title: The biology of photodynamic therapy in the gastrointestinal tract.
abstract: This article reviews current knowledge on the biology of photodynamic therapy on normal and diseased tissues in the gastrointestinal tract. There is little effect on connective tissue, so the mechanical integrity of the luminal gut is well preserved, even with full thickness damage. This makes photodynamic therapy suitable for treating small tumors, but strictures may occur after circumferential treatment of conditions like Barrett's esophagus unless a muscle-sparing photosensitizing agent is used. Animal studies show that the pancreas and surrounding tissues can tolerate photodynamic therapy, justifying pilot clinical trials on percutaneous, interstitial photodynamic therapy for localized, inoperable pancreatic cancers.
authors.affiliation: Department of Surgery, National Medical Laser Centre, Royal Free and University College Medical School, University College, London, England. s.bown@ucl.ac.uk
authors.forename: S G
authors.initials: SG
authors.lastname: Bown
authors.forename: L B
authors.initials: LB
authors.lastname: Lovat
mesh_terms: D000818:Animals; D004064:Digestive System / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects; D005767:Gastrointestinal Diseases / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D008027:Light; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use
chemical_list: D017319:Photosensitizing Agents