Photodynamic therapy of spontaneous animal tumors using the active component of hematoporphyrin derivative (DHE) as photosensitizing drug: clinical results.

Photodynamic therapy was performed on 25 primary spontaneous tumors in dogs and cats. The animals were injected with 2.5 mg/kg body wt. of tumor localizing fraction of hematoporphyrin derivative and treated 48 h later with laser light at 631 nm. In 5 cases the treatment was performed on the tumor bed after surgical excision of the tumor mass. An evaluation of clinical results is presented and discussed. Complete remission was obtained in 19 cases and partial remission in 6 cases.