Photodynamic therapy with m-tetrahydroxyphenyl chlorin for high-grade dysplasia and early cancer in Barrett's columnar lined esophagus

Abstract

Background: Many patients with high-grade dysplasia and localized adenocarcinoma in Barrett's esophagus have localized disease but are either unfit for major surgery or decline esophagectomy. Photodynamic therapy with the powerful photosensitizer m-tetrahydroxyphenyl chlorin may be a nonsurgical therapeutic option.

Methods: This is a pilot study to evaluate the efficacy and complications of m-tetrahydroxyphenyl chlorin photodynamic therapy. The design is a case series of 19 consecutive patients at a tertiary referral unit with a special interest in photodynamic therapy. The study included 7 patients with high-grade dysplasia and 12 with early esophageal cancer, who had refused or were unfit for esophagectomy. Three days after photosensitization with 0.15 mg/kg m-tetrahydroxyphenyl chlorin, red or green light was delivered endoscopically when using either a bare fiber or a diffuser device. Results were assessed by endoscopic surveillance.

Results: By using red light via the diffuser, 4/6 patients with cancer and 3/4 with high-grade dysplasia were successfully treated with photodynamic therapy alone. When using the bare-tipped fiber, there was one procedure-related death and only 1/5 patients with cancers were successfully treated. Two others were downgraded to high-grade dysplasia. With green light delivered via a diffuser, 0/3 patients with high-grade dysplasia are in long-term remission. Two serious complications arose (including one death) from taking multiple biopsy specimens too soon after therapy. Two esophageal strictures occurred.

Conclusions: Photodynamic therapy with m-tetrahydroxyphenyl chlorin is, potentially, a valuable therapeutic option for localized esophageal neoplasia. Red light via a diffuser device appears to be the most effective light-delivery technique. Biopsy specimens should not be taken for at least 2 months after treatment.