title: Patient predictors of esophageal stricture development after photodynamic therapy.
abstract: OBJECTIVE
  The most common significant adverse event after photodynamic therapy (PDT) with porfimer sodium is esophageal stricture formation. This study assessed whether pretreatment variables, including prior endoscopic therapy for Barrett's esophagus, are associated with post-PDT stricturing.
  
  
  METHODS
  Data from all patients who had undergone PDT with porfimer sodium for Barrett's esophagus with high-grade dysplasia, intramucosal carcinoma, or T1 cancer at our institution since 1997 were reviewed.
  
  
  RESULTS
  One hundred sixteen patients underwent 160 courses of PDT. The incidence of stricture formation after index PDT was 16% (19/116). For all PDT courses, the overall incidence of stricture was 23% (37/160). Stricture rate was significantly higher after a second PDT course compared with index PDT (43% vs 16%, P = .0007). There was no association between post-PDT stricture development and age, gender, body mass index, or prior endoscopic mucosal resection. Patients who developed a stricture had a longer length of Barrett's esophagus before treatment than those who did not develop a stricture (7.7 vs 5.7 cm for index PDT only, P = .025; 7.4 vs 5.7 cm for all PDT courses, P = .007). Length of Barrett's esophagus, multiple PDT courses, and presence of intramucosal carcinoma on pretreatment pathology were independent predictors of post-PDT stricture in a stepwise logistic regression analysis controlling for treatment variables, including treatment length.
  
  
  CONCLUSIONS
  An increased risk of stricture development was seen after multiple courses of PDT. An association between post-PDT stricture and length of Barrett's esophagus but not treatment length was also found. Endoscopic mucosal resection did not appear to influence the likelihood of stricture development after porfimer sodium-based PDT.
authors.affiliation: Gastrointestinal Unit and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts 02115, USA. pyachimski@partners.org
authors.forename: Patrick
authors.initials: P
authors.lastname: Yachimski
authors.forename: William P
authors.initials: WP
authors.lastname: Puricelli
authors.forename: Norman S
authors.initials: NS
authors.lastname: Nishioka
mesh_terms: D000368:Aged; D001471:Barrett Esophagus / Q000473:pathology / Q000628:therapy; D017323:Dihematoporphyrin Ether / Q000009:adverse effects* / Q000627:therapeutic use; D004938:Esophageal Neoplasms / Q000473:pathology / Q000628:therapy; D004940:Esophageal Stenosis / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D009367:Neoplasm Staging; D016017:Odds Ratio; D017319:Photosensitizing Agents / Q000009:adverse effects* / Q000627:therapeutic use; D010789:Phototherapy / Q000009:adverse effects*; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D017319:Photosensitizing Agents; D017323:Dihematoporphyrin Ether