[Photodynamic therapy of early squamous epithelial carcinomas and severe squamous epithelial dysplasias of the esophagus with 5-aminolevulinic acid].

INTRODUCTION: Photodynamic therapy (PDT) is a new local, endoscopically controlled therapeutic concept based on the selective sensitization of malignant and precancerous lesions prior to light-induced tissue destruction. 5-aminolaevulinic acid (5-ALA) appears to be a promising alternative photosensitizer with a high mucosa specificity without phototoxic side effects on the skin. We report on our experience with this new form of PDT in 24 patients.

PATIENTS AND METHODS: Five females and 19 males (aged 50 to 79 years) with histologically proven high-grade dysplasia (n = 9) and early cancer (normal EUS or uTlNOMO, n = 15) of the esophagus were included in this study. Four to six hours after oral ingestion of 5-ALA (dosage of 60 mg/kg b.w.) laser light irradiation was conducted with a dye laser system (XP 800 KTP/YAG, Laserscope, San José, USA) at a wavelength of 635 nm. With a light dose of 150 J/cm2.

RESULTS: The length of the segment with severe dysplasia or mucosal cancer varied between 0.5 and 9 cm (mean length: 3.6 cm). High-grade dysplasia was eradicated in all patients (9/9). In addition, 16 mucosal carcinomas in 15 patients were successfully treated in 8/16 cases with an average of 1.8 treatment sessions and a mean follow-up of 14.5 months (range: 3-31 months). A method-related mortality and morbidity was not observed.

CONCLUSIONS: Severe dysplasia and superficial (< or = 2 mm) mucosal cancer of the esophagus can be completely ablated by 5-ALA-PDT. Patients with early carcinoma thicker than 2 mm are not suitable for 5-ALA-PDT. PDT with 5-ALA has few side effects and might offer an alternative to esophagectomy or radio-chemotherapy.