The abstract has been submitted for presentation to the AANS 2026 meeting being held in San Antonio, TX, USA. Introduction: Oligodendrogliomas are an uncommon subset of gliomas that are molecularly defined by 1p/19q codeletion in the setting of an isocitrate dehydrogenase (IDH) 1/2 mutation. Standard-of-care management involves maximal safe resection followed by adjuvant chemoradiation with procarbazine, lomustine, and vincristine (PCV). Although PCV confers a durable survival advantage, treatment-limiting toxicity is common and often necessitates discontinuation. IDH inhibitors such as vorasidenib have demonstrated promising efficacy and more favorable tolerability profiles, but a paucity of comparative data across therapeutic classes limits optimal treatment decision-making. Methods: A systematic search was conducted through to 7 March 2025 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Eligible studies included adult patients (≥18 years) with IDH-mutant, 1p/19q-codeleted oligodendrogliomas treated with PCV chemotherapy or IDH inhibitors and with a minimum follow-up of 12 months. Outcomes of interest included overall survival (OS), progression-free survival (PFS), and grade ≥ 3 adverse events (AEs) that led to treatment discontinuation. Results: Twenty-eight studies met the inclusion criteria, with a total of 406 patients. All 406 patients carried a confirmed diagnosis of oligodendroglioma. For mixed-histology cohorts, only oligodendroglioma-specific data were extracted and analyzed. Among PCV cohorts, median PFS ranged from 24.3 months to 8.4 years and median OS was reported up to 14.7 years in long-term follow-up from RTOG 9402 and EORTC 26951. Grade ≥ 3 AEs resulted in treatment discontinuation in 65–70% of patients, primarily due to hematologic or neurologic events. In comparison, vorasidenib achieved a median PFS of 27.7 months in the phase III INDIGO trial (HR 0.39; 95% CI 0.27–0.56; p < 0.001), with median OS not yet reached at 14.2 months of follow-up. Grade ≥ 3 AEs occurred in 22.8% of patients and led to treatment discontinuation in only 1–3%, primarily due to asymptomatic transaminitis. Early real-world data from expanded-access programs similarly support these tolerability findings. Conclusions: While PCV chemotherapy remains the standard-of-care systemic therapy for oligodendroglioma supported by mature survival data, IDH inhibitors represent a mechanistically targeted alternative with encouraging early-phase outcomes and a significantly improved safety profile. Direct comparison across these regimens is constrained by differences in study design and limited long-term OS data for IDH inhibitors. Prospective head-to-head trials are essential for defining the optimal therapeutic sequence in this evolving treatment landscape. In the interim, we provide a recommend approach for current use.

Introduction: Iliac screws remain essential in cases requiring spinopelvic fixation, providing distal anchorage and construct stability across many surgical indications. However, traditional posterior-superior-iliac–spine (PSIS) entry screws are associated with hardware prominence, postoperative pain, and the need for side-to-side connectors to link with primary rods. The S2 alar-iliac (S2AI) technique addresses these drawbacks but some series have reported higher mechanical failure rates due to acute screw angulation. Furthermore, the S2AI trajectory violates the sacroiliac (SI) joint, potentially limiting use in cases with compromised sacral anatomy. The modified iliac screw (MIS) technique was developed to overcome these issues by shifting the entry point medial to the PSIS, maintaining iliac purchase while avoiding SI joint involvement. This scoping review synthesizes early clinical usage and implant performance of this emerging technique. Methods: A scoping review following PRISMA guidelines was conducted across PubMed, MEDLINE, and Embase through Sep 28, 2025. Eligible studies included reports describing patient outcomes following fixation using modified iliac screws. Results: A total of 162 patients across 6 studies were included. The cohort had a mean age of 64.5 years (range; 18–78). The most common indication was deformity (62.3%; n = 101), followed by fixation following tumor resection (17.9%; n = 29) and degenerative disease (9.3%; n = 15). The mean number of fixed vertebrae was 8.01 (range; 3–18). Mean follow-up time was 19.19 months (range; 3–74). Implant complications were reported in 36 cases (22.2%), commonly screw perforation ( n = 22), screw fracture ( n = 5), and screw loosening ( n = 4). Complications led to implant failure for 7 patient cases (4.3%). Conclusion: Early experiences with MIS fixation demonstrate promising clinical utility with acceptable rates of hardware-related complications and morbidity. However, existing evidence remains limited to small, heterogeneous series without standardized outcome reporting. Robust prospective investigations with larger cohorts and standardized long-term follow-up are needed to comprehensively characterize the safety, durability, and comparative performance of the MIS technique.

A subset of primary CNS vasculitis (PCNSV) cases can present with clinical and radiological features that closely resemble brain tumors, creating a significant diagnostic challenge for clinicians. Accurate differentiation between these entities is crucial for timely and appropriate management, as their treatment strategies and prognoses differ substantially. The authors report an illustrative case and summarize the published literature on tumor-mimicking PCNSV to show diagnostic features, treatment, and outcomes. This illustrative case involved a 35-year-old male initially presenting with stroke-like symptoms, whose MRI findings suggested a diffuse left hemispheric lesion concerning for glioma. Despite initial biopsies, the diagnosis remained unclear until a subsequent biopsy revealed PCNSV after a course of chemotherapy and radiation therapy. The review included 63 patients with tumor-mimicking PCNSV, with a mean age of 40 years. Common presentations were focal deficits (62%) and headaches (52%). MRI consistently showed T2/FLAIR-hyperintense lesions with variable enhancement and edema. Lymphocytic vasculitis was the predominant histological finding (76%). Most patients (92%) received high-dose steroids. Granulomatous findings were associated with lower odds of recurrence. Tumor-mimicking PCNSV poses a significant diagnostic challenge. Recognizing its diverse presentations is critical for prompt diagnosis and appropriate clinical management. https://thejns.org/doi/10.3171/CASE26201.

OBJECTIVE: Postoperative kyphosis remains a significant complication following intramedullary spinal tumor resection in pediatric patients, occurring in up to 50% of cases. Laminoplasty, rather than laminectomy, theoretically prevents this complication by preserving the integrity of the posterior column. This study aimed to evaluate the incidence of postoperative kyphosis following laminectomy versus laminoplasty in pediatric intramedullary spinal tumor resection. METHODS: A systematic literature search was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines across the PubMed, Embase, and MEDLINE databases for studies describing pediatric patients (< 18 years) undergoing intramedullary spinal tumor resection. The ROBINS-I (Risk of Bias in Non-randomized Studies–of Interventions) tool was used to assess risk of bias. A generalized linear mixed model with random intercepts was used to estimate pooled proportions of postoperative kyphosis using a logit transformation. For comparative analyses, studies reporting both laminectomy and laminoplasty arms were pooled using random-effects odds ratios. Heterogeneity was assessed using I ² statistics and Cochran’s Q test, and prediction intervals were calculated for pooled estimates. Meta-regression was used to evaluate study-level predictors of postoperative kyphosis. RESULTS: Among 385 records identified, 32 studies met inclusion criteria for systematic review, consisting of 280 pediatric patients undergoing intramedullary spinal tumor resection via laminectomy (n = 175) or laminoplasty (n = 105) with a mean follow-up of 78.4 months. Case reports were included in the qualitative synthesis and descriptive summaries but were excluded from quantitative pooling; 12 studies with extractable postoperative alignment outcomes contributed to meta-analysis (260 patients). In random-effects meta-analysis, the pooled prevalence of postoperative kyphosis was 36% (95% CI 19%–58%; prediction interval 2%–94%). Subgroup analysis showed a prevalence of 46% (95% CI 30%–62%) after laminectomy and 20% (95% CI 2%–73%) after laminoplasty. Comparative meta-analysis of 5 studies showed no significant difference between approaches (OR 1.24, 95% CI 0.32–4.83; I ² = 23.5%; prediction interval 0.25–6.14). In meta-regression, a higher rate of preoperative spinal deformity was linked to postoperative kyphosis (p = 0.0001), while age, sex, and number of levels exposed were not. CONCLUSIONS: Postoperative kyphosis frequently occurs following pediatric intramedullary spinal tumor resection, and no significant difference was found between laminectomy and laminoplasty. Higher study-level rates of preoperative deformity were associated with postoperative kyphosis. Higher-quality comparative studies and standardized postoperative reporting are needed to more confidently assess the relationship between surgical technique and deformity, especially for this vulnerable patient population. Systematic review registration no.: CRD420261286685 ( www.crd.york.ac.uk/prospero/ )

Chordomas are rare, locally aggressive spinal tumors. En bloc resection may improve local control but can cause substantial morbidity. Thermal ablation may provide a less invasive adjunct or alternative in selected cases. We systematically reviewed reports of radiofrequency ablation (RFA), cryoablation, laser interstitial thermal therapy, high-intensity focused ultrasound, and similar thermal techniques for spinal or sacral chordoma to characterize their clinical applications and reported clinical and radiographic outcomes across pre-resection, primary non-operative, and palliative settings. Eligible studies reported at least one ablation-related clinical or radiographic outcome. Data were descriptively synthesized, and risk of bias was assessed using the Joanna Briggs Institute criteria. Thirteen studies including 33 patients and 34 ablated sites were identified. Cryoablation was used in 21 patients, RFA in 11 patients, and laser interstitial thermal therapy in one patient. Ablation was used as a pre-resection adjunct, primary treatment for unresectable disease, or palliation for recurrent or metastatic lesions. Most reports described pain improvement, short-term local stability, and few major complications. We also report an L4 chordoma treated with CT-guided RFA and vertebroplasty before staged en bloc spondylectomy, without a new neurologic deficit or local recurrence at 18 months. Thermal ablation may be a technically feasible adjunct, primary non-operative option, or palliative strategy for carefully selected spinal and sacral chordomas. In the presented mobile-spine case, planned pre-spondylectomy RFA was feasible before staged en bloc resection; however, limited follow-up and sparse heterogeneous literature preclude conclusions regarding long-term local control, recurrence reduction, survival, or routine use. Ablation should not replace oncologically appropriate en bloc resection when that procedure can be safely achieved and should be considered selectively within multidisciplinary chordoma care.