Anatomically, cholangiocarcinomas may be more difficult to treat with stereotactic radiotherapy/radiosurgery than other liver lesions, due to their frequent close proximity to the duodenum. Even with a very focal radiation approach such as CyberKnife® radiosurgery, immediate approximation of the duodenal wall against the tumor volume predicts an increased risk of duodenal ulceration following treatment, warranting extreme caution in managing these lesions with focal ablative radiation approaches.

A sensible approach to an unresectable cholangiocarcinoma would be to perform laparotomy or laparoscopy to mobilize the duodenum and other sensitive GI tissues, packing them as far away for the tumor bed as possible, and implanting CyberKnife® fiducial markers for radiosurgery beam guidance during the same procedure. It would then be safer to proceed with CyberKnife® radiosurgery to the gross cholangiocarcinoma lesion, plus or minus conventional radiotherapy with 5-fluorouracil to treat potential spread of disease to regional lymph nodes.