2445 - Comparison of the Efficacy of Immune Therapy Combined with Radiotherapy in Non-Gene-Sensitive Mutant NSCLC Brain Metastasis Patients: A Comparison of Whole-Brain Radiotherapy and Stereotactic Radiosurgery
Presenter(s)
E. Munai1, Y. Wu2, W. Zhou3, D. Yang2, and D. Tao4; 1School of Medicine, Chongqing University, Chongqing, China, Chongqing, China, 2Radiation Oncology Center, Chongqing University Cancer Hospital, Chongqing, China, 3Department of radiotherapy oncology, Chongqing University Cancer Hospital & Chongqing Cancer Institute & Chongqing Cancer Hospital, Chongqing, China, 4Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China, China
Purpose/Objective(s): The rapid integration of immunotherapy (I) has demonstrated notable efficacy in patients with non-small cell lung cancer (NSCLC) and brain metastasis (BMs). However, the comparative efficacy of immunotherapy combined with whole-brain radiotherapy (WBRT) versus stereotactic radiosurgery (SBRT) in NSCLC patients with non-gene-sensitive mutations remains inadequately understood. This study aims to compare the efficacy and safety of WBRT+I and SBRT+I in NSCLC patients with BMs harboring non-gene-sensitive mutations.
Materials/Methods: This retrospective cohort study analyzed 160 NSCLC patients with non-gene-sensitive mutations and BMs, treated at Chongqing University Cancer Hospital between 2019 and 2024. The patients were divided into two groups: WBRT+I (n=80) and SBRT+I (n=80). Statistical analyses were performed using R version 4.3.3. Fisher’s exact test was used for categorical variables, and survival curves were estimated with Kaplan-Meier and log-rank tests. Univariate and multivariate Cox regression models were used to assess factors influencing overall survival (OS) and intracranial progression-free survival (iPFS). OS was defined as the time from BMs diagnosis to death or last follow-up, and iPFS as the time from diagnosis to the development of new intracranial lesions or disease progression.
Results: Among 160 patients from an initial cohort of 238 NSCLC patients with BMs, the SBRT+I group had a median OS of 26.7 months, significantly longer than the WBRT+I group’s 19.7 months (HR: 0.65, 95% CI: 0.44-0.97, P=0.022). For iPFS, the SBRT+I group had a median of 14.5 months, significantly longer than the 9.4 months in the WBRT+I group (HR: 0.64, 95% CI: 0.43-0.95, P=0.023). Multivariate analysis showed that synchronous BMs, prior thoracic treatment, absence of neurological symptoms post-radiotherapy (NSA), and better intracranial response (CR and PR) were independent predictors of OS and iPFS. In the WBRT+I group, one patient died from immune-related pneumonia, and others experienced immune-related thyroid dysfunction (n=3), immune dermatitis (n=5), and radiation-induced brain injury (n=8). In the SBRT+I group, one patient had grade II immune-related pneumonia, and others had immune-related thyroid dysfunction (n=4), immune dermatitis (n=3), and radiation-induced brain injury (n=3).
Conclusion: SBRT+I demonstrates superior efficacy and a more favorable side-effect profile compared to WBRT+I in non-gene-sensitive mutant NSCLC patients with BMs. These findings suggest SBRT+I as a promising treatment option. Future studies should further investigate personalized adjustments to immunotherapy and assess long-term follow-up effects to optimize treatment strategies and enhance patient quality of life.