Photo- and Immunotherapy Interface: Can Dendritic Cell Vaccines Overcome the Limitations of PDT?

Photodynamic therapy (PDT) occupies an important place in the arsenal of cancer treatment modalities; however, its efficacy is primarily limited by the local nature of its effects and by tumor cell resistance. The aim of this review is to analyze the fundamental principles and biological consequences of PDT, to summarize current data on the molecular and cellular mechanisms determining its efficacy, and to consider strategies for overcoming its limitations. Particular attention is paid to the mechanisms underlying resistance development and to the role of switching from non-immunogenic to immunogenic cell death in shaping the antitumor response. The potential integration of PDT with dendritic cell vaccination is considered a promising strategy for overcoming these limitations. The potential of vaccine-based approaches to activate specific antitumor immunity in aggressive cancers is highlighted, with emphasis on the advantages of dendritic cell vaccines in addressing the limitations of conventional PDT.