Tissue Analysis After Tumor Ablation for Liver Metastases Leading to Immediate Retreatment

Inclusion Criteria: * Diagnosis of liver metastases from various primary tumors * Confined liver disease or limited extrahepatic disease stable/controlled for at least 4 months (extrahepatic disease amenable to treatment is allowed) * Lesions of ≤3 cm in maximum diameter * At least one FDG-avid lesion to be treated\*\*\* * INR \< 1.5\* * Platelet count ≥ 50,000 Exclusion Criteria: * Age \< 18 * Less than 5 mm distance to a structure (GI or biliary tract), that cannot be protected from ablation injury with technical modifications such as hydro or air dissection * INR \> 1.5 that cannot be corrected with fresh frozen plasma \*\* * Platelet count of \<50,000 that cannot be corrected with transfusion * More than 3 tumors in the liver * More than 5 tumors of extrahepatic disease (including mediastinal nodes and pulmonary nodules, abdominal or other lymph nodes, and bone metastasis) * Presence of any peritoneal Carcinomatosis * For patients on Coumadin, general clinical guidelines for IR ablation will be followed. * For patients with no FDG-PET avid tumors aim 2 of the protocol will not be assessed