Objective To explore the influence of the radiochemotherapy mode and the number of syn-chronized chemotherapy cycles on the efficacy and overall survival(OS)time of the patients with limited-stage small cell lung cancer(LS-SCLC).Methods The clinical data of 85 patients with LS-SCLC receiving the thoracic radiotherapy(TRT)in the tumor radiotherapy department of this hospital from January 2018 to De-cember 2022 were retrospectively analyzed.The patients were divided into the synchronous chemotherapy group(n=43)and non-synchronous chemotherapy group(n=42)according to different radiochemotherapy modes.The OS and progress free survival(PFS)time was compared between the two groups,and the related prognostic influencing factors of LS-SCLC were analyzed.Results The last follow-up date was November 1,2023,and the median follow-up time in all groups was 39.6 months.The median OS time of the synchronous chemotherapy group and non-synchronous chemotherapy group was 30.6 months and 18.6 months respective-ly,and the difference was statistically significant(P<0.05).The median OS time of 1 cycle and 2 cycles in the synchronous chemotherapy group was 25.5 months and 33.6 months,and the difference was not statisti-cally significant(P>0.05).The Cox multivariate regression analysis results showed that the age,clinical stage and prophylactic cranial irradiation(PCI)were the independent prognostic influencing factors in the pa-tients with LS-SCLC.Conclusion The number of synchronized chemotherapy cycles has no significant influ-ence on the prognosis of LS-SCLC.

At present,concurrent chemoradiotherapy and prophylactic craniocerebral irradiation are the standard treatment for limited-stage small cell lung cancer.Despite its obvious efficacy,1/3 of patients still have local recurrence.In order to explore how to maximize control of local recurrence and improve survival,this article reviews the current status of radiotherapy for limited-stage small cell lung cancer,and explores its optimal timing,target area,dose,segmentation,and prophylactic craniocerebral irradiation.In addition,emerging therapies of radiotherapy combined with immunotherapy in limited-stage small cell lung cancer are also reviewed.