Results: Sixty-one pediatric patients were treated with CNS re-irradiation. Primary diagnoses included ependymoma (nZ18,30%), medulloblastoma/ PNET (nZ15,25%), germ cell tumor (nZ8,13%), infratentorial high grade glioma (nZ6,10%), supratentorial low grade glioma (nZ3,5%), supratentorial high grade glioma (nZ3,5%), infratentorial low grade glioma (nZ2,3%), and other (nZ6,10%). Median age at first course of RT was 8.5 years (range 0.5-19.5 years) and 12.3 years (range 3.3-30.2 years) at time of re-irradiation. Initial dose of RT was 54Gy in 47 patients (77%) and <54Gy in 14 patients (23%). Median time between initial and re-irradiation courses was 2.0 years. Location of relapse was infield in 45 patients and marginal/distant in 16 patients. Thirty-five patients (57%) underwent gross-or sub-total resection at time of recurrence. Techniques for reirradiation were IMRT (nZ40), 3D-RT (nZ9), SBRT (nZ4, 12-13Gyx1 or 5 Gyx5), protons (nZ4), combined modality (nZ2), 2D-RT (nZ1), and brachytherapy (nZ1). Conventional fractionation re-irradiation courses were 54Gy in 17 patients (28%) and <54Gy in 39 patients (72%). Radiation necrosis was detected in 2 cases after first course of RT and 2 additional patients after re-irradiation. Median overall survival following end of re-irradiation was 12.8 months in the entire cohort, 14.6 and 9.0 months for patients treated with radical versus palliative intent, respectively, and 20.5 and 8.4 months for patients with recurrent ependymoma and medulloblastoma following re-irradiation. Conclusions: CNS re-irradiation in pediatric patients may be a reasonable treatment option with moderate survival noted following repeat RT; although, prospective data characterizing rates of local control and toxicity are needed.