Faculty Bibliography

BACKGROUND:Glioblastoma intramedullary spinal cord metastasis (GISCM) is a rare sequela of high-grade astrocytoma and glioblastoma multiforme (GBM). Discrete intramedullary spinal cord metastases are less common than spinal leptomeningeal spread and may follow a more indolent course. Once identified as GISCM, palliative maximal safe resection of the tumor may be considered to alleviate neurological symptoms. Reports describing the surgical management of these rare lesions, including the use of emerging technologies that may aid in maximal safe resection, are sparse. A further understanding is also required regarding the course of disease and factors contributing to mortality in GISCM. METHODS:We reviewed the intraoperative management and clinical course of three patients treated for GISCM at our institution between 2015 and 2024. We additionally conducted a PRISMA-guided systematic literature review of PubMed Central, MEDLINE, and Bookshelf databases through May 26th, 2025, including original patient reports of GISCM from cranial astrocytoma or GBM. The disease course, management strategies, and causes of mortality in previously reported cases were analyzed. RESULTS:Our institutional cohort had a mean time to spinal metastasis of 26.2 months from diagnosis of cranial disease (range 17.5-40.5 months), with a mean survival of 9.2 months following maximal safe resection of extramedullary components (range 7-12 months). In two cases, intraoperative Stimulated Raman Histology (SRH) was employed to facilitate the rapid identification of metastatic GBM, thereby influencing surgical strategy. In one case, 5-aminolevulinic acid (5-ALA) was used to differentiate between tumor and spinal cord parenchyma, facilitating maximal safe debulking without neurological injury. Literature review identified 38 prior reported cases of GISCM, with a median time to spinal diagnosis of 11.0 months and a median survival of 3.5 months thereafter. The cause of death in the review cohort often involved multiple factors, and when analyzed for contributing factors to death, 38.7% involved cranial progression, 38.7% involved progression of spinal disease, and 29.0% involved medical complications. Gait ataxia at presentation was associated with shorter survival in review patients, potentially reflecting advanced disease with extramedullary cord compression. CONCLUSION/CONCLUSIONS:GISCM represents an entity distinct from leptomeningeal disease and may be managed in conjunction with recurrent cranial disease. Surgical debulking is a technically feasible strategy that can be safely facilitated using tools employed in the management of intracranial GBM, facilitating maximal safe resection without compromising survival.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Bone metastases, affecting more than 4.8% of patients with cancer annually, and particularly spinal metastases require urgent intervention to prevent neurological complications. However, the current process of manually reviewing radiological reports leads to potential delays in specialist referrals. We hypothesized that natural language processing (NLP) review of routine radiology reports could automate the referral process for timely multidisciplinary care of spinal metastases. METHODS:We assessed 3 NLP models-a rule-based regular expression (RegEx) model, GPT-4, and a specialized Bidirectional Encoder Representations from Transformers (BERT) model (NYUTron)-for automated detection and referral of bone metastases. Study inclusion criteria targeted patients with active cancer diagnoses who underwent advanced imaging (computed tomography, MRI, or positron emission tomography) without previous specialist referral. We defined 2 separate tasks: task of identifying clinically significant bone metastatic terms (lexical detection), and identifying cases needing a specialist follow-up (clinical referral). Models were developed using 3754 hand-labeled advanced imaging studies in 2 phases: phase 1 focused on spine metastases, and phase 2 generalized to bone metastases. Standard McRae's line performance metrics were evaluated and compared across all stages and tasks. RESULTS:In the lexical detection, a simple RegEx achieved the highest performance (sensitivity 98.4%, specificity 97.6%, F1 = 0.965), followed by NYUTron (sensitivity 96.8%, specificity 89.9%, and F1 = 0.787). For the clinical referral task, RegEx also demonstrated superior performance (sensitivity 92.3%, specificity 87.5%, and F1 = 0.936), followed by a fine-tuned NYUTron model (sensitivity 90.0%, specificity 66.7%, and F1 = 0.750). CONCLUSION/CONCLUSIONS:An NLP-based automated referral system can accurately identify patients with bone metastases requiring specialist evaluation. A simple RegEx model excels in syntax-based identification and expert-informed rule generation for efficient referral patient recommendation in comparison with advanced NLP models. This system could significantly reduce missed follow-ups and enhance timely intervention for patients with bone metastases.

Study DesignLiterature review with clinical recommendations.ObjectiveProviding a clear and concise overview based on the of key literature and consensus expert opinion on spinal fusion following stabilization for spine metastases and offer actionable recommendations on when to fuse and not fuse in this patient population.MethodsKey articles from the published literature on spinal metastases treated with stabilization followed by fusion were reviewed, and clinical recommendations were formulated. The recommendations are categorized as either strong or conditional based on an assessment of methodological quality and expert opinion. This assessment considers factors such as experience, risks, burdens, costs, patient values, and circumstances.ResultsFour articles were selected by practicing spinal oncology surgeons and each was evaluated for its methodological strength and its scientific evidence.ConclusionFusion rarely influences clinical outcomes in metastatic spine surgery. Treatment should prioritize mechanical stability, pain control, functional preservation, and timely continuation of oncologic therapy rather than pursuing bony arthrodesis. Fusion should be considered exclusively in select long-surviving patients, however routine attempts to enhance fusion or delay adjuvant therapy are not justified.[Formula: see text].

BACKGROUND AND OBJECTIVES/OBJECTIVE:Dural arteriovenous fistula (dAVF) surgery is a microsurgical procedure that requires confirmation of obliteration using formal cerebral angiography, but the lack of intraoperative angiogram or need for postoperative angiogram in some settings necessitates a search for alternative, less invasive methods to verify surgical success. This study evaluates the use of indocyanine green videoangiography FLOW 800 hemodynamic intraoperatively during cranial and spinal dAVF obliteration to confirm obliteration and predict surgical success. METHODS:A retrospective analysis was conducted using indocyanine green videoangiography FLOW 800 to intraoperatively measure 4 hemodynamic parameters-Delay Time, Speed, Time to Peak, and Rise Time-across venous drainage regions of interest pre/post-dAVF obliteration. Univariate and multivariate statistical analyses to evaluate and visualize presurgical vs postsurgical state hemodynamic changes included nonparametric statistical tests, logistic regression, and Bayesian analysis. RESULTS:A total of 14 venous drainage regions of interest from 8 patients who had successful spinal or cranial dAVF obliteration confirmed with intraoperative digital subtraction angiography were extracted. Significant hemodynamic changes were observed after dAVF obliteration, with median Speed decreasing from 13.5 to 5.5 s-1 (P = .029) and Delay Time increasing from 2.07 to 7.86 s (P = .020). Bayesian logistic regression identified Delay Time as the strongest predictor of postsurgical state, with a 50% increase associated with 2.16 times higher odds of achieving obliteration (odds ratio = 4.59, 95% highest density interval: 1.07-19.95). Speed exhibited a trend toward a negative association with postsurgical state (odds ratio = 0.62, 95% highest density interval: 0.26-1.42). Receiver operating characteristic-area under the curve analysis using logistic regression demonstrated a score of 0.760, highlighting Delay Time and Speed as key features distinguishing preobliteration and postobliteration states. CONCLUSION/CONCLUSIONS:Our findings demonstrate that intraoperative FLOW 800 analysis reliably quantifies and visualizes immediate hemodynamic changes consistent with dAVF obliteration. Speed and Delay Time emerged as key indicators of surgical success, highlighting the potential of FLOW 800 as a noninvasive adjunct to traditional imaging techniques for confirming dAVF obliteration intraoperatively.

OBJECTIVE:Chordomas are rare, locally aggressive primary neoplasms. Resection with negative margins is the primary recommended therapeutic approach, while adjuvant radiotherapy and chemotherapy can also play a role in their treatment in certain situations, including lesions with positive margins or those that are poorly differentiated or dedifferentiated. Cervical spine chordomas pose significant surgical challenges given their proximity to critical anatomical structures and the mechanical constraints of the cervical spine. In the current case series, authors aimed to explore the clinical and patient-reported outcomes (PROs) of the surgical treatment of cervical chordomas in a large multicenter cohort. METHODS:This multicenter case series analysis utilized data from the prospectively collected Primary Tumor Research and Outcomes Network (PTRON) registry, from its inception (May 16, 2016) to data extraction (February 29, 2024). The study population was restricted to patients with histologically confirmed cervical chordomas involving levels C0-7, who underwent surgical treatment at one of the participating centers, and for whom both the initially planned and postoperatively pathologically confirmed surgical margins were documented. Patient demographics, tumor characteristics, surgical and adjuvant treatments, local recurrence-free survival (LRFS), overall survival (OS), and perioperative adverse events were retrieved. PROs included the Spine Oncology Study Group Outcomes Questionnaire version 2.0 (SOSGOQ2.0), EQ-5D, and SF-36 version 2.0 (SF-36v2). RESULTS:Thirty-eight patients were identified, 12 of whom underwent true en bloc resection (EBR), 18 of whom underwent deliberate intralesional resection, and 8 of whom underwent EBR after intralesional surgery or in whom EBR failed. True EBR led to better LRFS (92% vs 83% vs 63%, respectively) and OS (83% vs 39% vs 50%, respectively). Surgical adverse events within 1 year were more frequent with true EBR (100% vs 39% vs 75%, respectively). EQ-5D, SOSGOQ2.0, and SF-36v2 showed improvement with true EBR, whereas the trends for PROs from the other groups were more variable. CONCLUSIONS:This multicenter case series analysis provides critical insights into the clinical outcomes and PROs in the largest cohort of surgically treated cervical spine chordomas described to date. It underscores the importance and challenges of wide resection for oncological control. It establishes the associated morbidity and provides an overview of PROs following surgery. These findings contribute valuable evidence to inform shared decision-making and optimize patient care.

Study DesignNarrative Review.ObjectivesTo summarize the scientific contributions generated from the AO Spine Knowledge Forum Tumor (AOSKFT) databases, focusing on primary spine tumors, and highlight key findings, research trends, and future directions.MethodsData from the Primary Tumor Retrospective (PT-Retro) and Primary Tumor Research Outcome Network (PTRON) registries were analyzed. The nineteen studies included were peer-reviewed manuscripts focused on primary spine tumors, excluding abstracts, book chapters, systematic reviews, and metastatic studies.ResultsThe PT-Retro registry compiled data from 1495 patients across 18 primary tumor histologies, offering insights into recurrence, survival, and treatment paradigms. Key findings emphasize the importance of Enneking-appropriate (EA) resection in improving survival and reducing recurrence in tumors such as chordoma, chondrosarcoma, and osteosarcoma. Genetic markers, including hTERT promoter mutations and rs2305089 SNP, were linked to prognosis in specific histologies. Benign tumors, such as giant cell tumors and aneurysmal bone cysts, demonstrated variable outcomes with different surgical approaches and selective arterial embolization.ConclusionsThe AOSKFT registries have significantly advanced knowledge in primary spine tumor management, emphasizing preoperative staging, surgical margins, and multidisciplinary approaches. International, multicentric registries are essential for studying rare diseases like primary spine tumors, enabling robust data collection, improved statistical power, and broader applicability of findings across diverse clinical settings. Ongoing prospective data collection through PTRON will further refine evidence-based care for these rare and challenging conditions.

STUDY DESIGN/METHODS:Delphi Consensus. OBJECTIVE:To define an optimal surgical composite outcome measure in patients with metastatic spine disease (OSCO-M) through international consensus among key opinion leaders. METHODS:Members of the AO Spine Knowledge Forum Tumor, an international group of dedicated spine oncology surgeons and oncologists, participated in a modified Delphi process between March 2023 and November 2024. The study was conducted in two parts. The first part aimed on identifying which outcome variables were deemed important to be included in the composite outcome. The second part focused on the definition of a successful outcome with regards to the agreed variables from Part 1. Each part consisted of a questionnaire and a consensus meeting. Consensus was achieved when a threshold of 70% agreement was reached. RESULTS:A total of 42 dedicated spine oncology surgeons and oncologists from North America, Latin America, Europe, and Asia participated. Over 87% of respondents agreed that composite measures reflect the multidimensional aspect of the surgical process more than an individual outcome variable. Most respondents (93%) agreed/strongly agreed that composite measures should be used to assess the quality of surgical care in spine oncology. Through consensus, the following three outcome variables were selected to define the OSCO-M: the absence of SAVES-V2 (Spinal Adverse Events Severity System, Version 2) Grade 3 adverse events or higher within 30 days of surgery, maintaining or improving ECOG (Eastern Cooperative Oncology Group) performance status at 90 days, and being ambulatory (with or without aid) at 90 days. CONCLUSION/CONCLUSIONS:This is the first study defining a composite outcome measure in oncologic surgery for spinal metastases derived from an international group of key opinion leaders in spine oncology. The OSCO-M may be useful for future research in spine tumor patients and serve as a benchmark to optimize outcomes.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The Patient-Generated Subjective Global Assessment (PG-SGA) is a standardized tool for assessing malnutrition in patients with cancer. The primary aim of this study was to assess the impact of preoperative nutritional status as measured by PG-SGA on survival in patients requiring surgical intervention and/or radiotherapy for spinal metastases. METHODS:Patients with spinal metastases who underwent surgery and/or radiation therapy for symptomatic spinal metastases were enrolled in the AO Spine Metastatic Tumor Research and Outcomes Network, a prospective international multicenter research registry, between September 2017 and August 2022. Using the PG-SGA, nutritional status was classified into 3 categories: A, well nourished; B, moderately malnourished; and C, severely malnourished. RESULTS:A total of 589 patients met the inclusion criteria; 362 were classified as well nourished (61%), 159 were moderately malnourished (27%), and 68 were severely malnourished (12%). The median survival was 491 days, 328 days, and 117 days for well-nourished, moderately malnourished, and severely malnourished patients, respectively. In the multivariate analyses, severe malnourishment (HR 2.5 95% CI 1.4-4.3, P < .01) and an ECOG performance status of 3 or 4 (HR 2.7 95% CI 1.2-6.0) remained associated with significantly worse survival. CONCLUSION/CONCLUSIONS:Malnutrition as measured by the PG-SGA demonstrated to be significantly and independently associated with postoperative survival. The PG-SGA is a simple and useful tool to identify spinal metastases patients at risk of early postoperative mortality, and inclusion in the preoperative evaluation of these patients should be considered.

Spinal dural arteriovenous fistulas (dAVFs) at the craniocervical junction are rare vascular lesions that can cause progressive myelopathy and paralysis. This video presents a 40-year-old male with a left C1 spinal dAVF, who experienced unsteadiness, dizziness, leg weakness, and intermittent facial numbness. Given the lesion's symptomatology, the patient underwent a C1 laminectomy and midline suboccipital craniectomy for definitive obliteration. The authors describe key surgical techniques for fistula exposure and obliteration, with intraoperative angiographic confirmation. Long-term follow-up confirmed complete persistent occlusion on angiography and resolution of his symptoms. This case highlights surgical strategies for managing dAVFs at the craniocervical level. The video can be found here: https://stream.cadmore.media/r10.3171/2025.7.FOCVID2573.

Metastatic spine disease represents a growing therapeutic challenge that demands a balance between incorporating emerging technologies while respecting the fundamental principles during clinical decision-making. Advances in adjuvant therapies, including stereotactic body radiotherapy (SBRT) and chemotherapy, have significantly improved long-term patient survival. Surgical decision-making should be guided by well-established frameworks such as the NOMS (neurologic, oncologic, mechanical, systemic) criteria, the ESCC (epidural spinal cord compression) scale, and the SINS (spinal instability neoplastic score), ensuring a structured and evidence-based approach to treatment. The integration of minimally invasive techniques, including percutaneous instrumentation, ablation techniques, and biportal endoscopic approaches, has reduced surgical morbidity and facilitated faster recovery. Additionally, carbon fiber implants are revolutionizing spinal stabilization by allowing better postoperative visualization of any local recurrence and easier radiation planning. SBRT has emerged as a critical modality, offering precise, high-dose radiation with minimal toxicity to the spinal cord, improving local tumor control and patient outcomes. A multidisciplinary approach remains paramount, requiring collaboration between spine surgeons, radiation oncologists, and medical oncologists. In this narrative review, we aim to provide a comprehensive overview of the current state of metastatic spine tumor management, focusing on: (1) fundamentals of metastatic spine care, (2) minimally invasive surgical techniques, (3) the use of carbon fiber screws, (4) SBRT, and (5) ways to maximize patient safety.