Cooperative clinical trial of photodynamic therapy with photofrin II and excimer dye laser for early gastric cancer.

Background And Objective: Photodynamic therapy (PDT) is a recently developed endoscopic method for treating malignant tumors. For obtaining more photodynamic action with less thermal effect, we employed as the excitation light source for PDT an excimer dye laser, which is a pulsed laser with extremely high peak power, instead of an argon dye laser, which is a continuous wave laser and has been used conventionally.

Study Design/materials And Methods: The effect of PDT using Photofrin II and the excimer dye laser was evaluated in 27 patients with early gastric cancer.

Results: Complete responses (CR) were obtained in 88% of 24 assessable patients and the response rate was 100%. CR was observed in all cases of lesions of superficial depressed type without ulceration and/or with tumor diameter less than 2 cm. Regarding toxicity, mild cutaneous reaction and photosensitivity were seen and lasted several weeks. There were no serious abnormalities in laboratory tests.

Conclusion: We conclude that PDT is a promising modality for early gastric cancer.