Proceedings of the British Journal of Radiology, Vascular effects in tumour therapy, 10 November 1989

In photodynamic therapy, two agents that are in themselves non-toxic: porphyrins, or related compounds, and visible light, in combination produce locally-cytotoxic moieties such as singlet molecular oxygen. In vitro, isolated tumour cells and three-dimensional spheroids are directly destroyed by photodynamic therapy (PDT) but following systemic injection in vivo, there is increasing evidence that tumour destruction is mediated by vascular injury.