Abstract
The period of photosensitization and subsequent photoprotection after fluorescence diagnosis and photodynamic therapy with aminolevulinic acid (ALA) or methylaminooxopentanoat (MAOP) is not well understood. During the last years many in vitro and in vivo studies were performed to gain more insight into this matter. The data of the reviewed studies are not very valid but first conclusions can be drawn. In general, the duration of the photosensitivity lasts for 24 - 36 hours. ALA-derivatives seem to induce higher and earlier photosensitization with higher phototoxicity in the tumour tissue than ALA itself. More rapid penetration, homogeneous distribution and higher selectivity is discussed as the main reason for the different characteristics of ALA and ALA-derivatives. In addition, it could be shown, that also the healthy skin can be highly photosensitized after application of ALA or MAOP. Therefore, all areas (neoplastic and healthy skin) treated with a photosensitizer should be kept protected from light after photodynamic therapy and especially fluorescence diagnosis. Otherwise, severe and unwanted phototoxic reactions induced by UV and also visible light may occur up to 36 hours after application of the photosensitizer. For protection light impermeable clothes and aluminium foil containing dressings are recommended.
Literatur
Kutane Photosensibilisierung und Photoprotektion. In: Szeimies RM, Jocham D, Landthaler M (Hrsg) Klinische Fluoreszenzdiagnostik und Photodynamische Therapie. Blackwell Verlag 2003: 372-382
plehmann@wuppertal.helios-kliniken.de
