Present Status of Photodynamic Therapy for Cancer of Upper Gastrointestinal Tract

Between 1981 and 1990, we treated 7 superficial esophageal cancer (SEC) and 44 early gas-tric cancer (EGC) lesions (41 cases) by photodynamic therapy (PDT) with an argon dye laser (ADL). The procedure was as follows: 3 mg/kg of HpD (Photofrin I) or 2 mg/kg of PHE (Photofrin II) was intravenously injected. Then about 50 hours later, the entire lesion plus a5 mm width of marginal mucosa was irradiated with an ADL at 630 nm wavelength transmitted endoscopically. The irradiation was delivered at 300 mW·5minutes/cm2 for a total dose of 90 J/cm2. Thus PDT was proved to be effective for the depressed type of EGC, especially for the type with ulceration. However, according to the depth of cancer invasion in 7 SEC and in 44 EGC, the rate of cure of submucosal carcinomas was only 33% (1/3) and 55% (11/20), while that of mucosal carcinomas was 100% (4/4) and 88% (21/24) in SEC and EGC, respectively. In 1990, therefore, we investigated an excimer dye laser (EDL) from Hamamatsu Photonics as the excitation light source for PDT. The irradiation with the EDL was delivered at 4 mJ per pulse with peak power of 400 kW and 40 pps at 630 nm wavelength for a total dose of more than 60 J/cm2. In this study, four cases of SEC, which consisted of 2 mucosal and 2 submucosal, and fifteen cases of EGC, which consisted of 11 mucosal and 4 submucosal, were treated by PDT with EDL, and local cure was obtained in all cases.