Trial Information

Phase I Study of Saline Linked Monopolar Surface Radiofrequency (RF) Ablation of Hepatic Tumors

Treatment Plan: Patients with resectable hepatic metastases confined to the liver and who
are referred to the Study Chairs will undergo routine work-up for hepatic resection.

Operative Procedure:

Stage I will be completed and the data analyzed before Stage II commences. Stage I data
will be used to define the safe levels for use in Stage II.

Stage I—Depth of coagulation with and without inflow occlusion at fixed times - and powers
below the popping threshold.

At surgery, in the absence of extrahepatic disease, the liver will be dissected in the usual
fashion for a bi-segmentectomy, hemihepatectomy or larger liver resection. Prior to
transection of the liver, saline linked RF ablations will be performed on normal liver
tissue within the area of resection away from the tumor and the proposed line of
transection.

1 cm and 2 cm diameters will be studied together in 8 patients. They will be treated for a
total of 18 minutes (9 min for 1 cm and 9 min for 2 cm with 9 minutes of inflow occlusion.
The 4 cm lesions will be studied in 8 other patients, 4 of whom will receive 9 minutes of
inflow occlusion.

After resection of the liver and establishment of resection margins on the tumor, the
ablated areas of normal liver tissue will be excised frozen and studied for depth of lesion
and examined by H & E and histological techniques using vital stains that will allow
definition of tissue depth.

Stage II—An ablate and resect Study

Once parameters have been defined on normal liver, the effect of surface RF ablation on
resectable hepatic tumors which come to the surface of the liver will be examined. In this
portion of the study, tumors will be treated with saline linked RF ablation with a power and
a duration of application which has been found to produce the maximum safe depth of
coagulation. The surface area of coagulation will be dependent upon the size of the tumor.
The area of treatment will encompass the tumor as well as a zone at least 0.5cm outside the
edge of the tumor. Inflow occlusion will be used in one half of the patients.

After resection of the liver and establishment of resection margins on the tumor, the
ablated areas will be excised frozen and studied for depth of lesion and examined by H & E
and histological techniques using vital stains that will allow definition of tissue depth.
Twelve tumors will be treated in 12 patients.

Pathology Evaluation

First Group of Patients The normal tissue exposed to RF will be resected, prepared for
histo-pathological studies and examined to determine the extent of tissue necrosis and
popping, if any.

Second Group of Patients Tumors exposed to RF ablation will be resected and the extent of
tissue necrosis and popping will be determined. Also, damage to normal tissue will be
examined.