Stereotactic Brain Biopsy Research Articles

A rare occurrence of primary basal ganglia germinoma in an adult patient

Background: Basal ganglia germinomas (BGGs) represent a diagnostic and management neurosurgical dilemma. Because of the rarity of these tumors in adults, the management strategies are not well defined. Case description: A 24-year-old man was presented with progressive left-sided hemiparesis. Cranial computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a heterogeneous lesion with few microcystic nodules, seen involving the right basal ganglia with calcification. A stereotactic brain biopsy (SBB) was obtained. Histopathology revealed BGG. The patient received whole-brain radiation therapy (WBRT) and reported marked improvement in symptoms with no recurrence during a follow-up period of four years. Conclusion: BGG should be considered a part of the differential diagnosis in young adults presented with hemiparesis and a heterogeneous lesion in the basal ganglia. Standard recommendations for the management of such rare lesions in adults are needed.

P07.02 Robot-assisted stereotactic brain biopsy combined with cortical mapping using navigated transcranial magnetic stimulation

Abstract BACKGROUND Frame-based stereotactic biopsy has been for decades the gold-standard method for taking samples of brain tumors for the histopathological diagnostic in cases when surgery was contraindicated. However, novel frameless techniques have been developed in order to facilitate the procedure for the neurosurgeon, and for the patient as well. Preoperative cortical mapping techniques enable the planning of the trajectory with the sparing of eloquent areas. MATERIAL AND METHODS A preoperative cortical mapping using navigated transcranial magnetic stimulation was performed in the case of a 37-year-old male that presented with headache. The MRI scan revealed multiple lesions located frontal lobe and temporal lobe on the right hemisphere and frontal and occipital lobes on the left hemisphere. The results of the preoperative cortical mapping were integrated into the neuronavigation system and used for the planning of the frameless based stereotactic brain biopsy. A biopsy procedure was performed using a robotic arm according to the planned trajectory. RESULTS The targeted lesion was the right frontal one. The planned trajectory took into account the results from the cortical mapping using nTMS, and the eloquent areas were avoided. The robotic arm guided the procedure and aligned to the entry point and trajectory. According to the histopathological result the lesion was a grade II diffuse astrocytoma. There were no perioperative complications. CONCLUSION To our knowledge, this is the first report that describes the use of a robot-guided frameless brain biopsy system combined with the preoperative mapping of the eloquent cortical areas using navigated transcranial magnetic stimulation. This approach is a safe one and carries less burden for the patient as well as for the surgeon.

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.

Outpatient stereotactic brain biopsies.

Outpatient neurosurgery is rising popularity leading to patients’ satisfaction and cost-savings. Although several North-American teams have shown the safety of outpatient stereotactic brain biopsies, few data from other countries with different health care systems are available. We therefore conducted a feasibility and safety study on the outpatient stereotactic brain biopsies. We prospectively examined all the consecutive stereotactic brain biopsies performed in an outpatient setting at our tertiary medical center, between June 2018 and September 2020. Among the 437 patients who underwent stereotactic brain biopsy during the study period, 40 (9.2%) patients were enrolled for an outpatient management. The sex ratio was 1 and the median age on biopsy day was 55 [41–66] years. The median distance from patients’ home to hospital was 17 km [3–47]. 95% of patients had pre-biopsy ASA score of 1 or 2 and mRs equal to 2 or less. The rate of same-day discharge was 100%. No patient experienced post-biopsy symptomatic complication necessitating readmission within the month following the biopsy. One patient (2.5%) resorted to an unplanned consultation. Histological findings obtained from brain biopsy led to a diagnosis in all patients; the most frequently found were neoplastic lesions (77.5%). Stereotactic brain biopsies can therefore be safely achieved on an outpatient setting in carefully selected patients. This process could be more widely adopted in other neurosurgical centers, without affecting the quality of patient’s health care and safety. In this article, we propose management guidelines and pre-biopsy checklist for performing ambulatory stereotactic brain biopsies.

Frameless stereotactic brain biopsy: technical considerations and clinical results regarding safety and efficacy

Frameless stereotactic brain biopsy: technical considerations and clinical results regarding safety and efficacy

Application of multimodal MRI and radiologic features for stereotactic brain biopsy: insights from a series of 208 patients

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<.01) and edema of lesions (p<.05). Enhancement (p<.01) is shown to be an important factor for obtaining a diagnostic biopsy. Furthermore, the edema trait of lesions (p<.01) showed the important factors of hemorrhage. Conclusions The radiological features of lesions and use of the most suitable MRI sequences during biopsy planning are recommended ways to improve the diagnostic yield and safety of this technique.

The role of surgical resection in primary central nervous system lymphoma: a single-center retrospective analysis of 70 patients

BackgroundThe aim of this study was to evaluate the effect of surgical resection and stereotactic biopsy on the complication rate, progression-free survival (PFS) and overall survival (OS) of 70 patients diagnosed at a single institution with primary central nervous system lymphoma (PCNSL) and to explore the predictors of selection for resection and the prognostic factors of PCNSL.MethodsA retrospective analysis was performed of 70 patients with PCNSL that was diagnosed by surgical resection or stereotactic brain biopsy in our department from January 2013 to May 2019. We divided the patients into two groups: a resection group (n = 28) and a stereotactic biopsy group (n = 42). Data on clinical characteristics, imaging findings, complication rates, PFS and OS were retrospectively reviewed and compared between these two groups. We also analysed the predictors of selection for resection and prognostic factors of PCNSL by multivariate analysis.ResultsThe median age was 53.3 ± 14.3 years, and there was a male predominance with a sex ratio of 1.33:1. The most common clinical manifestation was a headache. The complication rate in the resection group was 10.7% versus 7.1% in the stereotactic biopsy group, and there was no statistically significant difference. The rate of improvement in symptoms of the resection group was significantly higher than that of the stereotactic biopsy group. Multivariable analysis identified a single tumour and not involving deep structures as predictors of selection for resection. With a median follow-up of 30 months (range 1–110), the mean OS and PFS of all patients were 16.1 months and 6.2 months, respectively. Patients who underwent surgical resection had a mean OS of 23.4 months and PFS of 8.6 months versus 11.2 months and 4.6 months for those who had a brain biopsy performed. In addition, multivariable analysis showed that not involving deep structures and resection were favourable prognostic factors for PCNSL.ConclusionsThe outcomes of patients with PCNSL treated in our cohort are still poor. In our series, surgical resection might play a role in significantly improving OS and PFS compared with stereotactic biopsy in a subset of patients. The type of surgery and tumour location are prognostic factors for PCNSL.

Feasibility and accuracy of 3D printed patient-specific skull contoured brain biopsy guides.

ObjectiveDesign 3D printed skull contoured brain biopsy guides (3D‐SCGs) from computed tomography (CT) or T1‐weighted magnetic resonance imaging (T1W MRI).Study DesignFeasibility study.Sample PopulationFive beagle dog cadavers and two client‐owned dogs with brain tumors.MethodsHelical CT and T1W MRI were performed on cadavers. Planned target point was the head of the caudate nucleus. Three‐dimensional‐SCGs were created from CT and MRI using commercially available open‐source software. Using 3D‐SCGs, biopsy needles were placed into the caudate nucleus in cadavers, and CT was performed to assess needle placement accuracy, followed by histopathology. Three‐dimensional‐SCGs were then created and used to perform in vivo brain tumor biopsies.ResultsNo statistical difference was found between the planned target point and needle placement. Median needle placement error for all planned target points was 2.7 mm (range: 0.86–4.5 mm). No difference in accuracy was detected between MRI and CT‐designed 3D‐SCGs. Median needle placement error for the CT was 2.8 mm (range: 0.86–4.5 mm), and 2.2 mm (range: 1.7–2.7 mm) for MRI. Biopsy needles were successfully placed into the target in the two dogs with brain tumors and biopsy was successfully acquired in one dog.ConclusionThree‐dimensional‐SCGs designed from CT or T1W MRI allowed needle placement within 4.5 mm of the intended target in all procedures, resulting in successful biopsy in one of two live dogs.Clinical SignificanceThis feasibility study justifies further evaluation of 3D‐SCGs as alternatives in facilities that do not have access to stereotactic brain biopsy.

Frameless stereotactic brain biopsy: A prospective study on robot-assisted brain biopsies performed on 32 patients by using the RONNA G4 system.

We present a novel robotic neuronavigation system (RONNA G4), used for precise preoperative planning and frameless neuronavigation, developed by a research group from the University of Zagreb and neurosurgeons from the University Hospital Dubrava, Zagreb, Croatia. The aim of study is to provide comprehensive error measurement analysis of the system used for the brain biopsy. Frameless stereotactic robot-assisted biopsies were performed on 32 consecutive patients. Post-operative CT and MRI scans were assessed to precisely measure and calculate target point error (TPE) and entry point error (EPE). The application accuracy of the RONNA system for TPE was 1.95±1.11mm, while for EPE was 1.42±0.74mm. The total diagnostic yield was 96.87%. Linear regression showed statistical significance between the TPE and EPE, and the angle of the trajectory on the bone. The RONNA G4 robotic system is a precise and highly accurate autonomous neurosurgical assistant for performing frameless brain biopsies.

Frame-based versus frameless stereotactic brain biopsies: A systematic review and meta-analysis.

Background: Stereotactic brain biopsy techniques have been a focus of rapid technological innovation. The recent advent of frameless stereotaxy has invited the question of whether it can provide the same diagnostic yield as frame-based techniques, without increasing risk of harm to patients. The goal of this meta-analysis was to compare each of these techniques in terms of yield and safety.Methods: We independently searched four databases for English studies comparing frameless and frame-based stereotactic brain biopsies. Our primary outcome was biopsy diagnostic yield. Our secondary outcomes included mortality, morbidity (e.g., symptomatic postbiopsy intracranial hemorrhage, asymptomatic postbiopsy intracranial hemorrhage, new postbiopsy neurological deficit, and postbiopsy seizure), and frequency of repeat biopsy. We calculated pooled estimates and relative risks for dichotomous outcomes using Review Manager 5.3, with corresponding 95% confidence intervals.Results: A total of 3256 stereotactic brain biopsies (2050 frame based and 1206 frameless), from 20 studies, were included in our final analysis. The results did not demonstrate any significant difference between the two stereotactic systems in terms of diagnostic yield (risk ratio [RR] 1.00, 95% confidence interval [CI] 0.99–1.02, P = 0.64, I2 = 0%). The only significant difference was the increased frequency of asymptomatic hemorrhages in the frameless group (RR 1.37, 95% CI 1.06–1.75, P = 0.01, I2 = 0%). Application of Grading of Recommendations Assessment, Development, and Evaluation to the results yielded very low quality of all outcomes.Conclusion: Based on very low-quality evidence, both frame-based and frameless stereotaxy are safe and effective for biopsy of intracranial tumors. Further study of patient preference and cost comparing analysis is required to identify if either modality should be preferred.

Hemorrhagic Attitude in Frameless and Frame-Based Stereotactic Biopsy for Deep-Seated Primary Central Nervous System Lymphomas in Immunocompetent Patients: A Multicentric Analysis of the Last Twenty Years

Primary central nervous system lymphoma (PCNSL) is a rare manifestation of aggressive extranodal non-Hodgkin lymphoma. In patients with deep-seated lesions, stereotactic brain biopsy (SBB) is an accepted diagnostic procedure to obtain histopathologic confirmation. The aim of this study was to assess the feasibility, diagnostic yield, safety, and complications of stereotactic procedures in midline and deep-seated PCNSLs. Patients selected had received a histopathologic diagnosis of PCNSL localized in deep-seated midline structures, obtained by SBB. The intraoperative frozen section was executed as an integral part of the procedure. Computed tomography scan was performed after surgery. A total of 476 SBBs were performed between January 2000 and December 2019 . Of these SBBs, 91 deep-seated lesions had a histologic diagnosis of PCNSL. A significant increase of the incidence of PCNSL compared with all other diseases was observed (P < 0.0001). Eight patients (8.7%) showed a symptomatic hemorrhage, 4 of whom required craniotomy. There were 4 deaths and 2 cases of permanent morbidity. The hemorrhage risk in the PCNSL group was statistically significant (P= 0.0003) compared with other histotypes. In suspected cases of PCNSL, a histopathologic diagnosis is necessary to distinguish it from glioblastoma or other, nonmalignant conditions. Deep-seated PCNSLs present a higher risk of biopsy-related morbidity and mortality. Intraoperative frozen section increases the diagnostic yield and reduces the number of sampling procedures. Postoperative computed tomography seems to be warranted in patients with suspected PCNSL.

A single-centre study of frame-based stereotactic brain biopsies

Objective We aimed to evaluate the concordance between the image-based and the tissue-based diagnosis using frame-based stereotactic biopsy. Materials and methods 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. Results 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. Conclusions 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.

Acyclovir-Responsive Glioma: The Need for Vigilant Diagnosis

We report a case of an acyclovir-responsive glioma, which was initially misdiagnosed as herpes simplex encephalitis (HSE). Intravenous acyclovir alone, without corticosteroid, dramatically improved the patient’s symptoms and magnetic resonance imaging findings. He developed headache and amnesia after 1 year, when the stereotactic brain biopsy confirmed the final diagnosis of a glioblastoma, isocitrate dehydrogenase-1 wild-type. In retrospect, some of his sero-radiologic findings were not consistent with HSE. Polymerase chain reaction for herpes simplex virus in the cerebrospinal fluid tested negative. Parieto-occipital involvement and absence of post-treatment atrophy were also signs against HSE. We suggested that a low-grade glioma was present from the beginning and later underwent malignant transformation. The diagnosis of HSE should be made carefully. Acyclovir might also work on gliomas; this is confirmed by a typical clinical picture of HSE and a clear acyclovir-response. A vigilant review of the paraclinical features may shed light on the correct diagnosis. Key words: Encephalitis, herpes simplex; Glioblastoma; Neuroimaging; Neuropathology

Stereotactic Biopsy in The Diagnosis of Small Brain Lesion

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.&#x0D; 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.&#x0D; Materials and Methods: Twenty-five patients underwent stereotactic biopsy of brain lesions using“KOMAI” Stereotactic frame system and were enrolled.&#x0D; 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.&#x0D; 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.&#x0D; J Bangladesh Coll Phys Surg 2021; 39(1): 24-35

Comparing Fiducial-Based and Intraoperative Computed Tomography-Based Registration for Frameless Stereotactic Brain Biopsy

Objective: The aim of this work was to compare fiducial-based and intraoperative computed tomography (iCT)-based registration for frameless stereotactic brain biopsy. Methods: Of 50 frameless stereotactic biopsies with the VarioGuide, 30 cases were registered as iCT based and 20 as fiducial based. Statistical analysis of the target registration error (TRE), dose length product, effective radiation dose (ED), operation time, and diagnostic yield was performed. Results: The mean TRE was significantly lower using iCT-based registration (mean ± SD: 0.70 ± 0.32 vs. 2.43 ± 0.73 mm, p < 0.0001). The ED was significantly lower when using iCT-based registration compared to standard navigational CT (mean ± SD: 0.10 ± 0.13 vs. 2.23 ± 0.34 mSv, p < 0.0001). Post-biopsy iCT was associated with a significant lower (p < 0.0001) ED compared to standard CT (mean ± SD: 1.04 ± 0.18 vs. 1.65 ± 0.26 mSv). The mean surgical time was shorter using iCT-based registration, although the mean total operating room (OR) time did not differ significantly. The diagnostic yield was 96.7% (iCT group) versus 95% (fiducial group). Post-biopsy imaging revealed severe bleeding in 3.3% (iCT group) versus 5% (fiducial group). Conclusion: iCT-based registration for frameless stereotactic biopsies increases the accuracy significantly without negative effects on the surgical time or the overall time in the OR. Appropriate scan protocols in iCT registration contribute to a significant reduction of the radiation exposure. The high accuracy of the iCT makes it the more favorable registration strategy when taking biopsies of small tumors or lesions near eloquent brain areas.

Stereotactic Brain Biopsy Hemorrhage Risk Factors and Implications for Postoperative Care at a Single Institution: An Argument For Postoperative Imaging

To determine preoperative factors contributing to postoperative hemorrhage after stereotactic brain biopsy (STB), clinical implications of postoperative hemorrhage, and the role of postoperative imaging in clinical management. Retrospective review of STB (2005-2018) across 2 institutions including patients aged >18 years undergoing first STB. Patients with prior craniotomy, open biopsy, or prior STB were excluded. Preoperative variables included age, sex, neurosurgeon seniority, STB method. Postoperative variables included pathology, postoperative hemorrhage on computed tomography, immediate and 30-day postoperative seizure, infection, postoperative hospital stay duration, and 30-day return to operating room (OR). Analysis used the Fisher exact tests for categorical variables. Overall, 410 patients were included. Average age was 56.5 (±16.5) years; 60% (n= 248) were men. The majority of biopsies were performed by senior neurosurgeons (66%, n= 270); frontal lobe (42%, n= 182) and glioblastoma (45%, n= 186) were the most common location and pathology. Postoperative hemorrhage occurred in 28% (114) of patients with 20% <0.05 cm3 and 8% >0.05 cm3. Postoperative hemorrhage of any size was associated with increased rate of postoperative deficit within both 24 hours and 30 days, postoperative seizure, and length of hospital stay when controlling for pathology. Hemorrhages >0.05 cm3 had a 16% higher rate of return to the OR for evacuation, due to clinical deterioration as opposed to radiographic progression. Postbiopsy hemorrhage was associated with higher risk of immediate and delayed postoperative deficit and seizure. Postoperative computed tomography should be used to determine whether STB patients can be discharged same day or admitted for observation; clinical evaluation should determine return to OR for evacuation.

A comparison of the efficacy, safety, and duration of frame-based and Remebot robot-assisted frameless stereotactic biopsy

Objective 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. Patients and methods 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 (n = 35) and the Remebot robot group (n = 31). Data on clinical characteristics, total procedure length, overall discomfort, diagnostic yield, complications, and postoperative length of hospital stay were retrospectively reviewed and compared between these two groups. Results 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 (p < 0.001). There were no statistically significant differences in complication rate or postoperative duration of hospitalization between the two groups. The overall patient discomfort in the frame-based group was significantly greater than that in the Remebot robot group (visual analog scale score 2.7 ± 1.2 versus 1.5 ± 0.7, p = 0.001). Conclusions 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.

Risk factors for adverse events occurring after recovery from stereotactic brain biopsy in dogs with primary intracranial neoplasia.

BackgroundStereotactic brain biopsy (SBB) allows for histopathologic diagnosis of brain tumors. Adverse events (AE) occur in 5 to 29% of dogs after SBB, but risk factors associated with developing AE are poorly described.ObjectiveIdentify clinicopathologic, diagnostic imaging, or procedural variables that are associated with AE in dogs after SBB.AnimalsTwenty‐nine dogs with brain tumors.MethodsRetrospective, case‐control study. Dogs had laboratory investigations performed before SBB, as well as clinical examinations and diagnostic imaging of the brain before and after SBB. Cases experienced AE after SBB including transient exacerbation of preexisting neurologic deficits, transient new deficits, or permanent neurologic deficits. Controls had SBB performed without AE. Fisher's exact and Student's t tests were used to examine associations between the postulated risk factors and AE.ResultsAdverse events occurred in 8/29 (27%) dogs, and 7/8 AE (88%) were transient. Cases were significantly more likely to have T2W‐heterogenous tumors (88 versus 38%; P = .04) and lower platelet counts (194.75 ± 108.32 versus 284.29 ± 68.54 ×103/mm3, P = .006). Dogs with gradient echo signal voids present on baseline imaging were significantly more likely to have hemorrhage present after biopsy, and 7/8 (88%) of cases had hemorrhage on imaging after SBB.Conclusion and Clinical ImportanceTwenty‐seven percent of dogs undergoing SBB experience AE, with the majority of AE resolving with 1 week. Platelet counts should be ≥185 000/mm3 to minimize risk of SBB‐associated AE. Observation of intracranial hemorrhage after biopsy can have important clinical implications, as this was observed in 88% of dogs with AE.

Frameless Stereotactic Brain Biopsies: Comparison of Minimally Invasive Robot-Guided and Manual Arm-Based Technique.

Most brain biopsies are still performed with the aid of a navigation-guided mechanical arm. Due to the manual trajectory alignment without rigid skull contact, frameless aiming devices are prone to considerably lower accuracy. To compare a novel minimally invasive robot-guided biopsy technique with rigid skull fixation to a standard frameless manual arm biopsy procedure. Accuracy, procedural duration, diagnostic yield, complication rate, and cosmetic result were retrospectively assessed in 40 consecutive cases of frameless stereotactic biopsies and compared between a minimally invasive robotic technique using the iSYS1 guidance device (iSYS Medizintechnik GmbH) (robot-guided group [ROB], n=20) and a manual arm-based technique (group MAN, n=20). Application of the robotic technique resulted in significantly higher accuracy at entry point (group ROB median 1.5mm [0.4-3.2mm] vs manual arm-based group (MAN) 2.2mm [0.2-5.2mm], P=.019) and at target point (group ROB 1.5mm [0.4-2.8mm] vs group MAN 2.8mm [1.4-4.9mm], P=.001), without increasing incision to suture time (group ROB 30.0min [20-45min vs group MAN 32.5min [range 20-60min], P=.09) and significantly shorter skin incision length (group ROB 16.3mm [12.7-23.4mm] vs group MAN 24.2mm [18.0-37.0mm], P=.008). According to our data, the proposed technique of minimally invasive robot-guided brain biopsies can improve accuracy without increasing operating time while being equally safe and effective compared to a standard frameless arm-based manual biopsy technique.

Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety

ObjectiveTo evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous system (PACNS).MethodsA standardized stereotactic biopsy targeting MRI-positive lesions and collecting samples from the meninges and the cortex as well as from the white matter was performed in 23 patients with clinically suspected PACNS between 2010 and 2017. The relationship between biopsy yield and clinical characteristics, cerebrospinal fluid parameters, MR-imaging, time point of biopsy and exact localization of biopsy as well as number of tissue samples were examined.ResultsPACNS was confirmed in 7 of 23 patients (30.4%). Alternative diagnoses were identified in 7 patients (30%). A shorter time period between the onset or worsening of symptoms (p = 0.018) and ESBB significantly increased the diagnostic yield. We observed only minor and transient postoperative complications in 3 patients (13.0%). ESBB led to a direct change of the therapeutic regime in 13 of 23 patients (56.5%). Careful neuropathological analysis furthermore revealed that cortical samples were crucial in obtaining a diagnosis.ConclusionESBB is a safe approach with good feasibility, even in critically ill patients, and high diagnostic accuracy in patients with suspected PACNS changing future therapies in 13 of 23 patients (56.5%). Early biopsy after symptom onset/worsening is crucial and (sub)acute MRI-lesions should be targeted with a particular need for biopsy samples from the cortical layer.