Photodynamic therapy with 5-aminolevulinic acid is not effective in bile duct cancer

Background: The results of preliminary studies of photodynamic therapy (PDT ) for palliation of patients with bile duct cancer with hematoporphyrin der ivative have been good. Rapid elimination of a photosensitizer could potent ially shorten the time requirement for shielding from light. This would enh ance the benefit of this form of palliative treatment. Therefore the feasib ility of PDT was investigated for nonresectable bile duct cancer by using 5 -aminolevulinic acid. Methods: Four patients with nonresectable bile duct cancer underwent cholan giography, cholangioscopy, and intraductal US before PDT. Light activation was performed 5 to 7 hours after oral administration of 5-aminolevulinic ac id. All patients had an endoprosthesis placed in the bile duct after PDT. Results: Cholangioscopy 72 hours after PDT revealed superficial fibrinoid n ecrosis. However, 4 weeks after PDT there was no significant reduction in b ile duct stenoses. Two patients had infectious complications develop, but p hototoxicity was not observed. Conclusions: Although superficial tumor necrosis was evident, PDT with 5-am inolevulinic acid failed to significantly reduce malignant bile duct obstru ction. Therefore 5-aminolevulinic acid-PDT cannot be recommended for the pa lliative treatment of bile duct cancer.