Abstract Introduction As oncologic care continues to evolve with the advent of targeted therapies, survival of patients with metastatic spine disease (MSD) has also continued to improve. Thus, it is of an utmost priority for spine surgeons treating patients with MSD to understand the landscape of molecular subtypes and associated therapies. We sought to review the literature on this topic and develop a high-yield review for the treating spine surgeon. Methods A review of the literature was performed using PubMed, Google Scholar, and Medline databases. Histology-specific guidelines from the National Comprehensive Cancer Network (NCCN) were also reviewed. Articles that discussed the treatment of MSD patients with described molecular mutations with targeted therapies, as well as clinical outcomes, were included. Results The authors provide a framework for actionable mutations of malignancies commonly leading to MSD. Hormone receptor (HR) mutations as well as human epidermal growth factor receptor (HER2) mutations in primary breast cancer tumors confer a survival advantage as opposed to patients with triple negative breast cancer. Notably, a small number of patients with HR responsive breast cancer develop resistance to endocrine therapies in the setting of metastatic disease, and thus cannot receive targeted treatment following surgery. While prostate cancer is often initially hormone responsive, eventually tumors develop resistance, and few targeted therapies are limited. BRAF-targeted mutations for treatment of metastatic melanoma confer survival benefit when compared to chemotherapy alone. As with all systemic therapies, these medications all confer risk for patients undergoing surgical intervention, especially with regard to wound healing and bleeding. Conclusion While a vast range of targeted therapies exist, we present a review relevant to those treating patients with MSD. Many patients with MSD have a tumor histology with an actionable mutation, thus preserving neurologic function in these patients is of high priority but not without risk.

BACKGROUND CONTEXT:It is currently unknown what absolute change in Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0) represents a clinically meaningful change for a patient which causes challenges with the interpretation of the SOSGOQ2.0 total score or domain scores. PURPOSE:The aim of this study was to determine the minimally clinically important difference (MCID) for the SOSGOQ2.0 in patients with spinal metastases. STUDY DESIGN:An international multicenter prospective observational study by the AO Spine Knowledge Forum Tumor. PATIENT SAMPLE:Patients with spinal metastases who were treated with surgery and/or radiotherapy OUTCOME MEASURES: Health related quality of life (HRQOL) was evaluated using the SOSGOQ2.0 at predefined time points METHODS: The MCID values for the SOSGOQ2.0 were determined using both distribution-based as well as anchor-based methods. For the anchor-based method, the posttherapy questions of the SOSGOQ2.0 served as the anchor with response options collapsed into "improvement," "no change" and "deterioration." Spearman correlation coefficients were calculated to identify posttherapy items with a correlation of ≥0.30 with the corresponding domain scores. MCID values from the distribution-based methods were derived using the statistical characteristics of the study population and compared to the anchor-based results. RESULTS:A total of 317 patients had SOSGOQ2.0 data available at baseline and at 12 weeks posttreatment and were included in the final analyses. Anchor-based MCID values for improvement in the physical function, pain, mental health and social function domains were 10.2, 26.0, 14.4 and 17.2 respectively. Compared with the distribution-based approach, anchor-based MCIDs for improvement suggest that the patient-perceived improvement corresponds to a strong level of improvement. CONCLUSIONS:This is the first study to report MCID values for the SOSGOQ2.0 total score and domain scores. The distribution-based MCID estimates will help both clinicians as well as researchers with the interpretation of the effect of treatment for painful spinal metastases on patient reported health related quality of life (HRQOL). TRIAL REGISTRATION:Clinical trials identifier NCT01825161.

Study Design Narrative Review. Objectives To 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. Methods Data 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. Results The 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. Conclusions The 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.

BACKGROUND:Chordoma is a midline neoplasm accounting for approximately 20% of primary spinal tumors. Due to chordoma's locally aggressive nature, patients experience high rates of disease progression and have limited treatment options, highlighting an unmet clinical need. This underscores the importance of exploring novel therapeutic strategies. Oncolytic viral (OV) therapy uses genetically modified viruses to selectively replicate in tumor cells, mediate tumor cell lysis, and initiate a pro-inflammatory response within the infected tumor microenvironment (TME). The aim of the study was to evaluate the anti-chordoma effect of the replicating oncolytic adenovirus Delta-24-RGD. METHODS:The efficacy of Delta-24-RGD was assessed using in vitro approaches, ex vivo bone scaffolds, and in vivo murine models. Additionally, we explored the underlying mechanism of OV cytotoxicity, immunogenic cell death (ICD), brachyury modulation, and reshaping of the TME towards a pro-inflammatory state. RESULTS:Delta-24-RGD achieved viral infectivity, oncolysis, and ICD across multiple human chordoma cell lines and ex vivo bone scaffold models. In vivo murine xenograft models of human CH22 and U-CH1 chordoma treated with Delta-24-RGD resulted in tumor volume reduction, enhanced overall survival, and microenvironmental transcriptional modulation. Analyzing a human chordoma tissue microarray, the immunosuppressive macrophage marker CD163 was associated with shortened recurrence-free survival. Using macrophage/chordoma co-culture, OV infection achieved a reduction in macrophage CD163 expression and a concomitant pro-inflammatory macrophage polarization. CONCLUSIONS:The immunosuppressive chordoma TME is associated with clinical outcomes and our data suggests OV infection reverses this deleterious immunosuppressive profile. These studies provide a framework for future clinical implementation among chordoma patients.

Study DesignSystematic review and meta-analysis.ObjectivesWe sought to evaluate the association between pre-treatment symptom duration and outcomes in patients undergoing radiotherapy (RT)/surgery for metastatic epidural spinal cord compression (MESCC).MethodsA systematic review included publications evaluating the association between pre-treatment symptom duration and outcomes after RT/surgery in adults with MESCC. Primary exposure was pre-treatment symptom duration. Outcomes were motor-recovery, ambulation, survival and local control. Pooled-effect-estimates were calculated.Results Of 4639 studies, 37 met the inclusion criteria (26-RT,11-surgery). RT: All studies defined symptom duration as time from motor-weakness onset to RT. Longer symptom duration was associated with improved motor-recovery (Pooled-effect-estimate=2.08, 95%CI:1.68-2.58,p<0.001) and decreased mortality-risk (improved-survival)((Pooled-effect-estimate=0.72, 95%CI:0.69-0.76,p<0.001). Although longer symptom duration was consistently associated with better ambulation and lower local recurrence, few studies precluded meta-analysis. Surgery: Symptom duration was defined as time from neurological-deficit onset to surgery in 7/11 studies; three-studies used ambulatory status, and one-study used both. Longer symptom duration was associated with increased risk-of-death (worse-survival)(Pooled-effect-estimate=1.28, 95%CI:0.54-3.03,p=0.575), though statistically insignificantly. Meta-analysis for motor-recovery wasn't feasible, but most studies found longer symptom duration worsened motor-recovery, while ambulation findings were inconsistent.ConclusionSymptom duration was associated with differing outcome patterns by treatment modality. In RT cohorts, longer symptom duration was associated with improved survival and motor recovery. In surgical cohorts, it trended toward worse survival, though this did not reach statistical significance. Most surgical studies suggested an inverse association between symptom duration and motor recovery. These findings are exploratory, and should be interpreted in context of treatment selection-bias and between-cohort heterogeneity.

Abstract Introduction Given the palliative nature of treatment for metastatic spine disease (MSD), measuring surgical outcomes in this population requires examining comprehensive outcome variables. We sought to achieve an international consensus in how to measure success in the MSD population. Methods The AO Spine Knowledge Forum Tumor, consisting of dedicated spine oncology specialists, participated in a modified Delphi process between March 2023 and November 2024. The two part study asked which outcome variables were important to include in a composite outcome as well as what metrics would define a successful outcome. Results A total of 42 spine oncology surgeons and oncologists across North America, Latin America, Europe, and Asia participated. Over 90% of participants agreed or strongly agreed that composite measures should be used to assess the quality of surgical care when treating patients with MSD. Three outcome variables were selected to define a successful outcome as defined by the OSCO-M: the absence of a Spinal Adverse Events Severity System, Version 2 grade 3 adverse events or higher, maintaining or improving ECOG performance status at 90 days, and being ambulatory at 90 days. Conclusion This is the first study defining a composite measure outcome in oncologic surgery for spinal metastases derived from an international group of surgeons and oncologists who treat patients for MSD. The OSCO-M will be useful for defining clinical success in patients undergoing treatment for MSD.

Composite resection of vertebrae with the posterior chest wall is technically challenging and highly morbid. Improvements in surgical technique and spinal reconstruction have enabled composite resection procedures to be performed safely in highly selected patients with potential for long-term cure. Composite resections frequently require multiple or extended incisions and have high rates of complications. Chest wall reconstruction is performed for large defects not covered by the scapula. Improvements in spinal instrumentation have allowed for resection and stabilization of multiple vertebral levels. This article reviews current trends in management and outcomes for composite resections of the vertebrae and chest wall.

Chordomas are rare, locally aggressive tumors for which effective salvage options are limited once maximal surgical and radiation therapy have been exhausted. Laser interstitial thermal therapy (LITT) is a minimally invasive, MRI-guided ablative technique established for spinal metastases, but published experience with LITT for chordoma remains limited to isolated case reports. We report the largest clinical experience with spinal LITT (sLITT) for chordoma and review the existing literature. We performed a retrospective, IRB-approved single-institution case series of patients with histologically confirmed chordoma treated with sLITT. Clinical, operative, and radiographic data were abstracted, including tumor volumes, ablation parameters, and functional and oncologic outcomes. A systematic PubMed search was performed to identify all prior published reports of LITT for chordoma. Four patients underwent sLITT across five procedures, treating metastatic foci from primary sacral, clival, and cervical chordomas, as well as one primary thoracic lesion. sLITT was used as salvage treatment in four procedures and as primary treatment in one patient to avoid the morbidity of open surgery. Median time from diagnosis to LITT was 19.1 months (range 2.5–168.3), and pre-operative KPS was 90–100 in all patients. A median of four laser fibers and 16 ablations were used per procedure (12–15 W). Median case duration was 352.5 min and length of stay was two days. Postoperative SRS was administered in all but one procedure. All patients experienced volumetric tumor reduction on the earliest post-operative MRI (median 4.2 months, range 2.8–8.8), with a mean reduction of 25.7

OBJECTIVE:Unstable pathological spine fractures are common in patients with cancer. Minimally invasive percutaneous instrumentation has emerged as a less traumatic alternative to conventional open spinal fixation. As cancer patient survival continues to improve, the long-term durability of this strategy and the likelihood of achieving segmental fusion remain insufficiently studied. This study aimed to describe the clinical, oncological, and surgical characteristics, including outcomes and facet fusion rates, in patients with metastatic spine disease undergoing percutaneous pedicle screw fixation at a tertiary cancer center. METHODS:This retrospective cohort study evaluated patients treated using percutaneous pedicle screws and rods between 2014 and 2023. Patients without bone grafting and with postoperative imaging follow-up of more than 30 days were included. Demographic, clinical, oncological, surgical, and radiological data were collected. Postoperative CT scans were used to assess hardware breakage, screw loosening, and facet fusion, which was defined as complete bone bridging between adjacent vertebrae. RESULTS:A total of 109 patients (114 constructs) were evaluated. Most patients were nonsmokers, White, and obese, with a high prevalence of prior radiotherapy and low-grade epidural tumor at the unstable level. Short constructs (1 level above and below the affected vertebra) were used in 60% of cases. Cement augmentation of pedicle screws was performed in 97% of procedures. Postoperative CT scans demonstrated some degree of cement extravasation in 85.7% of cases, but all were asymptomatic. Pain significantly improved postoperatively (visual analog scale score improvement from 6.1 to 2.5; p < 0.01). Hardware failure occurred in 6.1% of cases (n = 7), and 12.3% (n = 14) required reintervention. Segmental facet fusion occurred in 44.7% of patients, although the number of facets fused per number of facets fixed remained low at all time points: 7% at 6 months, 10% at 1 year, and 24% at 2 years. CONCLUSIONS:Percutaneous pedicle screw and rod constructs provide effective and durable spinal stabilization with low complication rates and significant pain reduction. Segmental facet fusion was observed in nearly half of the patients in this study, but clinical benefits and hardware durability were independent of radiographic evidence of arthrodesis.

11527 Background: Unresectable/metastatic chordoma is a rare notochordal malignancy with no approved systemic treatments. EGFR is widely expressed on chordomas. Cetuximab is a recombinant, human/mouse chimeric monoclonal antibody that inhibits EGFR signaling. In vivo testing of cetuximab has demonstrated growth inhibition and regression of chordoma. An investigator-initiated, single center, phase II study (NCT05041127) was developed to evaluate the efficacy of cetuximab for patients (pts) with advanced/metastatic chordoma. Methods: Eligible pts were ≥18 years of age, had adequate organ function, and had an ECOG performance status (PS) of ≤2. Any prior line of therapy was allowed except EGFR inhibitors. A minimum of 10 pts and maximum of 29 pts were to be enrolled onto the trial based on Simon's two-stage optimal design (H 0 RR 5% vs H 1 RR 20%; one-sided α=0.05; power=80%). Pts received cetuximab 500 mg/m 2 IV Q2 weeks until disease progression or unacceptable toxicity. The primary end point was response rate (RR) according to RECIST 1.1. Secondary objectives included safety/tolerability and survival metrics. Efficacy was assessed in the modified intention-to-treat (mITT) population (≥1 dose; ≥1 post-baseline scan). Exploratory objectives included analysis of the EGFR pathway at 2 time points from research-related biopsies. Pt reported outcomes (PROs) were assessed with MDASI (general and spine) questionnaires at several time points on study. Results: From May 2022 to Dec 2025, 29 pts enrolled. 4 were excluded from the efficacy analysis (2 withdrawal, 1 cetuximab allergy, 1 has not completed the 1 st imaging assessment). Median age was 58 years (range 21-76), 15 (58%) were men, and 24 (92%) had ECOG PS of 0 or 1. The most common primary site was skull base (46%). Tumor was classified as locally recurrent in 8 pts (31%) and metastatic in 18 pts (69%). One median line of prior systemic therapy was noted (range, 0-6). At a median follow up of 28.7 months, 12 pts (48%) had radiographic cytoreduction (any tumor reduction [ATR]), but only 2 pts (8%) had a partial response (PR). Neither PR was associated with an EGFR gene alteration. Stable disease (SD) was noted in 23 pts (92%). Preliminary median PFS and median OS was 9.9 months (95% CI, 6.3 to 13.4) and 38.8 months (95% CI, 18.6 to NR), respectively. Significantly longer PFS was observed in SD-ATR (log-rank p=0.038), with median of 14.2 months in SD-ATR versus 9.6 months in SD without tumor reduction. 7/26 pts (27%) experienced a grade 3 cetuximab-related adverse event (AE), the most common being rash in 4 pts (15%). No grade 5 AE related to cetuximab was reported. Dose reduction occurred in 2 pts (8%). 4 pts (15%) discontinued the study due to toxicity. 4 pts remain on study. Conclusions: Although the primary end point has not been reached, 2 PRs are noted, and pts with SD-ATR have a longer PFS. Translational and PRO analysis are ongoing to better define biological predictors of cetuximab activity in chordoma. Clinical trial information: NCT05041127 .

BACKGROUND AND OBJECTIVES:Preoperative imaging provides surgeons with an initial estimate of tumor infiltration and the likelihood of achieving an en-bloc resection in spinal cord ependymomas, yet the definitive decision is made intraoperatively. This study characterizes the intraoperative ultrasound (iUS) features that guide real-time surgical strategy and are associated with successful en-bloc removal. METHODS:A retrospective review of iUS images obtained during resection of spinal cord ependymomas was performed. The presence of a peritumoral halo representing the transition zone between the tumor and the spinal cord, the dorsal sagittal area of the spinal cord overlying the tumoral poles, the presence and location of tumor cysts, and the diameter of the compressed spinal cord located ventral and dorsal to the tumor were assessed. Demographic and surgical data including extent and technique of resection, occurrence of intraoperative neurophysiological changes, and preoperative and postoperative neurological status were collected. RESULTS:The mean dorsal sagittal area of the spinal cord overlying the cranial pole was 0.1 cm2 (range 0-0.23 cm2), whereas the area overlying the caudal pole was 0.05 cm2 (range 0-0.16 cm2). All tumors exhibited a peritumoral halo, ranging from 0° to 360° in the axial view. The echogenicity of the halo was predominantly hypoechoic. Gross total resection was achieved in all cases, with en-bloc technique performed in 57% of patients. Intraoperative changes in somatosensory and motor evoked potentials were observed in all cases. Nevertheless, clinically, all patients remained neurologically stable in the postoperative period compared with preoperative. CONCLUSION:iUS identifies useful imaging features that allow surgeons to develop a structured resection plan before spinal cord manipulation. Future longitudinal studies are needed to validate whether the presence of a peritumoral halo or the extent of sagittal spinal cord area overlying the tumor poles are predictors of neurological and oncological outcomes.

Background and Objectives: Up to 40% of patients with cancer develop spinal metastases, and stereotactic spinal radiosurgery (SSRS) achieves high local control rates as definitive or postoperative treatment. Multiple tumor response assessments have been used but their compared clinical performance in post-surgical patients remains unclear. We sought to compare the applicability of RECIST1.1, MDACC and SPINO criteria. Materials and Methods: This IRB-approved retrospective study included patients with high-grade epidural spinal cord compression treated with decompressive surgery followed by adjuvant SSRS, with MRI follow-up available. Lesions were classified according to each of the scale’s objective (RECIST1.1 and MDACC) and subjective (SPINO [radiology reports]) criteria. Results: Ninety-four treated levels in 93 patients (median age 58.9 years) were analyzed. Most metastases were thoracic, and all cases had preoperative high-grade epidural spinal cord compression. Adjuvant SSRS was delivered in one or three fractions. Median follow-up was 16 months (range, 1–132), SPINO-based assessment was feasible in 100% of cases, RECIST1.1 in 43.6% and MDACC in 46.8%. Progressive disease criteria were met in 21.3% of cases using SPINO-based assessment, 19.5% using RECIST1.1, and 6.8% using MDACC. Conclusions: The SPINO recommendations provide a practical and comprehensive framework for radiographic response assessment in monitoring spinal metastases treated with a combination of surgical decompression and adjuvant SSRS.

OBJECTIVE:Metastatic disease at the craniocervical junction is rare. Typically, patients present with disabling neck pain and instability. To date, limited data exist to guide treatment strategies. In this study, the authors review 24 years of occipitocervical fusion outcomes at a tertiary cancer center with the aim of evaluating effectiveness with pain control and risk factors for complications. METHODS:Adult patients who underwent occipitocervical fusion for metastatic disease at a single institution between 2001 and 2024 were identified from a prospectively maintained database. Cases involving nonmetastatic conditions were excluded. Collected preoperative variables included patient demographics, baseline performance status, prior radiation treatments, lesion location, pathology type, and the degree of epidural spinal cord compression. The primary outcome was pain control, evaluated using the neck visual analog scale (VAS) and morphine milligram equivalents (MME) at immediate, 6-week, 3-month, and final follow-up intervals. Complications were extracted from electronic medical records and analyzed for associations with predisposing risk factors. RESULTS:A total of 126 patients underwent occipitocervical fusion, 57 of whom were treated for metastatic disease. Pain (mechanical or occipital neuralgia) was the most common presenting symptom (94.6%). Renal cell carcinoma (35.1%) was the most frequent metastatic histology. Pain outcomes showed significant improvement, with neck VAS scores decreasing from a median of 8 (IQR 5-10) preoperatively to 5 (IQR 3-7) by postoperative day 1, and further reductions to scores of 3 (IQR 0-4) at 6 weeks, 1 (IQR 0-3) at 3 months, and 1 (IQR 0-3) by the final follow-up. MME decreased from a median of 88.8 preoperatively to 53.5 at the last follow-up. The overall complication rate was 10.5%, with 7.0% attributed to wound healing disturbances. Only 3 patients required revision surgery. Age > 60 years trended toward increased complication risk (p = 0.06), although other factors were not significantly associated with complications. CONCLUSIONS:Occipitocervical fusion is a safe, effective option for managing painful metastases at the craniocervical junction, showing an acceptable complication rate and significant pain relief. This series is the largest reported on this condition.

STUDY DESIGN:Narrative Literature review. OBJECTIVE:To provide a general overview of important molecular markers and targeted therapies for the most common neoplasms (lung, breast, prostate and melanoma) that metastasize to the spine and offer guidance on how to best incorporate them in the clinical setting. METHODS:A narrative review of the literature was performed using PubMed, Google Scholar, Medline databases, as well as the histology-specific National Comprehensive Cancer Network guidelines to identify relevant articles limited to the English language. Relevant articles were reviewed for commonly described molecular mutations or targeted therapeutics, as well as associated clinical outcomes, and surgery-related risks. RESULTS:Molecular markers and targeted therapies have dramatically improved the survival of cancer patients. The increasing importance of prognostic molecular markers and targeted therapies provides rationale for their incorporation into clinical decision-making for patients diagnosed with metastatic spine disease. In this review, we discuss the molecular markers/mutations and targeted therapies associated with the most common malignancies that metastasize to the spine and provide a framework that the surgeon can utilize when evaluating patients for potential intervention. Finally, we provide case examples that highlight the importance of molecular prognostication and therapies in surgical decision-making. CONCLUSION:An integrated understanding of the implications of surgery, radiation, molecular markers and targeted therapies that guide prognostication and treatment is warranted in order to achieve the most favorable outcomes for patients with metastatic spine disease.

INTRODUCTION: Chordomas are locally aggressive neoplasms of the axial skeleton with recurrence rates approaching 40%. Moreover, recurrent chordomas are nearly impossible to eradicate—highlighting an unmet clinical need. METHODS: Using the replicating oncolytic adenovirus Delta-24-RGD, we investigate the efficacy chordoma treatment using in vitro approaches, ex vivo bone scaffolds, and in vivo murine models. Additionally, we explore the underlying mechanism of OV cytotoxicity, immunogenic cell death, Brachyury modulation, and reshaping of the TME towards a pro-inflammatory state. RESULTS: Across a panel of human chordoma cell lines, delta-24-RGD achieved viral infectivity, oncolysis and immunogenic cell death. This treatment response was similarly demonstrated in chordoma cultured in bone scaffold models. Delta-24-RGD infection was associated with concomitant Brachyury downregulation within both infected and uninfected chordoma cells in vitro, suggesting a pleiotropic effect following oncolytic viral infection. In vivo models of CH22 chordoma treated with delta-24-RGD demonstrated shrinkage in tumor volume and enhanced overall survival. Utilizing a human chordoma tissue microarray, the immunosuppressive macrophage marker CD163 was associated with shortened recurrence free survival. Using macrophage/chordoma co-culture, delta-24-RGD infection reduced macrophage expression of CD163. CONCLUSIONS: Delta-24-RGD achieves efficacy in multiple models of chordoma including mice bearing CH22 tumors. The chordoma TME is associated with clinical outcomes and delta-24-RGD infection reverses a deleterious immunosuppressive immune profile. These studies provide a framework for future clinical trial implementation for patients with metastatic or recurrent chordoma.

STUDY DESIGN: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. MATERIALS AND 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 2 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: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.

STUDY DESIGN:Systematic Review. OBJECTIVES: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:Narrative review of existing literature. OBJECTIVES: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.