Long term efficacy of Photodynamic Therapy (PDT) as an ablative therapy of high grade dysplasia in Barrett's oesophagus

Background: Barrett's high grade dysplasia (HGD) is a pre-malignant condition which requires treatment with either oesophagectomy or ablative endoscopic therapy. Endoscopic ablative techniques have evolved through Photodynamic Therapy (PDT) to more recently radiofrequency ablation (RFA). Although RFA has superseded PDT due to improved efficacy and safety profile there remains a significant cohort of patients previously treated by PDT where the long term outcome is unclear. This study's aim was to assess the long term efficacy of PDT in patients with Barrett's HGD. Methods: Between June 2002 and 2007 21 patients (16 male, median age 70) underwent PDT for HGD in Barrett's oesophagus. Patients received intravenous photosensitiser Photofrin (Porfimer sodium) forty eight hours prior to endoscopic light activation by laser light at 630 nm. The patients returned at 6-12 weekly intervals for repeat endoscopy and biopsy. Results: Sixteen patients remained free of HGD at median 62 (range 36-114) months. Three patients developed adenocarcinoma at 47, 48 and 54 months (15%). Two patients were treated endoscopically with RFA and YAG laser, while one patient had surgical resection. Four patients developed recurrent HGD treated with repeat PDT. There was a significant reduction in length of Barrett's segment (from 5 cm to 3 cm) post PDT. The stricture rate requiring endoscopic therapy was 37% and 10% of patients developed photosensitivity reactions. Conclusion: PDT successfully ablated HGD in 84% of patients and could therefore still be considered an effective salvage treatment for this condition in patients with co-morbidities precluding them for surgical resection.