1535 poster STEREOTACTIC RADIOTHERAPY AND RADIOSURGERY FOR LUNG TUMOURS AND METASTASES

95%of the PTV encompassed within the prescription isodose volume Patients were followed with CT and PET scan to detect disease recurrence Local recurrence was defined as an increase in size of tumor following treatment as most tumors shrunk following radiation Results: Median follow-up was 19 months (range, 448 months). KaplanMeier local control at 1 and 2 years was 84.9% and 84.9% respectively, overall survival (OS) at 1 and 2 years was 89.8% and 83.4% ,disease free Survival (DFS) at 1 and 2 years was 84.9% and 78%. We detected a late radiationinduced local fibrosis using CT imaging in most patients, but, till today, none of patients had any chronic symptoms Conclusions: These ppreliminary results suggest that CyberKnife-based SRT is a feasible approach for primary lung cancer, offering excellent in-field tumor control and low toxicity profile.Oowever more experience and a longer follow-up are necessary to determine the role of CK and to identify patients most likely to benefit from it