Sex Differences in Adult Incarceration After Pediatric Traumatic Brain Injury

Pediatric traumatic brain injury (pTBI) is a major risk factor associated with adulthood incarceration. Most research into the link between pTBI and adulthood incarceration has focused on incarcerated males, who comprise the vast majority of incarcerated adults, particularly in industrialized nations. In this review, we sought to identify sex-related differences in the incidence and pathophysiology of pTBI and subsequent risk of adulthood incarceration. A scoping review was undertaken using PubMed, Scopus, Ovid, and the Cochrane Library. Articles analyzing sex-related differences in pTBI and adult incarceration rates, studies conducted on an incarcerated population, and cohort studies, cross-sectional studies, clinical trials, systematic reviews, or meta-analyses were included in this review. Of the 85 unique results, 25 articles met our inclusion criteria. Male children are 1.5 times more likely to suffer a TBI than females; however, the prevalence of incarcerated adults with a history of pTBI is ∼35-45% for both sexes. Neurophysiologically, female sex hormones are implicated in neuroprotective roles, mitigating central nervous system (CNS) damage post-TBI, although this role may be more complex, given that injury severity and sequelae have been correlated with male sex whereas increased mortality has been correlated with female sex. Further investigation into the relationship between estrogen and subsequent clinical measurements of CNS function is needed to develop interventions that may alleviate the pathophysiological consequences of pTBI.

DOTATATE PET/MR Imaging Differentiates Secondary-Progressive from de Novo World Health Organization Grade 3 Meningiomas

BACKGROUND AND PURPOSE

WHO grade 3 meningiomas are rare and poorly understood and have a higher propensity for recurrence, metastasis, and worsened clinical outcomes compared with lower-grade meningiomas. The purpose of our study was to prospectively evaluate the molecular profile, PET characteristics, and outcomes of patients with World Health Organization grade 3 meningiomas who were imaged with gallium 68 (68Ga) DOTATATE PET/MR imaging.

MATERIALS AND METHODS

Patients with World Health Organization grade 3 meningiomas enrolled in our prospective observational cohort evaluating the utility of (68Ga) DOTATATE PET/MR imaging in somatostatin receptor positive brain tumors were included. We stratified patients by de novo-versus-secondary-progressive status and evaluated the differences in the PET standard uptake value, molecular profiles, and clinical outcomes.

RESULTS

Patients met the inclusion criteria (secondary-progressive: 7/14; de novo: 7/14). The secondary-progressive cohort had a significantly higher per-patient number of surgeries (4.1 versus 1.6; P = .011) and trended toward a higher number of radiation therapy courses (2.4 versus 1.6; P = .23) and cumulative radiation therapy doses (106Gy versus 68.3Gy; P = .31). The secondary-progressive cohort had a significantly lower progression-free survival compared with the de novo cohort (4.8 versus 37.7 months; P = .004). Secondary-progressive tumors had distinct molecular pathology profiles with higher numbers of mutations (3.5 versus 1.2; P = .024). Secondary-progressive tumors demonstrated higher PET standard uptake values (17.1 versus 12.4; P = .0021).

CONCLUSIONS

Our study confirms prior work illustrating distinct clinical outcomes in secondary-progressive and de novo World Health Organization grade 3 meningiomas. Furthermore, our findings support (68Ga) DOTATATE PET/MR imaging as a useful management strategy in World Health Organization grade 3 meningiomas and provide insight into meningioma biology, as well as clinical management implications.

Stereotactic Radiosurgery in the Management of Brain Metastases: A Case-Based Radiosurgery Society Practice Guideline

Purpose

Brain metastases are common among adult patients with solid malignancies and are increasingly being treated with stereotactic radiosurgery (SRS). As more patients with brain metastases are becoming eligible for SRS, there is a need for practical review of patient selection and treatment considerations.

Methods and Materials

Two patient cases were identified to use as the foundation for a discussion of a wide and representative range of management principles: (A) SRS alone for 5 to 15 lesions and (B) a large single metastasis to be treated with pre- or postoperative SRS. Patient selection, fractionation, prescription dose, treatment technique, and dose constraints are discussed. Literature relevant to these cases is summarized to provide a framework for treatment of similar patients.

Results

Treatment of brain metastases with SRS requires many considerations including optimal patient selection, fractionation selection, and plan optimization.

Conclusions

Case-based practice guidelines developed by the Radiosurgery Society provide a practical guide to the common scenarios noted above affecting patients with metastatic brain tumors.

Posterior cranial vault distraction in children with syndromic craniosynostosis: the era of biodegradable materials-a comprehensive review of the literature and proposed novel global application

Distraction osteogenesis is utilized to increase intracranial volume in the treatment of restrictive pathologies, most commonly syndromic synostosis. Children too young for open calvarial vault expansion or other systemic or local contraindications to a direct reconstructive approach benefit greatly from distraction osteogenesis, typically addressing posterior vault expansion. Wound infection, cerebrospinal fluid (CSF) leak, device failure, need for a second surgery for removal, and cost, are issues that can limit the use of this approach. These challenges are more pronounced in low- and middle-income countries (LMICs) due to lack of access to the device, the financial burden of the need for a second surgery, and the severity of the implications of infection and CSF leak. Over the last five decades, there has been an increased acceptance of bioresorbable instrumentation in craniofacial surgery. Poly L-lactic acid, polyglycolic acid, and polydioxanone are the most commonly used polymers. New resorbable fixation tools such as ultrasound-activated pins and heat-activated pins are superior to conventional bioresorbable screws in allowing attachment to thinner bone plates. In this paper, we present a review of the literature on cranial vault distraction and the use of bioresorbable materials and propose a novel design of a fully absorbable cranial distractor system using external magnetic distraction control, eliminating the need for external activation ports and a second surgery to remove the hardware. The application of this technology in LMIC settings could advance access to care and treatment options for patients with syndromic synostosis.

Assessing the state of LGBTQ+ diversity and inclusion in neurosurgery

OBJECTIVE

The aim of this study was to assess the diversity of neurosurgeons in terms of lesbian, gay, bisexual, transgender, and/or queer (LGBTQ+) gender and sexual minority status using the Graduation Questionnaire (GQ) as the single nationalized source of LGBTQ+ identification. Additionally, inclusivity was assessed through interviews by residents and attendings in the field.

METHODS

First, a PRISMA literature review was conducted and independently reviewed by two authors on studies involving LGBTQ+ representation in neurosurgery from PubMed, Web of Science, and Google Scholar. Then, aggregate responses of 16,901 participants' sexual and gender identities from the GQ administered between 2016 and 2022 were compiled. To statistically analyze the response frequencies, the authors performed a chi-square analysis. Finally, interviews were conducted with individuals who identify as LGBTQ+ and are currently neurosurgical residents or attendings. Direct invitations were extended to participate in interviews, and all participants gave informed consent prior to the interview. Interviews were conducted using standardized questions and were video recorded.

RESULTS

Two studies were identified by literature review that referenced the LGBTQ+ community in neurosurgery. A GQ chi-square analysis comparing neurosurgical with nonneurosurgical LGBTQ+ identification proved statistically insignificant (p = 0.65). More broad analysis of majority sexual and gender identification (heterosexual and cisgendered) compared with the total gender and sexual minority group also proved statistically insignificant (p = 0.32) in response frequency. Five interviews, including 4 residents and 1 attending, provided several overarching themes including self-identification as an invisible minority, self-limiting behavior to ensure inclusion, and LGBTQ+ status as a direct departure from the stereotypical neurosurgeon.

CONCLUSIONS

Results from the GQ analysis indicate that neurosurgery is achieving LGBTQ+ diversity of its incoming members comparable to that of other fields in medicine. However, qualitative data from the interviews and a lack of specific literature indicate that despite obtaining diversity, inclusion of LGBTQ+ neurosurgeons and trainees is lacking.

Cost-Effectiveness Analysis of 68Ga-DOTATATE PET/MRI in Radiotherapy Planning in Patients with Intermediate-Risk Meningioma

BACKGROUND AND PURPOSE

While contrast-enhanced MR imaging is the criterion standard in meningioma diagnosis and treatment response assessment, gallium 68Ga-DOTATATE PET/MR imaging has increasingly demonstrated utility in meningioma diagnosis and management. Integrating 68Ga-DOTATATE PET/MR imaging in postsurgical radiation planning reduces the planning target volume and organ-at-risk dose. However, 68Ga-DOTATATE PET/MR imaging is not widely implemented in clinical practice due to higher perceived costs. Our study analyzes the cost-effectiveness of 68Ga-DOTATATE PET/MR imaging for postresection radiation therapy planning in patients with intermediate-risk meningioma.

MATERIALS AND METHODS

We developed a decision-analytical model based on both recommended guidelines on meningioma management and our institutional experience. Markov models were implemented to estimate quality-adjusted life-years (QALY). Cost-effectiveness analyses with willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were performed from a societal perspective. Sensitivity analyses were conducted to validate the results. Model input values were based on published literature.

RESULTS

The cost-effectiveness results demonstrated that 68Ga-DOTATATE PET/MR imaging yields higher QALY (5.47 versus 5.05) at a higher cost ($404,260 versus $395,535) compared with MR imaging alone. The incremental cost-effectiveness ratio analysis determined that 68Ga-DOTATATE PET/MR imaging is cost-effective at a willingness to pay of $50,000/QALY and $100,000/QALY. Furthermore, sensitivity analyses showed that 68Ga-DOTATATE PET/MR imaging is cost-effective at $50,000/QALY ($100,000/QALY) for specificity and sensitivity values above 76% (58%) and 53% (44%), respectively.

CONCLUSIONS

68Ga-DOTATATE PET/MR imaging as an adjunct imaging technique is cost-effective in postoperative treatment planning in patients with meningiomas. Most important, the model results show that the sensitivity and specificity cost-effective thresholds of 68Ga-DOTATATE PET/MR imaging could be attained in clinical practice.

[68 Ga]-DOTATATE PET/MR-based evaluation of physiologic somatostatin receptor 2 expression in the adult pituitary gland as a function of age and sex in a prospective cohort

PURPOSE

The pituitary gland has the fourth highest physiologic avidity of [68 Ga]-DOTATATE. In order to guide our understanding of [68 Ga]-DOTATATE PET in clinical contexts, accurate characterization of the normal pituitary gland is first required. This study aimed to characterize the normal pituitary gland using dedicated brain [68 Ga]-DOTATATE PET/MRI as a function of age and sex.

METHODS

A total of 95 patients with a normal pituitary gland underwent brain [68 Ga]-DOTATATE PET examinations for the purpose of diagnosing CNS SSTR2 positive tumors (mean age: 58.9, 73% female). Maximum SUV of the pituitary gland was obtained in each patient. SUV of superior sagittal sinus was obtained to calculate normalized SUV score (SUVR) of the gland. The anatomic size of the gland was collected as maximum sagittal height (MSH). Correlations with age and sex were analyzed.

RESULTS

The mean SUV and SUVR of the pituitary gland were 17.6 (range: 7-59.5, SD = 7.1) and 13.8 (range: 3.3-52.6, SD = 7.2), respectively. Older females had significantly higher SUV of the pituitary gland compared to younger females. When stratified by age and sex, both older and younger females had significantly higher pituitary SUV than older males. SUVR did not differ significantly by age or sex. MSH of the pituitary gland in younger females was significantly greater than in younger males at all age cutoffs.

CONCLUSION

This study provides an empiric profiling of the physiological [68 Ga]-DOTATATE avidity of the pituitary gland. The findings suggest that SUV may vary by age and sex and can help guide the use of [68 Ga]-DOTATATE PET/MRI in clinical and research settings. Future studies can build on these findings to investigate further the relationship between pituitary biology and demographic factors.

Concurrent immunotherapy and re-irradiation utilizing stereotactic body radiotherapy for recurrent high-grade gliomas

BACKGROUND

Clinical trials evaluating immune checkpoint inhibition (ICI) in recurrent high-grade gliomas (rHGG) report 7%-20% 6-month progression-free survival (PFS), while re-irradiation demonstrates 28%-39% 6-month PFS.

AIMS

We evaluate outcomes of patients treated with ICI and concurrent re-irradiation utilizing stereotactic body radiotherapy/fractionated stereotactic radiosurgery (SBRT) compared to ICI monotherapy.

METHODS AND RESULTS

Patients ≥18-years-old with rHGG (WHO grade III and IV) receiving ICI + SBRT or ICI monotherapy between January 1, 2016 and January 1, 2019 were included. Adverse events, 6-month PFS and overall survival (OS) were assessed. Log-rank tests were used to evaluate PFS and OS. Histogram analyses of apparent diffusion coefficient maps and dynamic contrast-enhanced magnetic resonance perfusion metrics were performed. Twenty-one patients with rHGG (ICI + SBRT: 16; ICI: 5) were included. The ICI + SBRT and ICI groups received a mean 7.25 and 6.2 ICI cycles, respectively. There were five grade 1, one grade 2 and no grade 3-5 AEs in the ICI + SBRT group, and four grade 1 and no grade 2-5 AEs in the ICI group. Median PFS was 2.85 and 1 month for the ICI + SBRT and ICI groups; median OS was 7 and 6 months among ICI + SBRT and ICI groups, respectively. There were significant differences in pre and posttreatment tumor volume in the cohort (12.35 vs. 20.51; p = .03), but not between treatment groups.

CONCLUSIONS

In this heavily pretreated cohort, ICI with re-irradiation utilizing SBRT was well tolerated. Prospective studies are warranted to evaluate potential therapeutic benefits to re-irradiation with ICI + SBRT in rHGG.

Shared Objective Mentorship via Virtual Research and Education Initiatives for Medical Students and Residents in Neurosurgery: A Systematic Review and Methodological Discussion of the Neurosurgery Education and Research Virtual Group Experience

OBJECTIVE

Virtual mentorship and research programs are becoming increasingly popular to facilitate education and career development for students and residents. We review virtual research initiatives for early trainees in neurosurgery and describe our effort to expand access to resources and shared objective mentorship (SOM) via the novel Neurosurgery Education and Research Virtual Group (NERVE).

METHODS

A systematic review of neurosurgical programming delivered via a virtual platform was conducted using PubMed, Embase, and Scopus databases. Identified articles were screened. Those meeting prespecified inclusion criteria were reviewed in full and examined for relevant data. Data analysis was performed using Microsoft Excel, and means and standard deviations were calculated. Descriptive analysis of NERVE characteristics was also performed.

RESULTS

Of the 2438 identified articles, 10 were included. The most common (70%) implementation style was a webinar-based lecture series. The least common (10%) was a longitudinal curricular interest group. Of the total NERVE cohort, 90% were first generation medical students and 82% attended institutions without home programs. Survey results indicated 73.8% had contributed to at least 2 research projects throughout the year.

CONCLUSIONS

There is a scarcity of virtual neurosurgical resources which facilitate SOM opportunities for trainees. In our systematic review, NERVE is the only multi-institutional virtual initiative aimed at increasing access to neurosurgical education and research opportunities for the purpose of SOM among early trainees from disadvantaged backgrounds. This highlights the group's niche and potential impact on increasing diversity in neurosurgery, improving trainees' career development, and facilitating future resident research productivity.

SPIN-02 LEVERAGING AN MRI-GUIDED LINEAR ACCELERATOR PLATFORM FOR POST-OPERATIVE STEREOTACTIC BODY RADIATION THERAPY (SBRT) OF SPINAL METASTASES

PURPOSE/OBJECTIVE(S)

Post-operative spine SBRT presents unique clinical challenges. Spinal hardware produces CT and high-field strength MRI artifacts that obscure visualization of the spinal cord and unresected disease. Existing workflows incorporate additional invasive procedures with CT myelogram and quality control for these procedures can introduce uncertainty into SBRT planning. Reducing metallic imaging artifact with a low-field strength (0.35 T) MRI integrated into a MR-Linac (MRL) may facilitate superior visualization of the spinal cord, improved target delineation and treatment localization. The primary objective is to determine the feasibility of MRL-based simulation workflow to facilitate MR-guided post-operative spine SBRT without the need for CT myelogram or CT-based target delineation.

MATERIALS/METHODS

A single-institution, single-arm interventional feasibility study is planned. A total of 10 patients who underwent surgical resection of solid tumor spinal metastases with an indication for post-operative SBRT will be enrolled and undergo radiation planning and treatment on a MRL platform that combines a 6MV Linac and 0.35 T on-board MRI system. Enrolled subjects will undergo CT and MR simulation followed by standard-of-care post-operative spine SBRT and follow-up spine imaging every 3 months.

RESULTS

The primary endpoint is feasibility of MR-guided post-operative spine SBRT without CT myelogram. Feasibility is defined as > 70% of participants with clinically acceptable visualization/delineation as determined by blinded dual neuroradiologist review for clinically acceptable visualization/delineation of organs-at-risk (OARs) and target volume(s). Exploratory endpoints involve radiation dosimetry analysis of OARs and target volumes as well as documenting the use of adaptive planning. Radiation site progression-free survival will be recorded at 6-months after SBRT.

CONCLUSION

If feasible, an MRL-based workflow for post-operative spine SBRT represents a patient-centric approach to improve efficiency, minimize treatment delays, and avoid invasive procedures that may improve clinical management of solid tumor spinal metastases.

Neurosurgical Education for Medical Students: A Scoping Review

Neurosurgeons have a rich history of involvement in medical student education. We review the scope of related published works with the goal of highlighting recently increased efforts to innovate in neurosurgical education and discuss where future efforts must go. A scoping review was performed after comprehensive search of PubMed MEDLINE and Embase databases. Among the 2314 articles returned in the search, 54 were selected for inclusion and review. Articles are discussed in the context of neurosurgery electives, American Association of Neurological Surgeons chapters and medical school programs, national neurosurgery courses, neurosurgery education materials, neurosurgery career perceptions, and the impact of coronavirus disease 2019. Despite increasing need for neurosurgical education in medical school, available experiences in formal curricula are diminishing. Longitudinal exposure to neurosurgery throughout medical school will help ensure a foundational understanding of neurosurgical disease management for all physicians and provide a pathway of exploration, education, and mentorship for the most suitable candidates. Neurosurgery faculty mentorship is particularly important to ensure that the next generation of neurologic surgeons is well equipped to treat patients, catalyze innovative research, and espouse both diverse perspectives and novel ideas.

Reevaluating Innovations in Medical Student Neurosurgery Education: Lessons Learned Today from Data Collected Before COVID-19

OBJECTIVE

Virtual learning has made neurosurgery education more available to medical students (MSs) of all stages than ever before. We aimed to evaluate the impact of on-site learning in order to assess whether a return to this method of teaching, when safe, is warranted for MSs of all years.

METHODS

Registrants of the 2019 MS Neurosurgery Training Camps were sent precourse and postcourse surveys to assess changes in self-assessed confidence in concrete neurosurgical skills. Data were analyzed using a 2-tailed paired Student's t-test for continuous variables. A P value <0.05 was considered significant.

RESULTS

The 2019 Training Camp had 105 attendees, of whom 94 (89.5%) completed both surveys. Students reported statistically significant improvements in every surveyed skill area, except for understanding what is and is not sterile in an operating room. The cohort of MS 3/4 students indicated a postcourse decrease in confidence in their ability to understand what is and is not sterile in an operating room (93.69 ± 16.41 vs. 86.20 ± 21.18; P < 0.05). MS 3/4 students did not benefit in their ability to perform a neurologic examination or tie knots using a 1-handed technique.

CONCLUSIONS

Neurosurgical education initiatives for MSs should continue to be developed. Hands-on neurosurgical training experiences for MSs serve as a valuable educational experience. Improvement in training models will lead to capitalizing on MS education to better improve readiness for neurosurgical residency without concern for patient safety.

Interns Without Subinternships

Surgical interns who have completed medical school in the era of Covid-19 will not have the same experience gained through the traditional multi-month fourth-year surgical subinternships. During subinternships, medical students learn relevant anatomic and radiographic features of surgical pathologies, hone technical skills, and gain exposure to surgical consults and procedures. This lack of intensive exposure will have this cohort starting at a lower comfort and knowledge level compared to years prior. Residency programs, especially subspeciality programs, should review and utilize national resources to facilitate the transition to intern year, such as the American College of Surgeons Entering Resident Readiness Assessment and American College of Surgeons/ Association of Program Directors in Surgery/Association for Surgical Education Resident Prep Curriculum. We recommend the use of a specialty-tailored intern boot-camp and longitudinal curriculum that focuses on learning procedural skills and surgical conditions, anatomy, pathology, clinical examination, radiographic findings, surgical approach, and postoperative complications. These steps will help address knowledge gaps and promote intern readiness in this cohort of individuals.

Dynamic 68Ga-DOTATATE PET/MRI in the Diagnosis and Management of Intracranial Meningiomas

Purpose To evaluate dynamic gallium 68 (⁶⁸Ga) tetraazacyclododecane tetraacetic acid octreotate (DOTATATE) brain PET/MRI as an adjunct modality in meningioma, enabling multiparametric standardized uptake value (SUV) and Patlak net binding rate constant (K_i) imaging, and to optimize static acquisition period. Materials and Methods In this prospective study (ClinicalTrials.gov no. NCT04081701, DOMINO-START), ⁶⁸Ga-DOTATATE PET/MRI-derived time-activity curves (TACs) were measured in 84 volumes of interest in 19 participants (mean age, 63 years; range, 36-89 years; 13 women; 2019-2021) with meningiomas. Region- and voxel-specific K_i were determined using Patlak analysis with a validated population-based reference tissue TAC model built from an independent data set of nine participants. Mean and maximum absolute and relative-to-superior-sagittal-sinus SUVs were extracted from the entire 50 minutes (SUV₅₀) and last 10 minutes (SUV₁₀) of acquisition. SUV versus K_i Spearman correlation, SUV and K_i meningioma versus posttreatment-change Mann-Whitney U tests, and SUV₅₀ versus SUV₁₀ Wilcoxon matched-pairs signed rank tests were performed. Results Absolute and relative maximum SUV₅₀ demonstrated a strong positive correlation with Patlak K_i in meningioma (r = 0.82, P < .001 and r = 0.85, P < .001, respectively) and posttreatment-change lesions (r = 0.88, P = .007 and r = 0.83, P = .02, respectively). Patlak K_i images yielded higher lesion contrast by mitigating nonspecific background signal. All SUV₅₀ and SUV₁₀ metrics differed between meningioma and posttreatment-change regions (P < .001). Within the meningioma group, SUV₁₀ attained higher mean scores than SUV₅₀ (P < .001). Conclusion Combined SUV and Patlak K _i ⁶⁸Ga-DOTATATE PET/MRI enabled multiparametric evaluation of meningioma, offering the potential to enhance lesion contrast with K_i imaging and optimize the SUV measurement postinjection window. Keywords: Molecular Imaging-Clinical Translation, Neuro-Oncology, PET/MRI, Dynamic, Patlak ClinicalTrials.gov registration no. NCT04081701 © RSNA, 2022.

PET/MR Imaging of Somatostatin Receptor Expression and Tumor Vascularity in Meningioma: Implications for Pathophysiology and Tumor Outcomes

Background and Purpose

Meningiomas, the most common primary intracranial tumor, are vascular neoplasms that express somatostatin receptor-2 (SSTR2). The purpose of this investigation was to evaluate if a relationship exists between tumor vascularity and SSTR2 expression, which may play a role in meningioma prognostication and clinical management.

Materials and Methods

Gallium-68-DOTATATE PET/MRI with dynamic contrast-enhanced (DCE) perfusion was prospectively performed. Clinical and demographic patient characteristics were recorded. Tumor volumes were segmented and superimposed onto parametric DCE maps including flux rate constant (Kep), transfer constant (Ktrans), extravascular volume fraction (Ve), and plasma volume fraction (Vp). Meningioma PET standardized uptake value (SUV) and SUV ratio to superior sagittal sinus (SUVR_SSS) were recorded. Pearson correlation analyses were performed. In a random subset, analysis was repeated by a second investigator, and intraclass correlation coefficients (ICCs) were determined.

Results

Thirty-six patients with 60 meningiomas (20 WHO-1, 27 WHO-2, and 13 WHO-3) were included. Mean Kep demonstrated a strong significant positive correlation with SUV (r = 0.84, p < 0.0001) and SUVR_SSS (r = 0.81, p < 0.0001). When stratifying by WHO grade, this correlation persisted in WHO-2 (r = 0.91, p < 0.0001) and WHO-3 (r = 0.92, p = 0.0029) but not WHO-1 (r = 0.26, p = 0.4, SUVR_SSS). ICC was excellent (0.97–0.99).

Conclusion

DOTATATE PET/MRI demonstrated a strong significant correlation between tumor vascularity and SSTR2 expression in WHO-2 and WHO-3, but not WHO-1 meningiomas, suggesting biological differences in the relationship between tumor vascularity and SSTR2 expression in higher-grade meningiomas, the predictive value of which will be tested in future work.

A multidisciplinary management algorithm for brain metastases

The incidence of brain metastases continues to present a management issue despite the advent of improved systemic control and overall survival. While the management of oligometastatic disease (ie, 1-4 brain metastases) with surgery and radiation has become fairly straightforward in the era of radiosurgery, the management of patients with multiple metastatic brain lesions can be challenging. Here we review the available evidence and provide a multidisciplinary management algorithm for brain metastases that incorporates the latest advances in surgery, radiation therapy, and systemic therapy while taking into account the latest in precision medicine-guided therapies. In particular, we argue that whole-brain radiation therapy can likely be omitted in most patients as up-front therapy.

Assessing the long-term safety and efficacy of gamma knife and linear accelerator radiosurgery for vestibular schwannoma: A systematic review and meta-analysis

Background

Differences in long-term outcomes of single-fraction stereotactic radiosurgery (SRS) between gamma knife (GK) and linear accelerator (LINAC) systems for vestibular schwannoma (VS) management remain unclear. To investigate differences in safety and efficacy between modalities, we conducted a meta-analysis of studies over the past decade.

Methods

MEDLINE, EMBASE, and Cochrane databases were queried for studies with the following inclusion criteria: English language, published between January 2010 and April 2020, cohort size ≥30, and mean/median follow-up ≥5 years. Odds ratios (OR) compared rates of tumor control, hearing preservation, and cranial nerve toxicities before and after SRS.

Results

Thirty-nine studies were included (29 GK, 10 LINAC) with 6516 total patients. Tumor control rates were 93% (95% CI 91-94%) and 94% (95% CI 91-97%) for GK and LINAC, respectively. Both GK (OR 0.06, 95% CI 0.02-0.13) and LINAC (OR 0.47, 95% CI 0.29-0.76) reduced odds of serviceable hearing. Neither GK (OR 0.71, 95% CI 0.41-1.22) nor LINAC (OR 1.13, 95% CI 0.64-2.00) impacted facial nerve function. GK decreased odds of trigeminal nerve (TN) impairment (OR 0.55, 95% CI 0.32-0.94) while LINAC did not impact TN function (OR 1.45, 95% CI 0.81-2.61). Lastly, LINAC offered decreased odds of tinnitus (OR 0.15, 95% CI 0.03-0.87) not observed with GK (OR 0.70, 95% CI 0.48-1.01).

Conclusions

VS tumor control and hearing preservation rates are comparable between GK and LINAC SRS. GK may better preserve TN function, while LINAC decreases tinnitus rates. Future studies are warranted to investigate the efficacy of GK and LINAC SRS more directly.

The use of Mixed Reality for the treatment planning of unruptured intracranial aneurysms

BACKGROUND

A thorough comprehension of topographic neuroanatomy is paramount in neurosurgery. In recent years, great attention has been raised towards extended reality, which comprises virtual, augmented, and mixed reality (MR) as an aid for surgery. In this paper, we describe our preliminary experience with the use of a new MR platform, aiming to assess its reliability and usefulness in the planning of surgical treatment of unruptured intracranial aneurysms.

METHODS

We prospectively enrolled 5 patients, harboring a total of 8 intracranial unruptured aneurysms, undergoing elective surgical clipping. A wearable mixed-reality device (HoloLens) was used to display and interact with a holographic model during surgical planning. Afterward, a total of 10 among surgeons and residents filled in a 5-point Likert-scale evaluation questionnaire.

RESULTS

According to the participants' feedback, the main MR platform advantages were considered the educational value, its utility during patients positioning and craniotomy planning, as well as the anatomical and imaging interpretation during surgery. The graphic performance was also deemed very satisfactory. On the other hand, the device was evaluated as not easy to use and pretty uncomfortable when worn for a long time.

CONCLUSIONS

We demonstrated that MR could play important role in planning the surgical treatment of intracranial aneurysms by enhancing the visualization and understanding of the patient-specific anatomy.

Applications of augmented reality in the neurosurgical operating room: A systematic review of the literature

Advancements in imaging techniques are key forces of progress in neurosurgery. The importance of accurate visualization of intraoperative anatomy cannot be overemphasized and is commonly delivered through traditional neuronavigation. Augmented Reality (AR) technology has been tested and applied widely in various neurosurgical subspecialties in intraoperative, clinical use and shows promise for the future. This systematic review of the literature explores the ways in which AR technology has been successfully brought into the operating room (OR) and incorporated into clinical practice. A comprehensive literature search was performed in the following databases from inception-April 2020: Ovid MEDLINE, Ovid EMBASE, and The Cochrane Library. Studies retrieved were then screened for eligibility against predefined inclusion/exclusion criteria. A total of 54 articles were included in this systematic review. The studies were sub- grouped into brain and spine subspecialties and analyzed for their incorporation of AR in the neurosurgical clinical setting. AR technology has the potential to greatly enhance intraoperative visualization and guidance in neurosurgery beyond the traditional neuronavigation systems. However, there are several key challenges to scaling the use of this technology and bringing it into standard operative practice including accurate and efficient brain segmentation of magnetic resonance imaging (MRI) scans, accounting for brain shift, reducing coregistration errors, and improving the AR device hardware. There is also an exciting potential for future work combining AR with multimodal imaging techniques and artificial intelligence to further enhance its impact in neurosurgery.

Outcomes following upfront radiation versus monitoring in atypical meningiomas: 16-year experience at a tertiary medical center

Background

The role of postoperative upfront radiotherapy (RT) in the management of gross totally resected atypical meningiomas remains unclear. This single-center retrospective review of newly diagnosed histologically confirmed cases of World Health Organization (WHO) Grade II atypical meningioma at Weill Cornell Medicine from 2004 to 2020 aims to compare overall survival (OS) and progression-free survival (PFS) of postoperative upfront RT versus observation, stratified by resection status (gross total resection [GTR] vs subtotal resection [STR]).

Methods

Ninety cases of atypical meningioma were reviewed (56% women; median age 61 years; median follow-up 41 months).

Results

In patients with GTR, hazard ratio (HR) of PFS was 0.09 for postoperative upfront RT versus observation alone (95% confidence interval [CI] 0.01–0.68; P = .02), though HR for OS was not significant (HR 0.46; 95% CI 0.05–4.45; P = .5). With RT, PFS was 100% at 12 and 36 months (compared to 84% and 63%, respectively, with observation); OS at 36 months (OS36) was 100% (compared to 94% with observation). In patients with STR, though PFS at 36 months was higher for RT arm versus observation (84% vs 74%), OS36 was 100% in both arms. HR was not significant (HR 0.76; 95% CI 0.16–3.5; P = .73).

Conclusions

This retrospective study suggests postoperative upfront RT following GTR of atypical meningioma is associated with improved PFS compared to observation. Further studies are required to draw conclusions about OS.

Time to administration of stereotactic radiosurgery to the cavity after surgery for brain metastases: a real-world analysis

OBJECTIVE

Publications on adjuvant stereotactic radiosurgery (SRS) are largely limited to patients completing SRS within a specified time frame. The authors assessed real-world local recurrence (LR) for all brain metastasis (BM) patients referred for SRS and identified predictors of SRS timing.

METHODS

The authors retrospectively identified BM patients undergoing resection and referred for SRS between 2012 and 2018. Patients were categorized by time to SRS, as follows: 1) ≤ 4 weeks, 2) > 4-8 weeks, 3) > 8 weeks, and 4) never completed. The relationships between timing of SRS and LR, LR-free survival (LRFS), and survival were investigated, as well as predictors of and reasons for specific SRS timing.

RESULTS

In a cohort of 159 patients, the median age at resection was 64.0 years, 56.5% of patients were female, and 57.2% were in recursive partitioning analysis (RPA) class II. The median preoperative tumor diameter was 2.9 cm, and gross-total resection was achieved in 83.0% of patients. All patients were referred for SRS, but 20 (12.6%) did not receive it. The LR rate was 22.6%, and the time to SRS was correlated with the LR rate: 2.3% for patients receiving SRS at ≤ 4 weeks postoperatively, 14.5% for SRS at > 4-8 weeks (p = 0.03), and 48.5% for SRS at > 8 weeks (p < 0.001). No LR difference was seen between patients whose SRS was delayed by > 8 weeks and those who never completed SRS (48.5% vs 50.0%; p = 0.91). A similar relationship emerged between time to SRS and LRFS (p < 0.01). Non-small cell lung cancer pathology (p = 0.04), earlier year of treatment (p < 0.01), and interval from brain MRI to SRS (p < 0.01) were associated with longer intervals to SRS. The rates of receipt of systemic therapy also differed significantly between patients by category of time to SRS (p = 0.02). The most common reasons for intervals of > 4-8 weeks were logistic, whereas longer delays or no SRS were caused by management of systemic disease or comorbidities.

CONCLUSIONS

Available data on LR rates after adjuvant SRS are often obtained from carefully preselected patients receiving timely treatment, whereas significantly less information is available on the efficacy of adjuvant SRS in patients treated under "real-world" conditions. Management of these patients may merit reconsideration, particularly when SRS is not delivered within ≤ 4 weeks of resection. The results of this study indicate that a substantial number of patients referred for SRS either never receive it or are treated > 8 weeks postoperatively, at which time the SRS-treated patients have an LR risk equivalent to that of patients who never received SRS. Increased attention to the reasons for prolonged intervals from surgery to SRS and strategies for reducing them is needed to optimize treatment. For patients likely to experience delays, other radiotherapy techniques may be considered.

The World of Neurosurgery Reimagined Post COVID-19: Crisis ↔ Opportunities

The COVID-19 pandemic has impacted neurosurgery in unforeseeable ways. Neurosurgical patient care, research, and education have undergone extraordinary modifications as medicine and mankind have adapted to overcome the challenges posed by this pandemic. Some changes will disappear as the situation slowly recovers to a prepandemic status quo. Others will remain: This pandemic has sparked some long-overdue systemic transformations across all levels of medicine, including in neurosurgery, that will be beneficial in the future. In this paper, we present some of the challenges faced across different levels of neurosurgical clinical care, research, and education, the changes that followed, and how some of these modifications have transformed into opportunities for improvement and growth in the future.

COVID-19: A Time Like No Other in (the Department of) Neurological Surgery

Coronavirus disease 2019 (COVID-19) has disrupted lives and indelibly impacted the practice of medicine since emerging as a pandemic in March 2020. For neurosurgery departments throughout the United States, the pandemic has created unique challenges across subspecialties in devising methods of triage, workflow, and operating room safety. Located in New York City, at the early epicenter of the COVID-19 crisis, the Weill Cornell Medicine Department of Neurological Surgery was disrupted and challenged in many ways, requiring adaptations in clinical operations, workforce management, research, and education. Through our department's collective experience, we offer a glimpse at how our faculty and administrators overcame obstacles, and transformed in the process, at the height of the COVID-19 pandemic.

Neurosurgery in COVID-19 Ground Zero: The Weill Cornell Medicine Experience

The mobilization of subspecialty departments in reaction to the unique demands of the onset of the coronavirus disease 2019 (COVID-19) pandemic in New York City was swift and left little time for reflection and commemoration. The early days of the pandemic brought unprecedented stressors on the medical system that necessitated a restructuring of hospitals, reallocation of health care workers, and a shift in care and education paradigms to meet patient care demands and public health needs. As the number of cases, intensive care unit patients, and deaths skyrocketed in New York City, many struggled with a somewhat paradoxical difficulty in perceiving the human value of what these numbers mean. Easily lost in the statistics are the stories and experiences of the physicians and trainees who were counted on to halt their own clinical practices and adapt their skillsets to tackle the pandemic. In this article, we present 10 brief narratives from the student members of the Neurosurgery Publication Group at Weill Cornell Medical College and members of the Weill Cornell Medicine Neurological Surgery Residency Program and Department of Neurological Surgery faculty. Reflecting on these individual experiences gives us an opportunity to simultaneously contribute to a history of New York City's reaction to COVID-19 and commemorate the individuals who were impacted by or succumbed to this disease.

Dr. Thanjavur Santhanakrishna Kanaka-A Pioneer and Neurosurgical Innovator

BACKGROUND

Thanjavur Santhanakrishna Kanaka, M.B.B.S., M.S. (General Surgery), M.S. (Neurosurgery), Ph.D., and former Captain, Indian Army Medical Corps, was born on March 31, 1932. She became the first woman neurosurgeon in India and all of Asia.

METHODS

This manuscript was compiled through a combination of interviews and references to other articles and some of the published manuscripts of Dr. Kanaka and her colleagues.

RESULTS

Dr. Kanaka was a trailblazer for women in neurosurgery and a pioneer in functional and stereotactic neurosurgery. During her long and productive career, she authored dozens of articles reported in prestigious neurosurgical journals worldwide and helped inspire and train the next generations of neurosurgeons in India and abroad. Even after retirement, Dr. Kanaka continued to focus on serving the medical community through her Sri Santhanakrishna Padmavathi Health Care and Research Foundation in Chennai with the mission of serving underprivileged and senior citizens in the local community. In addition to her accomplishments as a practicing neurosurgeon, Dr. Kanaka's career was notable for her successful collaborations with biomedical engineers on medical device development using locally sourced materials and talent in India.

CONCLUSIONS

Through her innovative thinking, compassion for her patients, and unwavering resilience, Dr. Kanaka has continued to serve as an inspiration to all pursuing a career in academic medicine and neurosurgery.

Evidence-based practice of stereotactic radiosurgery: Outcomes from an educational course for neurosurgery and radiation oncology residents

Background:

As the field of brain and spine stereotactic radiosurgery (SRS) continues to grow, so will the need for a comprehensive evidence base. However, it is unclear to what degree trainees feel properly equipped to use SRS. We assess the perceptions and comfort level reported by neurosurgery and radiation oncology residents concerning the evidence-based practice of SRS.

Methods:

A continuing medical education (CME) course provided peer-reviewed updates regarding treatment with intracranial and spinal SRS. Presentations were given by neurosurgery and radiation oncology residents with mentorship by senior faculty. To gauge perceptions regarding SRS, attendees were surveyed. Responses before and after the course were analyzed using the Fisher’s exact test in R statistical software.

Results:

Participants reported the greatest knowledge improvements concerning data registries (P < 0.001) and clinical trials (P = 0.026). About 82% of all (n = 17) radiation oncology and neurosurgery residents either agreed or strongly agreed that a brain and spine SRS rotation would be beneficial in their training. However, only 47% agreed or strongly agreed that one was currently part of their training. In addition, knowledge gains in SRS indications (P = 0.084) and ability to seek collaboration with colleagues (P = 0.084) showed notable trends.

Conclusion:

There are clear knowledge gaps shared by potential future practitioners of SRS. Specifically, knowledge regarding SRS data registries, indications, and clinical trials offer potential areas for increased educational focus. Furthermore, the gap between enthusiasm for increased SRS training and the current availability of such training at medical institutions must be addressed.

Increases in female academic productivity and female mentorship highlight sustained progress in previously identified neurosurgical gender disparities

OBJECTIVE

A meta-analysis was performed to understand disparities in the representation of female authorship within the neurosurgical literature and implications for career advancement of women in neurosurgery.

METHODS

Author names for articles published in 16 of the top neurosurgical journals from 2002 to 2019 were obtained from MEDLINE. The gender of each author was determined using automated prediction methods. Publication trends were compared over time and across subdisciplines. Female authorship was also compared to the proportionate composition of women in the field over time.

RESULTS

The metadata obtained from 16 major neurosurgical journals yielded 66,546 research articles. Gender was successfully determined for 96% (127,809/133,578) of first and senior authors, while the remainder (3.9%) were unable to be determined through prediction methods. Across all years, 13.3% (8826) of articles had female first authorship and 9.1% (6073) had female senior authorship. Female first authorship increased significantly over time from 5.8% in 2002 to 17.2% in 2019 (p < 0.001). Female senior authorship also increased significantly over time, from 5.5% in 2002 to 12.0% in 2019 (p < 0.001). The journals with the highest proportions of female first authors and senior authors were the Journal of Neurosurgery: Pediatrics (33.5%) and the Asian Journal of Neurosurgery (23.8%), respectively. Operative Neurosurgery had the lowest fraction of female first (12.4%) and senior (4.7%) authors. There was a significant difference between the year-by-year proportion of female neurosurgical trainees and the year-by-year proportion of female neurosurgical first (p < 0.001) and senior (p < 0.001) authors. Articles were also more likely to have a female first author if the senior author of the article was female (OR 2.69, CI 2.52-2.86; p < 0.001). From 1944 to 2019, the Journal of Neurosurgery showed a steady increase in female first and senior authorship, with a plateau beginning in the 1990s.

CONCLUSIONS

Large meta-analysis techniques have the potential to effectively leverage large amounts of bibliometric data to quantify the representation of female authorship in the neurosurgical literature. The proportion of female authors in major neurosurgical journals has steadily increased. However, the rate of increase in female senior authorship has lagged behind the rate of increase in first authorship, indicating a disparity in academic advancement in women in neurosurgery.

[68Ga]-DOTATATE PET/MRI as an adjunct imaging modality for radiation treatment planning of meningiomas

Background

Meningiomas express high levels of somatostatin receptor 2 (SSTR2). SSTR2-targeted PET imaging with [⁶⁸Ga]-DOTATATE can aid with distinguishing residual meningioma from reactive changes in the postoperative setting. We present initial dosimetric analyses, acute events, and local control data utilizing [⁶⁸Ga]-DOTATATE PET/MRI-assisted target delineation for prospectively-treated intermediate-risk meningiomas.

Methods

Twenty-nine patients underwent DOTATATE PET/MRI meningioma evaluation in 2019. Eight patients with 9 postoperative meningiomas met RTOG 0539 intermediate-risk criteria (recurrent WHO grade I, 1/9; WHO grade II, 8/9). Target volumes were created using DOTATATE PET/MRI to determine residual disease and received a nominal dose of 35.0 Gy over 5 fractions. For comparison, cases were recontoured and planned with MRI alone per RTOG 0539 guidelines. Mean and maximum equivalent 2 Gy doses were generated for target volumes and organs at risk (OAR) within 1 cm of the PTV and compared using Wilcoxon matched pairs signed rank test.

Results

DOTATATE PET/MRI-guided planning significantly reduced mean PTV (11.12 cm³ compared to 71.39 cm³ based on MRI alone, P < .05) and mean and max dose to the whole brain, optic nerves, and scalp. PET/MRI plans resulted in at least 50% reduction of mean and max doses to the lens, eyes, chiasm, cochlea, brainstem, and hippocampi. One patient experienced focal alopecia. There were no local recurrences at 6 months.

Conclusion

Incorporating DOTATATE-PET/MRI for postoperative target delineation in patients with intermediate-risk intracranial meningiomas results in PTV reduction and decreased OAR dose. Our findings warrant larger studies evaluating DOTATATE-PET/MRI in the radiotherapeutic planning of postoperative meningiomas.

Alopecia following cranial stereotactic radiosurgery: A comprehensive review of the literature

Alopecia is often an undesirable side effect for patients undergoing radiation treatment. Although prophylaxis has been studied for alopecia following radiotherapy and chemotherapy, little research has been done in preventing radiosurgery induced alopecia. Past studies have found that increasing the dose of radiation delivered increases the degree of alopecia by generating a late regenerative response by the hair follicles (HFs). Various studies showed that using hair sparing techniques such as IMRT, VMAT, and HS-WBRT decreases the amount of dose to the scalp, thereby reducing hair loss. It has also been found that the location of the scalp with the highest degree of alopecia is that which is closest to area of greatest dose overlap. Accordingly, preventing dose overlap with arcs or cerrobend blocks has been shown to decrease alopecia. It has also been reported that hair loss is found in the area closer to the contour arcs where the dose is highest. We have reviewed the existing data on the prevention and treatment of radiation-induced alopecia and have presented here a comprehensive review of the reported data and relevant clinical considerations relating to dose, location, and scalp surface area (SSA).

Pregnancy and parental leave among neurosurgeons and neurosurgical trainees

OBJECTIVE

Despite recently heightened advocacy efforts relating to pregnancy and family leave policies in multiple surgical specialties, no studies to date have described female neurosurgeons' experiences with childbearing. The AANS/CNS Section of Women in Neurosurgery created the Women and Pregnancy Task Force to ascertain female neurosurgeons' experiences with and attitudes toward pregnancy and the role of family leave policies.

METHODS

A voluntary online 28-question survey examined the pregnancy experiences of female neurosurgeons and perceived barriers to childbearing. The survey was developed and electronically distributed to all members of the American Association of Neurological Surgeons and Congress of Neurological Surgeons who self-identified as female in February 2016. Responses from female resident physicians, fellows, and current or retired practicing neurosurgeons were analyzed.

RESULTS

A total of 126 women (20.3%) responded to the survey; 57 participants (49%) already had children, and 39 (33%) planned to do so. Participants overwhelmingly had or planned to have children during the early practice and senior residency years. The most frequent obstacles experienced or anticipated included insufficient time to care for newborns (47% of women with children, 92% of women planning to have children), discrimination by coworkers (31% and 77%, respectively), and inadequate time for completion of board requirements (18% and 51%, respectively). There was substantial variability in family leave policies, and a minority of participants (35%) endorsed the presence of any formal policy at their institution. Respondents described myriad unique challenges associated with pregnancy and family leave.

CONCLUSIONS

Pregnancy and family leave pose significant challenges to the recruitment, retention, and advancement of women in neurosurgery. It is thus imperative to promote clear family leave policies for trainees and practitioners, address discrimination surrounding these topics, and encourage forethought and flexibility to tackle obstacles inherent in pregnancy and the early stages of child rearing.

Medical Student Concerns Relating to Neurosurgery Education During COVID-19

Background

The coronavirus disease 2019 (COVID-19) pandemic has created significant obstacles within medical education. For medical students interested in pursuing neurosurgery as a specialty, the educational policies surrounding COVID-19 have resulted in unique challenges. The present study used a nationwide survey to identify the concerns of medical students interested in pursuing neurosurgery during the COVID-19 pandemic.

Methods

Students who had previously registered for medical student neurosurgery training camps were sent an online Qualtrics survey requesting them to assess how the COVID-19 pandemic was affecting their neurosurgical education. The Pearson χ² test and post hoc pairwise Fisher exact test were used for analysis of categorical variables, and the 2-tailed paired Student t test was used for continuous variables.

Results

The survey was distributed to 852 medical students, with 127 analyzed responses. Concerns regarding conferences and networking opportunities (63%), clinical experience (59%), and board examination scores (42%) were most frequently cited. Of the third-year medical students, 76% reported ≥1 cancelled or postponed neurosurgery rotation. On average, students were more likely to take 1 year off from medical school after than before the start of the COVID-19 pandemic, measured from 0 to 100 (25.3 ± 36.0 vs. 39.5 ± 37.5; P = 0.004). Virtual mentorship pairing was the highest rated educational intervention suggested by first- and second-year medical students. The third- and fourth-year medical students had cited virtual surgical skills workshops most frequently.

Conclusions

The results from the present nationwide survey have highlighted the concerns of medical students regarding their neurosurgery education during the COVID-19 pandemic. With these findings, neurosurgery organizations can consider targeted plans for students of each year to continue their education and development.

Extent of resection, molecular signature, and survival in 1p19q-codeleted gliomas

OBJECTIVE

Genomic analysis in neurooncology has underscored the importance of understanding the patterns of survival in different molecular subtypes within gliomas and their responses to treatment. In particular, diffuse gliomas are now principally characterized by their mutation status (IDH1 and 1p/19q codeletion), yet there remains a paucity of information regarding the prognostic value of molecular markers and extent of resection (EOR) on survival. Furthermore, given the modern emphasis on molecular rather than histological diagnosis, it is important to examine the effect of maximal resection on survival in all gliomas with 1p/q19 codeletions, as these will now be classified as oligodendrogliomas under the new WHO guidelines. The objectives of the present study were twofold: 1) to assess the association between EOR and survival for patients with oligodendrogliomas in the National Cancer Database (NCDB), which includes information on mutation status, and 2) to demonstrate the same effect for all patients with 1p/19q codeleted gliomas in the NCDB.

METHODS

The NCDB was queried for all cases of oligodendroglioma between 2004 and 2014, with follow-up dates through 2016. The authors found 2514 cases of histologically confirmed oligodendrogliomas for the final analysis of the effect of EOR on survival. Upon further query, 1067 1p/19q-codeleted tumors were identified in the NCDB. Patients who received subtotal resection (STR) or gross-total resection (GTR) were compared to those who received no tumor debulking surgery. Univariable and multivariable analyses of both overall survival and cause-specific survival were performed.

RESULTS

EOR was associated with increased overall survival for both histologically confirmed oligodendrogliomas and all 1p/19q-codeleted-defined tumors (p < 0.001 and p = 0.002, respectively). Tumor grade, location, and size covaried predictably with EOR. When evaluating tumors by each classification system for predictors of overall survival, facility setting, age, comorbidity index, grade, location, chemotherapy, and radiation therapy were all shown to be significantly associated with overall survival. STR and GTR were independent predictors of improved survival in historically classified oligodendrogliomas (HR 0.83, p = 0.18; HR 0.69, p = 0.01, respectively) and in 1p/19q-codeleted tumors (HR 0.49, p < 0.01; HR 0.43, p < 0.01, respectively).

CONCLUSIONS

By using the NCDB, the authors have demonstrated a side-by-side comparison of the survival benefits of greater EOR in 1p/19q-codeleted gliomas.

Clinical Considerations in Neurosurgical Radiosurgery in the Time of COVID-19

The COVID-19 pandemic is affecting all aspects of the healthcare ecosystem, including administration of stereotactic radiosurgery (SRS). The clinical and logistical challenges created by the COVID-19 public health crisis are clear, but the solutions to these issues are less readily apparent. The goal of this work is to use our experience at a large, academic medical center as a lens for interpreting the many looming issues specific to radiosurgery and its role in the treatment of brain and spine disorders. While the full impact of the pandemic remains to be seen, the aim of this paper is to provide a structural framework to optimize delivery of neurosurgically oriented radiosurgery with proposed clinical workflow strategies. Innovative solutions to the current pandemic crisis affecting the healthcare ecosystem will be driven by increased interdisciplinary and global dialogue.

Medical Students' Perceived Interests and Concerns for a Career in Neurosurgery

OBJECTIVE

The factors that attract and concern medical students about a career in neurosurgery have never been clearly characterized or delineated in a large nationwide cohort of medical students intending to pursue a career in neurosurgery. The objective of the present study was to characterize the factors that influence medical student interest in neurosurgery and assess the effects of a formal neurosurgery training course on participants' perceptions of a career in neurosurgery.

METHODS

Before the Medical Student Neurosurgery Training Camp for subinternship preparation, registered students were surveyed about their interest level in neurosurgery, factors that attracted or concerned them about a career in neurosurgery, attendance at a national neurosurgery conference or course, formal clinical neurosurgery exposure in medical school, and whether they had a resident or attending mentor in neurosurgery. At the end of the course, all the participants completed the surveyed again. P < 0.05 was considered significant on Pearson's χ² and Fisher's exact tests for categorical variables and 2-tailed paired Student's t tests for continuous variables.

RESULTS

Of the training camp attendees, >95% completed both pre- and postcourse surveys, including 41 first-year, 19 second-year, 30 third-year, and 5 fourth-year medical school students. The most common factors that concerned students about a career in neurosurgery were work-life balance (76%) and competitiveness (56%). All factors of concern were decreased in the postcourse survey, except for competitiveness. A small cohort (8.4%) of students had no concerns about a career in neurosurgery; this cohort had doubled to 17% after the course (P < 0.05). The students that indicated no concern had a greater postcourse interest level in neurosurgery (95.8 ± 8.7 vs. 86.7 ± 20.5; P < 0.05). Student reasons for an interest in neurosurgery included intellectually stimulating work (94%), interest in neurosciences (93%), effect on patients (84%), innovation and new technology (80%), research opportunities (77%), and prestige (24%). All reasons increased after the course, with the exception of prestige, which decreased to 22%.

CONCLUSION

A training camp for students pursuing a neurosurgery subinternship was effective in providing transparency and positively influencing the factors that attract and concern students about a career in neurosurgery. Characterization of medical student perceptions of neurosurgery from a large, nationwide cohort of students pursuing a subinternship has provided novel data and could help identify factors protecting against burnout later in life.

Placement of cesium-131 permanent brachytherapy seeds using the endoscopic endonasal approach for recurrent anaplastic skull base meningioma: case report and technical note

There are few therapeutic options available for the treatment of recurrent meningiomas that have failed treatment with surgery and external-beam radiation therapy (EBRT). As additional EBRT is clinically risky, brachytherapy offers an important alternative for optimizing local control. In skull base meningiomas, the endoscopic endonasal approach (EEA) has demonstrated an excellent extent of resection. However, in the case of recurrent, atypical, or residual meningiomas, the EEA alone may not be adequate to address microscopic, residual, highly proliferative disease. In this situation, local radioactive seed brachytherapy has been shown to improve control, but few reports of this technique exist. A 48-year-old right-handed man presented on multiple occasions with recurrence of an anaplastic skull base meningioma, after multiple prior gross-total resections and multiple rounds of radiotherapy had failed. The authors performed a maximally safe neurosurgical tumor resection via EEA supplemented by the intraoperative implantation of 131Cs low-dose permanent brachytherapy seeds. They describe a technique for permanent implantation of brachytherapy seeds and provide operative video of this technique. The authors submit that utilizing this technique in combination with EEA tumor resection renders a minimally invasive approach to improving local control in a patient with a recurrent anaplastic or atypical meningioma of the skull base.

Worldwide Access to Stereotactic Radiosurgery

Stereotactic radiosurgery is a safe and effective technology that can address a variety of neurosurgical conditions, but in many parts of the world, access remains an issue. Although the technology is increasingly available in the United States, Canada, Europe, and parts of Asia, poor access to central nervous system (CNS) imaging and inadequate treatment equipment in other parts of the world limit the availability of radiosurgery as a treatment option. In addition, epidemiologic data about cancer and CNS metastases in low-income countries are sparse and much less complete than in more developed countries, and the need for radiosurgery may be underestimated as a result. Current radiosurgical platforms can be expensive to install and require a substantial amount of personnel training for safe operation. Socioeconomic and political forces are relevant to limitations to and opportunities for improving access to care. Here we examine the current barriers to access and propose areas for future efforts to improve global availability of radiosurgery for neurosurgical conditions.

An overview of anti-epileptic therapy management of patients with malignant tumors of the brain undergoing radiation therapy

As our surgical, radiation, chemotherapeutic and supportive therapies for brain malignancies improve, and overall survival is prolonged, appropriate symptom management in this patient population becomes increasingly important. This review summarizes the published literature and current practice patterns regarding prophylactic and perioperative anti-epileptic drug use. As a wide range of anti-epileptic drugs is now available to providers, evidence guiding appropriate anticonvulsant choice is reviewed. A particular focus of this article is radiation therapy for brain malignancies. Toxicities and seizure risk associated with cranial irradiation will be discussed. Epilepsy management in patients undergoing radiation for gliomas, glioblastoma multiforme, and brain metastases will be addressed. An emerging but inconsistent body of evidence, reviewed here, indicates that anti-epileptic medications may increase radiosensitivity, and therefore improve clinical outcomes, specifically in glioblastoma multiforme patients.

Dynamic contrast-enhanced magnetic resonance imaging perfusion characteristics in meningiomas treated with resection and adjuvant radiosurgery

OBJECTIVE

There is a need for advanced imaging biomarkers to improve radiation treatment planning and response assessment. T1-weighted dynamic contrast-enhanced perfusion MRI (DCE MRI) allows quantitative assessment of tissue perfusion and blood-brain barrier dysfunction and has entered clinical practice in the management of primary and secondary brain neoplasms. The authors sought to retrospectively investigate DCE MRI parameters in meningiomas treated with resection and adjuvant radiation therapy using volumetric segmentation.

METHODS

A retrospective review of more than 300 patients with meningiomas resected between January 2015 and December 2018 identified 14 eligible patients with 18 meningiomas who underwent resection and adjuvant radiotherapy. Patients were excluded if they did not undergo adjuvant radiation therapy or DCE MRI. Demographic and clinical characteristics were obtained and compared to DCE perfusion metrics, including mean plasma volume (vp), extracellular volume (ve), volume transfer constant (Ktrans), rate constant (kep), and wash-in rate of contrast into the tissue, which were derived from volumetric analysis of the enhancing volumes of interest.

RESULTS

The mean patient age was 64 years (range 49–86 years), and 50% of patients (7/14) were female. The average tumor volume was 8.07 cm3 (range 0.21–27.89 cm3). The median Ki-67 in the cohort was 15%. When stratified by median Ki-67, patients with Ki-67 greater than 15% had lower median vp (0.02 vs 0.10, p = 0.002), and lower median wash-in rate (1.27 vs 4.08 sec−1, p = 0.04) than patients with Ki-67 of 15% or below. Logistic regression analysis demonstrated a statistically significant, moderate positive correlation between ve and time to progression (r = 0.49, p < 0.05). Furthermore, there was a moderate positive correlation between Ktrans and time to progression, which approached, but did not reach, statistical significance (r = 0.48, p = 0.05).

CONCLUSIONS

This study demonstrates a potential role for DCE MRI in the preoperative characterization and stratification of meningiomas, laying the foundation for future prospective studies incorporating DCE as a biomarker in meningioma diagnosis and treatment planning.

Optimal Timing and Sequence of Immunotherapy When Combined with Stereotactic Radiosurgery in the Treatment of Brain Metastases

Checkpoint immunotherapy (CIT) is an emerging and exciting treatment modality for the treatment of cancer. Much excitement has ensued in the potential of CIT to revolutionize the treatment and prognosis of brain metastases. The combination of stereotactic radiosurgery (SRS) and CIT has also been studied and showed promise compared with either treatment modality alone. However, several questions have arisen, in particular, the timing at which SRS and CIT should be administered relative to each other. We reviewed the reported data and attempted to offer a potential answer to this question.

Reirradiation of Recurrent Brain Metastases: Where Do We Stand?

Brain metastases occur in a large portion of patients with cancer. Although advances in radiotherapy have helped to improve survival, they have also raised questions regarding the best modality for retreatment in the context of recurrent disease. The spectrum of treatment options for recurrent intracranial metastatic disease after previous radiotherapy includes salvage stereotactic radiosurgery, whole brain radiotherapy, and brachytherapy. We have comprehensively reviewed the existing data on the efficacy and toxicity of the various reirradiation treatment modalities. We examined the key clinical considerations that guide patient selection, such as dose, tumor size, interval to retreatment, and local control and survival rates.

Analysis of national trends in neurosurgical resident attrition

OBJECTIVE

Resident attrition creates a profound burden on trainees and residency programs. This study aims to analyze trends in resident attrition in neurological surgery.

METHODS

This study followed a cohort of 1275 residents who started neurosurgical residency from 2005 to 2010. Data obtained from the American Association of Neurological Surgeons (AANS) included residents who matched in neurosurgery during this time. Residents who did not finish their residency training at the program in which they started were placed into the attrition group. Residents in the attrition group were characterized by one of five outcomes: transferred neurosurgery programs; transferred to a different specialty; left clinical medicine; deceased; or unknown. A thorough internet search was conducted for residents who did not complete their training at their first neurosurgical program. Variables leading to attrition were also analyzed, including age, sex, presence of advanced degree (Ph.D.), postgraduate year (PGY), and geographical region of program.

RESULTS

Residents starting neurosurgical residency from 2005 to 2010 had an overall attrition rate of 10.98%. There was no statistically significant difference in attrition rates among the years (p = 0.337). The outcomes for residents in the attrition group were found to be as follows: 33.61% transferred neurosurgical programs, 56.30% transferred to a different medical specialty, 8.40% left clinical medicine, and 1.68% were deceased. It was observed that women had a higher attrition rate (18.50%) than men (10.35%). Most attrition (65.07%) occurred during PGY 1 or 2. The attrition group was also observed to be significantly older at the beginning of residency training, with a mean of 31.69 years of age compared to 29.31 in the nonattrition group (p < 0.001). No significant difference was observed in the attrition rates for residents with a Ph.D. (9.86%) compared to those without a Ph.D. (p = 0.472).

CONCLUSIONS

A majority of residents in the attrition group pursued training in different medical specialties, most commonly neurology, radiology, and anesthesiology. Factors associated with an increased rate of attrition were older age at the beginning of residency, female sex, and junior resident (PGY-1 to PGY-2). Resident attrition remains a significant problem within neurosurgical training, and future studies should focus on targeted interventions to identify individuals at risk to help them succeed in their medical careers.

Quantitative assessment of cell contractility using polarized light microscopy

Cell contractility regulates multiple cell behaviors which contribute to both normal and pathological processes. However, measuring cell contractility remains a technical challenge in complex biological samples. The current state of the art technologies employed to measure cell contractility have inherent limitations that greatly limit the experimental conditions under which they can be used. Here, we use quantitative polarization microscopy to extract information about cell contractility. We show that the optical retardance signal measured from the cell body is proportional to cell contractility in 2-dimensional and 3-dimensional platforms, and as such can be used as a straightforward, tractable methodology to assess cell contractility in a variety of systems. This label-free optical method provides a novel and flexible way to assess cellular forces of single cells and monolayers in several cell types, fixed or live, in addition to cells present in situ in mouse tumor tissue samples. This easily implementable and experimentally versatile method will significantly contribute to the cell mechanics field.