Biliary tree malignancies.

Radiation therapy is used as definitive treatment for unresectable bile duct tumors, or as adjuvant therapy after resection. External beam irradiation of 45-50 Gy is generally given whenever feasible. Intraluminal brachy-therapy is a useful technique to deliver higher doses of radiation to the tumor while respecting the tolerance of the surrounding normal tissues. Brachytherapy can be given at a high dose rate or low dose rate via an in-dwelling biliary drainage catheter to boost external beam doses. Brachytherapy alone is reserved for palliative therapy. Techniques should be implemented with care to make them not only effective but safe. The long-term efficacy and morbidity of this mode of radiation should be studied further. Only large prospective trials can lead to resolution of some of the questions yet unsolved in treatment of these challenging malignancies.