The Evolving Landscape of Extracorporeal Photopheresis in Immunotherapy: A Comprehensive Bibliometric and Topic Modeling Analysis (1995–2024)

ABSTRACT Introduction Extracorporeal photopheresis (ECP) is an established immunomodulatory therapy for graft‐versus‐host disease (GVHD) and cutaneous T‐cell lymphoma and is increasingly investigated for immune‐related adverse events (irAEs). However, its collaborative networks, thematic evolution, and translational evidence gaps remain poorly characterized. Methods We analyzed 1268 ECP publications from the Web of Science Core Collection (1995–2024) using bibliometric analysis and Latent Dirichlet Allocation (LDA) topic modeling. Studies published after the search cutoff were considered only for clinical context. Results The United States, Germany, and Italy led publication output. Mann–Kendall analysis identified a significant change point around 2015. LDA revealed six thematic domains: early research emphasized dermatologic applications and solid organ rejection, whereas recent work shifted toward acute GVHD management and immunoregulatory mechanisms. Topic 6 captured mechanistic research on apoptosis and regulatory T‐cell–mediated immune tolerance. Contextual prospective evidence in GVHD and irAEs suggested corticosteroid‐sparing activity and generally favorable tolerability, but was limited by small cohorts, heterogeneous schedules and endpoints, and few randomized comparisons. Conclusion ECP has evolved into a broader immunomodulatory platform, whereas its use for irAEs remains investigational. Future research should prioritize multicenter randomized trials, pediatric‐specific protocols, predictive biomarkers, long‐term tumor‐control follow‐up in irAEs, and health‐economic evaluation.