Phase II Trial of Cryoablation for Treatment of Unresectable Colorectal Hepatic Metastases

OBJECTIVES: I. Evaluate the feasibility of conducting a multi-institutional clinical study of cryosurgery for liver metastases. II. Evaluate the morbidity and mortality of cryosurgery for liver metastases when applied in a multi-institutional setting. III. Evaluate the efficacy of cryosurgery for liver metastases as measured by total liver control, local lesion control, and overall survival.

OUTLINE: This is a multi-institutional study. Patients are first confirmed by exploratory laparotomy to have no extrahepatic metastases. They then undergo biopsy of the portal lymph node, after which, full mobilization of liver is recommended. Cholecystectomy is optional but recommended for treatment of tumors adjacent to the gallbladder. After mapping out the location and size of the metastatic tumor by ultrasound, cryoablation of the metastases is carried out. Cryoablation involves the delivery of nitrogen through metallic probes placed surgically into the center of the liver metastases. There are two freeze and thaw cycles for each lesion with synchronous intraoperative ultrasound monitoring of the cryoablation. One centimeter margin of cryoablation is determined by this ultrasound image. Treatment of the liver with regional chemotherapy is not allowed until radiographic and pathologic confirmation of disease progression in the liver. Follow-up is at 3 weeks after surgery and then every 3 months.

PROJECTED ACCRUAL: There will be a maximum of 45 patients accrued in approximately 3 years for this study. This is a two stage accrual design in which 17 patients are first accrued of which 15 should be eligible. If fewer than 11 of the initial 15 eligible patients show no evidence of disease at 3 months, the study stops and treatment is abandoned. If at least 11 patients show no evidence of disease, then 28 additional patients are accrued.