Initial biopsy and early re-resection practices in the treatment of glioblastoma among AANS/CNS tumor section surgeons

Complex Diagnostic Challenges in Glioblastoma: The Role of 18F-FDOPA PET Imaging

Glioblastoma multiforme (GBM) remains one of the most aggressive and lethal forms of brain cancer, characterized by rapid proliferation and diffuse infiltration into the surrounding brain tissues. Despite advancements in therapeutic approaches, the prognosis for GBM patients is poor, with median survival times rarely exceeding 15 months post-diagnosis. An accurate diagnosis, treatment planning, and monitoring are crucial for improving patient outcomes. Core imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are indispensable in the initial diagnosis and ongoing management of GBM. Histopathology remains the gold standard for definitive diagnoses, guiding treatment by providing molecular and genetic insights into the tumor. Advanced imaging modalities, particularly positron emission tomography (PET), play a pivotal role in the management of GBM. Among these, 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (18F-FDOPA) PET has emerged as a powerful tool due to its superior specificity and sensitivity in detecting GBM and monitoring treatment responses. This introduction provides a comprehensive overview of the multifaceted role of 18F-FDOPA PET in GBM, covering its diagnostic accuracy, potential as a biomarker, integration into clinical workflows, impact on patient outcomes, technological and methodological advancements, comparative effectiveness with other PET tracers, and its cost-effectiveness in clinical practice. Through these perspectives, we aim to underscore the significant contributions of 18F-FDOPA PET to the evolving landscape of GBM management and its potential to enhance both clinical and economic outcomes for patients afflicted with this formidable disease.

The detrimental effect of biopsy preceding resection in surgically accessible glioblastoma: results from the national cancer database

PURPOSE

Aggressive resection in surgically-accessible glioblastoma (GBM) correlates with improved survival over less extensive resections. However, the clinical impact of performing a biopsy before definitive resection have not been previously evaluated.

METHODS

We analyzed 17,334 GBM patients from the NCDB from 2010-2014. We categorized them into: "upfront resection" and "biopsy followed by resection". The outcomes of interes included OS, 30-day readmission/mortality, 90-day mortality, and length of hospital stay (LOS). The Kaplan-Meier methods and accelerated failure time (AFT) models were applied for survival analysis. Multivariable binary logistic regression were performed to compare differences among groups. Multiple imputation and propensity score matching (PSM) were conducted for validation.

RESULTS

"Upfront resection" had superior OS over "biopsy followed by resection" (median OS:12.4 versus 11.1 months, log-rank p = 0.001). Similarly, multivariable AFT models favored "upfront resection" (time ratio[TR]:0.83, 95%CI: 0.75-0.93, p = 0.001). Patients undergoing "upfront gross-total resection (GTR)" had higher OS over "upfront subtotal resection (STR)", "GTR following STR", and "GTR or STR following initial biopsy" (14.4 vs. 10.3, 13.5, 13.3, and 9.1 months;TR: 1.00 [Ref.], 0.75, 0.82, 0.88, and 0.67). Recent years of diagnosis, higher income, facilities located in Southern regions, and treatment at academic facilities were significantly associated with the higher likelihood of undergoing upfront resection. Multivariable regression showed a decreased 30 and 90-day mortality for patients undergoing "upfront resection", 73% and 44%, respectively (p < 0.001).

CONCLUSIONS

Pre-operative biopsies for surgically accessible GBM are associated with worse survival despite subsequent resection compared to patients undergoing upfront resection.

Early repeat resection for residual glioblastoma: decision-making among an international cohort of neurosurgeons

OBJECTIVE

The importance of extent of resection (EOR) in glioblastoma (GBM) has been thoroughly demonstrated. However, few studies have explored the practices and benefits of early repeat resection (ERR) when residual tumor deemed resectable is unintentionally left after an initial resection, and the survival benefit of ERR is still unknown. Herein, the authors aimed to internationally survey current practices regarding ERR and to analyze differences based on geographic location and practice setting.

METHODS

The authors distributed a survey to the American Association of Neurological Surgeons and Congress of Neurological Surgeons Tumor Section, Society of British Neurological Surgeons, European Association of Neurosurgical Society, and Latin American Federation of Neurosurgical Societies. Neurosurgeons responded to questions about their training, practice setting, and current ERR practices. They also reported the EOR threshold below which they would pursue ERR and their likelihood of performing ERR using a Likert scale of 1-5 (5 being the most likely) in two sets of 5 cases, the first set for a patient's initial hospitalization and the second for a referred patient who had undergone resection elsewhere. The resection likelihood index for each respondent was calculated as the mean Likert score across all cases.

RESULTS

Overall, 180 neurosurgeons from 25 countries responded to the survey. Neurosurgeons performed ERRs very rarely in their practices (< 1% of all GBM cases), with an EOR threshold of 80.2% (75%-95%). When presented with 10 cases, the case context (initial hospitalization vs referred patient) did not significantly change the surgeon ERR likelihood, although ERR likelihood did vary significantly on the basis of tumor location (p < 0.0001). Latin American neurosurgeons were more likely to pursue ERR in the provided cases. Neurosurgeons were more likely to pursue ERR when the tumor was MGMT methylated versus unmethylated, with a resection likelihood index of 3.78 and 3.21, respectively (p = 0.004); however, there was no significant difference between IDH mutant and IDH wild-type tumors.

CONCLUSIONS

Results of this survey reveal current practices regarding ERR, but they also demonstrate the variability in how neurosurgeons approach ERR. Standardized guidelines based on future studies incorporating tumor molecular characteristics are needed to guide neurosurgeons in their decision-making on this complicated issue.

Beyond guidelines: analysis of current practice patterns of AANS/CNS tumor neurosurgeons

INTRODUCTION

Evidence-based medicine guidelines are increasingly published and sanctioned by organized neurosurgery. However, implementation, interpretation, and use of clinical guidelines may vary substantially on a regional, national and international basis. Survey research can help bridge the gap by providing a snapshot of neurosurgeon attitudes, knowledge, and practices. The American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Section on Tumors formed a Survey Committee to formalize the process by which surveys are submitted and reviewed before distribution to our membership. The goal of this committee is to provide peer-review so that collected information will be scientifically robust and useful to the neurosurgical community.

METHODS

Surveys submitted to the AANS/CNS tumor section between 2015 and 2019 were reviewed and metrics such as response rate and publication status assessed.

RESULTS

Six surveys were submitted to the Survey Committee of the AANS/CNS section on tumors between 2015 and 2019. Four have been circulated to section members, of which three have been published. Response rate has averaged 19% (range 16-23%), a majority of respondents (mean 70%) practice in academic settings.

CONCLUSIONS

The AANS/CNS Section on Tumors Survey Committee has and continues to help promote and improve the practice of surveying our community to answer important questions that can advance future training, research, and practice. There remains significant room for improvement in response rates, but ongoing tumor section efforts to increase member engagement will likely improve these numbers.

Workplace Violence and Neurosurgery: Insights from a Nationwide Survey

OBJECTIVE

Workplace violence (WPV) against neurosurgeons is an understudied phenomenon, as previous research has focused on high-risk specialties like emergency medicine and psychiatry. We sought to fill in this gap in the literature by determining the frequency and type of WPV that neurosurgeons experience.

METHODS

We sent a 26-question online survey to members of the American Association of Neurological Surgery via SurveyMonkey. This survey contained questions about WPV experienced over the previous two years, as well as questions about security measures and workplace protocols for WPV.

RESULTS

We received 107 responses of 4757 surveys disseminated, a response rate of 2.25%. Although small, this response rate is representative of historical survey response rates. In total, 53.3% of our sample reported WPV, and 4.7% reported at least one physical assault. In total, 50.5% of respondents were afraid of becoming a victim of WPV, and 40.4% felt less secure today than when they began practicing. A total of 17.8% of respondents reported that they had obtained a weapon or a concealed weapon permit due to a perceived threat. Tests for association revealed that early career and female neurosurgeons were significantly more likely to receive verbal threats than other neurosurgeons (P = 0.049 and 0.01, respectively).

CONCLUSIONS

WPV is prevalent in neurosurgery at rates comparable with a range of other specialties. Many neurosurgeons feel unsafe in the workplace, with some taking significant actions such as weapon acquisition. An opportunity for education and resources regarding WPV exists, especially among early career and female neurosurgeons.

Variations in attitudes towards stereotactic biopsy of adult diffuse midline glioma patients: a survey of members of the AANS/CNS Tumor Section

Purpose

Diffuse midline gliomas are rare midline CNS malignancies that primarily affect children but can also affect adults. While radiation is standard treatment, prognosis remains fatal. Furthermore, due to its sensitive anatomic location, many physicians have been reluctant to perform biopsies without potential for improved prognosis. However, recent advancements in molecular-targeted therapeutics have encouraged greater tissue sampling. While the literature reflects this progress, the landscape of how clinicians actually manage these patients remains unclear. Our goal was to assess the attitudes of current practicing neurosurgical oncologists towards management of adult diffuse midline gliomas, reasons behind their practices, and factors that might influence these practices.

Methods

We created and distributed a survey with 16 multiple choice and open-ended questions to members of the Tumor Section of the Congress of Neurological Surgeons.

Results

A total of 81 physicians responded to the survey. Although time since training and volume of glioma patients did not significantly affect the decision to consider clinical trials or to offer biopsy, those that operated on fewer gliomas (< 25/year) were more likely to cite surgical morbidity as the primary reason not to biopsy these midline locations. Further, surgeons with access to more advanced molecular testing were significantly more likely to consider clinical trial eligibility when offering biopsies.

Conclusion

Factors that affect the management of diffuse midline gliomas and the role of biopsy are relatively uniform across the field, however, there were a few notable differences that reflect the changes within the neuro-oncology field in response to clinical trials.

Electronic supplementary material

The online version of this article (10.1007/s11060-020-03585-7) contains supplementary material, which is available to authorized users.