IMAGE-GUIDED
CRYOABLATION
LIVER METASTASIS
Patient Criteria for
Cryoablation of Liver Metastases
The goal of percutaneous cryoablation in the liver is the destruction of targeted tumor cells for local cure or palliation of focal disease in light of contraindications to surgery or failures with other therapies (such as systemic chemotherapy). The decisions required to determine the optimal treatment plan for any given patient are complex. A complete medical evaluation as well as detailed anatomic imaging and liver function studies should be carefully considered by a multi-disciplinary team before treatment options are discussed with the patient.
Definitive patient selection criteria for cryoablation of liver tumors have not been established. Currently, most patients who undergo liver cryoablation are those with secondary liver cancer whose disease is considered medically or technically inoperable or who do not desire surgery.
For patients with cancer that has metastasized to the liver, surgical resection remains the treatment of choice. However, metastases are generally considered inoperable if there are more than four lesions, both the right and left lobes of the liver are involved, or if a 1cm margin of clearance cannot be achieved because the tumor is located too close to vital structures. The presence of extrahepatic malignancy is also considered a contraindication in most cases, but these patients may still see some benefit from palliative cryotherapy.
Percutaneous cryoablation is generally limited to patients whose lesions are 5cm or smaller, and no more than four lesions are usually treated per session. The location of the tumor(s) is significant, as it is important that a margin of at least 1cm is obtained as prognosis is worse in the case of a smaller margin. Most studies have included patients with primary liver tumors or secondary liver involvement from colorectal carcinoma; however, cryoablation may be an option for patients with metastatic disease from less common primary sites such as neuroendocrine, small intestine and ovarian tumors.
Literature suggests that patients should be free of active infection, be hemodynamically stable, and that coagulation factors be corrected prior to intervention. |
