Stereotactic Needle Biopsy Research Articles

Readmission risk of malignant brain tumor patients undergoing laser interstitial thermal therapy (LITT) and stereotactic needle biopsy (SNB): a covariate balancing weights analysis of the National Readmissions Database (NRD).

Despite procedural similarities between laser interstitial thermal therapy (LITT) and stereotactic needle biopsy (SNB), LITT induces delayed, pro-inflammatory responses not associated with SNB that may increase the risk of readmission within 30- or 90- days. Here, we explore this hypothesis. We queried the National Readmissions Database (NRD, 2010-18) for malignant brain tumor patients who underwent elective LITT or SNB using International Classification of Diseases codes. Readmissions were defined as non-elective inpatient hospitalizations. Survey regression methods and a weighted analysis were utilized to adjust for demographic and clinical differences between LITT and SNB cohorts. During the study period, an estimated 685 malignant brain patients underwent elective LITT and 15,177 underwent elective SNB. Patients undergoing LITT and SNB exhibited comparable median lengths of hospital stay [IQR; LITT = 2 (1, 3); SNB = 1 (1, 2); p = 0.820]. Likelihood of routine discharge was not significantly different between the two procedures (p = 0.263). No significant differences were observed in the odds of 30- or 90-day unplanned readmission between the LITT and SNB cohorts after multivariable adjustment (all p ≥ 0.177). The covariate balancing weighted analysis confirmed comparable 30 or 90-day readmission risk between LITT and SNB treated patients (all p ≥ 0.201). The likelihood of 30- and 90-day readmission for malignant brain tumor patients who underwent LITT or SNB are comparable, supporting the safety profile of LITT as therapy for malignant brain cancers.

Resolution and Re-ossification of Orbital-Wall Langerhans Cell Histiocytosis Following Stereotactic Needle Biopsy.

Introduction Langerhans cell histiocytosis (LCH) is a rare disease that encompasses a spectrum of clinical syndromes. It is characterized by the proliferation and infiltration of white blood cells into organs or organ systems. Reports of management of these lesions have included biopsy, resection, curettage, radiation, and/or chemotherapy. Case Presentation A 40-year-old man presented with a history of right proptosis and retro-orbital pain and was found to have a lytic mass involving the greater wing of the sphenoid extending into the right orbit. A stereotactic needle biopsy using neuronavigation demonstrated this to be LCH. After no further treatment, the mass spontaneously resolved, with virtual normalization of the orbital magnetic resonance imaging at 10 months following the needle biopsy. The bony defect of the temporal bone caused by the mass also re-ossified following the needle biopsy. Discussion This report highlights the potential for an isolated LCH lesion to regress after simple needle biopsy, an outcome only rarely reported previously. Thus, expectant management of such lesions following biopsy or initial debridement should be considered prior to proceeding with additional treatment.

345 Comparable Safety Profile Between Laser Interstitial Thermal Therapy (LITT) and Stereotactic Needle Biopsy in 30-Day and 90-Day Readmission: A National Readmissions Database Analysis

INTRODUCTION: The procedural elements of Laser Interstitial Thermal Therapy (LITT, also known as stereotactic laser ablation (SLA)) and stereotactic needle biopsy are highly similar. METHODS: We queried the National Readmission Database (NRD, 2010-18) for patients who underwent elective LITT or biopsy using International Classification of Diseases 9th and 10th edition codes. Readmission was defined planned, related admissions following the index admission. Odds of 30- and 90-days readmission were calculated using multivariable logistic regression. RESULTS: 305 LITT and 7,419 needle biopsy treated brain tumor were identified. The LITT treated patients were younger (p < 0.001), female (p=0.008), and insured privately (compared to Medicare or Medicaid, p < 0.001). In terms of cancer type, a greater proportion of LITT cohort were patients brain metastasis (relative to primary brain cancer, 38.7% vs 7.2%, p < 0.001). There was no difference in non-routine discharge (LITT: 73.8%, n = 225 discharged to home vs biopsy: 80 %, n = 5,392, p = 0.826) or in-hospital mortality (0.3%,n=1 vs 0.7%, n = 50, p = 0.715). The most common neurosurgical reasons for readmissions at 30-days included unplanned readmission for index diagnosis (LITT: 2%, n = 7 vs biopsy: 3.7%, n = 272), infection (0.6%, n = 2 vs 0.46%, n = 34), seizure (0.3%, n = 1 vs 0.74%, n = 54) and cerebrovascular complication (0.3%, n = 1 vs 1%, n = 55) . The most common reason for non-neurosurgical readmission at 30 days for biopsy treated patients was deep vein thrombosis (DVT) / pulmonary embolism (PE) (0.46%, n = 35) and for LITT treated patients was an electrolyte abnormality (0.6%, n = 2). In both univariate and multivariable analyses, the odds of 30- and 90-days overall readmission, as well as neurosurgical and non-neurosurgical readmission were comparable between LITT and biopsy. CONCLUSION: The NRD analysis of 30- and 90-day readmission suggest comparable safety profile between LITT and stereotactic needle biopsy as treatment for brain tumor patients.

Initial Clinical Experience With ClearPoint SmartFrame Array–Aided Stereotactic Procedures

The ClearPoint SmartFrame Array (ClearPoint Neuro, Inc., Solana Beach, CA) system consists of a magnetic resonance imaging compatible frame supported by a customized neuro navigation software. This system received U.S. Food and Drug Administrationclearance for clinical use in January 2021. Our objective was to report initial safety data and user experience of SmartFrame Array-supported stereotactic procedures. We prospectively followed the first 10 consecutive patients who underwent stereotactic procedures supported by SmartFrame Array. Clinical and procedural data were recorded and compared to data obtained from prior cases with SmartFrame XG. Ten patients underwent stereotactic needle biopsy, stereotactic laser ablation (SLA), or combined biopsy/SLA procedures. For needle biopsies (n= 9), the average maximal diameter of the contrast-enhancing target lesion was 9.9 ± 2.8 mm. The radial error of stereotaxis was less than 2 mm. Definitive diagnosis was achieved in all cases. For procedures involving SLA (n= 5), 100% of the contrast-enhancing lesion was ablated. All patients were discharged home by postoperative day 2. There were no 30-day readmissions, morbidity, or mortality. The average stereotaxis time for the SmartFrame Array-aided single trajectory procedure was 80 ± 9.5 minutes, which compared favorably to that required for the earlier generation SmartFrame XG frame (111.5 ± 16.5 minutes; P < 0.01). The unique Array design supported stereotactic procedures that cannot be easily achieved with the previous SmartFrame XG frame. The SmartFrame Array system offers a more rigid and compact build to enhance procedural efficiency while maintaining accuracy and safety. The design supports multi-trajectory stereotaxis, allowing novel clinical applications.

Learning Curve Associated with ClearPoint Neuronavigation System: A Case Series

BackgroundThe ClearPoint neuronavigation system affords real-time magnetic resonance imaging (MRI) guidance during stereotactic procedures. While such information confers potential clinical benefits, additional operative time may be needed.MethodsWe conducted a retrospective analysis of procedural time associated with ClearPoint Stereotaxis, with hypothesis that this procedural time is comparable with that associated with frame-based biopsy.ResultsOf the 52 patients evaluated, the total procedural time for ClearPoint stereotactic biopsy averaged 150.0 (±40.4) minutes, of which 111.5 (±16.5) minutes were dedicated to real-time MRI acquisition and trajectory adjustment. This procedural time is within the range of those reported for frame-based needle biopsies. Approximately 5 minutes of the procedural time is related to the mounting of the MRI-compatible stereotactic frame. Based on the procedural time, we estimate that four cases are required in the learning curve to achieve this efficiency. Efficient algorithms for distortion corrections and isocenter localization are keys to ClearPoint stereotaxis. Routine quality assurance/control after each MRI software update and institutional information technology maintenance also contribute to efficiency. Real-time MRI is essential for definitive diagnosis in select cases.ConclusionsClearPoint stereotactic needle biopsy can be achieved in time frames comparable to frame-based stereotaxis. However, procedural efficiency requires 4 “learning curve” cases as well as vigilance in terms of MR distortion correction and information technology maintenance.

CTNI-20. FEASIBILITY OF SINGLE-PASS STEREOTACTIC NEEDLE BIOPSY IN RECURRENT GLIOBLASTOMA PATIENTS TO SUPPORT CLIA-CERTIFIED TUMOR PHARMACODYNAMICS FOR A PHASE 0/2 CLINICAL TRIAL

Abstract BACKGROUND In neuro-oncology clinical trials, pharmacodynamic (PD) analysis of tumor tissue before and after experimental therapy is challenging. Today, Phase 0 studies in brain tumor patients typically employ archival tissue from a prior resection as the baseline PD comparator. However, the time-interval between tissue acquisitions can be months to years and often includes confounding exposure to other therapies. Here, we demonstrate the feasibility of a pre-treatment, single-pass stereotactic needle biopsy to support CLIA-certified genetic screening and tumor PD analysis in a Phase 0/2 clinical trial. METHODS In support of an ongoing Phase 0/2 ‘trigger’ trial testing CDK4/6 plus ERK1/2 inhibition in recurrent glioblastoma (GBM), a single-pass stereotactic biopsy was completed in select patients prior to enrollment. Each biopsy yields six tissue cores for immunohistochemistry (IHC) and genetic characterization. Using CLIA-certified protocols, genomic DNA (gDNA) was extracted from two cores, followed by library preparation and next-generation sequencing of a customized panel of 37 genes (IvySeq). In the four remaining cores, IHC staining was performed for RB, pRB, pERK, pS6, CDKN2A, MIB-1, ClCas-3 and pH2AX. RESULTS Single-pass stereotactic needle biopsies were collected from five recurrent GBM patients. No intraoperative, perioperative, or radiographic evidence of morbidity was observed. 800-2400ng of gDNA was isolated from each stereotactic biopsy. IvySeq analysis detected CDKN2A deletion, ATRX loss, and mutations in IDH, PTEN and TP53 genes. Based on IHC and genetic analyses of the biopsied samples, three patients were enrolled into the Phase 0/2 clinical trial and baseline value were used for PD analysis. CONCLUSION Single-pass stereotactic needle biopsy is a feasible and safe strategy to collect pre-treatment tissue in support of a Phase 0 clinical trial, enabling CLIA-certified genetic analysis for trial screening and tumor PD analysis.

TH21. CEREBROSPINAL FLUID PROTEOMICS TARGETED FOR CENTRAL NERVOUS SYSTEM PROCESSES IN BIPOLAR DISORDER

Primary central nervous system lymphoma (PCNSL) is a rare tumor with a poor prognosis. Early brain biopsy is essential to avoid a diagnostic delay. To date, reports of successful diagnosis for PCNSL of the corpus callosum by endoscopic biopsy are rare.Herein, we report the case of an elderly woman with PCNSL of the corpus callosum who initially presented with rapidly progressive dementia. The condition was finally diagnosed by microscopic biopsy after unsuccessful endoscopic biopsy. Moreover, the postoperative course was uneventful. She is currently receiving systemic chemotherapy.Early diagnosis and subsequent systemic chemotherapy with or without whole brain radiotherapy are critical for PCNSL. Endoscopic biopsy may be a diagnostic option for suspected PCNSL, although stereotactic needle biopsy is most commonly used.Utilizing neuronavigation and 5-aminolevulinic acid (ALA) fluorescence guidance could be helpful in identifying lesions insufficiently exposed by endoscopic visualization. However, cerebrospinal fluid (CSF) loss due to the endoscopic approach through the ventricle might be a cause of neuronavigation misregistration.

Comparison of Frame-Based Versus Frameless Image-Guided Intracranial Stereotactic Brain Biopsy: A Retrospective Analysis of Safety and Efficacy

A definitive diagnosis of brain lesions not amenable to surgery is mainly made by stereotactic needle biopsy. The diagnostic yield and safety of the frameless versus frame-based image-guided stereotactic techniques is unclear. Our objective was to evaluate the safety and accuracy of frameless versus frame-based stereotactic brain biopsy techniques. A total of 278 patients (153 men; mean age: 65.5 years) with intra-axial brain lesions underwent frame-based (n= 148) or frameless image-guided stereotactic brain biopsy (n= 130) using a minimally invasive twist drill technique during 2010-2016 at Sheba Medical Center. Demographic, imaging, and clinical data were retrospectively analyzed. The diagnostic yield (>90%) did not differ significantly between groups. Overall morbidity (6.8% vs. 8.5%), incidence of permanent neurologic deficits (2.1% vs. 1.6%), mortality rate (0.7% vs. 0.8%), and postoperative computed tomography-detected asymptomatic (14.2% vs. 16.1%) and symptomatic (2.0% vs. 1.6%) bleeding also did not differ significantly between the frame-based and frameless cohorts, respectively. The diagnostic yield and complication rates related to the biopsy technique were not significantly associated with sex, age, entry angle to the skull and skull thickness, lesion location or depth, or radiologic characteristics. Diagnostic yield was significantly associated with the mean lesion volume. Smaller lesions were less diagnostic than larger lesions in both techniques (P= 0.043 frame-based and P= 0.048 frameless). The frameless biopsy technique is as efficient as the frame-based brain biopsy technique with a low complication rate. Lesion volume was the only predictive factor of diagnostic yield. The minimally invasive twist drill technique is safe and efficient.

Robotic guidance platform for laser interstitial thermal ablation and stereotactic needle biopsies: a single center experience.

While laser ablation has become an increasingly important tool in the neurosurgical oncologist’s armamentarium, deep seated lesions, and those located near critical structures require utmost accuracy during stereotactic laser catheter placement. Robotic devices have evolved significantly over the past two decades becoming an accurate and safe tool for stereotactic neurosurgery. Here, we present our single center experience with the MedTech ROSA ONE Brain robot for robotic guidance in laser interstitial thermal therapy (LITT) and stereotactic biopsies. We retrospectively analyzed the first 70 consecutive patients treated with ROSA device at a single academic medical center. Forty-three patients received needle biopsy immediately followed by LITT with the catheter placed with robotic guidance and 27 received stereotactic needle biopsy alone. All the procedures were performed frameless with skull bone fiducials for registration. We report data regarding intraoperative details, mortality and morbidity, diagnostic yield and lesion characteristics on MRI. Also, we describe the surgical workflow for both procedures. The mean age was 60.3 ± 15 years. The diagnostic yield was positive in 98.5% (n = 69). Sixty-three biopsies (90%) were supratentorial and seven (10%) were infratentorial. Gliomas represented 54.3% of the patients (n = 38). There were two postoperative deaths (2.8%). No permanent morbidity related to surgery were observed. We did not find intraoperative technical problems with the device. There was no need to reposition the needle after the initial placement. Stereotactic robotic guided placement of laser ablation catheters and biopsy needles is safe, accurate, and can be implemented into a neurosurgical workflow.

Clinical outcomes as a function of the number of samples taken during stereotactic needle biopsies: a meta-analysis.

Stereotactic needle biopsy remains the cornerstone for tissue diagnosis for tumors located in regions of the brain that are difficult to access through open surgery. We perform a meta-analysis of the literature to examine the relation between number of samples taken during biopsy and diagnostic yield, morbidity and mortality. We identified 2416 patients from 28 cohorts in studies published in PubMed database that studied stereotactic needle biopsies for tumor indications. Meta-analysis by proportions and meta-regression analyses were performed. On meta-analysis, the morbidity profile of the published needle biopsy studies clustered into three groups: studies that performed < 3 samples (n = 8), 3-6 samples (n = 13), and > 6 samples during biopsy (n = 7). Pooled estimates for biopsy related morbidity were 4.3%, 16.3%, and 17% for studies reporting < 3, 3-6, and > 6 biopsy samples, respectively. While these morbidity estimates significantly differed (p < 0.001), the diagnostic yields reported for studies performing < 3 biopsies, 3-6 samples, and > 6 samples were comparable. Pooled estimates of diagnostic yield for these three groups were 90.4%, 93.8%, and 88.1%, respectively. Mortality did not significantly differ between studies reporting differing number of samples taken during biopsy. Our meta-analysis suggests that morbidity risk in needle biopsy is non-linearly associated with the number of samples taken. There was no association between the number of biopsies taken, and diagnostic yield or mortality.

The utility of magnetic resonance spectroscopy in frame-less stereotactic needle biopsy of glioma

ObjectiveProton 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. MethodsDuring 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. Results65 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. ConclusionThe 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.

INNV-07. THE ROLE OF BIOPSY IN MOLECULAR DIAGNOSIS OF DIFFUSE INTRINSIC PONTINE GLIOMA PATIENTS

Abstract INTRODUCTION Diffuse intrinsic pontine glioma (DIPG) is an aggressive and fatal pediatric brain tumor. Due to its difficult anatomic location and infiltrative nature, DIPGs are not surgically resectable and more than 90% of children die within two years of diagnosis. Historically, standard of care has consisted of clinical and radiological diagnosis followed by palliative radiation for symptomatic relief. Although tumor biopsy is not necessary for diagnosis, there is debate as to whether the procedure provides benefits that outweighs its risk. Recent studies have proposed that biopsy-driven molecular characterization of these tumors can inform prognosis and identify potential treatment targets that could lead to clinical breakthroughs. METHODS This study was a retrospective chart review of 26 patients treated for a DIPG diagnosis between July 1998 and July 2019 at Cohen Children’s Medical Center. We compared outcomes of biopsied vs. non-biopsied DIPG patients through quantitative data analyzing the number and types of treatment given. We analyzed post-surgical data regarding safety of DIPG biopsies which were performed by optical stereotactic needle biopsy or robot-assisted stereotactic biopsy procedures. RESULTS There were no permanent biopsy complications in any patient and biopsy did not delay treatment as average hospital stay was 1.5 days. All biopsies collected sufficient material for next generation sequencing analysis and revealed targetable mutations for available clinical trial therapies. 67% of patients were subsequently enrolled in clinical trials, 75% of which required biopsy results for enrollment. MGMT promoter methylation assay results in all tested DIPG biopsy cases indicated resistance to temozolomide, the most common treatment agent given to non-biopsied patients. CONCLUSION Biopsy of DIPG tumors is a safe and accurate procedure that does not delay treatment and identifies molecular targets for individualized therapy. The role of biopsy in DIPG patients allows for molecular characterization of DIPG tumors which informs and increases treatment options.

Stereotactic Vacuum-Assisted Needle Biopsy Outcomes of Non-calcified Mammographic Lesions

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 age >50 years, lesion type, and size <15 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.

Abstract B118: Characteristics of patients with pseudoangiomatous stromal hyperplasia (PASH): A retrospective cohort study

Abstract Background: Pseudoangiomatous stromal hyperplasia (PASH) is a proliferative mesenchymal lesion of the breast histologically defined by dense collagenous stroma with spindle-shaped myofibroblasts. Characterization of patients with PASH has largely been limited to histologic and radiographic studies with small sample sizes due to the rarity of this benign condition. Furthermore, no existing studies of PASH have yet to consider race. Objectives: We undertook this study to identify subjects with PASH from electronic medical records (EMR) at the Vanderbilt University Medical Center (VUMC) and evaluate patient characteristics, including differences by race. Approach: We used natural language processing (NLP)-assisted searches to identify 283 subjects with pathology reports containing ‘PASH’ or ‘pseudoangiomatous stromal hyperplasia’. Results: We confirmed PASH by pathology report for 229 subjects (80.9%). The majority were Caucasian women, although 24 African Americans (10.5%) and 4 males (1.7%) with PASH were also identified. A total of 27 (11.8%) had a diagnosis of cancer as some point in their EMR, most frequently breast (74.1%) or thyroid (14.8%) cancer. The median age at PASH diagnosis was 45.4 years (range: 12.9-84.6) but this seemed lower among Asians (31.4 years). PASH was found more frequently in the left breast (54.8%) and was ascertained most often by core needle biopsy (76.0%), stereotactic needle biopsy (11.8%), or excision (7.0%). Among initially biopsied patients, 20 (9.9%) and 39 (19.3%) had subsequent biopsies and excisions, respectively. No significant differences in any of these characteristics by race were identified. Conclusions: This data confirms that PASH is not exclusive to Caucasians and suggests that patient characteristics do not differ by race. Analysis of additional characteristics and patient outcomes, with inclusion of EMR time, is currently underway. Citation Format: George Bukenya, Demetra Hufnagel, Nneka Anyawu, Stephanie Kurita, Alicia Beeghly-Fadiel. Characteristics of patients with pseudoangiomatous stromal hyperplasia (PASH): A retrospective cohort study [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B118.

Fluorescein-guided resection of gliomas

Standard of care in the management of high-grade gliomas includes gross total resection (GTR) followed by treatment with radiation and temozolomide. GTR remains one of the few independent prognostic factors for improved survival in this disease. Sodium fluorescein is an organic fluorophore that has been studied as a surgical adjunct to improve the likelihood of achieving GTR in gliomas. Though sodium fluorescein does not selectively accumulate in glioma cells, it allows for real-time identification of regions of blood brain barrier breakdown, corresponding to the contrast-enhancing cores of high-grade gliomas. In addition to its high predictive value for identifying pathologic tissue, use of fluorescein has been shown to improve rates of GTR. In stereotactic needle biopsies, it helps reduce procedure time by rapidly confirming the presence of diagnostic tissue. Furthermore, in non-enhancing, low-grade gliomas, it labels focal regions of vascular dysregulation that have been correlated with high-grade features. Fluorescein has also been shown to be significantly less expensive than other contemporary surgical adjuncts such as intraoperative ultrasound, intraoperative MRI, and the recently FDA approved fluorophore, 5-aminolevulinic acid (5-ALA). Here, we review the current literature on the effectiveness of fluorescein as a surgical tool in the resection of gliomas.

Current Trends for Improving Safety of Stereotactic Brain Biopsies: Advanced Optical Methods for Vessel Avoidance and Tumor Detection.

Stereotactic brain needle biopsies are indicated for deep-seated or multiple brain lesions and for patients with poor prognosis in whom the risks of resection outweigh the potential outcome benefits. The main goal of such procedures is not to improve the resection extent but to safely acquire viable tissue representative of the lesion for further comprehensive histological, immunohistochemical, and molecular analyses. Herein, we review advanced optical techniques for improvement of safety and efficacy of stereotactic needle biopsy procedures. These technologies are aimed at three main areas of improvement: (1) avoidance of vessel injury, (2) guidance for biopsy acquisition of the viable diagnostic tissue, and (3) methods for rapid intraoperative assessment of stereotactic biopsy specimens. The recent technological developments in stereotactic biopsy probe design include the incorporation of fluorescence imaging, spectroscopy, and label-free imaging techniques. The future advancements of stereotactic biopsy procedures in neuro-oncology include the incorporation of optical probes for real-time vessel detection along and around the biopsy needle trajectory and in vivo confirmation of the diagnostic tumor tissue prior to sample acquisition.

Intraoperative Molecular Imaging with Second Window Indocyanine Green Facilitates Confirmation of Contrast-Enhancing Tissue During Intracranial Stereotactic Needle Biopsy: A Case Series

Stereotactic needle biopsy provides a minimally invasive option for the diagnosis of intracranial lesions but is limited by inconclusive diagnoses on frozen pathology. For rapid pathology, 5-aminovelunic acid and sodium fluorescein have previously demonstrated potential as diagnostic adjuvants. Stereotactic biopsy with near-infrared (NIR) fluorophores has not been reported. We identified 5 representative cases using NIR fluorescent dye indocyanine green (ICG) administered in a high dose, delayed manner. Five patients underwent second window indocyanine green (SWIG)-guided stereotactic biopsy for diagnosis of suspected glioma or tumor recurrence. Up to 5 mg/kg ICG was administered approximately 24 hours prior to surgery. Biopsies were conducted in the standard fashion, targeting regions of suspected tumor using intraoperative frameless navigation. Samples were examined intraoperatively under standard visible light and for fluorescence using conventional NIR imaging platforms. Findings were correlated with frozen and final tumor pathology for all cases. A total of 10 biopsy specimens were obtained. Three did not fluoresce and did not demonstrate tumor on preliminary or final pathology, including a non-gadolinium-enhancing sample taken proximal to the final target. The remaining 7 fluoresced, of which 6 contained tumor and 1 contained necrosis. Fluorescence was also noted in a patient with radiation treatment effect. Overall fluorescence characteristics were highly concordant with preliminary and final diagnoses. SWIG provides rapid intraoperative confirmation of pathologic brain tissue by permeating neoplastic or inflammatory brain tissue via a mechanism similar to that of gadolinium enhancement. SWIG-guided stereotactic biopsy can improve surgical efficiency by enhancing confidence in acquisition of target tissue.

Molecular Features of Primary Central Nervous System Lymphoma in a Large Tissue Microarray

Molecular Features of Primary Central Nervous System Lymphoma in a Large Tissue Microarray

Tubular brain tumor biopsy improves diagnostic yield for subcortical lesions.

Molecular data has become an essential part of the updated World Health Organization (WHO) grading of central nervous system tumors. However, stereotactic needle biopsies provide only small volume specimens and limit the extent of histologic and molecular testing that can be performed. We assessed the use of a tubular retractor-based minimally invasive biopsy technique to provide improved tissue yield and diagnostic data compared to needle biopsy. Eighteen patients underwent an open transtubular biopsy compared to 146 stereotactic biopsies during the years of 2010-2018. Tubular biopsies resulted in a higher volume of tissue provided to the pathologist than needle biopsies (1.26cm3 vs. 0.3cm3; p < 0.0001). There was a higher rate of non-diagnostic sample with stereotactic compared to transtubular biopsy (13% vs. 0%; p = 0.13). Six patients who underwent stereotactic biopsy required reoperation for diagnosis, while no transtubular biopsy patient required reoperation in order to obtain a diagnostic specimen. Postoperative hematoma was the most common post-operative complication in both groups. Stereotactic transtubular biopsies are a viable alternative to stereotactic needle biopsies with excellent rates of diagnostic success and acceptable morbidity relative to the needle biopsy technique. As molecular data begins to increasingly drive treatment decisions, additional biopsy techniques that afford large tissue volumes may be necessary to adapt to the new needs of pathologists and treating oncologists.

Epigastric Paresthesia: Can It Be This Serious?

Intoduction: Paresthesia is an abnormal sensation caused by an altered sensory pathway anywhere from the peripheral nervous system up to the sensory cortex. Epigastric paresthesia is an unusual presentation that sometimes warrants an extensive workup to rule out any gastrointestinal pathology. In our patient the result of the workup was unexpected. Case Summary: A 58-year-old male with a history of hypertension and diabetes presented to the hospital with epigastric numbness and warmth sensation of 2 weeks duration. His numbness episodes were sudden, lasting 2-3 minutes, starting in the epigastric area, then spreading to the whole abdomen and extremities. These episodes were associated with nausea and vomiting but no abdominal pain, diarrhea or constipation. A Computed Tomography (CT) scans of the head, abdomen and pelvis were negative. Esophagogastroduodenoscopy (EGD) was negative for any pathology. Due to the suspicion of seizures, an Electroencephalogram (EEG) was done and showed spikes consistent with seizure tendency. A Magnetic Resonance Imaging (MRI) of the brain showed focal asymmetric enlargement of the left posterior medial temporal lobe with inhomogeneous mass enhancement concerning for a neoplasm (Figure 1-A, 2-A). A multi-disciplinary discussion including neurology, neurosurgery, and oncology thought that the MRI findings were secondary to enhancement from seizures, but the neoplastic process was not excluded. Patient was discharged on Levetiracetam 750 mg BID, with a scheduled MRI in 4 weeks. The repeat MRI showed increasing size and enhancement of the lesion concerning for a primary brain tumor (Figure 1-B, 2-B). As a result, a stereotactic needle biopsy and laser interstitial thermotherapy were performed, and the pathology showed high-grade glioma. His post-operative course was unremarkable, and he was discharged to follow up with neuro-oncology and neurosurgery. Conclusion: Epigastric paresthesia is a rare presentation, and when it is associated with GI upset it warrants a workup to rule out any GI pathology. Given the seriousness of the diagnosis in our patient, primary brain tumor should be considered with patients presenting with abdominal paresthesia.2477_A Figure 1. A: Brain mass at first presentation B: Brain mass 4 weeks later2477_B Figure 2. A: Brain mass at first presentation B: Brain mass 4 weeks later