits for grading, diagnostic and prognostic purposes, despite the small sample size studies due to the relatively low availability of the radiotracer.

OBJECTIVE The literature shows discrepancies in stereotactic brain biopsy complication rates, severities, and outcomes. Little is known about the timeline of postbiopsy complications. This study aimed to analyze 1) complications following brain biopsies, using a graded severity scale, and 2) a timeline of complication occurrence. The secondary objectives were to determine factors associated with an increased risk of complications and to assess complication-related management and extra costs. METHODS The authors retrospectively examined 1500 consecutive stereotactic brain biopsies performed in adult patients at their tertiary medical center between April 2009 and April 2019. RESULTS Three hundred eighty-one biopsies (25.4%) were followed by a complication, including 88.2% of asymptomatic hemorrhages. Symptomatic complications involved 3.0% of the biopsies, and 0.8% of the biopsies were fatal. The severity grading scale had a 97.6% interobserver reproducibility. Twenty-three (51.1%) of the 45 symptomatic complications occurred within the 1st hour following the biopsy, while 75.6% occurred within the first 6 hours. Age ≥ 65 years, second biopsy procedures, gadolinium-enhanced lesions, glioblastomas, and lymphomas were predictors of biopsy-related complications. Brainstem biopsy-targeted lesions and cerebral toxoplasmosis were predictive of mortality. Asymptomatic hemorrhage was associated with delayed (> 6 hours) symptomatic complications. Symptomatic complications led to extended hospitalization in 86.7% of patients. The average extra cost for management of a patient with postbiopsy symptomatic complication was $35,702. CONCLUSIONS Symptomatic complications from brain biopsies are infrequent but associated with substantial adverse effects and cost implications for the healthcare system. The use of a severity grading scale, as the authors propose in this article, helps to classify complications according to the therapeutic consequences and the patient’s outcome. Because this study indicates that most complications occur within the first few hours following the biopsy, postbiopsy monitoring can be tailored accordingly. The authors therefore recommend systematic monitoring for 2 hours in the recovery unit and a CT scan 2 hours after the end of the biopsy procedure. In addition, they propose a modern algorithm for optimal postoperative management of patients undergoing stereotactic biopsy.

To identify the outcomes of stereotactic vacuum-assisted large bore biopsies performed on sonographically-occult non-calcified mammographic lesions (NCL).In an IRB-approved retrospective study, we reviewed all NCL that underwent stereotactic biopsy from January 1, 2014 to December 31, 2017 at our institution, comparing patient age, lesion type, size and location with pathology outcome (benign, high-risk or malignant) using Wilcoxon-Mann-Whitney or Fisher's exact tests as appropriate. Multivariable logistic regression models were developed to decrease benign biopsies in our cohort with diagnostic performance assessed using receiver operating characteristic curve and area under the curve (AUC).Of 222 biopsied lesions in 213 patients, 79.3% (176/222) were benign, 5.9% (13/222) malignant, and 14.9% (33/222) high-risk. NCL were less likely to be malignant compared to calcifications biopsied in the same period [5.9% vs 19.0% (243/1279), p 0.001]. All 42 asymmetries and 33 architectural distortions were benign, while 8.7% (4/46) of masses and 8.9% (9/101) of focal asymmetries were malignant. Cancers were associated with older age (mean 65.2 vs 52.7 years, p 0.001), smaller size (mean 9.5 mm vs 15.5 mm, p 0.01), and concurrent breast cancer (p 0.01) compared to benign/high-risk lesions. Multivariable logistic regression model using patient age50 years, lesion type, and size15 mm had a high diagnostic performance [AUC=0.89, 95%CI (0.83, 0.94)], and yielded the highest PPV [0.24; 95%CI (0.13, 0.38)], and highest number of avoided, unnecessary biopsies (172/209, 82%).NCL biopsied under stereotactic guidance have low cancer yield (5.9%). A multivariate model integrating age, lesion size and type could potentially help avoid unwarranted biopsies in our cohort.

This study was designed to present our experience and recommendations regarding the management of pediatric brainstem and peduncular low-grade gliomas (LGGs). Retrospective analysis was performed for pathologically proven brainstem or cerebellar peduncular LGGs in patients admitted between 2014 and 2019. These lesions were classified into the dorsal exophytic, focal brainstem, cervicomedullary, lower peduncular, and upper peduncular groups, and this classification was the basis for the surgical approach for the lesions. Sixty-two pediatric patients were included, and their distribution among the aforementioned groups were as follows: 12, 12, 3, 16, and 19 cases in the dorsal exophytic, focal brainstem, cervicomedullary, upper peduncular, and lower peduncular groups, respectively. Stereotactic biopsy was performed for all cases in the focal brainstem group, whereas other groups underwent open excision. Gross total resection (GTR) was achieved in 20 cases (40%), near-total resection (NTR) was achieved in 17 cases (34%), and subtotal resection (STR) was achieved in 13 cases (26%). The extent of GTR and NTR for the upper peduncular, lower peduncular, dorsal exophytic, and cervicomedullary groups were 81.2%, 68.4%,75%, and 66.6%, respectively. Then, 32 cases received chemotherapy. The 3- and 5-year progression-free survival rates were 95% (95% confidence interval (CI) 89.5–100%) and 90.3% (95% CI 79.9–100%), respectively. A significant difference in the 3-year progression-free survival rate was observed between the GTR and NTR groups (p = 0.06; 100% vs. 88.2% (95% CI 72.9–100%)). Surgery plays a definitive curative role in grossly resected cases. Additionally, the role of surgical debulking should be considered, even if GTR is impossible. Meanwhile, chemotherapy showed a beneficial role in patients with focal brainstem lesions and progressive lesions, those with STR, and some patients with NTR.

OBJECTIVEPrimary central nervous system lymphoma (PCNSL) is a rare CNS tumor with a poor prognosis. It is usually diagnosed by needle biopsy and treated mainly with high-dose chemotherapy. Resection is currently not considered a standard treatment option. A possible prolonged survival after resection of PCNSL lesions in selected patients has been suggested, but selection criteria for surgery, especially for solitary lesions, have never been established.METHODSThe authors retrospectively searched their patient database for records of adult patients (≥ 18 years) who were diagnosed and treated for a solitary PCNSL between 2005 and 2019. Patients were divided into groups according to whether they underwent resection or needle biopsy. Statistical analyses were performed in an attempt to identify variables affecting outcome and possible survival advantage and to characterize subgroups of patients who would benefit from resection of their tumor compared with undergoing biopsy only.RESULTSA total of 113 patients with a solitary lesion of PCNSL were identified; 36 patients underwent resection, and 77 had a diagnostic stereotactic biopsy only. The statically significant preoperative risk factors included age ≥ 70 years (adjusted HR 9.61, 95% CI 2.42–38.11; p = 0.001), deep-seated lesions (adjusted HR 3.33, 95% CI 1.13–9.84; p = 0.030), and occipital location (adjusted HR 4.26, 95% CI 1.08–16.78; p = 0.039). Having a postoperative Karnofsky Performance Scale (KPS) score < 80 (adjusted HR 3.21, 95% CI 1.05–9.77; p = 0.040) and surgical site infection (adjusted HR 4.27, 95% CI 1.18–15.47; p = 0.027) were significant postoperative risk factors after the adjustment and selection by means of other possible risk factors. In a subgroup analysis, patients younger than 70 years who underwent resection had a nonsignificant trend toward longer survival than those who underwent needle biopsy (median survival 35.0 months vs 15.2 months, p = 0.149). However, patients with a superficial tumor who underwent resection had significantly longer survival times than those who underwent needle biopsy (median survival 34.3 months vs 8.9 months, p = 0.014). Patients younger than 70 years who had a superficial tumor and underwent resection had significantly prolonged survival, with a median survival of 35.0 months compared with 8.9 months in patients from the same group who underwent needle biopsy (p = 0.007).CONCLUSIONSSpecific subgroups of patients with a solitary PCNSL lesion might gain a survival benefit from resection compared with undergoing only a diagnostic biopsy.

Objective This study assessed the short-term and the long-term breast cancer rate in patients with benign histopathologic results after a vacuum-assisted stereotactic biopsy (VASB) for calcifications. Methods In a retrospective cohort study, all consecutive patients who had a benign diagnosis after VASB to analyze breast calcifications. Data of breast cancer development at short-term (four years) and long-term follow-up was gathered. Breast cancer rates in our cohort were compared to the breast cancer incidence in the general population. Results Of 1376 patients who underwent VASB to analyze breast calcifications, 823 had a benign histopathologic diagnosis. During short-term follow-up, eight patients developed breast cancer. During the mean long-term follow-up period of 9.3 ± 3.1 years, 22 patients were diagnosed with ipsilateral breast cancer. The incidence rate of breast cancer after benign biopsy was comparable to the rate in the general population. Conclusion In patients with VASB-confirmed benign calcifications of the breast, we found no excess incidence of ipsilateral breast cancer during ten years follow-up. Therefore, in patients with an increased risk of breast cancer (due to a history of breast cancer or familial risk) annual mammography should be sufficient. Patients with a population-based risk may be monitored via biennial mammography by the national screening program. More frequent screening would provide no benefit., Highlights • 1% developed ipsilateral breast cancer in four-year follow-up after biopsy. • 3% developed ipsilateral breast cancer in ten-years follow-up after biopsy. • No statistically significant excess incidence of breast cancer after benign calcifications. • A benign histopathologic result after VASB can be considered a safe decision tool.

The current standard of diagnosing central nervous system (CNS) lymphoma is stereotactic biopsy, however the procedure has a risk of surgical complication. Liquid biopsy of the CSF is a less invasive, non‐surgical method that can be used for diagnosing CNS lymphoma. In this study, we established a clinically applicable protocol for determining mutations in MYD88 in the CSF of patients with CNS lymphoma. CSF was collected prior to the start of chemotherapy from 42 patients with CNS lymphoma and matched tumor specimens. Mutations in MYD88 in 33 tumor samples were identified using pyrosequencing. Using 10 ng each of cellular DNA and cell‐free DNA (cfDNA) extracted from the CSF, the MYD88 L265P mutation was detected using digital PCR. The conditions to judge mutation were rigorously determined. The median Target/Total value of cases with MYD88 mutations in the tumors was 5.1% in cellular DNA and 22.0% in cfDNA. The criteria to judge mutation were then determined, with a Target/Total value of 0.25% as the cutoff. When MYD88 mutations were determined based on these criteria, the sensitivity and specificity were 92.2% and 100%, respectively, with cellular DNA; and the sensitivity and specificity were 100% with cfDNA. Therefore, the DNA yield, mutated allele fraction, and accuracy were significantly higher in cfDNA compared with that in cellular DNA. Taken together, this study highlights the importance of detecting the MYD88 L265P mutation in cfDNA of the CSF for diagnosing CNS lymphoma using digital PCR, a highly accurate and clinically applicable method., Development of a liquid biopsy for less invasive diagnosis of CNS lymphoma is in progress. In this study, the conditions for detecting the MYD88 L265P mutation by digital PCR were set, and extremely high accuracy was confirmed. This method is fully clinically feasible.

Background The brainstem has the critical role of regulating cardiac and respiratory function and it also provides motor and sensory function to the face via the cranial nerves. Despite the observation of a brainstem lesion in a radiological examination, it is difficult to obtain tissues for a pathological diagnosis because of the location and small volume of the brainstem. Thus, we aimed to share our 6‐year experience with stereotactic biopsies from brainstem lesions and confirm the value and safety of stereotactic biopsy on this highly eloquent area in this study. Methods We retrospectively reviewed the medical records of 42 adult patients who underwent stereotactic biopsy on brainstem lesions from 2015 to 2020. The radiological findings, surgical records, pathological diagnosis, and postoperative complications of all patients were analyzed. Results Histopathological diagnoses were made in 40 (95.2%) patients. Astrocytic tumors were diagnosed in 29 (69.0%) patients, diffuse large B cell lymphoma in 5 (11.9%) patients, demyelinating disease in 4 (9.5%) patients, germinoma in 1 (2.4%) patient, and radiation necrosis in 1 (2.4%) patient. In the 40 patients with successful stereotactic biopsy, 10 (25.0%) patients had inconsistent preoperative radiological diagnosis and postoperative pathological diagnosis. In addition, there was a difference between the treatments prescribed by the radiological and pathological diagnoses in 8 out of 10 patients whose diagnoses changed after biopsy. There was no operative mortality among the 42 patients. Conclusions A pathological diagnosis can be made safely and efficiently in brainstem lesions using stereotactic biopsy. This pathological diagnosis will enable patients to receive appropriate treatment., Three approaches to stereotactic biopsy for brainstem and a Venn diagram showing the location of 42 brainstem lesion that performed stereotactic biopsy.

Primary central nervous system lymphoma (PCNSL) most commonly (>95%) constitutes a specific kind of diffuse large B-cell lymphoma, which shows expression of CD20, CD19 and CD79a antigens on its surface and belongs to non-germinal center B-cell-like type (non-GCB). This results from both its limited localization as well as immunophenotypic and molecular features. It frequently has an aggressive clinical course and its prognosis remains highly uncertain. PCNSL’s development in areas normally free from lymphoid tissue has not been adequately explained thus far. PCNSL is usually a solitary lesion (60–70%), with the majority (c.60%) occurring in supratentorial areas, and less frequently in telencephalic nuclei and periventricular areas, corpus callosum, infratentorial structures, spinal cord or orbital cavities. Lymphoid cells can occasionally create diffuse infiltration with no mass effect — a PCNSL variant known as lymphomatosis cerebri. Reported clinical symptoms depend on the localization of the tumor in central nervous system. The most common include: cognitive impairment, behavioral changes, focal neurological deficit and symptoms of increased intracranial pressure. A final diagnosis of PCNSL requires histopathological evaluation of tissue samples obtained usually during a stereotactic biopsy. Identifying lymphoid cells in cerebrospinal fluid may also be sufficient. Chemotherapy combined with radiotherapy is the standard treatment of PCNSL. For many years, surgical treatment has been controversial. This provides constant encouragement to explore effective treatment methods, with neurosurgical involvement waiting to be further defined.

BACKGROUND Insular diffuse glioma resection is at risk of vascular injury and of postoperative new neurocognitive deficits. OBJECTIVE To assess safety and efficacy of surgical management of insular diffuse gliomas. METHODS Observational, retrospective, single-institution cohort analysis (2005-2019) of 149 adult patients surgically treated for an insular diffuse glioma: transcortical awake resection with intraoperative functional mapping (awake resection subgroup, n = 61), transcortical asleep resection without functional mapping (asleep resection subgroup, n = 50), and stereotactic biopsy (biopsy subgroup, n = 38). All cases were histopathologically assessed according to the 2016 World Health Organization classification and cIMPACT-NOW update 3. RESULTS Following awake resection, 3/61 patients had permanent motor deficit, seizure control rates improved (89% vs 69% preoperatively, P = .034), and neurocognitive performance improved from 5% to 24% in tested domains, despite adjuvant oncological treatments. Resection rates were higher in the awake resection subgroup (median 94%) than in the asleep resection subgroup (median 46%; P

Objectives To describe the case of a 12-year-old girl with a rare plurihormonal pituitary macroadenoma secreting prolactin (PRL), growth hormone (GH), thyroid-stimulating hormone (TSH), and alpha subunit (α-SU). Case presentation The patient experienced recurrent headaches and progressing loss of vision in one eye. During the examination, abnormalities such as tall stature, coarse facial features, enlarged feet and hands, tachycardia, hand tremor, hyperhidrosis, galactorrhea, and goiter were observed. Head magnetic resonance imaging (MRI) revealed a solid tumor in the anterior and middle cranial fossa, measuring 80 × 50 × 55 mm. A stereotactic biopsy revealed plurihormonal Pit-1 positive pituitary adenoma secreting PRL, GH, and TSH. A pituitary hyperfunction with PRL, GH, TSH, and α-SU excess was diagnosed. The patient was successfully treated pharmacologically with dopamine agonists and somatostatin analogue, and a decrease of tumor volume (30%) was achieved. Conclusions When neurosurgery is not possible, long-term pharmacological treatment of plurihormonal pituitary macroadenoma can be a safe and relatively effective alternative.

Objective Proton magnetic resonance spectroscopy (1H—MRS) can benefit the differentiation of gliomas preoperative grading and facilitate guiding biopsy. This study was to investigate the optimal metabolite or metabolic ratios of MRS for the biopsy target delineating by using the technique of MRS imaging guided frame-less stereotactic biopsy. Methods During a 4 year period between the Sep 2012 and Oct 2016, 57 patients (25 women, 32 men; mean age, 46.4) with histologic diagnosis of glioma, who underwent the 1H—MRS imaging guided frameless stereotactic biopsy, were retrospectively reviewed. The metabolite or metabolic ratios values of MRS was measured. And the sensitivity, specificity, accuracy as well as the area under the curve (AUC) of those parameters for glioma grading are calculated based on the receiver operating characteristic curve (ROC) analysis. Results 65 stereotactic biopsy samples from 57 patients were histopathologically clarified to HGGs (25) or LGGs (40) for quantitative analysis. The Cho, Cho/NAA and Cho/Cr values of LGGs group were significantly lower than that of HGGs (P = 0.09, 0.001, 0.003), and the NAA value of LGGs group was significantly higher than that of HGGs (P = 0.001). The cutoff value of 3.65 for the Cho/NAA ratio provided the best combination of sensitivity (92.0%), specificity (95.0%), and diagnostic accuracy (93.8%) for identifying glioma grade, which was superior to other parameters. Conclusion The results of our study provided evidence that Cho/NAA ratio had the superior diagnostic performance in distinguishing glioma grade, indicating that the spot of highest Cho/NAA ratio was optimal metabolic targets for spectroscopic guided tissue sampling in homogenous glioma.

OBJECTIVES We reviewed our institutional experience during a 10-year period for improvement of safety and efficacy of stereotactic biopsy procedures. METHODS We performed a retrospective review of inpatient summaries, stereotactic worksheets and radiologic investigations of 208 consecutive patients, who underwent MRI-guided stereotactic biopsies between March 2010 and March 2020. RESULTS The overall diagnostic yield was 96.2%. CT-confirmed intracranial hemorrhage occurred in 17 patients (8.2%), and the overall mortality rate was 0.5%. Combined MRS and PWI helped target selection in 27 cases (13.0%), the diagnostic yield was 100%. The results of the regression analysis revealed that non-diagnostic biopsy specimen significantly correlated with the cystic trait (p

Background In the treatment for glioblastoma (GBM), treatment modalities, such as bevacizumab (BEV) and carmustine wafers implants have been approved in Japan since 2013. However, it is unclear whether such a trend in treatment complexity can accelerate treatment centralization. The aim of this study was to reveal the current trend in the treatment of GBM in Japan. Methods We used diagnostic procedure combination (DPC) database to analyze the data of 1,774 patients from 305 institutions between April 2016 and March 2019. To analyze the situations associated with first-line BEV use during concurrent TMZ (temozolomide)-radiotherapy, we compared TMZ alone and TMZ–BEV groups. Results Of the 1,774 patients with GBM, tumor removal by craniotomy was performed in 1,572 (88.6%) patients, and stereotactic biopsy was performed in 156 (8.8%) patients. A total of 1,229 (69.3%) patients underwent radiotherapy, and 1,287 (72.5%) patients underwent chemotherapy. TMZ alone was administered to 878 (68.2%) and TMZ combined with BEV in 381 (29.6%) patients. In the TMZ–BEV group, as compared to the TMZ-alone group, the rate of discharge to home was significantly lower (P = 0.0044), and the rate of stereotactic biopsy was significantly higher (P P = 0.1240). Conclusion First-line BEV administration seems to be selected properly regardless of the institutional scale. This Japan-wide study of GBM treatment revealed that high level and newly introduced treatments have been steadily generalized in Japanese institutions.

Patients with glioblastoma (GBM) need bold new approaches to their treatment, yet progress has been hindered by a relative inability to dynamically track treatment response, mechanisms of resistance, evolution of targetable mutations, and changes in mutational burden. We are writing on behalf of a multidisciplinary group of academic neuro-oncology professionals who met at the collaborative Christopher Davidson Forum at Washington University in St Louis in the fall of 2019. We propose a dramatic but necessary change to the routine management of patients with GBM to advance the field: to routinely biopsy recurrent GBM at the time of presumed recurrence. Data derived from these samples will identify true recurrence vs treatment effect, avoid treatments with little chance of success, enable clinical trial access, and aid in the scientific advancement of our understanding of GBM.

Introduction: Stereotactic biopsy of brain stem lesions in children evolved from a controversial background but the current trend seems towards a safe procedure that will yield diagnostic accuracy to guide targeted and individualized treatments. Aims and Objectives: To confirm safety, accuracy and usefulness of biopsy of brain stem lesions using our institutional experience on two index cases that underwent stereotactic procedures. Methodology: A review of two case reports were conducted to expose diagnostic success and procedure-related highpoints. Results: In both cases presented the procedure was uneventful, yielded the desired diagnostic tissue and there were no procedure related complications. Conclusion: Stereotactic biopsy of pediatric brain stem lesion is safe. Tissue sampling was accurate in both cases and served as a prerequisite more targeted oncology referral and potentially individualized treatment.

Purpose To analyze the rate of potentially avoidable needle biopsies in mammographically suspicious calcifications if supplementary Contrast-Enhanced MRI (CE-MRI) is negative. Methods Using predefined criteria, a systematic review was performed. Studies investigating the use of supplemental CE-MRI in the setting of mammographically suspicious calcifications undergoing stereotactic biopsy and published between 2000 and 2020 were eligible. Two reviewers extracted study characteristics and true positives (TP), false positives, true negatives and false negatives (FN). Specificity, in this setting equaling the number of avoidable biopsies and FN rates were calculated. The maximum pre-test probability at which post-test probabilities of a negative CE-MRI met with BI-RADS benchmarks was determined by a Fagan nomogram. Random-effects models, I2-statistics, Deek’s funnel plot testing and meta-regression were employed. P-values, Highlights • A negative breast MRI can downgrade up to 80.6% of suspicious microcalcifications, potentially avoiding vacuum-assisted breast biopsies. • Up to a pretest probability of 22% , a negative breast MRI result would not exceed the 2% cancer rate required for a BI-RADS 3 category assignment.

Frameless stereotactic navigation is used to direct the trajectory and biopsy site of target lesions. We report on a novel intra-operative stimulating (IOS) probe that is integrated into a commercially available stereotactic biopsy needle with the rationale that stimulation of the intended biopsy site should predict functional tissue thus preventing inadvertent biopsy of eloquent tissue. Patients undergoing brainstem biopsies for atypical lesions were offered the additional stimulation procedure. The IOS probe was used to deliver stimulation in an attempt to determine the proximity of eloquent tissue. Once the desired location of the biopsy needle was achieved, the IOS probe was inserted down the centre of the biopsy needle and the stimulus applied. If no action potential was recorded, biopsies from four quadrants of the lesion were taken. If however a compound action potential was recorded, a new target was selected. Nine patients had the biopsy and stimulation procedure performed. The median age was 36 months. A minimum of 8 samples were obtained from each patient. Biopsy material was adequate to obtain a diagnosis in all 9 patients. In 2 cases use of the device influenced the insertion trajectory or biopsy site. No patients experienced any complications directly attributable to either the biopsy procedure or application of the stimulation. Use of the IOS probe for intra-operative stimulation of the intended brainstem biopsy site was found to be safe and feasible. The addition of stimulation using the IOS probe can be done with minimal change in workflow.

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal non‑Hodgkin lymphoma that is unique and different from systemic diffuse large B‑cell lymphomas. The median age at diagnosis of PCNSL is 65 years and its incidence is rising rapidly in the elderly population. A total of ≥20% of all patients with PCNSL are ≥80 years old. Notably, age has been identified as an independent poor prognostic factor for PCNSL. Elderly patients have an inferior prognosis to that of younger patients and are more severely affected by iatrogenic toxicity; therefore, elderly patients represent a unique and vulnerable treatment subgroup. The present review summarized the available literature to provide an improved understanding of the epidemiology, clinical characteristics, diagnosis, prognosis and management of PCNSL in the elderly population. Notably, the incidence of PCNSL in immunocompetent elderly patients, predominantly in men, is increasing. For the diagnosis of CNSL, imaging‑guided stereotactic biopsy is considered the gold standard. When stereotactic biopsy is not possible or conclusive, certain biomarkers have been described that can help establish a diagnosis. PCNSL has a very poor prognosis in the elderly, even though several prognostic scoring systems exist and several prognostic markers have been reported in patients with PCNSL. Furthermore, the treatment of elderly patients remains challenging; it is unlikely that a novel agent could be used as a curative monotherapy; however, a combination of novel agents with polychemotherapy or its combination with other novel drugs may have therapeutic potential.

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. 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. 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. 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.

We aimed to evaluate the concordance between the image-based and the tissue-based diagnosis using frame-based stereotactic biopsy.Medical records of biopsy procedures from 2000 to 2017 were reviewed. The radiologists' preoperative reports, biopsy procedures and postoperative histopathological diagnoses were retrieved. We compared the preoperative image-based diagnosis with the final histopathological diagnosis.We identified 125 biopsy procedures performed in 123 patients. The concordance between image-based and histopathological diagnoses varied between 53.3% and 87.5%. The concordance of diagnosis concerning both tumor entity (i.e. cell type) and WHO grade was 54.6%. The diagnostic yield was 95.2%. There was overall morbidity of 10.4%, and a mortality rate of 0.8%. Minor complications occurred in 4.0% of the cases, while clinically significant complications occurred in 6.4% of the cases.There was suboptimal concordance between radiological and histopathological diagnosis. Also, there was a tendency of histopathological undergrading. We confirm that frame-based stereotactic biopsies have a high diagnostic yield and a low rate of clinically significant complications and mortality.

Introduction: The posterior fossa is the most common intracranial location for pediatric ependymoma. While ependymoma usually arises from the ventricular lining of the fourth ventricle as a solid mass, it rarely originates from the brainstem. Grade II ependymomas also infrequently appear as a cavitary ring-enhancing lesion. Case Presentation: We describe a case of a 6-year-old boy with an ependymoma arising within the medulla with imaging features of a thick-walled rim-enhancing cavitary lesion. A stereotactic biopsy was obtained which confirmed a grade II ependymoma. The patient received focal proton beam radiation therapy and is doing well with no concerns for disease progression at 28 months after diagnosis. Conclusion: Posterior fossa ependymomas typically arise from ependymal cells within the fourth ventricle or foramina of Luschka. They rarely invade or arise within the brainstem parenchyma. Our case had atypical imaging findings in addition to the atypical tumor location. The lesion was described as a thick-walled rim-enhancing focal cystic necrotic lesion centered within the medulla with surrounding nonenhancing expansile infiltrative changes. Ring-enhancing lesions can be seen in patients with anaplastic ependymoma, but is not commonly reported in grade II ependymomas. In summary, this report highlights a unique case of a posterior fossa ependymoma in a pediatric patient arising in an atypical brainstem location as well as having unique imaging features.

Introduction: Malignant gliomas refer to grade III or IV brain tumors defined according to the World Health Organization (WHO) classification. They are a heterogeneous group of pathologies and represent a serious health problem by their frequency, severity and treatment difficulties. The prognosis of malignant gliomas remains poor despite all the medical advances. Materials and Methods: It is a retrospective study included 20 cases of malignant glial tumors treated at the medical oncology department, Fattouma Bourguiba hospital in Monastir between 2012 and 2016, according to the STUPP protocol. Results: These were 12 men and 8 women with a median age of 43. Clinical signs were not very specific, dominated by intracranial hypertension and deficit signs. Imagery referred to the diagnosis of malignant gliomas in 1st intention. Surgery consisted of a macroscopically complete exeresis in (15%) cases, a partial exeresis in (50%), the rest of the patients had a stereotactic biopsy. Histology found GBM in 16 patients (80%), 2 cases of Grade III anaplastic astrocytoma (10%), 1 case of anaplastic oligodendroglioma (5%), and 1 case of Grade III anaplastic eppendymoma (5%). Most of our patients received concurrent radio-chemotherapy and adjuvant TMZ chemotherapy was administered in 15 patients, 7 of whom received the full 6 scheduled cures. A relapse treatment was decided in only one of the 12 patients who relapsed. 6 patients are still alive. The median survival is 11.27 months. In our series, overall survival was related to histological type (p = 0.006) and neurological status assessed at the end of RT-CT (p = 0.001). While age, general condition score, type of surgery, and post-therapeutic development did not show a statistically significant relationship, although survival rates were consistent with the criteria assessed. Conclusion: Malignant gliomas are rare tumors, bad prognosis, aggravated in Tunisia by a diagnostic delay. The creation of a multidisciplinary neuro-oncology group can help to improve management.

The diffuse midline glioma, H3K27M-mutant subtype, occurs mainly in children as a result of mutations in the histone H3 (H3F3A) and HIST1H3B (K27M) genes and is characterized by diffuse tumor growth in central nervous system (CNS) midline structures. Due to its nonspecific clinical manifestations, viral encephalitis is often confused with other central nervous system diseases. In this case, we reported a young male patient who was admitted to the hospital chiefly complaining of “diplopia for more than two months and aggravated walking instability for more than 10 days”. After admission, relevant patient blood and cerebrospinal fluid (CSF) tests were completed, and no obvious abnormalities were found. Chest CT suggested pulmonary infection; magnetic resonance imaging (MRI) and contrast-enhanced CT, PET-CT and other imaging examinations of the head all indicated a high possibility of viral encephalitis. Symptoms of fever were improved in the patient after treatment with antiviral therapy and anti-infection therapy. However, symptoms of neurological function loss, such as double vision and adverse right limb movement, persisted. Finally, stereotactic biopsies of deep brain lesions were carried out and sent to the pathology department, which led to a diagnosis of diffuse midline glioma, H3K27M-mutant subtype (WHO IV). His family chose to perform conservative treatment in another hospital, and the patient died four months later. To conclude, when clinical symptoms of suspected viral encephalitis appear in the course of diffuse midline glioma, it can result in confusion regarding clinical diagnosis and treatment. Clinicians should ensure proper early recognition and identification of the disease.

Background The gram-negative aerobic bacterium Moraxella osloensis is an opportunistic pathogen in brain tissues. Case summary The gram-negative aerobic bacterium Moraxella osloensis was isolated from a patient's brain tissue during a stereotactic biopsy. Conclusion This is the first report of a brain tissue infection with Moraxella osloensis possibly causing brain gliomatosis.

BACKGROUND: Accurate identification and discrimination of post treatment changes from recurrent disease remains a challenge for patients with intracranial malignancies despite advances in molecular and magnetic resonance imaging. We have explored the ability of readily available Rubidium-82 chloride ((82)RbCl) positron emission tomography (PET) to identify and distinguish progressive intracranial disease from radiation necrosis in patients previously treated with radiation therapy. METHODS: Six patients with a total of 9 lesions of either primary (N.=3) or metastatic (N.=6) intracranial malignancies previously treated with stereotactic radiation surgery (SRS) and persistent contrast enhancement on MRI underwent brain (82)RbCl PET imaging. Two patients with arteriovenous malformations previously treated with SRS, also had brain (82)RbCl PET imaging for a total of 11 lesions studied. Histological confirmation via stereotactic biopsy/excisional resection was obtained for 9 lesions with the remaining 2 classified as either recurrent tumor or radiation necrosis based on subsequent MRI examinations. (82)RbCl PET time activity curve analysis was performed which comprised lesion SUV(max), contralateral normal brain SUV(max), and tumor to background ratios (TB(max)). RESULTS: (82)RbCl demonstrates uptake greater than normal brain parenchyma in all lesions studied. Time activity curves demonstrated progressive uptake of (82)RbCl in all lesions without evidence of washout. While recurrent disease demonstrated a greater mean SUV(max) compared to radiation necrosis, no statistically significant difference between lesion SUV(max) nor TB(max) was found (P>0.05). CONCLUSIONS: (82)RbCl PET produces high-contrast uptake of both recurrent disease and radiation necrosis compared to normal brain. However, no statistically significant difference was found between recurrent tumor and radiation necrosis.

Neuroparacoccidiodimycosis (NPDM) is an uncommon granulomatous disease, which more frequently affects immunocompromised male patients over 30 years of age in the course of chronic lung disease. Paracoccidioides brasiliensis (PB) is an endemic fungus in Brazil, and grows as thick-walled yeast (with round to oval bodies) measuring 10 µm to 60 µm in diameter. Neuroparacoccidiodimycosi may develop many years after transmission and/or primary lung involvement. The authors describe a case of NPDM affecting a male patient, 52 years of age, farmer, heavy smoker, with clinical complaint of headache, asthenia, seizures, and prostration in the previous nine months. Upon physical examination, the patient presented regular general condition, without other relevant physical alterations. Computed tomography (CT) showed multiple bilateral pulmonary nodules associated to enlargement of the mediastinal lymph node. Magnetic resonance imaging (MRI) and CT scans of the central nervous system showed six heterogeneous nodular lesions compromising the frontal and parietal lobes, the largest one measuring 3.8 × 3.2 × 3.2 cm. The hypothesis of a neoplastic process compromising the lung and brain was considered. A biopsy of the mediastinal lymph node showed epithelioid granulomas, which exhibited round, thin-walled fungal structures in Grocott silver stain. The stereotactic biopsy of the frontal lesion was constituted by necrotic tissue admixed with some round to oval, thin-walled fungi measuring 10 µm to 60 µm, compatible with PB (identified on Grocott silver stain/confirmed in culture). The diagnosis of NPDM was then established. The employed therapeutic regimen was intravenous amphotericin B, itraconazole, and sulfamethoxazole-trimetropin. After ninety days of clinical follow-up, no episodes of seizures/neurological deficits were identified, and a marked decrease in the number and size of the lung and brain lesions were found.

Background: Stereotactic neurosurgery involves mapping the brain in a three-dimensional coordinate system. With the help of MRI and CT scans and 3D computer workstations, neurosurgeons are able to accurately target any area of the brain especially deep seated and brain stem. Objectives: Stereotactic brain biopsy is a minimally invasive procedure that uses this technology to obtain samples of brain tissue for diagnostic purpose of multiple brain disorder where start to any medication was impossible or no response to any medical management for long term. Materials and Methods: Twenty-five patients underwent stereotactic biopsy of brain lesions using“KOMAI” Stereotactic frame system and were enrolled. Results: Of the 25 cases, positive tissue biopsy was found in 20 cases. In 5 patients, biopsy showed gliotic brain tissue or normal brain tissue. There was no post-operative new deficits or mortality seen. Conclusion: Stereotaxy is minimally invasive procedure having no complication. So, before starting any medication blindly stereotactic tissue diagnosis can help a lot in many medical and surgical diseases. J Bangladesh Coll Phys Surg 2021; 39(1): 24-35

Background Frameless stereotactic biopsy represents a minimally invasive procedure used for the histopathological diagnosis of brain tumors or to safely approach deep-seated lesions near eloquent areas not amenable for classical neurosurgical procedures. Traditionally, biopsy is performed relying on anatomical landmarks, but it can lead itself to intra- and postoperative complications, such as hemorrhage and fiber disruption. Diffusion tensor imaging (DTI) tractography represents a useful tool that can analyze the individual fiber tract conformation in cases of brain tumor and consequently identify the best biopsy trajectory, preserving white matter pathways. In our study, we present a novel technique that is based on the use of preoperative DTI for biopsy. Methods Between January 2018 and January 2020, data about patients who underwent frameless biopsy using DTI tractography were retrospectively reviewed. The inclusion criterion was adult patients eligible for elective surgery for a single or multiple deep-seated lesions with contraindications to complete surgical resection. Results We included 12 patients (mean age of 67.9 [±9.6] years). A single cranial lesion was detected in 7 cases, and multiple lesions in 5 cases. The use of DTI enabled the identification of white matter pathways in all cases and adjustment of the biopsy trajectory based on anatomical landmarks in 7 cases. Postoperative hematoma was reported in 1 case, and histological diagnosis was obtained in 11 cases. Conclusion According to our results, tractography is a useful tool that can enhance the safety of cerebral lesions biopsy sparing any fiber tract damages.

Aim: Although screening mammography has a high sensitivity in the clinical detection of nonpalpable breast cancer, most mammographically suspicious lesions referred to biopsy are seen to be benign. The rate of malignancy in such lesions that are biopsied with needle–wire localization ranges from 10 to 36%. In this study, we aimed to compare with the literature the pathological results and Breast Imaging Reporting and Data System (BI-RADS) scores of lesions subjected to mammography and excisional biopsy after ultrasonography-guided needle–wire localization and calculate a positive predictive value for each category.Materials and Methods: By electronically reviewing patient files and using the International Statistical Classification of Diseases and Related Health Problems (ICD-10) codes, we identified patients who underwent excisional biopsy after stereotactic marking at the General Surgery Clinic of the Istanbul Sisli Hamidiye Etfal Training and Research Hospital between January 2003 and March 2009. A total of 64 patients were included in the study, of whom 43 had benign and 21 had malignant lesions on postoperative histopathological examination. Data on patient demographic characteristics, indications for marking, and histopathological diagnoses were recorded. The patient BI-RADS scores were determined based on the mammography and breast ultrasonography reports. The BI-RADS classification and histopathological examination results were compared in percentages. Results: The mean patient age was 48.9 (32–76) years. Based on the mammography reports, the most common indications for stereotactic marking and excisional biopsy were microcalcification cluster and spiculated mass. Histopathological examination results revealed malignancy in 8%, 51%, and 100% of the patients whose BI-RADS scores were mammographically determined to be BI-RADS 3, BI-RADS 4, and BI-RADS 5, respectively. Discussion and Conclusion: The BI-RADS-based classification of lesions detected by mammography and ultrasonography can help in predicting malignancy. While BI-RADS 4 and BI-RADS 5 lesions are referred to biopsy primarily, short-term follow-up of BI-RADS 3 lesions as an alternative to biopsy could reduce unnecessary biopsies., Amaç: Tarama mamografisi nonpalpabl meme kanserinin klinik tespitinde yüksek sensitivite göstermekle birlikte, mamografide saptanan ve biyopsi önerilen şüpheli lezyonların çoğunun benign olduğu görülmektedir. Tel lokalizasyonu ile biyopsi yapılan bu lezyonlarda malignite oranı %10–36 aralığında değişmektedir. Bu çalışmada mamografi ve ultrasonografi eşliğinde tel lokalizasyonu sonrasında eksizyonel biyopsi yapılan lezyonların patolojik sonuçlarının ve Meme Görüntüleme Raporlama ve Veri Sistemi (the Breast Imaging Reporting and Data System—BI-RADS) skorlarının literatür ile karşılaştırılması ve her kategori için pozitif öngörü değerinin hesaplanması amaçlanmıştır.Gereç ve Yöntemler: Elektronik ortamda hasta dosyaları incelenerek ve Hastalıkların ve İlgili Sağlık Sorunlarının Uluslararası İstatistiksel Sınıflaması (ICD-10) kodları kullanılarak, Ocak 2003—Mart 2009 döneminde Şişli Hamidiye Etfal Eğitim ve Araştırma Hastanesi Genel Cerrahi Kliniği’nde stereotaktik işaretleme sonrasında eksizyonel biyopsi yapılan hastalar belirlendi. Toplamda (postoperatif histopatolojik inceleme sonucuna göre 43’ü benign, 21’i malign lezyonlu) 64 hasta çalışmaya dahil edildi. Hastaların demografik özelliklerine, işaretleme nedenlerine ve histopatolojik tanılara dair veriler kaydedildi. Mamografi ve meme ultrasonografi raporları incelenerek hastaların BI-RADS skorları belirlendi. BI-RADS sınıflaması ve histopatolojik inceleme sonuçları yüzde (%) üzerinden karşılaştırıldı. Bulgular: Ortalama hasta yaşı 48,9 (32–76) yıldı. Mamografi raporlarına göre, stereotaktik işaretleme ve eksizyonel biyopsi için en sık neden mikrokalsifikasyon kümesi ve spiküler kitle idi. Histopatolojik inceleme sonuçlarına göre, BI-RADS skoru mamografide BI-RADS 3, BI-RADS 4 ve BI-RADS 5 olarak tespit edilen hastaların sırasıyla %8’inde, %51,8’inde ve %100’ünde malignite saptandı.Tartışma ve Sonuç: Mamografi ve ultrasonografide saptanan lezyonların BI-RADS temelinde sınıflandırılması malignitenin öngörülmesine yardımcı olabilir. BI-RADS 4 ve BI-RADS 5 lezyonlarda ilk planda biyopsi yapılırken, BI-RADS 3 lezyonlarda biyopsiye alternatif olarak kısa dönem takip yapılması gereksiz biyopsileri azaltabilir.

We describe a patient who had primary glioblastoma (GB) and malignant melanoma (MM). A 78-year-old man presented with several weeks to months of history of gait disturbance, confusion, memory disturbance, and worsening speech. Imaging studies performed on admission revealed a large frontotemporal lobe mass associated with the surrounding zone of vasogenic edema. Given the patient's medical history of incomplete biopsy of a midback tumor performed three weeks before, the presumptive clinical diagnosis was metastatic MM. Pathological examination of frozen sections of fragmented specimens obtained at stereotactic biopsy performed on admission revealed a high-grade malignant neoplasm characterized by discohesive cells in a blue myxoid background and abundant foci of tumor necrosis. Given these features, in conjunction with the abovementioned pathological report, the frozen section diagnosis by the neuropathologist was "neoplasm identified, favor melanoma." Due to the paucity of lesional tissue, a limited immunohistochemistry performed on the permanent sections revealed positive staining of lesional cells for Sox10 alone using a multiplex MART1/Sox10 immunostain and S-100 protein, an immunohistochemical profile supporting the presumptive frozen section diagnosis. A tumor debulk procedure, performed two weeks later, revealed histopathologic features most compatible with GB, IDH wild-type. Thus, additional immunohistochemistry on the permanent sections revealed positive staining of glial fibrillary acidic protein (GFAP), Sox10, and S-100 protein as well as negative staining of gp100, a complex carbohydrate matrix protein in embryonic melanosomes, using a specific antibody HMB45. The concomitant occurrence of MM and GB in our patient underscores the association between these two entities. Our literature review suggests that the sporadic co-occurrence of these two conditions is likely not serendipitous.

Background Open and stereotactic transfrontal or transcerebellar approaches have been used to biopsy brainstem lesions. Method In this report, a stereotactic posterior and midline approach to the distal medulla oblongata under microscopic view is described. The potential advantages and limitations are discussed, especially bilateral damage of the X nerve nuclei. Conclusion This approach should be considered for biopsy of distal and posterior lesions. We strongly recommend the use of direct microscopic view to identify the medullary vessels, confirm the midline entry point, and avoid potential shift of the medulla. Further experience is needed to confirm safety and success rate of this approach.

Background The early diagnosis of basal ganglia and thalamus germinomas is often difficult due to the absence of elevated tumor markers, and atypical clinical symptoms and neuroimaging features. Case summary Four male children aged 8 to 15 years were diagnosed with germinomas in the basal ganglia and thalamus by stereotactic biopsy from 2017 to 2019. All patients developed hemiplegia except patient 4 who also had cognitive decline, speech disturbance, nocturnal enuresis, polydipsia, polyuria, precocious puberty and abnormalities of thermoregulation. All four cases were alpha-fetoprotein and beta-human chorionic gonadotrophin (β-HCG) negative except patient 3 who had slightly elevated β-HCG in cerebrospinal fluid (CSF). No malignant cells were detected in the patients' CSF. Brain magnetic resonance imaging findings were diverse in these patients with the exception of the unique and common characteristics of ipsilateral hemisphere atrophy, especially in the cerebral peduncle. All patients were diagnosed with germinomas of the basal ganglia and thalamus by stereotactic brain biopsy. Conclusion Stereotactic brain biopsy is necessary to confirm the diagnosis of ectopic germinomas. Serial neuroimaging studies can not only differentiate disease but also determine the biopsy site.

Radiation necrosis (RN) occurs in 5% to 25% of patients with brain metastases treated with stereotactic radiosurgery. RN must be distinguished from recurrent tumor to determine appropriate treatment. Stereotactic biopsy remains the gold standard for identifying RN. Initial treatment of RN often involves management of edema using corticosteroids, antiangiogenic therapies, and hyperbaric oxygen therapy. For refractory symptoms, surgical resection can be considered. Minimally invasive stereotactic laser ablation has the benefit of providing tissue diagnosis and treating RN or recurrent tumor with similar efficacy. Laser ablation should be considered for lesions in need of intervention where the diagnosis requires tissue confirmation.

Stereotactic biopsies are an established tool for obtaining diagnosis of unclear brain lesions. However, non-diagnostic biopsies still occur. We aimed to analyze the contemporary diagnostic yield of stereotactic biopsies, predictors for non-diagnostic biopsies, outcome, and follow-up strategy after non-diagnostic biopsy. We conducted a single-center retrospective study of 311 adult patients undergoing stereotactic biopsies due to a newly diagnosed lesion at our department between 2012 and 2018. Patient data regarding comorbidities, presenting symptoms, imaging features, and non-invasive diagnostic procedures were obtained. The overall diagnostic yield was 86.2% and differed significantly between the various suspected diagnosis groups and was the highest when suspecting primary brain tumor compared with non-neoplastic lesions (91.2% vs. 73.3%, p > 0.001). Predicators for non-diagnostic biopsies were small lesion size, lack of contrast-enhancement, presence of sepsis, or underlying hemato-oncological disease. In case of non-diagnostic biopsy, a re-biopsy was performed in 12 cases, revealing a final diagnosis in 75%. In 16 cases, empiric therapy was started based on the suspected underlying disease. Close follow-up was performed in the remaining 15 cases. We showed that stereotactic biopsy is a safe procedure with reasonable diagnostic yield even for non-neoplastic lesions, when non-invasive diagnostic was inconclusive. In addition, we developed treatment recommendations for cases of non-diagnostic biopsies.

The aim of this study was to compare the efficacy, safety, and duration of Remebot robot-assisted frameless brain biopsy with those of standard frame-based stereotactic biopsy.A retrospective analysis of 66 patients undergoing stereotactic brain biopsy in our department from January 2015 to January 2019 was performed. We divided the patients into two groups: the frame-based group (No significant difference in diagnostic yield was detected in the two groups, with frame-based biopsy having a diagnostic yield of 91.4% and Remebot robot-assisted frameless brain biopsy having a diagnostic yield of 93.5%. The duration of the total procedure was 116.5 min for the frame-based biopsy and 80.1 min for the Remebot robot-assisted frameless brain biopsy (Remebot robot-assisted frameless brain biopsy was as efficacious and safe as standard stereotactic frame-based biopsy. However, frameless biopsy can alleviate the suffering of the patient and reduce the total duration of the procedure. Remebot robot-assisted frameless brain biopsy is easy to use and better accepted by patients than frame-based biopsy.

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.

To describe a case series of children with thalamic tumors treated at our institution in a 5-year period. A retrospective and observational study was performed. The records of 15 patients between 2013 and 2018 were analyzed. 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. 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.

Standard-of-care management of atypical ductal hyperplasia (ADH) is surgical excision. Multiple studies have identified features of ADH in patients at low risk for upgrade who may benefit from omission of surgical excision. Patients with an ipsilateral breast cancer have been excluded from studies investigating observation for the management of ADH. This was a retrospective review of women with both a breast cancer and an ipsilateral separate site of ADH diagnosed on percutaneous biopsy, who underwent excision of both sites from 2008 to 2018. Radiographic and pathologic features of ADH and cancer were analyzed, including imaging size, biopsy modality, distance between sites, cancer subtype, grade, prognostic markers, ADH foci, and presence of necrosis or micropapillary features. Final pathology at the ADH site was used to determine upgrade. Multivariable logistic regression was performed to identify variables significantly associated with ADH upgrade to malignancy. Among 62 women meeting the inclusion criteria, 11 (17.7%) upgraded to malignancy [9 ductal carcinoma in situ (DCIS), 2 invasive cancer] at the site of ADH. Upgrade was significantly higher with ipsilateral DCIS (p = 0.03), ultrasound biopsy at the ADH site (p = 0.01), and ADH with necrosis (p = 0.04). The group at lowest risk for upgrade had stereotactic biopsy and ADH without necrosis (0% upgrade). The presence of breast cancer does not significantly increase the likelihood for upgrade at a separate site of ipsilateral concurrent ADH above contemporary reported upgrade rates of ADH alone (10–30%). When considering breast conservation for breast cancer, omitting excision of the site of ADH can be considered when low-risk features are present.

Purpose Diffuse midline gliomas are rare midline CNS malignancies that primarily affect children but can also affect adults. While radiation is standard treatment, prognosis remains fatal. Furthermore, due to its sensitive anatomic location, many physicians have been reluctant to perform biopsies without potential for improved prognosis. However, recent advancements in molecular-targeted therapeutics have encouraged greater tissue sampling. While the literature reflects this progress, the landscape of how clinicians actually manage these patients remains unclear. Our goal was to assess the attitudes of current practicing neurosurgical oncologists towards management of adult diffuse midline gliomas, reasons behind their practices, and factors that might influence these practices. Methods We created and distributed a survey with 16 multiple choice and open-ended questions to members of the Tumor Section of the Congress of Neurological Surgeons. Results A total of 81 physicians responded to the survey. Although time since training and volume of glioma patients did not significantly affect the decision to consider clinical trials or to offer biopsy, those that operated on fewer gliomas ( Conclusion Factors that affect the management of diffuse midline gliomas and the role of biopsy are relatively uniform across the field, however, there were a few notable differences that reflect the changes within the neuro-oncology field in response to clinical trials.

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. 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. 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.

Purpose/aim: Lymphomatosis cerebri (LC) and cauda equina lymphoma are both rare forms of primary central nervous system lymphoma (PCNSL). LC is characterized by diffuse bilateral non-enhancing (or partially enhancing) inltrative lesions without mass effect, which can be easily confused with other forms of leukoencephalopathy and, thus, lead to delays in diagnosis.Case report: For the first time, a case of LC concomitant with cauda equina involvement confirmed by brain stereotactic biopsy is presented.Conclusions: This case highlights the necessity of using a multimodal strategy in diagnosing PCNSL, including multimodal magnetic resonance, cerebral spinal fluid cytology, flow cytometry and fluorodeoxyglucose positron emission tomography/computed tomography.

Introduction. According to the recommendations of Russian and international professional associations, treatment of germinomas can be initiated without histological verification of the diagnosis, since it can be based on biochemical tumor markers. However, patients with brain germinomas usually have normal levels of these markers; therefore, histological verification is required. Stereotactic biopsy and transcranial biopsy are sometimes associated with a risk of damage to crucial anatomical structures. Currently, both biopsy and total removal of sellar and parasellar tumors can be performed via endoscopic endonasal approach. The study objective is to demonstrate the possibility of using endoscopic transsphenoidal approach for biopsy and total removal of chiasmosellar germinomas. Materials and methods. Thirteen patients with primary chiasmosellar germinomas underwent endoscopic endonasal interventions in N. N. Burdenko National Medical Research Center for Neurosurgery between 2010 and 2017. The “Germinoma-2008” protocol was used in the subsequent treatment of these patients. The male to female ratio was 2.25 : 1; mean age was 21.1 years (6–38 years).Results. The surgery volume varied between biopsy (n = 4) and partial (n = 5) or complete (n = 4) tumor removal. The diagnosis was histologically verified in all patients. None of the patients developed liquorrhea and / or meningitis in the postoperative period, which suggests that the surgery was effective and safe. Conclusion. The endoscopic endonasal approach for histological verification of the diagnosis and removal of chiasmosellar germinomas is safe and effective.

Background 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. Methods 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. Results 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. Conclusions 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.

Brain tumors comprise a heterogeneous group of diseases, featuring different biology, prognosis, and treatment. The most known forms are malignant gliomas and metastases. Brain biopsy is a recognized technique in the management of intracranial space-occupying lesions and tumors in particular. Tumor heterogeneity of malignant brain lesions has been described and can lead to significant sampling errors in stereotactic biopsy. Different methods have been used to perform biopsies, including biopsy guided by CT or RMI, echoguided or stereotactic. The choice of the target with the help of PET and MRI with spectroscopy allows one to identify metabolically more active areas of the tumor, and in this way reduce the rate of negative results.

Aim To retrospectively assess the effectiveness and safety of BLES stereotactic biopsy of suspicious calcifications and investigate possible predictive factors for underestimation. Methods and materials Between January 2014 and January 2016, 400 biopsies of suspicious calcifications were performed in our Department using the BLES stereotactic device. The mean age of our population was 58.5 years (range 39-78 years). The final surgical results were used as gold standard. The effectiveness of the method was statistically evaluated. Mammographic size, grade, molecular type, and presence of comedo type/necrosis were assessed as predictive factors. Results 90/400 (22.5%) cases were cancers (20% invasive cancers, 80% non-invasive cancers). 38/400 cases were atypical lesions (9.5%). No underestimation was found in atypical lesions that underwent surgery (29/38 cases). Downgrade was achieved in 45.5% of cases (with complete removal in 34.4%), concordance in 43.3%, and upgrade was found in 15.5% of the cases; the initial mammographic size and the grade of the cancers were found to be statistically significant predictive factors. The total complication rate was 8.75%. Conclusions Breast lesion excision system is a highly accurate and safe stereotactic biopsy technique of suspicious calcifications with low underestimations and high downgrade/removal rates with the potential to alter the final surgical decision in selected cases.

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.

Background Digital breast tomosynthesis (DBT)-guided biopsy is increasingly used in practice. It is important to know expected changes in biopsy targets, pathologic results, and discordance rates. Purpose To compare biopsy target types, pathologic results, and discordance rates for 2 years preceding and 2 years following implementation of DBT-guided biopsy. Materials and Methods All 9-gauge vacuum-assisted core biopsies from a single tertiary breast center that used digital mammography (DM) stereotactic guidance from 2013 to 2015 and DBT-guided biopsy from 2015 to 2017 were retrospectively reviewed. All mammographic examinations were performed with DBT. Patient demographics, biopsy target type, pathologic reports, surgical excision specimens when available, breast density, and imaging follow-up results were recorded. Biopsy targets and discordance rates between radiologic and pathologic examinations were compared between the two biopsy groups. Generalized mixed modeling was used to examine results before and after DBT-guided biopsy. Results A total of 1313 women underwent 1405 breast biopsies: 643 by using DM (August 2013 to July 2015) (median age, 56 years; interquartile range, 49-66 years) and 762 by using DBT (August 2015 to July 2017) (median age, 58 years; interquartile range, 50-67 years), (P = .58). Calcifications were the most common biopsy target for both groups, constituting 89.9% (578 of 643) of DM-guided biopsies and 71.1% (542 of 762) of DBT-guided biopsies (P = .03). The rate of architectural distortion biopsies was 2.0% (13 of 643) with DM-guided biopsy and 17.7% (135 of 762) with DBT-guided biopsy (P = .01). Although overall malignancy rate was similar for DM-guided biopsy (27.8% [179 of 643]) and DBT-guided biopsy (24.8% [191 of 762], P = .54), DBT-guided biopsy helped identify a similar percentage of invasive malignancies (37.4% [72 of 191] vs 29.0% [52 of 179] at DM P = .35), but more radial sclerosing lesions (8.3% [95% confidence interval {CI}: 6.0, 10.0] vs 1.7% [95% CI: 1.0, 3.1]) (P = .01). The discordance rate was 1.4% (95% CI: 1.0, 2.7) with DM-guided biopsy and 4.5% (95% CI: 3.2, 6.3) with DBT-guided biopsy (P = .01). Of the 34 discordant DBT-guided biopsies, 30 were architectural distortions. Conclusion With the transition to digital breast tomosynthesis-guided biopsy, more architectural distortions were biopsied, more radial sclerosing lesions were identified, and more discordance existed in radiologic and pathologic examinations, with a similar percentage of carcinomas diagnosed. © RSNA, 2020 Online supplemental material is available for this article.

Objective Frame-based stereotactic biopsy (FSB) remains the “gold standard” for obtaining diagnostic samples of intracranial lesions to guide therapy. Nevertheless, diagnostic yield is highly variable. This study aims to provide an analysis of diagnostic yield, surgical complications, and factors associated with obtaining nondiagnostic samples in a contemporary FSB series. Methods A retrospective cohort study was conducted of all adult patients with imaging-documented lesions undergoing FSB at our institution between 2013 and 2018. Diagnostic accuracy, lesion characteristics associated with nondiagnostic biopsy, and surgical complications were evaluated. A biopsy was considered nondiagnostic if all frozen samples and the final pathology yielded normal brain tissue or nonspecific reactive tissue unless the “reactive” pathology was consistent with radiation injury from prior therapy. Results Our search identified 198 FSB patients. Mean (standard deviation) age was 62 ± 17 years, and 44.2% were female. Median procedure time was 32 minutes. A definitive histologic diagnosis was established in 187 cases (94.4% diagnostic yield). Mean lesion diameter was 31.9 ± 16.8 mm. Multivariable logistic regression revealed only lesion diameter to be significantly associated with diagnostic result (odds ratio for nondiagnostic result: 0.94 per mm diameter decrease, 95% confidence interval 0.87–0.99, P = 0.028). On univariable analysis, diagnosis of central nervous system lymphoma appeared to increase the risk of a nondiagnostic biopsy (P = 0.025), but this association disappeared when controlling for lesion size and steroid administration before biopsy. Eight patients (4.0%) developed postoperative hemorrhagic complications, 3 of whom required reoperation, and another expired. Conclusions This study demonstrates that diagnostic yield from contemporary FSB is high and depends predominantly on lesion size.

BACKGROUND AND PURPOSE: Gliomas are highly heterogeneous tumors, and optimal treatment depends on identifying and locating the highest grade disease present. Imaging techniques for doing so are generally not validated against the histopathologic criterion standard. The purpose of this work was to estimate the local glioma grade using a machine learning model trained on preoperative image data and spatially specific tumor samples. The value of imaging in patients with brain tumor can be enhanced if pathologic data can be estimated from imaging input using predictive models. MATERIALS AND METHODS: Patients with gliomas were enrolled in a prospective clinical imaging trial between 2013 and 2016. MR imaging was performed with anatomic, diffusion, permeability, and perfusion sequences, followed by image-guided stereotactic biopsy before resection. An imaging description was developed for each biopsy, and multiclass machine learning models were built to predict the World Health Organization grade. Models were assessed on classification accuracy, Cohen κ, precision, and recall. RESULTS: Twenty-three patients (with 7/9/7 grade II/III/IV gliomas) had analyzable imaging-pathologic pairs, yielding 52 biopsy sites. The random forest method was the best algorithm tested. Tumor grade was predicted at 96% accuracy (κ = 0.93) using 4 inputs (T2, ADC, CBV, and transfer constant from dynamic contrast-enhanced imaging). By means of the conventional imaging only, the overall accuracy decreased (89% overall, κ = 0.79) and 43% of high-grade samples were misclassified as lower-grade disease. CONCLUSIONS: We found that local pathologic grade can be predicted with a high accuracy using clinical imaging data. Advanced imaging data improved this accuracy, adding value to conventional imaging. Confirmatory imaging trials are justified.