Increasing the diagnostic yield of stereotactic brain biopsy using intraoperative histological smear

Anticipating complications in stereotactic brain biopsy: a predictive approach

Stereotactic brain biopsy is a critical procedure in neurosurgery, particularly for the diagnosis of brain tumors and cryptogenic neurological diseases. Despite its safety profile, biopsy procedures carry a risk of complications. This study aimed to identify predictors of symptomatic complications in a large cohort and develop a risk prediction score. This retrospective single-center study examined data from 2,338 stereotactic brain biopsies performed over 15 years. The primary outcomes included complication rates, severity, timing, and management. Factors such as patient demographics, medical history, lesion characteristics, and biopsy procedures were analyzed. Predictive models were created using least absolute shrinkage and selection operator (LASSO) regression to select key variables with cross-validation and a random forest algorithm for further refinement. Owing to insufficient predictive performance for clinical use, we used variables selected by LASSO regression to construct an analytical multivariate model. Symptomatic complications occurred in 3.9% (95% confidence interval (CI) 3.1-4.7) of cases, with 0.8% being fatal. Of the symptomatic complications, 46.2% occurred within the first hour following biopsy and 71.4% within two hours. Key predictive factors included biopsy repetition (odds ratio, 3.3; 95%CI [1.1-9.6], p = 0.050), advanced age (1.2 [1.02-1.4], p = 0.048), lesion location (brainstem (4.1 [1.6-10.4], p = 0.004), pineal region (16.2 [3.0-89.4], p = 0.001), deep brain (1.8 [1.1-2.9], p = 0.016)), and toxoplasmosis (4.9 [1.4-17.7], p = 0.038). The best predictive model achieved an area under the curve (AUC) of only 0.64 and the random forest models had poorer discriminative accuracy (AUC < 0.6). Symptomatic complications following stereotactic brain biopsy are rare, but are associated with specific patient profiles. Although predictive modeling provided moderate accuracy, further refinement is necessary for reliable risk stratification. Awareness of high-risk patient characteristics and rigorous procedural planning are essential for minimizing complications. Future studies should explore advanced predictive methods and refine the risk assessment tools to improve patient outcomes.

The utilization of cytology for intraoperative diagnosis of primary central nervous system lymphoma

To investigate the diagnostic value of intraoperative cytology and rapid immunocytochemistry in primary central nervous system lymphoma. 254 cases of lymphoma and 82 cases of non-lymphoma were collected from 2010 to 2023. Frozen section(FS) was using alone in 44 cases during 2010-2014, FS and intraoperative cytology(IC) were using in 251 cases during 2015 to 2022. Rapid immunocytochemical(RICC, CD20, GFAP) were using with FS + IC in 41 cases during 2021 to 2023. Method One: According to the results of archives, statistic the diagnostic accuracy of lymphoma during three time periods. Method Two: All cases were randomly renumbered, 4 neuropathologists compared the accuracy of independent histology and that of combining cytology. The archives showed the diagnostic accuracy of FS in PCNSL was 77.27%, FS + IC was 86.06%, FS + IC + RICC was 92.68%. The retrospective study demonstrated the diagnostic accuracy of FS was 79.76%, FS + IC was 87.33% and FS + IC + RICC was 92.68%. The positive predictive value, negative predictive value, sensitivity, specificity and accuracy of CD20 were 100%, 76.92%, 90.32%, 100% and 92.68%, respectively. The results of the paired χ2 test was no statistically significant difference (0.05 < P < 0.1) between FS + IC + RICC and immunohistochemical (IHC) diagnosis of paraffin sections. The integration of IC + RICC + FS diagnosis can significantly enhance the intraoperative diagnostic accuracy of PCNSL and rectify potential errors that may occurred when relying solely on FS diagnosis.

Surgical results in patients with CNS lymphoma. Comparison of predictive value of intraoperative MRI and intraoperative histological examination for diagnostic biopsy yield

Introduction

Central nervous system lymphoma poses significant diagnostic challenges, with stereotactic biopsy being the gold standard for diagnosis. Intraoperative magnetic resonance imaging and intraoperative histological examination are utilized to enhance biopsy yield, yet their comparative efficacy remains unclear.

Research question

This study aims to compare the diagnostic yield of intraoperative magnetic resonance imaging and intraoperative histological examination in stereotactic brain biopsies for central nervous system lymphoma.

Materials and methods

A retrospective analysis was conducted on 115 patients who underwent stereotactic brain biopsies for central nervous system lymphoma. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of intraoperative magnetic resonance imaging and intraoperative histological examination were assessed and compared.

Results

Out of 125 surgeries, frameless biopsies were the most common, accounting for 74.4 percent. Intraoperative magnetic resonance imaging demonstrated a sensitivity of 80.00 percent and a specificity of 98.51 percent (AUC = 0.893, p = 0.004), whereas intraoperative histological examination showed a sensitivity of 66.67 percent and a specificity of 59.09 percent (AUC = 0.629, p = 0.459).

Discussion and conclusions

The study emphasizes the critical role of intraoperative examinations, thus improving precision and diagnostic yield in the surgical management of central nervous system lymphoma. Intraoperative magnetic resonance imaging outperforms intraoperative histological examination in terms of sensitivity and specificity for confirming positive biopsy yields in central nervous system lymphoma, thereby reducing the need for additional surgeries. These findings support the routine use of intraoperative magnetic resonance imaging in the surgical strategy for central nervous system lymphoma to improve diagnostic accuracy and patient outcomes.

Sodium fluorescein and 5-aminolevulinic acid fluorescence- guided biopsy in brain lesions: a systematic review and meta-analysis

PURPOSE

Stereotactic brain biopsies are highly efficient for diagnosing intracerebral pathologies, particularly when surgical resection is infeasible. Fluorescence-based agents such as 5-aminolevulinic acid (5-ALA) and fluorescein sodium (NaFl) can enhance diagnostic accuracy and safety, improving the visualization of lesional tissues. This meta-analysis aimed to evaluate their effect on diagnostic yield and complication rates of brain biopsies.

METHODS

This study adhered to Cochrane and PRISMA guidelines. We assessed studies for diagnostic yield and complication rates. Data was analyzed using a random-effects model in RStudio. Diagnostic accuracy measures such as sensitivity and predictive values were calculated based on fluorescence visibility in biopsy samples.

RESULTS

Thirty-two non-randomized studies were included, comprising 947 patients, with a mean age ranging from 37 to 77 years, and a mean sample number ranging from 1 to 15 specimens. Diagnostic yields were high: 93% for NaFl and 96% for 5-ALA. Major complications occurred in 3% of procedures with both agents, while minor complications were reported in 7% and 5% with NaFl and 5-ALA respectively. The Negative-predictive-value (NPV) of 5-ALA and NaFl were 8-11% and 60-80% respectively. NaFl demonstrates higher sensitivity and specificity at 84% and 100% compared to 5-ALA's 66%. and 85% respectively.

CONCLUSION

5-ALA and NaFl provide high diagnostic yields with acceptable safety profiles in stereotactic biopsies. NaFl showed higher sensitivity and specificity. NaFl outperforms 5ALA in terms of NPV making it more efficient for small lesions near eloquent regions or major blood vessels. The significance of these findings can be further ascertained through randomized trials.

Diagnostic yield of postmortem brain examination following premortem brain biopsy for neoplastic and nonneoplastic disease

Medical autopsies have decreased in frequency due in part to advances in radiological techniques and increased availability of molecular and other ancillary testing. However, premortem diagnosis of CNS disease remains challenging; while ∼90% of brain tumor biopsies are diagnostic, only 20%-70% of biopsies for presumed nonneoplastic disease result in a specific diagnosis. The added benefits of performing an autopsy following surgical brain biopsy are not well defined. A retrospective analysis was performed of patients who underwent brain biopsy and autopsy at Brigham and Women's Hospital from 2003 to 2022. A total of 135 cases were identified, including 95 (70%) patients with primary CNS neoplasms, 16 (12%) with metastatic tumors, and 24 (18%) with nonneoplastic neurological disease. Diagnostic concordance between biopsy and autopsy diagnosis was excellent both for primary CNS neoplasms (98%) and metastatic tumors (94%). Conversely, patients with nonneoplastic disease received definitive premortem diagnoses in 7/24 (29%) cases. Five (21%) additional patients received conclusive diagnoses following autopsy; 8 (33%) received a more specific differential diagnosis compared to the biopsy. Overall, autopsy confirmed premortem diagnoses or provided new diagnostic information in 131/135 (97%) cases, highlighting the value in performing postmortem brain examination in patients with both neoplastic and nonneoplastic diseases.

Use of fluorescein sodium-assisted intraoperative sample validation to maximize the diagnostic yield of stereotactic brain biopsy: progress toward a new standard of care?

OBJECTIVE

In patients with contraindication to open resection, histological diagnosis is obtained through a stereotactic biopsy (SB). Missed diagnoses and sampling errors are important limitations of SB; therefore, various ways have been proposed to increase the diagnostic yield (DY). Intraoperative histopathology can obtain a DY exceeding 98% but with several drawbacks, namely prolonged operative times and logistic concerns. The objective of this study was to evaluate whether intraoperative validation of samples with fluorescein sodium can obtain a high DY with the same ease of use as standard SB.

METHODS

One hundred three consecutive cases of frameless neuronavigated SB performed at the authors' center from May 2013 to June 2021 were included. Two groups were compared: 46 patients underwent standard nonassisted SB (nSB), and 57 patients underwent fluorescein sodium-assisted SB (fSB). Data were collected retrospectively before 2017 and prospectively thereafter. DY, operative time, and rate of complications were compared between the two groups. The surgical technique for fSB was standardized, and a novel classification system for intraoperative fluorescence findings was developed.

RESULTS

Statistically significant differences between the two groups were identified. The DY of the fSB group (100%, 95% CI 93.73%-100%) was significantly greater than that of the nSB group (89.13%, 95% CI 80.14%-98.13%) (p = 0.0157). No statistically significant differences were observed in terms of mean operative time (p = 0.7104), intraoperative complications (p = 0.999), or postoperative complications (p = 0.5083).

CONCLUSIONS

Compared with standard nSB, fSB showed a significantly higher DY and similar surgical time and rate of complications. The ease of use, wide diagnostic spectrum, and low cost make fluorescein sodium preferable to other fluorophores. The present study strengthens the limited data in the literature indicating routine use of fSB. The proposed workflow suggests that fSB should be the standard of care for contrast-enhanced cases. Intraoperative histopathology should be limited to nonenhancing cases, and nSB should be avoided. Future prospective multicenter studies will be useful for further validation of our findings.

Advances, technological innovations, and future prospects in stereotactic brain biopsies

Stereotactic brain biopsy is one of the most frequently performed brain surgeries. This review aimed to expose the latest cutting-edge and updated technologies and innovations available to neurosurgeons to safely perform stereotactic brain biopsy by minimizing the risks of complications and ensuring that the procedure is successful, leading to a histological diagnosis. We also examined methods for improving preoperative, intraoperative, and postoperative workflows. We performed a comprehensive state-of-the-art literature review. Intraoperative histology, fluorescence, and imaging techniques appear as smart tools to improve the diagnostic yield of biopsy. Constant innovations such as optical methods and augmented reality are also being made to increase patient safety. Robotics and integrated imaging techniques provide an enhanced intraoperative workflow. Patients' management algorithms based on early discharge after biopsy optimize the patient's personal experience and make the most efficient possible use of the available hospital resources. Many new trends are emerging, constantly improving patient care and safety, as well as surgical workflow. A parameter that must be considered is the cost-effectiveness of these devices and the possibility of using them on a daily basis. The decision to implement a new instrument in the surgical workflow should also be dependent on the number of procedures per year, the existing stereotactic equipment, and the experience of each center. Research on patients' postbiopsy management is another mandatory approach to enhance the safety profile of stereotactic brain biopsy and patient satisfaction, as well as to reduce healthcare costs.

Roles and outcomes of stereotactic biopsy for adult patients with brainstem lesion

PURPOSE

This study aimed to assess the benefit-risk ratio by determining diagnostic yield and safety of brainstem biopsies in adult patients. The secondary objectives were (i) to compare brainstem biopsy safety and postbiopsy patients' outcomes and survival with those of patients biopsied for a brain or cerebellar lesion, and (ii) to assess the impact of brainstem biopsy on final diagnosis and further therapeutic management.

METHODS

Among 1784 stereotactic biopsies performed in adult patients at a tertiary center between April 2009 and October 2020, we retrospectively examined 50 consecutive brainstem biopsies. We compared variables regarding diagnostic yield, safety and post-biopsy outcomes between brainstem biopsy patients and brain/cerebellum biopsy patients.

RESULTS

Brainstem biopsy led to a diagnosis in 86% of patients (94.6% in patients with suspected tumor). Lesion contrast enhancement on imaging was the sole predictor of obtaining a diagnosis. Rates of symptomatic complications and mortality were significantly higher in brainstem biopsy patients compared to brain/cerebellum biopsy patients (20% vs 0%; p < 0.001 and 6% vs 0%; p = 0.01, respectively). Transfrontal trajectory and prebiopsy swallowing disorders were predictors of brainstem biopsy-related symptomatic complications. Brainstem biopsy findings led to diagnostic change in 22% of patients.

CONCLUSIONS

Stereotactic biopsy in adult patients with brainstem lesion has a high diagnostic yield. Although stereotactic brainstem biopsy is associated with more functional and fatal complications than biopsies targeting the brain/cerebellum, its safety profile appears acceptable. Thus, the benefit-risk ratio of stereotactic biopsy in patients with brainstem lesion is favorable but should nevertheless be carefully weighted on a case-by-case basis.

Indicators of correct targeting in stereotactic biopsy of intracranial lesions

Background:

Confirmation of whether a stereotactic biopsy was performed in the correct site is usually dependent on the frozen section or on novel tumor-specific markers that are not widely available. Immediate postoperative computed tomography (CT) or magnetic resonance (MR) is routinely performed in our service after biopsy. In this retrospective study, we have carefully analyzed these images in an attempt to determine the presence of markers that indicate appropriate targeting.

Methods:

Medical records and neuroimages of patients who underwent stereotactic biopsy of intracranial lesions were reviewed. The following variables were assessed: age, sex, anatomopathology, lesion site, complications, diagnostic accuracy, and the presence of image markers.

Results:

Twenty-nine patients were included in this case series. About 96.6% of the biopsies were accurate according to the permanent section. Of the 86.2% of patients with intralesional pneumocephalus on the postoperative images, 51.7% additionally presented petechial hemorrhage. In 13.8% of the cases, no image markers were identified.

Conclusion:

This is the first report of intralesional pneumocephalus and petechial hemorrhage as indicators of appropriate targeting in stereotactic biopsy. In the majority of the cases, an immediate postoperative head CT, which is widely available, can estimate how adequate the targeting is. To use intralesional pneumocephalus/ petechial hemorrhages as not only postoperative but also as intraoperative markers of appropriate targeting, it is advised that the surgical wound should be temporarily closed and dressed after the biopsy so that the patient can undergo a CT/MR scan and be checked for the presence of theses markers before removing the stereotactic frame.

Diagnostic Yield and Complication Rate of Stereotactic Biopsies in Precision Medicine of Gliomas

Background

An integrated diagnosis consisting of histology and molecular markers is the basis of the current WHO classification system of gliomas. In patients with suspected newly diagnosed or recurrent glioma, stereotactic biopsy is an alternative in cases in which microsurgical resection is deemed to not be safely feasible or indicated. In this retrospective study, we aimed to analyze both the diagnostic yield and the safety of a standardized biopsy technique.

Material and Methods

The institutional database was screened for frame-based biopsy procedures (January 2016 until March 2021). Only patients with a suspected diagnosis of glioma based on imaging were included. All tumors were classified according to the current WHO grading system. The clinical parameters, procedural complications, histology, and molecular signature of the tissues obtained were assessed.

Results

Between January 2016 and March 2021, 1,214 patients underwent a stereotactic biopsy: 617 (50.8%) for a newly diagnosed lesion and 597 (49.2%) for a suspected recurrence. The median age was 56.9 years (range 5 months−94.4 years). Magnetic resonance imaging (MRI)-guidance was used in 99.3% of cases and additional positron emission tomography (PET)-guidance in 34.3% of cases. In total, stereotactic serial biopsy provided an integrated diagnosis in 96.3% of all procedures. The most frequent diagnoses were isocitrate dehydrogenase (IDH) wildtype glioblastoma (n = 596; 49.2%), oligodendroglioma grade 2 (n = 109; 9%), astrocytoma grade 3 (n = 108; 8.9%), oligodendroglioma grade 3 (n = 76; 6.3%), and astrocytoma grade 2 (n = 66; 5.4%). A detailed determination was successful for IDH 1/2 mutation in 99.4% of cases, for 1p/19q codeletion in 97.4% of cases, for TERT mutation in 98.9% of cases, and for MGMT promoter methylation in 99.1% of cases. Next-generation sequencing was evaluable in 64/67 (95.5%) of cases and DNA methylome analysis in 41/44 (93.2%) of cases. Thirteen (1.1%) cases showed glial tumors that could not be further specified. Seventy-three tumors were different non-glioma entities, e.g., of infectious or inflammatory nature. Seventy-five out of 597 suspected recurrences turned out to be post-therapeutic changes only. The rate of post-procedural complications with clinical symptoms of the Common Terminology Criteria for Adverse Events (CTCAE) grade 3 or higher was 1.2% in overall patients and 2.6% in the subgroup of brainstem biopsies. There was no fatal outcome in the entire series.

Conclusion

Image-guided stereotactic serial biopsy enables obtaining reliable histopathological and molecular diagnoses with a very low complication rate even in tumors with critical localization. Thus, in patients not undergoing microsurgical resection, this is a valuable tool for precision medicine of patients with glioma.

A preliminary study of the diagnostic efficacy and safety of the novel boring biopsy for brain lesions

Existing methods for biopsy of intraparenchymal brain lesions, including stereotactic biopsy and open block biopsy, have advantages and disadvantages. We propose a novel biopsy method, called “boring biopsy,” which aims to overcome the drawbacks of each conventional method. This method is less invasive and allows obtaining continuous specimens of sufficient volume. We aimed to assess the feasibility and efficacy of using boring biopsy for intraparenchymal brain lesions. We included 26 consecutive patients who underwent boring biopsy for intraparenchymal lesions. Columnar continuous specimens from the surface of the normal brain tissue to the tumor margin and the center of the lesion were obtained using the boring biopsy method. We used a catheter introducer with original modifications to create a cylindrical biopsy tool for surgery. Columnar continuous specimens were successfully obtained. Histopathological diagnosis was based on cellular changes and differentiation from normal tissues to the core of the lesion and established in all cases. No permanent deficits, major adverse outcomes, or deaths were observed. This novel technique may improve diagnostic accuracy and reduce invasiveness associated with brain biopsy. This method may become the next standard procedure, particularly in some cases where histological evaluation is paramount, and conventional biopsy methods are not suitable.

Brain Biopsy for Neurological Diseases of Unknown Etiology in Critically Ill Patients: Feasibility, Safety, and Diagnostic Yield

OBJECTIVES

Brain biopsy is a useful surgical procedure in the management of patients with suspected neoplastic lesions. Its role in neurologic diseases of unknown etiology remains controversial, especially in ICU patients. This study was undertaken to determine the feasibility, safety, and the diagnostic yield of brain biopsy in critically ill patients with neurologic diseases of unknown etiology. We also aimed to compare these endpoints to those of non-ICU patients who underwent a brain biopsy in the same clinical context.

DESIGN

Monocenter, retrospective, observational cohort study.

SETTING

A French tertiary center.

PATIENTS

All adult patients with neurologic diseases of unknown etiology under mechanical ventilation undergoing in-ICU brain biopsy between January 2008 and October 2020 were compared with a cohort of non-ICU patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among the 2,207 brain-biopsied patients during the study period, 234 biopsies were performed for neurologic diseases of unknown etiology, including 29 who were mechanically ventilated and 205 who were not ICU patients. Specific histological diagnosis and final diagnosis rates were 62.1% and 75.9%, respectively, leading to therapeutic management modification in 62.1% of cases. Meningitis on prebiopsy cerebrospinal fluid analysis was the sole predictor of obtaining a final diagnosis (2.3 [1.4-3.8]; p = 0.02). ICU patients who experienced therapeutic management modification after the biopsy had longer survival (p = 0.03). The grade 1 to 4 (mild to severe) complication rates were: 24.1%, 3.5%, 0%, and 6.9%, respectively. Biopsy-related mortality was significantly higher in ICU patients compared with non-ICU patients (6.9% vs 0%; p = 0.02). Hematological malignancy was associated with biopsy-related mortality (1.5 [1.01-2.6]; p = 0.04).

CONCLUSIONS

Brain biopsy in critically ill patients with neurologic disease of unknown etiology is associated with high diagnostic yield, therapeutic modifications and postbiopsy survival advantage. Safety profile seems acceptable in most patients. The benefit/risk ratio of brain biopsy in this population should be carefully weighted.

Infratentorial Stereotactic Biopsy of Brainstem and Cerebellar Lesions

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

Severity, timeline, and management of complications after stereotactic brain biopsy

OBJECTIVE

The literature shows discrepancies in stereotactic brain biopsy complication rates, severities, and outcomes. Little is known about the timeline of postbiopsy complications. This study aimed to analyze 1) complications following brain biopsies, using a graded severity scale, and 2) a timeline of complication occurrence. The secondary objectives were to determine factors associated with an increased risk of complications and to assess complication-related management and extra costs.

METHODS

The authors retrospectively examined 1500 consecutive stereotactic brain biopsies performed in adult patients at their tertiary medical center between April 2009 and April 2019.

RESULTS

Three hundred eighty-one biopsies (25.4%) were followed by a complication, including 88.2% of asymptomatic hemorrhages. Symptomatic complications involved 3.0% of the biopsies, and 0.8% of the biopsies were fatal. The severity grading scale had a 97.6% interobserver reproducibility. Twenty-three (51.1%) of the 45 symptomatic complications occurred within the 1st hour following the biopsy, while 75.6% occurred within the first 6 hours. Age ≥ 65 years, second biopsy procedures, gadolinium-enhanced lesions, glioblastomas, and lymphomas were predictors of biopsy-related complications. Brainstem biopsy-targeted lesions and cerebral toxoplasmosis were predictive of mortality. Asymptomatic hemorrhage was associated with delayed (> 6 hours) symptomatic complications. Symptomatic complications led to extended hospitalization in 86.7% of patients. The average extra cost for management of a patient with postbiopsy symptomatic complication was $35,702.

CONCLUSIONS

Symptomatic complications from brain biopsies are infrequent but associated with substantial adverse effects and cost implications for the healthcare system. The use of a severity grading scale, as the authors propose in this article, helps to classify complications according to the therapeutic consequences and the patient's outcome. Because this study indicates that most complications occur within the first few hours following the biopsy, postbiopsy monitoring can be tailored accordingly. The authors therefore recommend systematic monitoring for 2 hours in the recovery unit and a CT scan 2 hours after the end of the biopsy procedure. In addition, they propose a modern algorithm for optimal postoperative management of patients undergoing stereotactic biopsy.

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.

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.

[Stereotactic photodynamic therapy for recurrent glioblastoma. Case report and literature review]

We report a patient with recurrent glioblastoma in eloquent brain area. Stereotactic fluorescence biospectroscopy and stereotactic photodynamic therapy of tumor in opercular area of the left frontal lobe under neurophysiological monitoring were carried out. Literature data on this issue were analyzed.

Neurological diseases of unknown etiology: Brain-biopsy diagnostic yields and safety

BACKGROUND

For nonneoplastic neurological diseases, no recommendation exists regarding the place or appropriate timing of brain biopsy. The aim of this study was to evaluate the diagnostic yield and safety of brain biopsies from patients with neurological diseases of unknown etiology.

METHODS

We performed a retrospective cohort study from January 1, 2008 to December 31, 2018. We analyzed 1847 brain-biopsied patients, including 178 biopsies indicated for neurological diseases of unknown etiology. Specific histological and final diagnosis rates, positive diagnosis-associated factors, complication rate and complication-associated factors were assessed.

RESULTS

Specific histological diagnosis and final diagnosis rates were 71.3% and 83.1%, respectively, leading to therapeutic management change(s) for 75.3% of patients. Brain- biopsy-related mortality and permanent neurological morbidity occurred in 1.1% and 0.6% of the patients, respectively. The multivariable logistic-regression model retained (odds ratio [95% CI] only immunodepression (2.2 [1.1-4.7]; P=.04) as being independently associated with specific histological diagnosis, while supratentorial biopsy-targeted lesions (4.1 [1.1-15.2]; P=.04) were independently associated with a final diagnosis. Biopsies obtained from comatose patients were less contributive to the diagnosis (0.2 [0.05-0.7]; P=.01). Prebiopsy platelet count <100 G/L (28.5 [1.8-447]; P=.02), hydrocephalus (6.3 [1.2-15.3]; P=.02) and targeted lesions <1 cm (4.3 [1.2-15.3]; P=.03) were independently associated with brain biopsy-related complications.

CONCLUSION

For highly selected patients with neurological diseases of unknown etiology, brain biopsy has a high diagnostic yield and low frequency of severe complications. We advocate that this procedure be considered early in the diagnosis algorithm of these patients.

Complications after frame-based stereotactic brain biopsy: a systematic review

Stereotactic frame-based brain biopsy is one of the most used procedures to obtain brain tissue. This procedure is usually considered as mini-invasive, quick, efficient, and safe even if results of the different studies are widely heterogenous. The objective of this review of the literature is to describe and analyze the complications of stereotactic frame-based brain biopsy. About 132 articles were found after a research in the Medline database. We only considered English references published between 1994 and June 2019. Additional studies were found by using the references from articles identified in the original search. This systematic review was conducted according to PRISMA guidelines. After applying exclusion criteria, we eventually considered 25 relevant studies. The mortality rate varies from 0.7 to 4%. Overall morbidity ranges from 3 to 13%. Most of the complications are revealed by the following symptoms: neurological impairment (transient or permanent), seizure, and unconsciousness. Symptomatic hemorrhage range varies from 0.9 to 8.6%, whereas considering asymptomatic bleeding, the range may be up to 59.8%. Complications were clinically evident within minutes to a few hours after the biopsy. Corrective surgeries are very rare (< 1%). Complications occurring after a frame-based stereotactic brain biopsy are rare but with serious side effects. It rarely leads to death or to permanent neurological impairment. Description and classification of complications are often heterogeneous in the literature. The use of a grading scale could help comparisons between series from around the world. Future studies should establish a score that allows neurosurgeon to predict post-biopsy complications.

Efficacy of a Second Brain Biopsy for Intracranial Lesions after Initial Negativity

Background and Purpose

The rationale for performing a second brain biopsy after initial negativity is not well evaluated in the literature. This study was designed to 1) assess the efficacy of a second brain biopsy when the first biopsy was nondiagnostic, 2) identify possible factors associated with an increased diagnostic rate in the second biopsy, and 3) analyze additional morbidity induced by the second biopsy.

Methods

We performed a retrospective cohort study from 2009 to 2019, during which 1,919 patients underwent a brain biopsy, including 30 who were biopsied twice (1.6%). The specific histological diagnosis rate, diagnosis-associated factors, and complication rate were assessed for the 30 twice-biopsied patients.

Results

The second biopsy allowed a specific histological diagnosis in 86.7% of the patients who had initially undergone a nondiagnostic brain biopsy [odds ratio (OR)=7.5, 95% confidence interval (CI)=3.0–18.7, p<0.001]. The multivariate analysis showed that only prebiopsy corticosteroid administration (OR=2.6, 95% CI=1.1–6.0, p=0.01) was an important factor in predicting a nondiagnostic biopsy. None of the patients developed a symptomatic complication after the first biopsy, while two (6.0%) patients experienced a transient complication after the second biopsy (p=0.49).

Conclusions

Performing a second brain biopsy in patients who have an initial nondiagnostic biopsy is effective in most cases. We advocate that a second biopsy be systematically considered in the diagnosis algorithm of these patients after it has been verified that molecular testing cannot help to obtain a diagnosis. Corticosteroid administration can lead to nondiagnostic biopsies and should be avoided when possible during the prebiopsy period.