ESTRO 2021 Abstract Book

S990

ESTRO 2021

Conclusion The presence of driver mutations (EGFR/RET/ROS1/BRAF) correlated with significant residual tumor after CRT, however, FGFR and KRAS had favorable pathologic regression. PDL1 staining did not correlate with pathologic regression. PO-1194 A predictive model for OS in patients treated with Stereotactic Radiotherapy for early-stage NSCLC P. Borghetti 1 , G. Costantino 1 , V. Santoro 2 , M. Sepulcri 3 , M. Maddalo 1 , D. Greco 1 , F. Frassine 1 , P. Vitali 1 , E. Pastorello 1 , S. La Mattina 1 , G. Volpi 1 , J. Imbrescia 1 , S.M. Magrini 1 1 ASST Spedali Civili and University of Brescia, Radiation Oncology, Brescia, Italy; 2 Istituto Oncologico Veneto IRCCS, Radiation Oncology, Padova, Italy; 3 Istituto Oncologico Veneto IRCCS , Radiation Oncology, Padova, Italy Purpose or Objective Purpose/Objective: To build a predictive model of OS in a cohort of patients with early stage NSCLC undergoing SBRT Materials and Methods Material/methods: 139 consecutive non surgical patients (pts) treated with SBRT for early-stage NSCLC at two institution were retrospectively analyzed. All pts received 55 Gy in 5 fractions or 60 Gy in 8 fractions. Gender, age, smoking status, Charlson Comorbidity Index (CCI), COPD GOLD classification, ECOG Performance Status (PS), Body Mass Index, educational qualification, history of other neoplasms (ONeo) and other oncological