charts were retrospectively reviewed. Patient and treatment characteristics and complication rates were analyzed using descriptive statistics, chisquare test, and independent t-test. Oncologic outcomes were analyzed using the Kaplan-Meier method. Results: Median age at diagnosis was 15 years (range, 1-39). Median duration of follow-up was 7.2 years. Of 66 patients, 38 received radiation therapy (RT) and chemotherapy (CT) and 25 received RT alone; radiation volumes encompassed the craniospinal axis in 39% vs. 64%, respectively, the tumor bed and whole ventricles in 16% vs. 24%, and the tumor bed alone in 45% vs. 12% (pZ0.02). Two patients (3%) had CT alone, then died prior to further treatment, and one patient was treated with surgery alone. At 5 and 10 years, relapse-free survival (RFS) was 80% and 76%, disease-specific survival was 86% and 81%, and overall survival was 86% and 81%. For patients treated with RT alone, RFS was 83% at 5 years and 83% at 10 years, while for patients treated with RT and CT, RFS was 79% at 5 years and 75% at 10 years (pZ0.44). Forty (61%) of 66 patients developed at least one hormone deficiency: 15 (23%) had deficiencies in growth hormone, 28 (42%) in thyroid stimulating hormone, 23 (35%) in adrenocorticotropic hormone, 23 (35%) in gonadotropins, and 25 (38%) in antidiuretic hormone. Diplopia occurred in 26/66 patients (39%) and decreased acuity in 19/66 patients (29%). Six patients (8%) had cerebrovascular events (CVEs), 3 after surgery, and 3 after RT. Eight (12%) patients developed seizure disorders, 4 due to disease, 2 after surgery, 1 after RT, and 1 after CT. Twenty-one patients (32%) developed cognitive impairment. In patients followed for more than 5 years, secondary neoplasms occurred in 15% (4/27) of the patients with a median follow-up 9.5 years, who received CSRT, compared to none of the 19 patients with a median follow-up of 10.5 years, who received RT to a smaller volume (pZ0.08); these 4 neoplasms were glioblastoma, grade 1 meningioma, Hodgkin lymphoma and basal cell carcinoma of the skin. Conclusion: We report favorable population-based outcomes in patients treated for intracranial germinoma. Smaller radiation volumes were used in those treated with RT and CT versus RT alone. RFS was not significantly different between patients who received RT and CT versus RT alone. Patients treated for intracranial germinoma experience a wide range of clinically significant complications. Author Disclosure: A.C. Lo: None. K. Taguchi: None. A. Nichol: Research Grant; Varian Medical Systems. Honoraria; Varian Medical Systems. Travel Expenses; Electa. A.F. Howard: None. H. Hasan: None. K. Goddard: None.