Photodynamic combinational therapy in cancer treatment

Photodynamic therapy (PDT) has attracted widespread attention in recent years as a non-invasive and highly selective approach for cancer treatment. PDT involves the activation of a photosensitizer by an appropriate wavelength of light, generating transient levels of reactive oxygen species (ROS). However, the utilization of PDT against deep tumors has been greatly limited by insufficient luminous flux and the occurrence of peripheral tissue damage. Therefore, experts have begun to explore whether the combination of PDT with other treatments can improve its efficacy. In this review, we have collected articles about experiments (in vitro and in vivo) and clinical research on photodynamic combination therapies in recent years, roughly divided into four parts corresponding to PDT combined with chemotherapy, radiotherapy, immunotherapy and other therapies, to compare the therapeutic effects of the combination therapy and monotherapy. The results showed that photodynamic combination treatments, in general, perform better than single treatment modalities. Thus, the increased therapeutic effects, reduced side effects and coordination treatment effects of PDT are worth of further exploration.