Intracavitary irradiation treatment via the inferior vena cava for caudate lobe invasion in hepatic hilar bile duct cancer.

Cancer invasion to the caudate lobe of the liver is considered an important prognostic factor in hepatic hilar bile duct cancer, and caudate lobectomy is required in cases with massive invasion. In many cases, however, the invasion is difficult to confirm even at intraoperative examination. As the caudate lobe is close to the inferior vena cava, it can be irradiated by a source in the inferior vena cava. In this paper, intracavitary irradiation of the caudate lobe via the inferior vena cava is proposed instead of resection for possible, but not confirmed, invasion. In experiments on dogs, intracavitary irradiation was performed by remote after-loading using 60Co at a dose of 20 and 300 Gy via the inferior vena cava. The radiation is so highly concentrated on the designated target that an anticancer effect can be expected. No noteworthy side effects were observed by functional and morphological studies after 20 Gy irradiation. This treatment has been applied clinically, with favorable results. This treatment modality is a non-surgical caudate lobectomy aimed at avoiding useless, and potentially hazardous, resection.