In photodynamic therapy (PDT), red light is administered 24 - 72 hours post intravenous (i.v.) injection of hematoporphyrin derivatives (HpD). In an earlier animal model study, more effective therapeutic response was obtained when red light irradiation was carried out 15 mins after the injection of HpD. The effectiveness of this immediate PDT protocol has been correlated to the high serum level of HpD immediately after administration and the destruction of the microcirculation system as the dominant tumor destruction mechanism. This study examines the pharmacokinetics and the serum levels of HpD in rats and also in human patients. Such data can assist in defining the optimum time delay for light irradiation in the PDT of cancer.
展开▼