Meso-tetrahydroxyphenylchlorin (mTHPC) fluorescence kinetics in mice

Analysis of sensitizer kinetics is essential for the performance of light irradiation when tumor concentration and tumor-to-normal tissue ratios are optimal. In our study, nude mice were grafted with human adenocarcinoma 15 days before m-THPC IP injection. Fluorescence was recorded through an optic fiber spectrofluorometer at 650, the most intense, and 714 nm, and intensity was proportional to the injected dose. In tumor, skin and muscle, maximum fluorescence was obtained with 1.6 mg/kg 72 h after injection (44 counts per second). Tumor- to-skin and -muscle ratios obtained by HPLC analysis and spectrofluorometric measurements decreased between 12 and 72 h (15 to 1.5), indicating that tumor selectivity decreases with time.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.