P10.13.B A LONG-TERM FOLLOW-UP STUDY: STEREOTACTIC BRACHYTHERAPY USING IODINE-125 SEEDS IN CHILDREN AND ADOLESCENT WITH LOW GRADE GLIOMAS

Abstract BACKGROUND Low grade gliomas (LGG) represent common tumors in children. Considering local treatment options surgery is highly effective but is often limited by tumor localization in eloquent areas (midline structures, pons etc.). Here stereotactic brachytherapy (SBT) has been reported to offer a minimally invasive and effective treatment alternative. We present long-term data of children and adolescents with LGG treated with SBT. MATERIAL AND METHODS We included all pediatric and adolescent patients, who underwent SBT using Iodine-125 Seeds, with a cumulative therapeutic dose of 50-65 Gy and a follow up of more than 12 months. Patient data were analyzed in terms of clinical outcome, overall survival, time to progression and incidence of treatment related complications. RESULTS We identified 122 patients of which 86 patients received SBT as primary treatment, 14 patients underwent SBT due to residual tumor after initial resection and 22 were treated for recurrence after previous therapy. The median follow-up was 174 months. No procedure-related deaths occurred and the 30-day related morbidity was zero. Estimated overall survival (Kaplan-Meier) was 93% after 10 years and 87% after 20 years. Progression-free survival was 93% after 10 years and 81% after 20 years. CONCLUSION In our cohort SBT provides favorable long-term tumor control while maintaining a low risk of treatment related events. Thus, SBT should be taken into account as treatment option for low grade gliomas in pediatric and adolescent patients.