Optimization of light dosimetry for photodynamic therapy of Barrett's esophagus: efficacy vs. incidence of stricture after treatment.

Abstract

BACKGROUND:

Photodynamic therapy (PDT) may be used to ablate high-grade dysplasia/early stage cancer (HGD/T1) in patients with Barrett's esophagus. PDT may result in esophageal stricture. This nonrandomized, unblinded, dose de-escalation study in consecutive patients was designed to determine the lowest light dose effective for ablation of HGD/T1 while reducing the incidence of stricture.

METHODS:

A total of 113 patients received an injection of porfimer sodium (2 mg/kg). Three days later, 630 nm light was delivered by using a 20-mm-diameter PDT balloon at doses of 115 J/cm (n=59), 105 J/cm (n=18), 95 J/cm (n=17), or 85 J/cm (n=19). Treatment efficacy was determined by obtaining biopsy specimens of the treated area 3 months later. The incidence of stricture was determined by the need for esophageal dilation to treat dysphagia. A stricture was considered severe if 6 or more dilations were required.

RESULTS:

The incidence of severe stricture was related to the light dose. At 115 J/cm, 15.3% of patients developed severe strictures compared with 5.3% to 5.6% of those treated with the lower doses. At a light dose of 115 J/cm, 17.0% of patients had residual HGD/T1. Light doses of 105 J/cm, 95 J/cm, and 85 J/cm resulted in residual HGD/T1 in 33.3%, 29.4%, and 31.6% of patients, respectively. None of the observations were statistically significant.

CONCLUSIONS:

Decreasing the light dose below 115 J/cm appeared to result in a reduced incidence rate of severe stricture but higher relative frequencies of residual HGD/T1 in Barrett's esophagus.

• Authors: Masoud Panjehpour, Bergein F Overholt, Mary N Phan, John M Haydek
• Journal: Gastrointestinal endoscopy (Gastrointest Endosc) Vol. 61 Issue 1 Pg. 13-8 (Jan 2005) ISSN: 0016-5107 [Print] United States
• PMID: 15672050 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Antineoplastic Agents
• Dihematoporphyrin Ether

Topics

• Adult
• Aged
• Aged, 80 and over
• Antineoplastic Agents (therapeutic use)
• Barrett Esophagus (drug therapy, pathology)
• Dihematoporphyrin Ether (therapeutic use)
• Dose-Response Relationship, Radiation
• Esophageal Neoplasms (drug therapy, pathology)
• Esophageal Stenosis (etiology, prevention & control)
• Female
• Follow-Up Studies
• Hematoporphyrin Photoradiation (adverse effects, methods)
• Humans
• Male
• Middle Aged
• Neoplasm Staging
• Relative Biological Effectiveness
• Treatment Outcome