Efficacy and Safety of High-Dose Rate Brachytherapy With Immunotherapy and Chemotherapy as Second-Line Treatment for Advanced Non-Small Cell Lung Cancer

Study Title: Exploring the Efficacy and Safety of High-Dose Rate Brachytherapy Combined with Immunotherapy and Chemotherapy as a Second-Line Treatment in Patients with Advanced Non-Small Cell Lung Cancer Background: Non-small cell lung cancer (NSCLC) is a significant health concern in China, accounting for approximately 18.1% of new cancer cases in 2022. Despite advancements in targeted therapies and immunotherapies, patients with advanced NSCLC who progress after initial treatment face limited options and poor prognosis. This study aims to address this unmet clinical need by investigating a novel combination therapy. Objectives: Primary: To evaluate the objective response rate (ORR) of high-dose rate (HDR) brachytherapy combined with immune checkpoint inhibitors (ICIs) and chemotherapy in advanced NSCLC patients. Secondary: To assess progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and safety of the combination therapy. Study Design: This is a single-center, retrospective, propensity score-matched study comparing two treatment approaches: Study group: HDR brachytherapy + ICIs + chemotherapy Control group: ICIs + chemotherapy alone Treatment Protocol: Study group: Patients will receive HDR brachytherapy (30Gy single fraction), followed by pembrolizumab and docetaxel chemotherapy within 1-3 days. Control group: Patients will receive pembrolizumab and docetaxel chemotherapy without brachytherapy. Key Scientific Questions: Evaluate the potential improvement in second-line treatment efficacy for advanced NSCLC patients through the combination therapy. Investigate the mechanisms by which HDR brachytherapy enhances the effectiveness of ICIs and chemotherapy. Analyze the differential efficacy of the combination therapy across various subgroups of NSCLC patients. Rationale: Recent evidence suggests that radiotherapy can exert immunomodulatory effects, potentially enhancing immune treatment responses. High-dose radiotherapy has been shown to improve local control and survival rates in early-stage NSCLC when combined with immunotherapy. This study extends this concept to advanced NSCLC as a second-line treatment option. Significance: This research addresses a critical gap in current treatment options for advanced NSCLC patients who have progressed after immunotherapy. It aims to: Improve patient outcomes in terms of quality of life and survival. Advance scientific understanding of the interaction between radiotherapy and immunotherapy. Explore potential biomarkers for treatment response prediction. Contribute to the development of more personalized treatment strategies in oncology. Innovation: This is the first study to investigate HDR brachytherapy combined with ICIs and chemotherapy for previously treated advanced NSCLC patients. The novel combination strategy shows potential for improved efficacy and safety, offering new options for second-line treatment of advanced NSCLC. Expected Outcomes: The study aims to demonstrate improved ORR, PFS, and OS in the combination therapy group compared to the control group. It also seeks to establish the safety profile of the combination therapy and identify patient subgroups that may benefit most from this approach. Conclusion: This study represents a significant step towards addressing the unmet needs of advanced NSCLC patients who have progressed after initial treatment. By exploring this innovative combination therapy, the research aims to contribute valuable insights to the field of oncology and potentially improve treatment outcomes for this challenging patient population.