2151 Management and Prognostic Features of Lower Grade Glioma, An Evolving ParadigmdThe NCI Experience, 1995 to Present J.R. Bear, 1 J. Hsieh, 2 H. Ning, 2 M. Mackey, 2 T. Cooley-Zgela, 2 K.A. Camphausen, 2 M. Gilbert, 3 and A.V. Krauze 4 ; 1 Walter Reed National Military Medical Center, Bethesda, MD, 2 Radiation Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, 3 Neuro-Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, 4 Radiation Oncology Branch, National Cancer Institute, Bethesda, MD Purpose/Objective(s): The management of glioma has evolved to increasing reliance on molecular characterization over histological find- ings. We aimed to analyze glioma management and molecular findings in the NCI NIH glioma patient cohort spanning the last 22 years in an effort to elucidate the impact of molecular characterization on response to ra- diation therapy (RT) as well as additional prognostic features as a platform for ongoing molecular and dosimetric analysis. Materials/Methods: 102 patients with a diagnosis of grade II and grade III glioma were evaluated between 1995 and 2017, 95 were included in the analysis following thorough chart review. Kaplan-Meier analysis was per- formed for the purpose of comparison amongst patient and disease variables molecular characterization (IDH mutation, 1p19q deletion), management trends, overall survival (OS) and progression free survival (PFS). Results: 95 patients median age 37 (10-72) with original diagnosis of 21 astrocytoma, 8 Oligoastrocytoma, 20 Olidodendroglioma, 29 Anaplastic As- trocytoma, 3 Anaplastic Oligoastrocytoma, 12 Anaplastic Oligodendroglioma, 2 anaplastic glioneuronal tumor were analyzed. With a median follow-up of 7.3 years, median OS for WHO Grade 2 and Grade 3 cohorts were 8.6 years and 4.8 years (pZ.02), with median PFS of 6.9 vs 4.5 years (pZ.56). When further stratified by molecular marker subtype, gliomas with 1p/19q co-dele- tion compared to 1p/19q intact had OS of 7.1 years vs 5.0 (pZ.05) and PFS of 5.7 vs 2.6 (pZ.22). Gliomas with IDH mutation compared to IDH wild type had OS of 5.5 vs 3.6 years (pZ.03) and PFS of 5.3 vs 3.6 years (pZ.78). Comparing patients treated with RT versus no RT by histologically based WHO subtype was not associated with a statistically significant difference in OS (RT 7.1 years vs no RT 6.2 years, pZ.25) with a trend toward worse PFS in the RT group (RT 5.5 years vs no RT 5.9 years, pZ.06). However, when analyzed by molecular subtyping, patients with 1p/19q codeletion and IDH mutated tumors treated with RT had improved OS with 1p/19q co-deleted OS 7.9 years vs 1p/19q intact 4 years, (pZ.04). IDH mutated glioma OS was 6.8 years vs IDH wild type 3.85 years (pZ.01). PFS analyzed by molecular subtype did not demonstrate a significant difference between groups with 1p/ 19q co-deleted PFS 6.5 years vs 1p/19q intact 3.7 years, pZ.98, and IDH mutated PFS 5.5 years vs IDH wild type 3.5 years, (pZ0.62). Conclusion: Previously reported trends were validated in the NCI NIH population. In contrast to histologic WHO grading, molecular character- ization was prognostic for OS and predictive for response to RT. The ongoing addition of deep sequencing analysis results to imaging and RT dosimetry characteristics will further define prognostic and predictive factors in the evolving management of this challenging patient population. Author Disclosure: J.R. Bear: None. J. Hsieh: None. H. Ning: None. M. Mackey: None. T. Cooley-Zgela: None. K.A. Camphausen: None. M. Gilbert: None. A.V. Krauze: None. 2152 Risk Factors Associated with Interval Time between Initial Non-Small Cell Lung Cancer (NSCLC) Diagnosis and Development of Brain Metastases Y. Bian, 1 C.C. Wu, 1 C.H. Tai, 1 A. Saraf, 1 J.I.S. Andrews, 1 M.E. Lapa, 1 T. Nanda, 2 A. Yaeh, 2 S.K. Cheng, 3 and T.J.C. Wang 4 ; 1 Department of Radiation Oncology, Columbia University Medical Center, New York, NY, 2 ColumbiaUniversity College of Physicians and Surgeons, New York, NY, 3 Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY, 4 Department of Neurological Surgery, Columbia University Medical Center, New York, NY Purpose/Objective(s): Lung cancer remains the leading cause of brain metastases (BM). Our goal is to identify potential NSCLC risk factors associated with decreased time to BM. Materials/Methods: We retrospectively reviewed all NSCLC patients with BM treated with radiotherapy at a single institution from 1997 to 2015. Interval time (IT) to BM development was defined as pathological diag- nosis of NSCLC to radiographic diagnosis of BM. Patients were stratified by clinical stage of initial NSCLC diagnosis. Stage 4 patients with BM present on initial staging MRI were excluded from the study. Prognostic factors were analyzed through the Kaplan-Meier method and Cox pro- portional hazards model. Survival curves were calculated with the Kaplan- Meier method using development of BM as the primary endpoint. Results: A cohort of 109 patients were included in this study for analysis. Median IT for the entire cohort was 23 months. On Kaplan-Meier analysis for IT clinical stage at primary diagnosis, tumor histology, and surgical history showed significant differences between groups Stage III patients had median IT of 22 months and stage IV patients had median IT of 16 months compared to stage I patients with a median IT of 62 months. Non- adenocarcinoma histology had a median IT of 9 months compared to adenocarcinoma histology with a median IT of 25 months. Patients with no surgical resection of primary lung cancer had a median IT of 16 months compared to patients who underwent surgical resection with a median IT of 46 months. On univariate analysis stage III, stage IV, nodal-status of N2 disease, nodal-status of N3 disease, no surgical resection of primary lung cancer, and non-adenocarcinoma tumor histology were associated with decreased IT. On multivariate analysis stage III, stage IV, no surgical resection of primary lung cancer, and non-adenocarcinoma tumor histol- ogy were associated with decreased IT. Conclusion: Clinical stage, tumor histology, and surgical history could be associated with timing to BM development in NSCLC patients and should be further investigated to better characterize patients at risk for developing brain metastases at a shorter time interval. Author Disclosure: Y. Bian: None. C. Wu: None. C. Tai: None. A. Saraf: None. J.I. Andrews: None. M.E. Lapa: None. T. Nanda: None. A. Yaeh: None. S.K. Cheng: None. T.J. Wang: Consultant; Doximity, Merck. Advisory Board; American Cancer Society North Jersey. Travel Expenses; Abbvie. 2153 Radiation Retinopathy Following I-125 Plaque Brachytherapy for Uveal Melanoma as Evaluated by Optical Coherence Tomographic Angiography C. Binder, 1 A. Skalet, 2 J. Yali, 3 L. Liu, 3 A. Miller, 3 D. Wilson, 3 R.J. Crilly, 1 C.R. Thomas Jr, 4 D. Huang, 3 and A.Y. Hung 4 ; 1 Oregon Health and Science University, Portland, OR, 2 Oregon Health and Sciences University, Portland, OR, 3 Oregon Health and Sciences University, Portland, OR, 4 Oregon Health & Science University, Knight Cancer Institute, Portland, OR Purpose/Objective(s): Uveal melanoma is the most common primary intraocular malignancy in adults. Eye sparing treatment with plaque brachytherapy yields excellent local control but often results in significant vision loss. Radiation induced vascular compromise can cause ischemia and edema, leading to optic neuropathy and retinopathy. Optical coherence tomographic angiography (OCTA) is a unique tool capable of providing in vivo insight into the effects of radiation on vasculature. This cross- sectional study uses OCTA to measure peripapillary retinal capillary cir- culation in eyes treated with I-125 plaque brachytherapy. Materials/Methods: 15 subjects with uveal melanoma in 1 eye treated with I- 125 plaque brachytherapy participated. Treated eyes had clinically apparent radiation retinopathy and/or optic neuropathy at the time of post-treatment OCTA. Treatments occurred 1-9 years prior to OCTA. Plaques were loaded with I-125 seeds to deliver 85Gy in 100 hours. The optic disc D50 at the retinal surface was calculated. Capillary circulation was measured by OCTA using 4.5x4.5 mm optic disc scans. OCTA was performed post-treatment. The peripapillary capil- lary density was calculated for the inner retina (inner limiting membrane to outer plexiform layer) in treated eyes and compared to fellow eyes using a paired t-test. Volume 99  Number 2S  Supplement 2017 Poster Viewing E65