Introduction
For the purposes of cryoablation planning, hepatic malignancies can be divided into primary hepatic neoplasms and metastatic disease. While the performance of the cryoablation procedure is similar for both primary and metastatic lesions, patient selection and follow-up is very different. In both cases, proper patient selection and treatment ideally involves a multidisciplinary team with skills in systemic chemotherapy, embolization, internal radiation, surgery, ablation, transplantation, and supportive care, as appropriate, to optimize the patient's treatment.
Hepatocellular carcinoma (HCC) accounts for the majority of primary hepatic malignancies, and also the corresponding bulk of ablations for primary liver masses. The incidence of hepatocellular carcinoma has been steadily rising due to the increase in hepatitis B and C, and the affected patient population is becoming younger. In the setting of chronic viral hepatitis and subsequent cirrhosis, there is a strong “field effect” on susceptible liver tissue that places the patient at risk for developing hepatocellular carcinoma as well as synchronous and metachronous sites of disease.
Colon cancer is the most common metastatic liver lesion. Because of the pattern of portal blood flow, the liver is often the initial and sometimes the only site of metastasis. While other primary cancers such as melanoma, carcinoid, renal cell carcinoma, and pancreatic neoplasms metastasize to the liver, these tumors are highly associated with systemic spread, making locoregional therapies less effective.