Clinical value of radial endobronchial ultrasound combined with metagenomic next-generation sequencing in the malignant tumors patients with pulmonary infection.

INTRODUCTION: Patients treated with systemic anti-tumor therapies are more likely to develop pulmonary infections due to weakened immune systems. This study aims to evaluate the clinical application of radial endobronchial ultrasound (R-EBUS) combined with metagenomic next-generation sequencing (mNGS) in the diagnosis and treatment of pulmonary infections among patients undergoing systemic anti-tumor therapy. METHODS: This study is a single-center retrospective analysis that includes 84 patients with pulmonary infections following systemic anti-tumor therapy. Patients were stratified into sepsis (SOFA score ≥2, n=32) and non-sepsis (SOFA score <2, n=52) groups based on Sepsis-3.0 criteria. BALF samples were subjected to both mNGS and conventional microbiological tests (CMT). Pathogen profiles, diagnostic performance, clinical impact on antimicrobial therapy, and microbiome diversity were analyzed. RESULTS: mNGS demonstrated a significantly higher positive detection rate than CMT (95.24% vs. 30.95%, P < 0.001). mNGS identified a broader spectrum of pathogens, including bacteria, fungi, and viruses, and detected mixed infections more frequently than CMT. The clinical impact of mNGS was positive in 84.52% of cases, primarily by initiating targeted therapy or confirming empirical treatment. Microbiome analysis revealed significantly lower alpha diversity (Shannon, ACE, Chao1 indices) in the severe group compared to the non-severe group. DISCUSSION: EBUS-guided mNGS of BALF was associated with improved pathogen detection in malignancy patients with pulmonary infections, leading to a high rate of beneficial antimicrobial adjustments. Distinct microbial signatures are associated with infection severity, suggesting potential diagnostic and therapeutic implications.