Photodynamic therapy for gastrointestinal tumors.
Photodynamic therapy is based on the administration of a compound that is preferentially accumulated by a tumor and which causes tumor destruction after exposure to light of a specific wavelength. The photosensitizers most commonly used in treating tumors of the gastrointestinal tract are porphyrins--hematoporphyrin derivative and dihematoporphyrin ether. These compounds have been used with success to produce reduction in tumor size of esophageal, gastric, and colorectal cancers. In some instances long-lasting complete remission have been observed after photodynamic therapy. New developments include photosensitizers that react to light of a longer wavelength, which is able to penetrate tissue to a greater depth, the use of 5-aminolevulinic acid, which is preferentially converted to porphyrin in malignant cells, and combination of photodynamic therapy with thermic laser, radiotherapy, or chemotherapy.
Wilson
J H
JH
Dept. of Internal Medicine, Erasmus University, Rotterdam, The Netherlands.
van Hillegersberg
R
R
van den Berg
J W
JW
Kort
W J
WJ
Terpstra
O T
OT
D015179:Colorectal Neoplasms / Q000188:drug therapy; D004938:Esophageal Neoplasms / Q000188:drug therapy; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy*; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy; D010778:Photochemotherapy