Trial Information

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.