Evaluating the Efficacy and Survival Outcomes of Radiation Therapy in Spinal Low-Grade Glioma Across Different Age Groups: Insights from the National Cancer Database

Introduction: Spinal low-grade glioma (LGG) is a rare and aggressive central nervous system malignancy affecting all age groups, and surgical resection is the current mainstay of treatment. Radiation therapy is frequently applied; however, the clinical effects remain controversial, and protocols for its optimal use still lack consensus. This study aims to assess the clinical effects of radiation in patients with spinal LGG, explore its efficacy across age groups, and provide insights for clinical decision-making.

Methods: Patients with glioma graded 1 or 2 were identified from the National Cancer Data Base from 2004 to 2017 and were categorized into two groups: radiation and no-radiation. We further categorized patients by age: pediatric (0–21 years), adult (22–64 years), and geriatric (≥65 years). Univariate analyses were performed. Kaplan-Meier survival analysis was used to assess overall survival (OS). Cox proportional hazards model and logistic regression model was used to identify potential risk factors.

Results: Out of 884 LGG patients identified, 353 received radiation therapy while 531 did not. Sex and racial distributions were similar between two groups, but the mean age of the radiation group was significantly higher than the no-radiation group (45.9 ± 21.7 years vs. 29.7 ± 22.4 years, p< 0.001). Within the radiation group, adult patients comprised the largest proportion, followed by geriatric and pediatric patients (60.6%, 22.1%, 17.2%, p=0.036), however, pediatric patients received the highest total dose, followed by adults and geriatric patients (p=0.013). Kaplan-Meier (KM) survival analysis revealed that radiation treatment was associated with worse overall survival (OS) compared to no-radiation in all age groups (p < 0.0001). Additionally, radiation doses below 45Gy negatively impact the OS (p < 0.0001). Cox proportional Hazards model was found to be the most predictive, confirmed by ROC analysis (AUC=0.69) and C-index test (C-index=0.68). Multivariate cox regression analysis identified radiation associated with increased risk (HR=1.92, p< 0.001), with low dose radiation ( < 45Gy) particularly associated with a drastically elevated risk (HR=5.29, p< 0.001).

Conclusion : Radiation therapy negatively impacts survival in all age groups, with doses below 45 Gy particularly detrimental. These findings emphasize the need for multidisciplinary decision-making in the application of radiation therapy to optimize patient outcomes.