CLINICAL-EVALUATION OF THE CUTANEOUS PHOTOTOXICITY OF 5,10,15,20-TETRA(M-HYDROXYPHENYL)CHLORIN

The cutaneous phototoxic reaction induced by intravenous injection of 5,-10,-15,-20-tetra(m-hydroxyphenyl)chlorin (mTHPC) has been clinicall y evaluated in patients undergoing photodynamic therapy. These tests w ere performed on the backs of 23 patients with a solar simulator at va rious times after drug administration ranging from 5 h to 57 days. The mTHPC doses ranged from 0.1 to 0.3 mg/kg, and the illuminations laste d from 30 s up to 8 min. These tests have shown that the duration of t he skin photosensitization induced after a typical therapeutic dose of mTHPC (0.15 mg/kg) is less important than with Photofrin((R)) (2 mg/k g), The level of mTHPC in the skin was also assessed in vivo and at ti mes corresponding to the irradiations using an optical fiber-based spe ctrofluorometer. This study indicates that the light-induced fluoresce nce spectroscopy of mTHPC enables prediction of the degree of photosen sitivity of the skin.