Iontophoretic Photosensitization of the Skin Re-evaluated by Colorimetric Imaging in Senile Patients

• Published in: Bioimages Vol. 19; pp. 1 - 6
• Main Authors: Akimoto, Makio, Nomoto, Mayumi, Miyakawa, Michio, Miyazaki, Michio, Omi, Tokuya, Nishimura, Tomonori, Maeda, Kazuhisa
• Format: Journal Article
• Language: English
• Published: Tokyo Bioimaging Society 01.01.2011; 日本バイオイメージング学会; Japan Science and Technology Agency
• Subjects: 5-aminolevulinic acid (5-ALA); Epidermis; iontophoresis; optical imaging; photodynamic therapy; skin disease
• ISSN: 0919-2719
• DOI: 10.11169/bioimages.19.1

The combination of light and chemicals to treat tumors and inflammatory diseases is widely practiced in clinical medicine, and is contributing to the photodynamic therapy (PDT) of various diseases in dermatological fields. In PDT for skin cancers, 5-aminolevulinic acid (5-ALA) is applied topically to the affected area to be absorbed percutaneously through passive diffusion. It typically requires 4 — 6 h for the photosensitizer to penetrate the epidermis deep enough for PDT. In this study, we attempted to shorten the penetration time by using monophasic pulse iontophoresis in Bowen's disease patients. In all subjects, the production of protoporphyrin IX was confirmed after iontophoretic application of 5-ALA as reaching the levels comparable to those reached by the conventional occlusive dressing technique. The effect of ALA-PDT on the patients' skin was assessed by colorimetric imaging. Skin biopsies showed disappearance of tumor cells from the treated lesion.