6950 Photodynamic therapy using 5 amino laevulinic acid for high grade dysplasia in barrett's esophagus.

Abstract

Background: Photodynamic therapy (PDT) using 5-amino levulinic acid (ALA) may heal dysplasia in Barrett s esophagus. We present our initial clinical findings using this technique. Patients and Methods: Five patients (4 men, 1 woman, age 70-86) with high-grade dysplasia (HGD) or intramucosal carcinoma (T1m) were treated on 9 occasions. All were unfit for surgery. Patients were photosensitized with ALA 60 mg/kg in 3 divided doses over 2 hours. Treatment was given 6 hours after the initial dose of ALA at 100J/cm2 and a power of 100 mW/cm2, using either a diode laser at 630 nm (3 treatments) or a copper vapor tuneable dye laser (6 treatments). The initial 3 treatments were carried out under general anesthesia. Later treatments were under conscious sedation. Biopsies were taken 1-4 days after therapy to assess depth of necrosis and at 8 weeks to check for healing. Results: Three patients with HGD had complete regression of dysplasia. The patient with T1m carcinoma was cured, but still has a focus of HGD that will be retreated. One patient had regression of extensive HGD but a small focus of LGD remains. None of the treatment sessions using the 630 nm laser effected cure, whereas 5/7 sessions using 635 nm light did. Two patients were treated for lesions crossing the cardia and in both cases, necrosis was noted along the greater curve up to 5cm beyond the treated area. Necrosis was best assessed at 2 or 3 days after therapy. At this time, viable glands were detected histologically within necrotic mucosa. Complete regression of Barrett's mucosa was not seen, but squamous epithelium did partially regenerate. In one patient, squamous epithelium regenerated to cover a residual dypalstic gland and in another 2, non-dysplastic glands became buried under endoscopically normal squamous mucosa. Conclusions: ALA-PDT is a promising technique for treating HGD in Barrett's esophagus, but full thickness mucosal necrosis is not reliably achieved and squamous regeneration may mask dysplastic glands. Further laboratory studies are needed before it can be used routinely. Background: Photodynamic therapy (PDT) using 5-amino levulinic acid (ALA) may heal dysplasia in Barrett s esophagus. We present our initial clinical findings using this technique. Patients and Methods: Five patients (4 men, 1 woman, age 70-86) with high-grade dysplasia (HGD) or intramucosal carcinoma (T1m) were treated on 9 occasions. All were unfit for surgery. Patients were photosensitized with ALA 60 mg/kg in 3 divided doses over 2 hours. Treatment was given 6 hours after the initial dose of ALA at 100J/cm2 and a power of 100 mW/cm2, using either a diode laser at 630 nm (3 treatments) or a copper vapor tuneable dye laser (6 treatments). The initial 3 treatments were carried out under general anesthesia. Later treatments were under conscious sedation. Biopsies were taken 1-4 days after therapy to assess depth of necrosis and at 8 weeks to check for healing. Results: Three patients with HGD had complete regression of dysplasia. The patient with T1m carcinoma was cured, but still has a focus of HGD that will be retreated. One patient had regression of extensive HGD but a small focus of LGD remains. None of the treatment sessions using the 630 nm laser effected cure, whereas 5/7 sessions using 635 nm light did. Two patients were treated for lesions crossing the cardia and in both cases, necrosis was noted along the greater curve up to 5cm beyond the treated area. Necrosis was best assessed at 2 or 3 days after therapy. At this time, viable glands were detected histologically within necrotic mucosa. Complete regression of Barrett's mucosa was not seen, but squamous epithelium did partially regenerate. In one patient, squamous epithelium regenerated to cover a residual dypalstic gland and in another 2, non-dysplastic glands became buried under endoscopically normal squamous mucosa. Conclusions: ALA-PDT is a promising technique for treating HGD in Barrett's esophagus, but full thickness mucosal necrosis is not reliably achieved and squamous regeneration may mask dysplastic glands. Further laboratory studies are needed before it can be used routinely.