Heated lipiodol as an embolization agent for transhepatic arterial embolization in VX2 rabbit liver cancer model

Abstract

Purpose: To evaluate the therapeutic effect of heated (60 degrees C) lipiodol via hepatic artery administration in a rabbit model of VX2 liver cancer.

Materials and methods: Thirty male New Zealand white rabbits were randomly divided into three groups with 10 rabbits assigned to each group. VX2 carcinoma cells were surgically implanted into the left hepatic lobe. The tumors were allowed to grow for 2 weeks, and studies were performed until the diameter of the tumors detected by ultrasonograph reached 2-3cm. Under anesthesia, trans-catheter hepatic arterial embolization was performed and doxorubicin-lipiodol (37 degrees C) (1mL), lipiodol (60 degrees C) (1mL) or control (physiological saline (37 degrees C) (1mL)) solution was injected into the hepatic arteries of animals in the three groups. One week later, the volume of the tumor was measured by ultrasonograph again. The serum of all rabbits was collected before injection and at 4 and 7 days after injection, and the level of aspartate aminotransferase (AST) was checked. The survival period of the three groups of rabbits after treatment was also recorded. During the last course of their disease, the rabbits were given analgesics to relieve suffering.

Results: The tumor growth rate in the lipiodol (60 degrees C) group (0.92+/-0.21, tumor volume from 1811+/-435 to 1670+/-564mm(3)) was significantly lower than that in the control group (3.48+/-1.17, tumor volume from 1808+/-756 to 5747+/-1341mm(3)) (P<0.05) and in the doxorubicin-lipiodol (37 degrees C) group (1.69+/-0.26, tumor volume from 1881+/-641 to 2428+/-752mm(3)) (P<0.05). Consequently, the survival period of the animals in the lipiodol (60 degrees C) group (41.0+/-3.0 days) was significantly greater than that in the doxorubicin-lipiodol (37 degrees C) group (38.0+/-2.5 days) (P<0.05). On the other hand, there was no statistically significant difference in serum AST levels between the lipiodol (60 degrees C) group (148.2+/-11.3UL(-1)) and the doxorubicin-lipiodol (37 degrees C) group (139.7+/-12.3UL(-1)) (P>0.05). However, the serum AST level in the lipiodol (60 degrees C) group was significantly higher at 4 days after injection (P<0.05) than in the control group (68.6+/-6.6UL(-1)).

Conclusions: Treatment with lipiodol (60 degrees C) resulted in an effect on serum AST levels similar to that caused by treatment with doxorubicin-lipiodol (37 degrees C). Thus, lipiodol (60 degrees C) treatment could greatly prolong the survival period of rabbits with VX2 cancer by inhibiting tumor growth.