Porphyrins and related macrocycles: Combining photosensitization with radio- or optical-imaging for next generation theranostic agents.

This review summarises recent research into combining the photosensitizing properties of porphyrins with imaging techniques such as PET and NIR fluorescence for so called "theranostic" applications, which combine biomedical imaging and therapeutic potential into a single administered substance. The photophysical mechanisms of both the therapeutic and diagnostic properties of porphyrins are discussed, as well as key characteristics that are required in order to deliver the most effective treatment.