Craniospinal irradiation for treatment of metastatic pediatric low-grade glioma.

Patients with disseminated pediatric low-grade glioma (LGG) initially treated with chemotherapy frequently experience disease progression, with 5-year event-free survival (EFS) of <20% and 10-year overall survival (OS) of approximately 70%. This study aimed to describe outcomes of metastatic pediatric LGG treated with craniospinal irradiation (CSI). A retrospective study was performed of all patients with metastatic pediatric LGG treated with CSI at a single institution. EFS was defined as survival without disease progression or secondary high-grade glioma. Dates were counted from the first day of irradiation. We identified 12 eligible patients; all had histologically confirmed LGG. Metastatic disease was present at initial presentation in 9 patients. The median age at CSI was 9.3 years. The 5-year EFS and OS were 71% (95% CI 33.7-89.5) and 70% (95% CI 32.9-89.2), respectively. No deaths were observed among the patients who underwent subtotal resection (STR) before radiotherapy, whereas 3 patients who had undergone biopsy died (OS log-rank P = 0.01). EFS may be longer among patients who underwent STR before RT (EFS log-rank P = 0.03), with a hazard ratio for biopsy of 8.4 (vs. STR; 95% CI 0.8-84.0, P = 0.07). No patient experienced acute toxicity of grade 3 or higher. Patients with metastatic pediatric LGG treated with CSI experienced longer EFS than historical cohorts treated with chemotherapy alone, with similar OS. CSI may be considered in the management of metastatic pediatric LGG, particularly in older children experiencing progression after chemotherapy.