Table 1 Inclusion criteria

Inclusion criteria

 • Liver metastases considered not suitable for surgery, because of being technically or medically inoperable or because of patient refusal;

 • Maximum tumor diameter less than 6 cm;

 • No more than 3 liver lesions;

 • Normal liver volume greater than 1000 cm3;

 • No evidence of progressive or untreated gross disease outside of the liver;

 • No prior radiation therapy to the targeted area;

 • Adequate liver function, defined as total bilirubin < 3 mg/dL, albumin > 2.5 g/dL, normal prothrombin time (PT)/partial thromboplastin time (PTT) unless on anticoagulants, and serum levels of aspartate aminotransferase (AST) and alanine amynotransferase (ALT) less than 3 times the upper limit of normal;

 • No concurrent chemotherapy allowed, either within 14 days before SBRT or until the first revaluation thereafter;

 • No active connective tissue disorders;

 • Karnofsky Performance Status 70;

 • Minimum age 18 years;

 • Written informed consent.