Gamma knife radiosurgery in pediatric neuro-oncology: histology-specific outcomes and age-adapted procedural strategies

PURPOSE: Gamma Knife radiosurgery (GKRS) is increasingly applied in pediatric neuro-oncology; however, integrated analyses of outcomes and procedural factors remain limited. This study evaluated histology-specific outcomes and technical considerations of GKRS for pediatric brain tumors. METHODS: This study retrospectively analyzed 139 GKRS procedures performed in 108 pediatric patients (age 3-18 years) with brain tumors between 2002 and 2024. The clinical, radiological, dosimetric, and anesthetic data were analyzed. Progression-free survival (PFS) was estimated by Kaplan-Meier analysis and stratified by tumor histology. RESULTS: The mean age at GKRS was 12.4 years (M: F ratio 1:1.16). The most common histologies were craniopharyngiomas (31 procedures), vestibular schwannomas (20), and pilocytic astrocytomas (16). The mean target coverage was 96.9% and the mean prescription dose was 18 Gy. Frameless mask fixation was feasible from age 6 and frame-based fixation from age 12. General anesthesia was required in 25.9%, predominantly in younger or uncooperative patients (8.5 vs 14.0 years, p < 0.001). Pediatric-type diffuse high-grade gliomas had the poorest outcomes (PFS 2.6 months, 100% mortality). Craniopharyngiomas showed high recurrence (48%) but a long failure interval (35.8 months) and low mortality (8%). Benign and low-grade tumors showed durable local control with a 5-year PFS exceeding 70%. CONCLUSION: GKRS provides durable local control in selected benign and low-grade pediatric brain tumors; however, outcomes remain poor in aggressive histologies, with high rates of progression and mortality. These findings highlight the importance of histology-based patient selection and integration of GKRS into multimodal treatment strategies. Age-adapted procedural approaches facilitate safe application in pediatric patients.