Photodynamic therapy in the treatment of malignant tumours of the skin and head and neck.

Photodynamic therapy utilizes a tumour-localizing photosensitive substance which, when activated by light of an appropriate wavelength, releases cytotoxic substances causing destruction of the malignant tumour with preservation of surrounding normal tissues. In this technique the only drug/light combination which has been regularly used to date is that of haematoporphyrin derivative and red light at a wavelength of 630 nm usually produced by a dye or gold vapour laser. A pilot/feasibility study was set up in Southampton in 1983, with ethical permission, to treat tumours of the skin and head and neck which had failed all other treatment modalities or for which there was no practical alternative therapy. Thirty-eight patients were treated in this study and all tumours showed a response; significant palliation was achieved in a number of patients. Basal cell carcinomas and the multiple lesions of Bowen's disease were found to be particularly suitable for this form of therapy and prolonged local control was achieved in a number of patients.