Even Local Control of Metastatic Lung Tumors Is Worse Than That of Primary Lung Cancer in Patients Treated With Stereotactic Body Radiation Therapy

baseline pulmonary functions, inoperability reason and smoking status), tumor (including size, T stage, location, histology and PET SUV) or treatment (including dose/fractionation) factors were significantly associated with LTS compared to non-LTS. The median survival (months) for non-LTS was 23.4 vs 81.6 for LTS. Comparing non-LTS to LTS, 2-year local recurrence free, disease failure free, distant metastases free, nodal failure free and overall survival rates (as %) were: 90.2 vs 100; 58 vs 97.2; 66.2 vs 100; 82.5 vs 100, respectively. The overall rate of any grade toxicity was 22% (of which 63% were reported in non-LTS and 37% in LTS), with chest wall related pain representing 71.1% of reported toxicities. There were no grade 3 or novel late toxicities noted in the LTS. At last follow up, the overall rates (%) of local, lobar, regional nodal and distant failure for LTS were 10.5, 13.2, 5.3 and 15.8. Eight pts. developed a second lung primary, 3 (1.7%) were non-LTS and 5 (3%) were LTS. Conclusions: Pts. surviving 5 years after lung SBRT show excellent local control, low regional nodal relapse and modest distant relapse rates without unusual late toxicities. Age at diagnosis and gender favored being a LTS but no other patient, treatment or tumor factor was associated with long term survival suggesting the appropriateness of lung SBRT for all medically inoperable lung cancer due to lack of clear selectors for those who will be LTS. Author Disclosure: G.M. Videtic: None. C.A. Reddy: None. N.M. Woody: None. T. Djemil: None. K. Stephans: None.