title: Topical photodynamic therapy with endogenous porphyrins after application of 5-aminolevulinic acid. An alternative treatment modality for solar keratoses, superficial squamous cell carcinomas, and basal cell carcinomas?
abstract: BACKGROUND
  Topical photodynamic therapy with endogenous porphyrins consists of irradiation of a tumor with visible light after the application of exogenous 5-aminolevulinic acid.
  
  
  OBJECTIVE
  To assess the effectiveness of this modality, patients with precancerous conditions and various skin cancers were treated.
  
  
  METHODS
  Thirteen patients with 70 skin lesions were enrolled. Standard treatment involved the topical application of 20% 5-aminolevulinic acid in an oil-in-water emulsion. The emulsion was applied under an occlusive dressing for 4 to 8 hours before exposure to photoactivating light.
  
  
  RESULTS
  We observed a complete response after a single treatment for all 9 solar keratoses, 5 of 6 early invasive squamous cell carcinomas, and 36 of 37 superficial basal cell carcinomas. Only 1 of 10 nodulo-ulcerative basal cell carcinomas completely resolved. Eight cutaneous metastases of malignant melanoma were therapeutic failures.
  
  
  CONCLUSIONS
  Topical photodynamic therapy with endogenous porphyrins is effective for superficial epithelial skin tumors.
authors.affiliation: Department of Dermatology, University of Graz, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Wolf
authors.forename: E
authors.initials: E
authors.lastname: Rieger
authors.forename: H
authors.initials: H
authors.lastname: Kerl
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000008:administration & dosage* / Q000378:metabolism; D002280:Basal Cell Carcinoma / Q000188:drug therapy / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007642:Keratosis / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy / Q000379:methods*; D011166:Porphyrins / Q000096:biosynthesis* / Q000502:physiology; D012878:Skin Neoplasms / Q000188:drug therapy*
chemical_list: D011166:Porphyrins; D000622:Aminolevulinic Acid