Research hotspots and emerging frontiers in photodynamic therapy for basal cell carcinoma: A global bibliometric analysis (2001-2025).

BACKGROUND: Basal cell carcinoma (BCC) is the most prevalent cutaneous malignancy. It correlates strongly with ultraviolet exposure. The incidence of BCC continues to climb annually. Consequently, the demand for safe, cosmetically favorable, and highly effective therapies is pressing. Photodynamic therapy (PDT) has captured significant research interest due to its therapeutic efficacy against BCC. This study aims to investigate current research hotspots, knowledge gaps, and future trends concerning PDT in BCC management.

METHODS: We mapped the research landscape and developmental trends of dermatological PDT for BCC. This analysis utilized visual knowledge graphs derived from the Web of Science Core Collection (WoSCC) and Scopus. A comprehensive literature search covered publications on BCC and PDT from 2001 to 2025. Search queries were conducted in English. Subsequent evaluations included scientific performance analysis, collaboration networks (authors, institutions, and countries), reference co-citation networks, and keyword burst analysis. We utilized VOSviewer, CiteSpace, and Bibliometrix to process the resulting data.

RESULTS: The initial search retrieved 2458 records. Following deduplication and data conversion, 1551 articles were included in the final analysis. Publication volume surged notably between 2004 and 2009. The United States and the United Kingdom emerged as the primary contributing nations. Maastricht University was identified as the leading research institution. References exhibiting the highest centrality predominantly centered on key consensus guidelines established by the International Society for Photodynamic Therapy. They also focused on the therapeutic efficacy and cosmetic advantages in treating nodular BCC. High-frequency keywords were dominated by "Photodynamic therapy" and "Basal cell carcinoma." Furthermore, cluster analysis mapped all keywords into three fundamental domains: disease classification, core pharmacology and mechanisms, and combined or controlled treatment modalities. Within the analyzed corpus of 1551 papers, R. Szeimies and C. Morton emerged as the most prolific authors. They made the most substantial contributions to the field. Keyword analysis also illuminated other high-frequency terms. These included Actinic keratosis, Squamous cell carcinoma, Aminolevulinic acid, Methyl aminolevulinate, Imiquimod, and Pain. Finally, the keyword timeline visualization revealed several emerging research hotspots. Notably, these are optical coherence tomography, immunotherapy, drug delivery, and the hedgehog pathway.

CONCLUSION: PDT offers a dual advantage over conventional therapies for BCC. It successfully balances clinical efficacy with superior cosmetic outcomes. This study represents the first global, quantitative literature analysis on the intersection of BCC and PDT. It identifies several established research hotspots. These encompass the metabolic mechanisms of photosensitizer precursors, the expansion of targeted clinical indications, and the management of pain-related adverse events. Furthermore, we identified a shift toward novel research frontiers. Emerging trends heavily focus on precise localization through non-invasive optical imaging and the development of innovative carriers to breach the skin barrier. They also highlight advanced diagnostic and therapeutic protocols that integrate immunomodulators with molecular targeted pathways. Ultimately, these findings provide valuable navigational guidance for future research endeavors.