title: Eradication of high-grade dysplasia in columnar-lined (Barrett's) oesophagus by photodynamic therapy with endogenously generated protoporphyrin IX.
abstract: BACKGROUND
  High-grade dysplasia in columnar-lined (Barrett's) oesophagus presents a difficult therapeutic dilemma. Choices for management are endoscopic surveillance to detect a cancer or oesophagectomy. One carries the risk of missing invasive cancer, the other carries worrying morbidity and mortality. We have used endoscopic photodynamic therapy to eradicate high-grade dysplasia.
  
  
  METHODS
  After the oral administration of 5-aminolaevulinic acid, the accumulation of the endogenously generated photosensitiser protoporphyrin IX was measured with quantitative fluorescence microscopy. Five patients with histologically confirmed high-grade dysplasia were treated with endoscopic photodynamic therapy with 630 nm laser light to activate the photosensitiser.
  
  
  RESULTS
  Protoporphyrin IX accumulated in the dysplastic epithelium rather than the adjacent stroma. Selective necrosis of the dysplastic epithelium in columnar-lined oesophagus occurred after light activation. High-grade dysplasia was eradicated in all patients and squamous regeneration occurred after acid suppression with a protonpump inhibitor. There were no complications or recurrence of dysplasia after 26-44 months' endoscopic and histological follow-up. In two cases we saw non-dysplastic Barrett's epithelium underneath regenerative squamous mucosa.
  
  
  CONCLUSIONS
  High-grade dysplasia in columnar-lined oesophagus can be eradicated by endoscopic photodynamic therapy with endogenously generated PpIX. Remaining non-dysplastic Barrett's epithelium will require surveillance, but overall the technique has interrupted or delayed the worsening of the dysplasia through to carcinoma. This technique may prevent the need for surgical excision in these patients.
authors.affiliation: Gloucester Gastroenterology Group, Gloucestershire Royal Institute of Medical Sciences, Gloucestershire Royal Hospital, UK.
authors.forename: H
authors.initials: H
authors.lastname: Barr
authors.forename: N A
authors.initials: NA
authors.lastname: Shepherd
authors.forename: A
authors.initials: A
authors.lastname: Dix
authors.forename: D J
authors.initials: DJ
authors.lastname: Roberts
authors.forename: W C
authors.initials: WC
authors.lastname: Tan
authors.forename: N
authors.initials: N
authors.lastname: Krasner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000627:therapeutic use*; D001471:Barrett Esophagus / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy / Q000379:methods*; D011524:Protoporphyrins / Q000378:metabolism*
chemical_list: D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX