Bibliometric analysis in the field of photobiomodulation in the last two decades: research trends and evolution of hot topics.

BACKGROUND: Photobiomodulation (PBM) has evolved into a vibrant interdisciplinary field. Despite rapid research expansion, a comprehensive quantitative mapping of its knowledge structure, key contributors, and emerging trends remains lacking. METHODS: We conducted a bibliometric analysis of PBM publications from the Web of Science Core Collection (2006-2025). Knowledge mapping utilized CiteSpace, VOSviewer, and the bibliometrix R package. Additionally, PubMed clinical trial data were extracted to cross-validate bibliometric trends with actual clinical practice. RESULTS: We identified 4,907 publications, exhibiting a compound annual growth rate of 14.67%. Michael R. Hamblin was the most prolific author (n=100, h-index=54), and Lasers in Medical Science was the core journal (n=1,180). Brazil dominated global output (32.2%, n=1,579), led by the University of São Paulo (n=821). Thematic analysis highlighted "photobiomodulation" and "low-level laser therapy" as fundamental themes, while "Alzheimer's disease" emerged as a specialized, rapidly growing niche. CONCLUSIONS: Over two decades, PBM has matured into a promising mainstream therapeutic modality. Future research must prioritize the standardization of treatment parameters, alongside deeper exploration of biological mechanisms and long-term clinical validation. This 20-year mapping provides a strategic roadmap to guide evidence-based PBM practice.