Photodynamic Therapy for Hilar Bile Duct Cancer

Lee, Sang Hyub

Abstract

Hilar cholangiocarcinoma is a fatal malignancy leading to high mortality rate despite recent therapeutic advances, and the photodynamic therapy has been noted as an emerging palliative strategy for the hilar cholangiocarcinoma. Photodynamic therapy is the treatment selectively destructing cancer tissue through the laser beam irradiation with particular wavelengths. Photosensitizer administered before the treatment is accumulated in malignant tissue, and activated in the limits of those wavelengths. The procedure is performed under percutaneous transhepatic biliary drainage or endoscopic retrograde cholangiopancreatography, and more appropriate for the periductal infiltrating type rather than mass-forming type of cholangiocarcinoma due to the shallow penetrating depth (<4.5 mm). Recent investigations demonstrated the survival gain of 4-6 months in patients with cholangiocarcinoma when it is added to palliative biliary drainage. In addition, newly developed 3rd generation photo sensitizer has enabled longer therapeutic effect with less skin phototoxicity than before. However, there are still some limitations should be concerned, including lack of large-scaled prospective studies, shallow penetrating depth of tumoricidal effects, lack of treatment response measure, and relatively expensive cost. Addressing these matters through the larger prospective studies or technical improvement may lead new era of photodynamic therapy not only for the palliative purpose but also in the therapeutic field of cholangiocarcinoma.