From Photodynamic Therapy
C. Fritsch, K. Lang, K.W. Schulte, W. Neuse, T. Ruzicka, P. Lehmann


The topical cutaneous application of ?-aminolevulinic acid (ALA) induces porphyrin formation in skin, preferentially in tumor tissues. Irradiation of the porphyrin-enriched tumor tissue with Wood's light leads to emission of a typical brick-red fluorescence. This principle may be used as a diagnostic procedure which is termed fluorescence diagnosis with ALA-induced porphyrins (FDAP) or photodynamic diagnosis (PDD). In FDAP, tumors and precancerous lesions of the skin reveal a homogenous intensive fluorescence. Psoriatic lesions also show a strong but non-homogenous porphyrin fluorescence. FDAP in preoperative planning is a valuable method to determine the peripheral borders of a given tumor. The histopathological extensions of the tumors correlate well with the borders detected by the specific fluorescence. The main indications of FDAP are the delineation of clinically ill-defined skin tumors and the control of the efficacy of other tumor therapies.

Photodynamic therapy (PDT) with various photosensitizers has been proven to be highly efficient in the treatment of skin tumors. However, most valid data are available for ALA only, which has been shown to effectively sensitize solar keratoses and superficial basal cell carcinomas with porphyrins. Initial squamous cell carcinomas also show good response to ALA-PDT. Treatment of psoriasis by PDT is a subject under investigation. During the last decade numerous studies on PDT for dermatological diseases have been published, the more important ones are reviewed here.

List of abbreviations


? -Aminolevulinic acid


Basal cell carcinoma


Bowen's disease

Products & Services
Flow Cytometers
Flow cytometers use laser beams to characterize single cells as they pass by at high speed.
UV Light Systems
UV light systems provide ultraviolet light for identification, tracing, curing, disinfection or processing applications.
Dye Lasers
Dye lasers use a dye solution as an active medium. Their output is a short pulse of broad spectrum content with a high achievable gain.
MRI (Magnetic Resonance Imaging) Machines
MRI machines use a radiological technique employing magnetism, radio waves, and a computer to produce images of body structures.
Laser Scanning Cytometers
Laser scanning cytometers (LSCs) are biological instruments which automatically determine the biochemical components of cells, as well as their morphology and cellular location in situ.

Topics of Interest

Herwig Kostron Overview Photodynamic applications, such as photodynamic therapy (PDT) and most recently photodynamic diagnosis (PDD) are currently undergoing intensive clinical investigations as an...

Charles J. Gomer, Angela Ferrario, Karl von Tiehl, Margaret A. Schwartz, Prakash S. Gill, Natalie Rucker 6.1 Photodynamic therapy Photodynamic therapy (PDT) is an effective localized procedure for...

Nathalie Rousset, Ludovic Bourr , Sonia Thibaud Photodynamic therapy (PDT), by exposure of tissues to a specific wavelength of laser light, induces the photoactivation of a sensitizer that is...

Silicon phthalocyanine Pc 4 photodynamic therapy (Pc 4-PDT) has emerged as a potentially effective treatment for cutaneous T-cell lymphoma (CTCL). Noninvasive reflectance and fluorescence spectroscopy...

Anne C.E. Moor, Bernhard Ortel, Tayyaba Hasan, Corresponding Author 2.1 Introduction Photodynamic therapy (PDT) may be considered to be coming of age. There have been a number of regulatory approvals...