Photodynamic therapy of human skin tumors using topical application of 5-aminolevulinic acid dimethylsulfoxide (DMSO) and edetic acid disodium salt (EDTA)

摘要

Abstract: The results of photodynamic therapy (PDT) in 48patients bearing basal cell carcinoma (BCC) and 7patients with squamous cell carcinoma (SCC) of the skinare described. Five- aminolevulinic acid (5-ALA) wasapplied topically in two formulations. The firstformulation contained 20% of 5-ALA in a base cream, andthe second formulation (5-ALA composite cream),contained an additional 2% of dimethylsulfoxide (DMSO)and 2% of edetic acid disodium salt (EDTA). The creamswere left on the skin for 2 - 5 hours. Production ofprotoporphyrin (PP) was measured in situ by alaser-induced fluorescence (LIF) method. The results offluorescence measurement clearly indicate that PPaccumulation in tumors induced by the 5-ALA compositecream was markedly higher than that induced by the5-ALA cream. The tumors were light-irradiated (600 -720 nm) after 4 - 5 hours of cream applications, usingthe light delivery system Versa-Light by a light doseof 100 J/cm$+2$/. The clinically superficial BCC tumorswere highly responsive to PDT; the overall result inBCC patients was an 85.4% complete response.Histological examination showed an initial edematousreaction, followed by necrosis and completedisappearance of the tumor. The superficial SCC tumorsshowed a 100% complete response after PDT. Theulcerated nodular SCC showed partial responses. !15