Photodynamic therapy of small adenocarcinomas with methylene blue

Photodynamic therapy (PDT) is a new method in the treatment of small/early malignancies. It is based on the interaction of a photosensitiser, light and cellular oxygen. A new therapeutic concept with locally applied 1 % of methylene blue into the tumour and subsequent radiation (argon laser pumped dye laser, 665 nm, 100 mW/cm(2), 100 J/cm(2)) was first tested in xenotransplanted carcinomas and then clinically applied. The animal experiments showed a tumour volume reduction of 1:12, as compared to a control group, two weeks after the first PDT-application. After the second PDT-treatment 6 out of 10 tumours were destroyed. Four carcinomas showed inhibited growth after the treatment. The method was clinically applied in 3 patients with local tumour recurrence in the area of the anastomosis after oesophagus resection. 72 hours after PDT-treatment 4-5 mm tumour necrosis could be proven experimentally. PDT was repeated at the same site within 2 weeks. There were no experimental or clinical complications during or after PDT. The treated tumour areas showed no local tumour growth within 6 months after PDT-treatment.