Photodynamic therapy of gastrointestinal cancers

A new photosensitizer (PS), meso-tetrahydroxyphenyl-chlorin(m-THPC), has been clinically evaluated for photodynamic therapy (PDT) of early squamous cell carcinomas located in the upper aerodigestive tract, the oesophagus and the tracheobronchial tree. The injected doses ranged between 0.1 - 0.3 mg/kg m-THPC and the wavelength of the excitation light was either at 514 nm or 652 nm. The evaluation of the m-THPC induced phototoxicity was carried out on healthy mucosae of the bronchi, the oral cavity and the skone cell population to the other. Appearance of aneuploid populations after PDT suggests that destruction of sensitive cell populations allows the growth of initially non FCM detectable aneuploid clones. MDA assay could thus be a good prognostic tool although larger series of patients are needed. 115© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.