title: The effect of photodynamic therapy (PDT) on oesophageal motility and acid clearance in patients with Barrett's oesophagus.
abstract: BACKGROUND
  Barrett's oesophagus is the major risk factor for oesophageal adenocarcinoma. It is proposed that long-term re-epithelialisation, which has been achieved following ablation using 5-aminolaevulinic acid (5-ALA) photodynamic therapy (PDT) may reduce the risk of malignant change. However, it is not known whether PDT modifies oesophageal motility.
  
  
  OBJECTIVE
  To assess oesophageal pH and motility before and after PDT ablation in treated and untreated areas of the oesophagus.
  
  
  METHODS
  Twelve patients (10 male) with Barrett's oesophagus, median segment length 4 cm, were treated with PDT ablation. Twenty-four hours pH assessment and oesophageal manometry were performed before and 4-6 weeks after ablation. PDT was carried out using 635 nm red light, 4-6h after administration of 30 mg/kg 5-ALA. Proximal (untreated) and distal (treated) oesophageal resting pressure, wave amplitude, percentage peristalsis and percentage study time oesophageal pH<4, were assessed. Proton pump inhibitors (PPI) were administered throughout the study.
  
  
  RESULTS
  There were no significant differences in oesophageal motility in treated or untreated areas of the oesophagus after PDT compared to pre-treatment values. Patients who continued to experience oesophageal acid exposure required more treatments to achieve complete Barrett's ablation.
  
  
  CONCLUSIONS
  Oesophageal motility following ALA-PDT suggests a trend toward enhanced wave propagation however continued oesophageal acid exposure may affect PDT efficacy.
authors.affiliation: Academic Unit of Surgical Oncology, University of Sheffield, UK. J.Globe@sheffield.ac.uk
authors.forename: J
authors.initials: J
authors.lastname: Globe
authors.forename: A
authors.initials: A
authors.lastname: Smythe
authors.forename: C J
authors.initials: CJ
authors.lastname: Kelty
authors.forename: M W R
authors.initials: MW
authors.lastname: Reed
authors.forename: N J
authors.initials: NJ
authors.lastname: Brown
authors.forename: R
authors.initials: R
authors.lastname: Ackroyd
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000008:administration & dosage* / Q000494:pharmacology; D001471:Barrett Esophagus / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010778:Photochemotherapy / Q000379:methods*; D054328:Proton Pump Inhibitors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D054328:Proton Pump Inhibitors; D000622:Aminolevulinic Acid