Efficacy and toxicity of stereotactic body radiotherapy for un-resectable stage III non-small cell lung cancer patients unfit for concurrent chemoradiation therapy: a retrospective study.

Background: In this study, we evaluated the efficacy and toxicity of stereotactic body radiotherapy (SBRT) as replacement strategy of conventionally fractionated radiation therapy in stage III non-small cell lung cancer (NSCLC) patients unfit for concurrent chemoradiation therapy (CRT). Methods: We analyzed the clinical outcomes in patients with unresectable stage III NSCLC who received SBRT from January 1, 2013 to December 31, 2018. Both induction and consolidation chemotherapy were allowed. The survival rates and toxicities were calculated using the Kaplan-Meier method, and potential risk factors were investigated by multivariate Cox regression. Results: A total of 213 consecutive patients who had received SBRT were enrolled. The median overall survival (OS) and progression-free survival (PFS) were 36.5 months and 16.1 months respectively. The estimated 1-, 2- and 3-year OS rates were 90.6%, 73.7% and 52.0%, respectively and the corresponding PFS rates were 69.5%, 25.4% and 15.0%, respectively. Treatment failures were largely (n = 151, 70.9%) distant metastases, with low rates of local (n = 74, 34.74%) and regional (n = 76, 35.68%) recurrences. In 13.1% patients (n = 28), ≥ grade (G) 3 toxicities were identified, including radiation pneumonia (n = 20, 9.4%) and bronchopulmonary hemorrhage (n = 8, 3.8%). None of the patients suffered from ≥ G 3 late toxic effects. Compared with patients with peripheral tumors, patients with central tumors had lower median OS (P<0.001) and the biological effective dose (BED) was not a predictor for OS. Conclusions: SBRT combined with chemotherapy for stage III NSCLC produced favorable treatment outcomes with acceptable toxicity. For patients with central tumors, an appropriate BED reduction can be considered. Further studies are warranted. Trial registration: Retrospectively registered. [ABSTRACT FROM AUTHOR]