Global research trends and intellectual structure of immune checkpoint inhibitor–associated pneumonitis: a bibliometric analysis (2000–2025

Aims: Immune checkpoint inhibitor (ICI)–associated pneumonitis has emerged as a clinically significant immune-related adverse event accompanying the expanding use of immunotherapy in oncology. This study aimed to evaluate the global research landscape, thematic evolution, and intellectual structure of publications related to ICI-associated pneumonitis through bibliometric analysis. Methods: A comprehensive bibliometric analysis was conducted using the Web of Science Core Collection (WoSCC) database. Publications published between 2000 and 2025 were identified using a topic search (TS)-based Boolean query including major ICIs and pneumonitis-related terminology. Although the search period started in 2000, eligible publications were identified beginning from 2009. Only article and review article document types were included. Following exclusion of publications indexed in 2026 and manual relevance screening, 1,660 publications were included in the final analysis. Data were analyzed using the bibliometrix package in R through the Biblioshiny interface. Citation analysis, collaboration networks, keyword co-occurrence mapping, thematic mapping, and historiographic citation analyses were performed. Results: Scientific production increased markedly after 2015, paralleling the widespread clinical adoption of ICIs. The United States and China emerged as the leading contributors and major international collaboration hubs. Frontiers in Oncology was the most productive journal, whereas Lancet Oncology demonstrated the highest citation impact. Naidoo J was identified as the most productive author. Keyword co-occurrence and thematic mapping analyses demonstrated that nivolumab, immunotherapy, pneumonitis, and non-small cell lung cancer constituted the dominant research themes. Historiographic citation analysis revealed a transition from early descriptive toxicity reports toward biomarker-oriented and precision-based management approaches. Institutional productivity analysis highlighted the prominent role of major academic oncology centers, including MD Anderson Cancer Center and Harvard-affiliated institutions. Conclusion: Research on ICI-associated pneumonitis has expanded rapidly over the past decade and evolved from descriptive clinical observations toward mechanistic and translational investigations. Current research trends increasingly focus on biomarker discovery, risk stratification, and optimization of multidisciplinary management strategies. This bibliometric analysis provides a comprehensive overview of the intellectual and thematic development of the field and may guide future research directions in immunotherapy-related pulmonary toxicity.