Stereotactic Biopsy Research Articles

Clinical characteristics and prognostic factors of adult brainstem gliomas: A retrospective analysis of histologically-proven 40 cases.

To illustrate the clinical characteristics and prognostic factors of adult patients pathologically confirmed with brainstem gliomas (BSGs). Clinical data of 40 adult patients pathologically diagnosed with BSGs admitted to Beijing Shijitan Hospital from 2009 to 2022 were recorded and retrospectively analyzed. The primary parameters included relevant symptoms, duration of symptoms, Karnofsky performance status (KPS), tumor location, type of surgical resection, diagnosis, treatment, and survival. Univariate and multivariate analyses were evaluated by Cox regression models. The gliomas were located in the midbrain of 9 patients, in the pons of 14 cases, in the medulla of 5 cases, in the midbrain and pons of 6 cases and invading the medulla and pons of 6 cases, respectively. The proportion of patients with low-grade BSGs was 42.5%. Relevant symptoms consisted of visual disturbance, facial paralysis, dizziness, extremity weakness, ataxia, paresthesia, headache, bucking, dysphagia, dysacousia, nausea, dysphasia, dysosmia, hypomnesia and nystagmus. 23 (57.5%) patients accepted stereotactic biopsy, 17 (42.5%) patients underwent surgical resection. 39 patients received radiotherapy and 34 cases were treated with temozolomide. The median overall survival (OS) of all patients was 26.2 months and 21.5 months for the median progression-free survival (PFS). Both duration of symptoms (P = .007) and tumor grading (P = .002) were the influencing factors for OS, and tumor grading was significantly associated with PFS (P = .001). Duration of symptoms for more than 2 months and low-grade are favorable prognostic factors for adult patients with BSGs.

Abstract PO5-07-09: ACCURACY OF STEREOTACTIC VACCUM-ASSISTED BREAST BIOPSY FOR INVESTIGATING SUSPICIOUS CALCIFICATIONS IN 2,021 PATIENTS A PUBLIC HOSPITAL IN BRAZIL

Abstract Backgroud: the gold standard for breast biopsy procedures is currently an open excision of the suspected lesion. The cost and morbidity associated with this procedure has prompted many physicians to evaluate less invasive, alternative procedures. More recently, image-guided percutaneous core-needle biopsy has become a frequently used method for diagnosing palpable and non-palpable breast lesions. Although sensitivity rates for core-needle biopsy are high, it has the disadvantage of histological underestimation. Vacuum-assisted stereotactic biopsy (VASB) was developed to overcome some of these negative aspects of core-needle biopsy. Objectives: to evaluate the accuracy of vacuum-assisted stereotactic biopsy (VASB) in the investigation of non palpable suspicious calcifications. Methods: it was a retrospective study from July 2012 to December 2020, in which 2,021 women with suspicious calcifications detected on mammography (BI-RADS 4 and 5) had VASB performed at Hospital Estadual Pérola Byington, São Paulo, Brazil. Fragments were obtained and sent to anatomopathological study; a metal clip was placed on the biopsy site. Four groups were analyzed, based on the biopsy results: benign, precursor lesions, Ductal Carcinoma In Situ (DCIS) and Invasive Ductal Carcinoma (ICD). Results: patients median age was 55y (49-63y). Pathology results on VASB were classified respectively as benign n=1,340 (66.3%), precursor lesions n=84 (4.1%), DCIS n=441 (21.8%) and ICD n=156 (7.7%). The 60 patients with results benign on VASB, because anatomopathological disagreement, surgery was performed, with the following results: benign n=30 (50%), ICD e DCIS n=21 (35%) e precursor lesions n=9 (15%). The sensitivity of the method was 91.7 %, specificity was 97.1%, false negative rate was 3%, positive predictive value was 92.4%, negative predictive value was 96.9%. Conclusion: the VASB method has a good accuracy to distinguish lower and higher risk lesions groups comparing to the gold standard. It has high predictive value in both benign and malignant lesions, guiding therapeutic planning. Keywords: Calcifications; Vacuum-assisted stereotactic biopsy; Breast cancer; Diagnosis. Citation Format: Andressa Amorim, Andre Mattar, Marcelo Antonini, Reginaldo Coelho Lopes, Luciana Damous, Luiz Henrique Gebrim, Marina Diogenes, Marcellus Ramos. ACCURACY OF STEREOTACTIC VACCUM-ASSISTED BREAST BIOPSY FOR INVESTIGATING SUSPICIOUS CALCIFICATIONS IN 2,021 PATIENTS A PUBLIC HOSPITAL IN BRAZIL [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-07-09.

The 3-Dimensional Intelligent Structured Light Technique: A New Registration Method in Stereotactic Neurosurgery.

Surface-based facial scanning registration emerged as an essential registration method in the robot-assisted neuronavigation surgery, providing a marker-free way to align a patient's facial surface with the imaging data. The 3-dimensional (3D) structured light was developed as an advanced registration method based on surface-based facial scanning registration. We aspire to introduce the 3D structured light as a new registration method in the procedure of the robot-assisted neurosurgery and assess the accuracy, efficiency, and safety of this method by analyzing the relative operative results. We analyzed the results of 47 patients who underwent Ommaya reservoir implantation (n = 17) and stereotactic biopsy (n = 30) assisted by 3D structured light at our hospital from January 2022 to May 2023. The accuracy and additional operative results were analyzed. For the Ommaya reservoir implantation, the target point error was 3.2 ± 2.2 mm and the entry point error was 3.3 ± 2.4 mm, while the operation duration was 35.8 ± 8.3 minutes. For the stereotactic biopsy, the target point error was 2.3 ± 1.3 mm and the entry point error was 2.7 ± 1.2 mm, while the operation duration was 24.5 ± 6.3 minutes. The 3D structured light technique reduces the patients' discomfort and offers the advantage of a simpler procedure, which can improve the clinical efficiency with the sufficient accuracy and safety to meet the clinical requirements of the puncture and navigation.

A Challenging Case of Primary Central Nervous System Lymphoma: Diagnostic Dilemmas and Therapeutic Insights

Introduction: Primary Central Nervous System Lymphoma (PCNSL) is a rare malignancy primarily located in the brain, spinal cord, leptomeninges, and eyes. The origin of PCNSL is uncertain, but it is thought to arise from lymphocytes within the central nervous system. Diagnosis and treatment can be complex, especially in immunocompetent patients. Case Report: A 65-year-old immunocompetent woman presented with symptoms including weight loss, severe weakness, and left hemiplegia. Initial brain MRI revealed an irregular mass with vasogenic edema in the right parietal lobe. Stereotactic biopsy confirmed large cell lymphoma (T-cell variant). The patient initially responded well to high-dose steroid treatment. Subsequent chemotherapy and radiotherapy were planned, but due to a positive PCR test, treatment was delayed. Discussion: PCNSL presents with non-specific symptoms, making early diagnosis challenging. Diagnostic tools such as MRI, PET-CT, and immunohistochemistry play crucial roles. Steroid use before biopsy should be cautious, as it may affect tissue necrosis and diagnosis accuracy. Prompt diagnostic and therapeutic measures are essential for improved outcomes. Conclusion: PCNSL is a rare and aggressive malignancy with a poor prognosis if left untreated. Early diagnosis and appropriate treatment, including chemotherapy and radiotherapy, are crucial for patient survival. Larger studies are needed to further understand and manage this challenging condition.

A comment on "An MRI radiomics approach to discriminate hemorrhage prone intracranial tumors before stereotactic biopsy".

A comment on "An MRI radiomics approach to discriminate hemorrhage prone intracranial tumors before stereotactic biopsy".

Preoperative Corticosteroids Reduce Diagnostic Accuracy of Stereotactic Biopsies in Primary Central Nervous System Lymphoma: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES: Despite general acceptance that corticosteroid therapy (CST) should be withheld before biopsy for suspected primary central nervous system lymphoma (PCNSL), there remains conflicting evidence surrounding the precise impact of preoperative CST on the histopathological diagnosis. The objective of this systematic review and meta-analysis was to describe and quantify the effects of preoperative CST on the diagnostic accuracy of biopsies for PCNSL. METHODS: Primary articles were screened from Ovid MEDLINE, Embase, Web of Science, and Scopus databases. Meta-analysis was performed for immunocompetent patients with histologically confirmed PCNSL. Subgroup and regression analyses were performed to assess the effects of biopsy type, CST duration, dose, and preoperative taper on the diagnostic accuracy. In addition, the sensitivity of cerebrospinal fluid (CSF) analyses for PCNSL was assessed. RESULTS: Nineteen studies, comprising 1226 patients (45% female; mean age: 60.3 years), were included. Preoperative CST increased the risk of nondiagnostic biopsy with a relative risk (RR) of 2.1 (95% CI: 1.1-4.1). In the stereotactic biopsy subgroup, the RR for nondiagnostic biopsy was 3.0 (95% CI: 1.2-7.5). CST taper, duration, and dose did not significantly influence diagnostic biopsy rates. The sensitivity of CSF cytology, including flow cytometry, for PCNSL was 8.0% (95% CI: 6.0%-10.7%). CONCLUSION: Our results suggest that preoperative CST reduces the diagnostic yield of stereotactic biopsies for PCNSL. We found no evidence that tapering CST before biopsy improves diagnostic rates. CSF analysis currently has a poor sensitivity for the diagnosis of PCNSL.

Assessing the malignancy of suspicious breast microcalcifications: the role of contrast enhanced mammography.

To assess the role of contrast-enhanced mammography (CEM) in predicting the malignancy of breast calcifications. We retrospectively evaluated patients with suspicious calcifications (BIRADS 4) who underwent CEM and stereotactic vacuum-assisted biopsy (VAB) at our institution. We assessed the sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) of CEM in predicting malignancy of microcalcifications with a 95% confidence interval; we performed an overall analysis and a subgroup analysis stratified into group A-low risk (BIRADS 4a) and group B-medium/high risk (BIRADS 4b-4c). We then evaluated the correlation between enhancement and tumour proliferation index (Ki-67) for all malignant lesions. Data from 182 patients with 184 lesions were collected. Overall the SE of CEM in predicting the malignancy of microcalcifications was 0.70, SP was 0.85, the PPV was 0.82, the NPV was 0.76 and AUC was 0.78. SE in group A was 0.89, SP was 0.89, PPV was 0.57, NPV was 0.98 and AUC was 0.75. SE in group B was 0.68, SP was 0.80, PPV was 0.87, NPV was 0.57 and AUC was 0.75. Among malignant microcalcifications that showed enhancement (N = 52), 61.5% had Ki-67 ≥ 20% and 38.5% had low Ki-67 values. Among the lesions that did not show enhancement (N = 22), 90.9% had Ki-67 < 20% and 9.1% showed high Ki-67 values 20%. The absence of enhancement can be used as an indicative parameter for the absence of disease in cases of low-suspicious microcalcifications, but not in intermediate-high suspicious ones for which biopsy remains mandatory and can be used to distinguish indolent lesions from more aggressive neoplasms, with consequent reduction of overdiagnosis and overtreatment.

Searching for a twinkling artefact in breast microcalcifications using B-flow ultrasonic non-doppler technology: a prospective study

INTRODUCTION: The rapid rejuvenation of breast cancer in recent years has made it necessary to look for non-X-ray methods of imaging microcalcifications in women not yet covered by mammography screening. Developing technologies to see these microcalcifications on ultrasound is a promising goal, potentially reducing the number of unnecessary biopsies.OBJECTIVE: Evaluation of factors influencing the ability of the B-flow technique to detect the presence of a flickering artifact in patients with microcalcifications detected by mammography.MATERIALS AND METHODS: A prospective study of 57 patients with microcalcifications detected on mammograms was conducted. The Nondoppler technology of B-flow ultrasound examination was used for targeted ultrasound with the search for these areas during ultrasound. The possibilities of visualization of the twinkle artifact were evaluated for various microcalcifications in size, distribution, their number, and for pathological processes of different nature. Images in B-flow mode were found to be positive when a bright local flash occurred against a dark background in B-mode. Verification of diagnostic findings was performed by ultrasound-guided core- biopsy from areas with a twinkle artifact (in the presence of an imaging area during ultrasound) or with stereotactic biopsy (in the absence of visualization of the suspicious area with ultrasound with B-flow).Statistics: The ANOVA test was used for triple pairwise comparisons between positive groups. The p&lt;0.05 value was considered statistically significant.RESULTS: According to the results of the study, out of 57 cases with microcalcifications, 34 (60%) recorded a twinkle artifact. The amount of microcalcifications with a visualized twinkle effect in B-flow was significantly higher in benign processes 34 (82.9%) out of 41, and less often in malignant 8 (50%) out of 16 (p=0.035). The effect of calcification morphology on the mammogram on their detection by ultrasound in the B-flow mode (p=0.035) was statistically significant. The most frequently manifested twinkle artifact were rounded, regular-shaped calcifications in 19 (95%) out of 20, which were found in granulomatous mastitis, fibrocystic changes, fibroadenomas, sclerosing adenosis, as well as polymorphic calcifications in 7 (63.6%) of 11. In the B-flow mode, it was not possible to obtain a twinkle artifact mainly with point small calcifications of 9 (69.2%) out of 13, and in all cases with linear or linear branching calcifications. In amorphous microcalcifications, the characteristics of background echogenicity and the presence or absence of a nodal component in the gray scale mode had a much greater influence on the appearance of the twinkle effect in the normal B-mode, whereas in the B-flow mode, these characteristics did not have a decisive effect on the appearance of a flickering artifact (p=0.8). The density of distribution of microcalcifications, the size of calcifications, the final pathomorphology, mammography characteristics, the background environment during ultrasound by the presence or absence of nodular formation and anechoic zones, did not affect the appearance of a bright flash in the B-flow mode.DISCUSSION: The density of calcification distribution was not decisive for the appearance of a shimmering artifact in the B-flow mode. The flicker artifact is recorded both in grouped microcalcifications and in single ones. B-flow can help to detect calcifications that are not visible in the usual B-flow mode due to the lack of pronounced tissue contrast. But this artifact cannot be used to differentiate between benign and malignant processes.CONCLUSION: The B-flow technique is promising for clarifying the twinkle artifact in the detected microcalcifications on the mammogram, which could potentially increase the incidence of ultrasound-guided trephine biopsies by detecting more areas with microcalcification accumulations. 

When sarcoidosis hits down: a case of prostatic sarcoidosis.

A 69-year-old North African male with established diagnosis of sarcoidosis underwent a stereotactic prostate biopsy with fusion technique. At the histological analysis, non-necrotizing micro-granulomas were highlighted in 2 samples, while the immunohistochemicalstaining resulted negative for CK903/p63/racemase. To the best of our knowledge, only 16 cases of prostatic sarcoidosis have been reported in literature. With this case report we describe an incidental diagnosis of prostatic involvement of sarcoidotic disease and briefly review and discuss the available literature on the topic.

Three-Dimensional Structure Light Robot-Assisted Frameless Stereotactic Brain Biopsy.

To assess the feasibility, accuracy, and safety of 3-dimensional (3D) structure light robot-assisted frameless stereotactic brain biopsy. Five consecutive patients (3 males, 2 females) were included in this study. The patients' clinical, imaging, and histological data were analyzed, and all patients received a 3D structure light robot-assisted frameless stereotactic brain biopsy. The raw and/or analyzed data of the study are available from the corresponding author. The statistical results showed a mean age of 59.6 years (range 40-70 years), a mean target depth of 60.9 mm (range 53.5-65.8 mm), a mean radial error of 1.2 ± 0.7 mm (mean ± SD), a mean depth error of 0.7 ± 0.3 mm, and a mean absolute tip error of 1.5 ± 0.6 mm. The calculated Pearson product-moment correlation coefficient (r = 0.23) revealed no correlation between target depth and absolute tip error. All biopsy needles were placed in line with the planned trajectory successfully, and diagnostic specimens were harvested in all cases. Histopathological analysis revealed lymphoma (2 cases), lung adenocarcinoma (1 case), glioblastoma multiforme (1 case), and oligodendroglioma (1 case). Surface registration using the 3D structure light technique is fast and precise because of the achievable million-scale point cloud data of the head and face. 3D structure light robot-assisted frameless stereotactic brain biopsy is feasible, accurate, and safe.

1232 Outpatient Stereotactic Needle Biopsy Is a Cost-effective Strategy for Brain Tumor Patient Decision-making That Enhances Clinical Trial Accrual

INTRODUCTION: Although neuroradiological techniques have expanded, stereotactic needle biopsy is a simple, ubiquitous,and immediate strategy for established or potential brain tumor patients with atypical clinical and/or radiographic findings. METHODS: Outpatient stereotactic needle biopsies performed by a single surgeon from August 2020 through November 2022 were retrospectively reviewed. Electronic medical records were queried for clinical, perioperative, and tumor demographics. Financial records were queried for insurance and payment reports. Descriptive statistics were used to characterize comparisons among collected variables. RESULTS: 107 consecutive stereotactic needle biopsy procedures were conducted in adult brain tumor patients. All biopsies were performed using a single needle-pass in the outpatient setting, targeting supratentorial lesions in 89.7% of cases. Tissue diagnosis was established in 96% of procedures, with glioma being the most common histology. No intraoperative or perioperative complications occurred. Four patients (3.7%) were admitted overnight due to urinary retention (n = 2) and asymptomatic tract hemorrhage (n = 2), respectively. Insurance approval was sought preoperatively from non-commercial (31.7%) and commercial (68.3%) payors and approved in all cases. Postoperatively, 30.8% of patients received an experimental therapeutic on the basis of tissue analysis. CONCLUSIONS: We report the largest experience to date with outpatient stereotactic needle biopsy in newly-diagnosed and recurrent brain tumor patients. Our findings identify this strategy as a cost-effective alternative to advanced imaging that facilitates clinical trial accrual through tissue acquisition.

Multimodality Imaging of Benign and Malignant Diseases of the Nipple-Areolar Complex.

The nipple-areolar complex (NAC), a unique anatomic structure of the breast, encompasses the terminal intramammary ducts and skin appendages. Several benign and malignant diseases can arise within the NAC. As several conditions have overlapping symptoms and imaging findings, understanding the distinctive nipple anatomy, as well as the clinical and imaging features of each NAC disease process, is essential. A multimodality imaging approach is optimal in the presence or absence of clinical symptoms. The authors review the ductal anatomy and anomalies, including congenital abnormalities and nipple retraction. They then discuss the causes of nipple discharge and highlight best practices for the imaging workup of pathologic nipple discharge, a common condition that can pose a diagnostic challenge and may be the presenting symptom of breast cancer. The imaging modalities used to evaluate and differentiate benign conditions (eg, dermatologic conditions, epidermal inclusion cyst, mammary ductal ectasia, periductal mastitis, and nonpuerperal abscess), benign tumors (eg, papilloma, nipple adenoma, and syringomatous tumor of the nipple), and malignant conditions (eg, breast cancer and Paget disease of the breast) are reviewed. Breast MRI is the current preferred imaging modality used to evaluate for NAC involvement by breast cancer and select suitable candidates for nipple-sparing mastectomy. Different biopsy techniques (US -guided biopsy and stereotactic biopsy) for sampling NAC masses and calcifications are described. This multimodality imaging approach ensures an accurate diagnosis, enabling optimal clinical management and patient outcomes. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

An MRI radiomics approach to discriminate hemorrhage prone intracranial tumors before stereotactic biopsy.

To explore imaging biomarkers predictive of intratumoral hemorrhage for lesions intended for elective stereotactic biopsy. This study included a retrospective cohort of 143 patients with 175 intracranial lesions intended for stereotactic biopsy. All the lesions were randomly split into a training dataset (n=121) and a test dataset (n=54) at a ratio of 7:3. 34 lesions were defined as "hemorrhage-prone tumors" as hemorrhage occurred between initial diagnostic MRI acquisition and the scheduled biopsy procedure. Radiomics features were extracted from the contrast-enhanced T1WI and T2WI images. Features informative of hemorrhage were then selected by the LASSO algorithm and an SVM model was built with selected features. The SVM model was further simplified by discarding features with low importance calculated using a "permutation importance" method. The model's performance was evaluated with confusion matrix-derived metrics and AUC value on the independent test dataset. Nine radiomics features were selected as hemorrhage related features of intracranial tumors by the LASSO algorithm. The simplified model's sensitivity, specificity, accuracy, and AUC reached 0.909, 0.930, 0.926, and 0.949 (95%CI: 0.865-1.000) on the test dataset in the discrimination of "hemorrhage-prone tumors". The permutation method rated feature "T2_gradient_firstorder_10Percentile" as the most important, the absence of which decreased the model's accuracy by 10.9%. Radiomics features extracted on contrast-enhanced T1WI and T2WI sequences were predictive of future hemorrhage of intracranial tumors with favorable accuracy. This model may assist in the arrangement of biopsy procedures and the selection of target lesions in patients with multiple lesions.

Combination of Tractography, Intraoperative Computed Tomography and 5-Aminolevulinic Acid Fluorescence in Stereotactic Brain Biopsies: A Case Series.

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

A Biopsy-Controlled Prospective Study of Contrast-Enhancing Diffuse Glioma Infiltration Based on FET-PET and FLAIR.

Accurately defining glioma infiltration is crucial for optimizing radiotherapy and surgery, but glioma infiltration is heterogeneous and MRI imperfectly defines the tumor extent. Currently, it is impossible to determine the tumor infiltration gradient within a FLAIR signal. O-(2-[18F]fluoroethyl)-L-tyrosine (FET)-PET often reveals high-grade glioma infiltration beyond contrast-enhancing areas on MRI. Here, we studied FET uptake dynamics in tumor and normal brain structures by dual-timepoint (10 min and 40-60 min post-injection) acquisition to optimize analysis protocols for defining glioma infiltration. Over 300 serial stereotactic biopsies from 23 patients (mean age 47, 12 female/11 male) of diffuse contrast-enhancing gliomas were taken from areas inside and outside contrast enhancement or outside the FET hotspot but inside FLAIR. The final diagnosis was G4 in 11, grade 3 in 10, and grade 2 in 2 patients. The target-to-background (TBRs) ratios and standardized uptake values (SUVs) were calculated in areas used for biopsy planning and in background structures. The optimal method and threshold values were determined to find a preferred strategy for defining glioma infiltration. Standard thresholding (1.6× uptake in the contralateral brain) in standard acquisition PET images differentiated a tumor of any grade from astrogliosis, although the uptake in astrogliosis and grade 2 glioma was similar. Analyzing an optimal strategy for infiltration volume definition astrogliosis could be accurately differentiated from tumor samples using a choroid plexus as a background. Early acquisition improved the AUC in many cases, especially within FLAIR, from 56% to 90% sensitivity and 41% to 61% specificity (standard TBR 1.6 vs. early TBR plexus). The current FET-PET evaluation protocols for contrast-enhancing gliomas are limited, especially at the tumor border where grade 2 tumor and astrogliosis have similar uptake, but using choroid plexus uptake in early acquisitions as a background, we can precisely define a tumor within FLAIR that was outside of the scope of current FET-PET protocols.

Stereotactic frame-based biopsy of infratentorial lesions via the suboccipital-transcerebellar approach with the Zamorano-Duchovny stereotactic system—a retrospective analysis of 79 consecutive cases

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

The Utility of Spectroscopic MRI in Stereotactic Biopsy and Radiotherapy Guidance in Newly Diagnosed Glioblastoma.

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.

Rapid Vision Loss Due to Multifocal Glioma: A Diagnostic Challenge.

This is a unique case report in medical literature for its detailing of diagnostics of an uncommon presentation of a rapid unexplained bilateral vision loss of a 73-year-old male diabetic patient. This report highlights the crucial role of advanced molecular diagnostics in difficult neurological cases and also elucidates the difficulties involved in diagnosing optic nerve glioblastoma, an exceptionally rare and aggressive tumour. Slow and progressive loss of vision over 2 months, ultimately developing almost complete visual impairment in both eyes and a defect of right eye field of vision conclusively highlighted that the likely etiology was neuro-ophthalmic. Initially, the conditions were suspected to be an extended spectrum of diabetic eye disease complications but further deterioration was a hint towards something more substantive. This entailed in-depth diagnosis processes that included an MRI and the analysis of cerebrospinal fluid. The important discovery was through stereotactic biopsies of the optic nerve revealing a high-grade glial neoplasm. Next generation sequencing confirmed the pathology as IDH-wildtype glioblastoma. Despite management, his vision continued to deteriorate. Hence, an aggressive clinical course was followed. This case highlights the important learning need in considering glioblastoma of the optic chiasm as part of the differential diagnosis of rapid vision loss, which may present as multifocal brain lesions, especially in casesof rapid loss of vision where initial workup is negative. Quite a useful lesson that can be drawn from this case relates to the diagnostic process with advanced molecular profiling, more attention given to clinical suspicion and cutting-edge diagnostic tools applied in atypical presentation of neurological conditions.

Image-guided biopsy of intracranial lesions in children, with a small robotic device: a case series.

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

Gamma-delta T-cell lymphoma of the central nervous system: A case report and review of the literature.

Primary T-cell lymphoma (TCL) of the central nervous system (CNS) is a rare and potentially aggressive entity. We describe a case of TCL presenting in the basal ganglia with γδ receptor expression and a remarkably aggressive clinical course. To the best of our knowledge, this is the fifth reported case of γδ TCL presenting in the CNS. We review existing literature, including the previously reported cases of γδ TCL of the CNS. In our case, a 69-year-old male presented with acute onset dysarthria and right-sided weakness, with initial imaging concerning for stroke. Repeat imaging demonstrated a 2.6-cm mass in the left basal ganglia-corona radiata. Pathologic examination of a stereotactic biopsy revealed TCL with γδ receptor phenotype. The patient suffered rapid clinical decline and passed away within 6 weeks of initial diagnosis. This represents an important differential diagnosis and sheds light on the potentially poor prognosis conferred by γδ TCL of the CNS.