Faculty Bibliography

OBJECTIVE:Mentorship and training relationships shape the careers and influence of neurosurgeons. Network analysis can reveal structural characteristics and key individuals who support network connectivity and drive the field's development. This endeavor analyzed the U.S.-based neurosurgical training network derived from NeurosurGen.com. METHODS:A network graph was constructed representing neurosurgical training relationships, including chairperson-trainee, program director-trainee, and coresident connections. Graph- and node-level metrics, with a focus on centrality measures, were calculated for a trainer-trainee subgraph. RESULTS:The network consisted of 8840 neurosurgeons represented as nodes, and 382,143 relationships represented as edges. It evolved from an early small-world structure to a hierarchical and decentralized structure dominated by local clusters. Demographic shifts over time reflected increasing diversity and inclusion, with greater representation of female, Hispanic, Asian, and Black trainees across 285 training programs. Nodes were preferentially connected via residency, and the connectivity among underrepresented populations improved in concert with increased representation. Harvey W. Cushing was the quintessential neurosurgeon-influencer in the United States, ranking highly across most centrality measures over time. CONCLUSIONS:The neurosurgical training network is sparse but interconnected, typical of large real-world professional networks. While many small groups of neurosurgeons are closely tied within their immediate training hierarchy and peer group, in modern neurosurgery, each surgeon is only connected to a small fraction of the total network. Highly central individuals have played critical roles in linking disparate groups and shaping network structure. Increasing diversity in recent decades indicates progress toward inclusivity, although overall representation remains low.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Neurosurgical clinical research depends on medical data collection and evaluation that is often laborious, time consuming, and inefficient. The goal of this work was to implement and evaluate a novel departmental data infrastructure (Neuro Data Hub) designed to provide specialized data services for neurosurgical research. Data acquisition would become available purely by request. METHODS:through collaboration between Department Leadership and Medical Center Information Technology, integrating it with Institutional Review Board workflows and an existing Epic electronic health record Datalake infrastructure. The system implementation included monthly departmental meetings and an asynchronous Research Electronic Data Capture-based request system. Data requests submitted between August 2023 and November 2024 were analyzed and categorized as basic, complex, or Natural Language Processing (NLP)-augmented, with optional visualization and database creation services. Request volumes, types, and execution times were assessed. RESULTS:The Hub processed 39 research data requests (2.6/month), comprising 3 basic, 22 complex, and 14 NLP-augmented requests. Two complex requests included visualization services, and one NLP request included database creation. Average request execution time was 36.5 days, with NLP-augmented requests showing increasing adoption over time. CONCLUSION/CONCLUSIONS:The Neuro Data Hub represents a paradigm shift from centralized to department-level data services, providing specialized support for neurosurgical research and democratizing access to institutional data. While effective, implementation may be limited by institutional information technology infrastructure requirements. This model could serve as a template for any form of medical-clinical research program seeking to improve data accessibility and research capabilities.

Background Arteriovenous malformations (AVMs) in eloquent brain regions pose significant challenges due to the increased risk of neurologic deficits associated with treatment. Although stereotactic radiosurgery (SRS) and endovascular embolization are used as standalone approaches, their comparative outcomes in eloquent brain AVMs remain unclear. Purpose To directly compare the outcomes of standalone endovascular embolization versus SRS for patients with AVMs in the eloquent brain. Materials and Methods This retrospective multicenter study analyzed patients with AVMs located in eloquent brain regions treated with standalone SRS or embolization from January 2010 to December 2023 as part of the Multicenter International Study for Treatment of Brain AVMs, or MISTA, consortium. Angiographic outcomes were assessed using digital subtraction arterial angiography, MR angiography, or CT angiography. Propensity score weighting (PSW) was used to account for baseline differences. Results A total of 119 patients were included (median age, 35 years [IQR, 21-54 years]; 64 female), with 96 patients treated with SRS and 23 with embolization. SRS achieved 71% (61 of 86 patients) complete obliteration at last follow-up compared with 56% (10 of 18 patients) in the embolization group (odds ratio [OR], 1.95; P = .20) before adjustment. After PSW, SRS achieved higher odds of complete obliteration at last follow-up (OR, 15.58; P = .001) compared with embolization. Before PSW, the SRS group had higher rates of modified Rankin Scale (mRS) scores 0-2 at last follow-up (95% [86 of 91 patients] vs 71% [15 of 21 patients]; OR, 6.8; P = .004) and a lower rate of hemorrhagic complications (5.2% [five of 96 patients] vs 26% [six of 23 patients]; OR, 0.15; P = .005) compared with embolization. Mortality rates were 2.1% (two of 96) in the SRS group and 4.3% (one of 23) in the embolization group (OR, 0.46; P = .54). After PSW, there was no evidence of a difference between SRS and embolization in mRS scores 0-2 (OR, 2.04; P = .45) or hemorrhagic complications (OR, 0.60; P = .63). Conclusion SRS was associated with a higher obliteration rate compared with embolization in patients with eloquent brain AVMs, whereas there was no evidence of a difference in functional outcomes or complications after adjustment. © RSNA, 2025 See also the editorial by Russell in this issue.

Gamma knife stereotactic radiosurgery is one of the most common procedures performed to manage patients with vestibular schwannoma. With a history that spans over 40 years, there has been continued evolution in radiosurgery technique and understanding of outcomes. The goal has always been to achieve long-term inactivation of tumor growth, commonly with tumor volumetric regression, and preservation of neurologic function. Challenges remain particularly pertaining to hearing preservation and other related symptoms such as those related to balance and tinnitus. Current discussions span a variety of topics including the importance of cochlear dose, the timing of the radiosurgery intervention as opposed to initial observation, the interpretation of imaging changes after radiosurgery, and the value of hearing augmentation strategies.

The current management of vestibular schwannomas (VS) includes observation, microsurgery, and stereotactic radiosurgery (SRS) or radiotherapy. Both microsurgery (MS) and irradiation have the potential for treatment failures. For microsurgical failures, options include observation, revision surgery, and SRS. SRS is most commonly used, as it carries a low risk of adverse events. Salvage MS following previous MS is reserved for specific cases and is often surgically challenging. For radiosurgical failures, both salvage MS and repeat SRS may be used. Salvage MS following SRS also tends to be challenging, although excellent facial nerve outcomes are achievable. Furthermore, repeat SRS is an emerging concept and should be considered in small tumors that are growing but are asymptomatic. This chapter is aimed at reviewing an approach to failure of primary interventions for vestibular schwannomas, with an emphasis on the time interval between modalities, tumor control rates, functional outcomes, and complications.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Upfront stereotactic radiosurgery (SRS) could be an option for nonfunctioning pituitary adenomas (NFPA) unsuitable for surgery. Only small series evaluate the results of upfront SRS; the aim of the study was to report patient outcomes from a large, international patient cohort. METHODS:The study evaluated tumor control and complications after single-session SRS in a multicentric cohort of untreated NFPA. RESULTS:In total, 132 patients (median age 51.2 [IQR: 27.1] years at SRS, median volume 2.1 [IQR: 2.9] cm3) were included. The probability of tumor control was 100% (95% CI: 100-100), 98.1% (95% CI: 94.6-100), and 92.4 (95% CI: 81.6-100) at 3, 5, and 8 years after SRS. The cumulative probability of new pituitary deficit was 11.7% (95% CI: 3.8-18.9), 24.4% (95% CI: 12.1-35.1), and 29.5% (95% CI: 12.1-26.9) at 3, 5, and 8 years, respectively. No new visual field defect occurred. Before SRS, 50 patients (37.9%) presented with a visual field defect with a complete improvement in 17 (34.7%), partial improvement in 12 (24.5%), and stability in 19 (38.8%) at a last follow-up of 2.2 (3.9) years. One patient (2.0%) worsened after SRS. Before SRS, 10 patients (7.6%) presented with an oculomotor nerve palsy. One patient (0.8%) developed a new transient nerve palsy. At a last follow-up of 2.5 (4.4) years, 5 patients (45.4 35.7%) had a stability of their palsy, 1 had a partial improvement (9.1%), and 5 (45.4%) had a complete improvement. CONCLUSION/CONCLUSIONS:Upfront SRS represents an option for appropriately selected patients with NFPA, and it exhibits a favorable efficacy and safety profile, but a longer follow-up is required. Visual improvement is low, and careful selection of patient is required.

BACKGROUNDAND OBJECTIVE/UNASSIGNED:The authors compareocclusion rates in grade I-III AVMs in smokers and non-smokers, using propensity score matching (PSM). METHODS:The authors performed a subgroup analysis of the MISTA consortium, a multicenter registry that includes patients aged 1 to 89 years with AVMs treated between January 2010 and December 2023. Only grade I-III AVMs were included. PSM was used to control confounders. Primary endpoints included angiographic obliteration. RESULTS:A total of 353 patients with bAVMs, with a median age of 37, were included in this study: 236 were never smokers, and 117 were current or previous smokers. After 1:1 PSM of smokers and non-smokers, 33 matched pairs were obtained. The smokers were more likely to display complete obliteration at last imaging follow-up compared to non-smokers (57.6 % vs. 27.3 %;p < 0.01). The median time to last clinical(p = 0.45)and angiographic(p = 0.33)follow up was not statistically different between the two groups.There were no statistically significant differences between the two matched groups in the incidence of post-SRS edema (p = 0.23), post-treatment rupture (0 %), overall mortality (p = 0.31), and functional status at the last follow-up (p = 0.69). CONCLUSION/CONCLUSIONS:Individuals with a positive history of smoking are more likely to achieve complete obliteration of grades I-III bAVMs following SRS treatment. However, smokers do not differ from non-smokers in terms of the incidence of post-treatment rupture, overall mortality, or functional status at the last follow-up.

Leptomeningeal carcinomatosis (LC) is a severe complication of metastatic breast cancer (mBC), with rising incidence. The prognosis for patients with LC has been poor, with a median overall survival of approximately four months. However, recent therapeutic advances, in particular the introduction of trastuzumab deruxtecan have dramatically changed the landscape of CNS metastases and improved outcomes. Here, we present the case of a 42-year-old woman with recurrent HER2+ breast cancer who developed extensive LC after multiple lines of treatment. Despite progressive disease, the patient exhibited a sustained response to trastuzumab deruxtecan, a novel antibody-drug conjugate (ADC), for 15 months, which was further extended by adding tucatinib. This case underscores the potential of ADCs, like trastuzumab deruxtecan, in controlling both brain metastases and leptomeningeal disease, offering hope for prolonged survival in patients with aggressive HER2+ mBC. Additionally, we highlight the evolving role of clinical trials, molecular profiling, and interdisciplinary care in managing this challenging condition. Ongoing trials continue to investigate new therapeutic options for HER2+ mBC with CNS involvement, promising to further improve outcomes and quality of life for patients facing this devastating disease.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Arteriovenous malformations (AVMs) with perinidal aneurysms and single draining vein are associated with an elevated risk of rupture and increased procedural complexity. The role of preoperative embolization in this high-risk anatomical subset remains unclear. This study aimed to evaluate the safety and efficacy of microsurgery with preoperative embolization, compared with microsurgery alone in patients with such AVMs. METHODS:We conducted a multicenter retrospective analysis of an AVM registry from the MISTA (Multicenter International Study for Treatment of Brain AVMs) consortium and included AVMs with perinidal aneurysms and a single draining vein. Baseline characteristics, angiographic outcomes, functional outcomes, and complication rates were compared. Propensity score weighting (PSW) using the covariate balancing method was applied to adjust for baseline differences. RESULTS:Out of a total of 1919 patients, 65 met the inclusion criteria; 45 patients underwent preoperative embolization followed by microsurgery, and 20 underwent microsurgery alone. After adjustment, complete obliteration rates were similar between groups (OR 0.87, 95% CI 0.04 to 16.33, P=0.92), as were rates of functional independence at discharge and follow-up. Overall complication, symptomatic complication, and mortality rates did not differ significantly between groups. However, permanent complications were significantly lower in patients with preoperative embolization (OR 0.06, 95% CI 0.004 to 0.84, P=0.03). DISCUSSION/CONCLUSIONS:In patients with AVMs featuring perinidal aneurysms and single draining vein, preoperative embolization followed by microsurgery was associated with fewer permanent complications and no increase in adverse outcomes compared with microsurgery alone. However, given the small number of events, this finding should be interpreted cautiously.