Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Scholarly output is accelerating in medical domains, making it challenging to keep up with the latest neurosurgical literature. The emergence of large language models (LLMs) has facilitated rapid, high-quality text summarization. However, LLMs cannot autonomously conduct literature reviews and are prone to hallucinating source material. We devised a novel strategy that combines Reference Publication Year Spectroscopy-a bibliometric technique for identifying foundational articles within a corpus-with LLMs to automatically summarize and cite salient details from articles. We demonstrate our approach for four common spinal conditions in a proof of concept. METHODS:Reference Publication Year Spectroscopy identified seminal articles from the corpora of literature for cervical myelopathy, lumbar radiculopathy, lumbar stenosis, and adjacent segment disease. The article text was split into 1024-token chunks. Queries from three knowledge domains (surgical management, pathophysiology, and natural history) were constructed. The most relevant article chunks for each query were retrieved from a vector database using chain-of-thought prompting. LLMs automatically summarized the literature into a comprehensive narrative with fully referenced facts and statistics. Information was verified through manual review, and spine surgery faculty were surveyed for qualitative feedback. RESULTS:Our tandem approach cost less than $1 for each condition and ran within 5 minutes. Generative Pre-trained Transformer-4 was the best-performing model, with a near-perfect 97.5% citation accuracy. Surveys of spine faculty helped refine the prompting scheme to improve the cohesion and accessibility summaries. The final artificial intelligence-generated text provided high-fidelity summaries of each pathology's most clinically relevant information. CONCLUSION/CONCLUSIONS:We demonstrate the rapid, automated summarization of seminal articles for four common spinal pathologies, with a generalizable workflow implemented using consumer-grade hardware. Our tandem strategy fuses bibliometrics and artificial intelligence to bridge the gap toward fully automated knowledge distillation, obviating the need for manual literature review and article selection.

STUDY DESIGN/METHODS:Narrative Review. OBJECTIVE:Contextualized by a narrative review of recent literature, we propose a wound complication prevention and management algorithm for spinal oncology patients. We highlight available strategies and motivate future research to identify optimal and individualized wound management for this population. METHODS:We conducted a search of recent studies (2010-2022) using relevant keywords to identify primary literature in support of current strategies for wound complication prevention and management following spine tumor surgery. When primary literature specific to spine tumor cases was not available, data were extrapolated from studies of other spine surgery populations. Results were compiled into a proposed clinical algorithm to guide practice considering available evidence. RESULTS:Based on available literature, we recommend individualized stratification of patients according to identifiable risk factors for wound complication and propose several interventions which might be employed preventatively, including intrawound antibiotic administration, negative pressure wound therapy, and primary flap closure of the surgical wound. Of these, the available evidence, weighing possible risks vs benefits, most strongly favors primary flap closure of surgical wounds, particularly for patients with multiple risk factors. A secondary algorithm to guide management of wound complications is also proposed. CONCLUSIONS:Wound complications such as SSI and dehiscence remain a significant source of morbidity following spine tumor surgery. Triaging patients on an individualized basis according to risk factors for complication may aid in selecting appropriate prophylactic strategies to prevent these complications. Future research in this area is still needed to strengthen recommendations.

STUDY DESIGN/METHODS:Narrative review of existing literature. OBJECTIVES/OBJECTIVE:Significant technological advancements in radiotherapy planning and delivery have enabled new radiotherapy techniques for the management of spine tumors. The objective of this study was to provide a comprehensive summary of these treatment techniques for practicing spine surgeons. METHODS:A narrative review of the existing literature on stereotactic body radiation therapy (SBRT) and particle beam therapy (PBT) for the treatment of spine tumors was performed. The characteristics, implementation and evidence supporting these strategies in the management of primary spinal neoplasms were summarized. RESULTS:The clinical effectiveness of SBRT for the control and symptom palliation of metastatic spinal tumors are well demonstrated in multiple clinical trials. Risks such as fracture, radiculopathy and plexopathy exist after spine SBRT, necessitating an individualized approach in a well experienced multidisciplinary setting. SBRT should be considered a key component of a well-rounded treatment plan for metastatic spine tumors in combination with surgery, vertebral augmentation, and drug therapy, where indicated, to achieve optimal patient outcomes. Additionally, PBT and SBRT are also leading to promising results for primary spine tumors, though comparative effectiveness studies and prospective clinical trials are required to establish these modalities more formally as alternatives to conventionally fractionated photon radiotherapy. CONCLUSIONS:SBRT and PBT are emerging as effective and well tolerated treatment options for primary and metastatic spine tumors. Additional investigation is needed to personalize these treatment options and further strengthen these approaches as key components in a multidisciplinary approach to the management of spinal neoplasms.

STUDY DESIGN/METHODS:Systematic review and clinimetric analysis. OBJECTIVES/OBJECTIVE:Frailty and sarcopenia predict worse surgical outcomes among spinal degenerative and deformity-related populations; this association is less clear in the context of spinal oncology. Here, we sought to identify frailty and sarcopenia tools applied in spinal oncology and appraise their clinimetric properties. METHODS:, 2000, until June 2022. Study characteristics, frailty tools, and measures of sarcopenia were recorded. Component domains, individual items, cut-off values, and measurement techniques were collected. Clinimetric assessment was performed according to Consensus-based Standards for Health Measurement Instruments. RESULTS:). Frailty and sarcopenia measures lacked or had uncertain content and construct validity. Frailty measures were objective except the Johns-Hopkins Adjusted Clinical Groups. All tools were feasible except the Hospital Frailty Risk Score (HFRS). Positive predictive validity was observed for the HFRS and in select studies employing the mFI-5, MSTFI, and L3-TPA/VBA. All frailty tools had floor or ceiling effects. CONCLUSIONS:Existing tools for evaluating frailty and sarcopenia among patients undergoing surgery for spinal tumors have poor clinimetric properties. Here, we provide a pragmatic approach to utilizing existing frailty and sarcopenia tools, until more clinimetrically robust instruments are developed.

STUDY DESIGN/METHODS:Systematic Review. OBJECTIVES/OBJECTIVE:Formalized terminology for pain experienced by spine cancer patients is lacking. The common descriptors of spine cancer pain as mechanical or non-mechanical is not exhaustive. Misdiagnosed spinal pain may lead to ineffective treatment recommendations for cancer patients. METHODS:We conducted a systematic review of pain terminology that may be relevant to spinal oncology patients. We provide a comprehensive and unbiased summary of the existing evidence, not limited to the spine surgery literature, and subsequently consolidate these data into a practical, clinically relevant nomenclature for spine oncologists. RESULTS:Our literature search identified 3515 unique citations. Through title and abstract screening, 3407 citations were excluded, resulting in 54 full-text citations for review. Pain in cancer patients is typically described as nociceptive pain (somatic vs visceral), neurologic pain and treatment related pain. CONCLUSIONS:We consolidate the terminology used in the literature and consolidated into clinically relevant nomenclature of biologic tumor pain, mechanical pain, radicular pain, neuropathic pain, and treatment related pain. This review helps standardize terminology for cancer-related pain which may help clinicians identify pain generators.

STUDY DESIGN/METHODS:Scoping review. OBJECTIVE:To identify which markers are used as surrogates for malnutrition in metastatic spine disease and which are the most studied outcomes associated with it. METHODS:A scoping review was performed by searching the PubMed/Medline, EMBASE, and Web of Science databases up to July 2022. We searched for articles exploring markers of malnutrition in spine oncology patients including but not limited to albumin, body weight, weight loss, and nutrition indices. A narrative synthesis was performed. RESULTS:A total of 61 articles reporting on 31,385 patients met inclusion criteria. There were 13 different surrogate markers of nutrition, with the most common being albumin in 67% of studies (n = 41), body weight/BMI in 34% (n = 21), and muscle mass in 28% (n = 17). The most common studied outcomes were survival in 82% (n = 50), complications in 28% (n = 17), and length of stay in 10% (n = 6) of studies. Quality of life and functional outcomes were assessed in 2% (n = 1) and 3% (n = 2) of studies, respectively. Out of 61 studies, 18% (n = 11) found no association between the examined markers and outcome. CONCLUSION/CONCLUSIONS:Assessment of nutritional status in patients with spinal metastases is fundamental. However, there is lack of a comprehensive and consistent way of assessing malnutrition in oncologic spine patients and therefore inconsistency in its relationship with outcomes. A consensus agreement on the assessment and definition of malnutrition in spine tumor patients is needed.

STUDY DESIGN/METHODS:Delphi study. OBJECTIVE:The objective of this study was to identify risk factors associated with the development and/or progression of neurological deficits in patients with metastatic spinal disease. METHODS:A three-round Delphi study was conducted between January-May 2023 including AO Spine members, comprising mainly neurosurgeons and orthopedic surgeons. In round 1, participants listed radiological factors, patient characteristics, tumor characteristics, previous cancer-related treatment factors and additional factors. In round 2, participants ranked the factors on importance per category and selected a top 9 from all factors. Kendall's W coefficient of concordance was calculated as a measure of consensus. In the final round, participants provided feedback on the rankings resulting from round 2. Lastly, the highest-ranking factors were more clearly defined and operationalized by an expert panel. RESULTS:Over two hundred physicians and researchers participated in each round. The factors listed in the first round were collapsed into 12 radiological factors, 14 patient characteristics, 6 tumor characteristics and 12 previous cancer-related treatment factors. High agreement was found in round 3 on the top-half lists in each category and the overall top 9, originating from round 2. Kendall's W indicated strong agreement between the participants. 'Epidural spinal cord compression', 'aggressive tumor behavior' and 'mechanical instability' were deemed most influential for the development of neurological deficits. CONCLUSION/CONCLUSIONS:This study provides factors that may be related to the development and/or progression of neurological deficits in patients with metastatic spinal disease. This list can serve as a basis for future directions in prognostication research.

STUDY DESIGN/METHODS:Systematic review. OBJECTIVES/OBJECTIVE:The objective of this review paper was to summarize targeted molecular therapy options for spinal chordoma and chondrosarcoma, and to provide an update on the relevant clinical trials open for recruitment. METHODS:A systematic review of the current literature was performed, according to PRISMA guidelines, to summarize the latest developments in non-surgical molecular treatment options for low grade malignant primary spinal tumours. We also summarize those actively recruiting clinical trials based on clinicaltrials.gov. RESULTS:A total of 73 studies and completed clinical trials were reviewed. Twenty actively recruiting clinical trials (eight for chordoma and twelve for chondrosarcoma) were identified. CONCLUSIONS:There is a strong need to find new therapeutic options to complement surgical resection and radiation therapy, which remain the cornerstone of management. Targeted therapies against molecular pathways show promise as compared to conventional chemotherapy.

STUDY DESIGN/METHODS:Systematic review. OBJECTIVE:In patients with extradural metastatic spine disease, we sought to systematically review the outcomes and complications of patients with intermediate Spinal Instability Neoplastic Score (SINS) lesions undergoing radiation therapy, percutaneous interventions, minimally invasive surgeries, or open spinal surgeries. METHODS:Following PRISMA guidelines for systematic reviews, MEDLINE, EMBASE, Web of Science, the Cochrane Database of Systematic Reviews and the Cochrane Center Register of Controlled Trials were queried for studies that reported on SINS intermediate patients who underwent: 1) radiotherapy, 2) percutaneous intervention, 3) minimally invasive, or 4) open surgery. Dates of publication were between 2013-22. Patients with low- or high-grade SINS were excluded. Outcome measures were pain score, functional status, neurological outcome, ambulation, survival, and perioperative complications. RESULTS:Thirty-nine studies (n = 4554) were included that analyzed outcomes in the SINS intermediate cohort. Radiotherapy appeared to provide temporary improvement in pain score; however, recurrent pain led to surgery in 15%-20% of patients. Percutaneous vertebral augmentation provided improvement in pain. Minimally invasive surgery and open surgery offered improvement in pain, quality of life, neurological, and ambulatory outcomes. Open surgery may be associated with more complications. There was limited evidence for radiofrequency ablation. CONCLUSION/CONCLUSIONS:In the SINS intermediate group, radiotherapy was associated with temporary improvement of pain but may require subsequent surgery. Both minimally invasive surgery and open spinal surgery achieved improvements in pain, quality of life, and neurological outcomes for patients with spine metastases. Open surgery may be associated with more complications.

STUDY DESIGN/METHODS:Narrative review. OBJECTIVES/OBJECTIVE:This article aims to provide a narrative review of the current state of research for liquid biopsy in spinal tumors and to discuss the potential application of liquid biopsy in the clinical management of patients with spinal tumors. METHODS:A comprehensive review of the literature was performed using PubMed, Google Scholar, Medline, Embase and Cochrane databases, and the review was limited to articles of English language. All the relevant articles which were identified to be related to liquid biomarker study in spinal tumors, were studied in full text. RESULTS:Liquid biopsy has revolutionized the field of precision medicine by guiding personalized clinical management of cancer patients based on the liquid biomarker status. In recent years, more research has been done to investigate its potential utilization in patients with tumors from the spine. Herein, we review the liquid biomarkers that have been proposed in different spine malignancies including chordoma, chondrosarcoma, Ewing sarcoma, osteosarcoma, astrocytoma and ependymoma. We also discuss the wide window of opportunity to utilize these liquid biomarkers in diagnosis, treatment response, monitoring, and detection of minimal residual disease in patients with spinal tumors. CONCLUSIONS:Liquid biomarkers, especially blood-derived circulating tumor DNA, has a promising clinical utility as they are disease-specific, minimally invasive, and the procedure is repeatable. Prospective studies with larger populations are needed to fully establish its use in the setting of spinal tumors.