Managing liver metastases with conformal radiation therapy

A subgroup of liver metastases, especially those emanating from colorectal carcinoma, may be cured. Surgical excision is accepted as the mainstay of treatment for these malignancies; unfortunately, however, the majority of patients presents with advanced unresectable hepatic involvement and have no standard treatment option available. Radiation therapy (RT) has not played a significant role in managing liver metastases, because the liver has little tolerance to radiation. In patients with good hepatic function, however, very-high-dose RT may be used safely and effectively if a small volume of the liver (< 25%) is irradiated. In particular, RT, and especially three-dimensional conformal RT (3D-CRT), may be used to manage medically unfit patients or those with an unresectable metastatic liver lesion. This review discusses existing literature on use of various types of RT, including whole-liver irradiation, partial hepatic irradiation with 3D-CRT, and hypofractionated high-dose irradiation with stereotactic body RT, and future directions for this treatment modality.