NSRG-14. SAFETY AND EFFICACY OF GAMMA KNIFE RADIOSURGERY FOR PEDIATRIC BRAIN TUMORS

Abstract

Radiation therapy (RT) remains a standard of care adjuvant therapy for the treatment of many pediatric brain tumors. However, standard external beam RT is associated with effects on neurocognitive abilities, endocrine function, and the development of secondary malignancies. Since 2002, we have treated 160 pediatric (<18yo) brain tumor patients (median age = 12yrs, age range 2-18yrs) with gamma knife (GK) stereotactic radiosurgery after maximal surgical resection. Tumor types included low grade glioma, ependymoma, medulloblastoma, and metastatic neuroblastoma. Some patients with malignant or metastatic tumors were treated after failing conventional fractionated radiation and/or chemotherapy. GK patients were treated with single, outpatient sessions and those >10yrs generally required only conscious sedation for frame placement. No patients required post-GK admission and there were no reported acute toxicities or long term complications including radiation necrosis or development of secondary malignancy over a median follow-up of 8yrs (range 1-17yrs). The physics employed by GK stereotactic radiosurgery offers potential for significantly decreasing exposure of healthy brain to ionizing radiation, and, therefore, may offer significant safety benefits for pediatric patients with localized brain tumors. The outcomes of GK for pediatric brain tumors are favourable in our experience. In an accompanying abstract, we present outcome data of 23 patients treated with GK for grade I-II astrocytomas. Over the past 16yrs, we have found GK SRS to be effective, well tolerated, and safe in the pediatric population.