Abstract: Objective To evaluate the clinical significance of local radiotherapy(LT) in oligo-residual lesions of advanced non-small cell lung cancer(NSCLC) treated with tyrosine kinase inhibitors(TKIs). Methods A retrospective study was conducted in 61 patients with stage Ⅳ NSCLC who developed oligo-residual disease after TKI therapy at Peking Union Medical College Hospital from February 2018 to May 2024. The patients were stratified into two groups: the LT group(n=31, receiving local consolidative therapy or ablation while continuing systemic therapy) and the non-LT group(n=30, receiving systemic therapy alone). Progression-free survival(PFS), overall survival(OS), and treatment-related safety were compared between the groups. Results The LT group showed a prolonged PFS compared to the non-LT group(31 vs. 23 months, P= 0.171), although the difference did not reach statistical significance. Patients undergoing LT also had a longer median OS(54 vs. 42 months, P=0.713), although the difference did not achieve statistical significance. A total of 7 patients(22.6%) in the local radiotherapy group developed radiation pneumonitis of any grade, including 4 patients(12.9%) with grade 1 pneumonitis and 3 patients(9.7%) with grade 2 pneumonitis.Univariate and multivariate analyses indicated that the number of metastatic lesions, sex, ECOG performance status, targeted therapy regimen, and best response to targeted therapy were factors associated with patient prognosis. Among these variables, ECOG performance status and smoking status were identified as independent predictors of PFS. Conclusions In NSCLC patients with oligo-residual lesions after TKI therapy, LT preliminarily appears to prolong progression-free survival without significantly increasing treatment-related adverse events.

Key words: non-small cell lung cancer, targeted therapy, oligo-residual disease, local consolidative therapy, local ablative therapy