Photodynamic therapy combined with radiotherapy combination in murine melanoma treatment

Melanoma is the type of skin cancer with the highest mortality rate and presents resistance mechanisms to several treatment techniques. Radiotherapy (RT) generates free radicals that react with cellular macromolecules such as DNA, RNA, proteins and membranes, causing dysfunction and cell death. This damage can favor the result of a consecutive application of photodynamic therapy (PDT), either by allowing greater penetration of the photosensitizer into the cells or by weakening the defense mechanisms. On the other hand, PDT promotes direct damage to the cell that can activate an immune response against tumor cells, which can optimize the effect of another technique applied in sequence, such as RT. This study compares different combinations of RT and PDT in the treatment of melanoma using balb/c nude mice and B16F10 cell line.