title: Non-coherent light for photodynamic therapy of superficial tumours in animals.
abstract: Cultured 9L cells were incubated with varying concentrations of pheophorbide-a-hexyl ether (HPPH) and then exposed to 665-nm red light from a non-coherent light source or a dye laser. Cell death was produced by both light sources, with the non-coherent light being most effective at the highest HPPH concentrations. To assess the feasibility of using the non-coherent light source for clinical photodynamic therapy (PDT), four dogs and three cats presenting with spontaneous superficial tumours were injected intravenously with 0.15 mg kg(-1) of HPPH, 1 h before their tumours were irradiated with 665-nm non-coherent light (50 mW cm(-2), 100 J cm(-2)). Of the nine tumours treated, there were eight complete responses, all occurring in animals with squamous cell carcinoma. After 68 weeks of follow-up, the median initial disease-free interval had not been reached. These data suggest that non-coherent light sources may be efficacious for photodynamic therapy of spontaneous superficial tumours in animals, representing a cost-effective alternative to medical lasers in both veterinary and human oncology.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, USA.
authors.forename: K B
authors.initials: KB
authors.lastname: Reeds
authors.forename: T D
authors.initials: TD
authors.lastname: Ridgway
authors.forename: R G
authors.initials: RG
authors.lastname: Higbee
authors.forename: M D
authors.initials: MD
authors.lastname: Lucroy