e13582 Background: Overall survival (OS) of metastatic non-small cell lung cancer (NSCLC) patients (pts) is improving with the development of targeted therapies (TARGET) and immunotherapy (IMMUNO), however is limited by disease progression (PD) which necessitates a change in systemic therapy. Stereotactic body radiation therapy (SBRT) can allow NSCLC pts to stay longer with the same therapy by eliminating oligometastatic progression (OMP) improving progression free survival (PFS) and OS. Methods: 100 pts with metastatic NSCLC undergoing chemotherapy (CHEMO), IMMUNO or TARGET that had OMP defined as less than 4 sites of metastasis and underwent SBRT were evaluated for PFS and OS. PFS1: Time between initiation of systemic therapy and development of OMP. PFS2: Time between OMP treated with SBRT and development of further PD requiring a change in systemic therapy. Pts received IMMUNO for second line and beyond. Robotic SBRT was delivered in 1-5 fractions on consecutive days or every other day. SBRT doses were determined based on the disease site and dose tolerance of the adjacent organs. Results: Brain metastasis (BM) were seen in 45 pts and 55 pts had extracranial metastasis (EM). 34 pts were receiving CHEMO, 34 Target and 32 IMMUNO at the time of OMP. Main endpoints (m) are shown (Table) Pts with BM that received SBRT were able to continue the same therapy for a period of 6.5-9 extra months due to the control of BM. Pts with EM that have developed PD were able to continue the same therapy 17-21 extra months due to the ablation of OMP by SBRT. Overall PFS was: 16.5m for BM and 34m for EM and the OS were: 31m and 53m respectively. Conclusions: Substantial prolongation was observed in PFS/OS compared with historical controls thanks to the use of SBRT in pts that develop OMP while on systemic therapy. SBRT allowed patients to continue with the same systemic treatment. Our CHEMO cohort is composed of long term survivors under therapy and may not represent the average PFS/OS of pts on CHEMO. Survival data from prospective trials will be essential in determining the value of this resource-intensive treatment.[Table: see text]