Using thermosensitive chemotherapy agent to improve the effect of radiofrequency ablation for liver tumors：an animal experiment / 介入放射学杂志

ABSTRACT

Objective To investigate the pathologic mechanism of radiofrequency ablation ( RFA ) combined with intravenous infusion of thermosensitive liposome encapsulated vinorelbine (TL-Vin) in treating liver tumors, and to analyze the effect of combination therapy on the long-term survival rate. Methods H22 liver adenocarcinoma tissue was subcutaneously implanted into ICR mice to establish the animal models. At the first experimental period, 40 mice were randomly and equally divided into 5 groups to receive different therapeutic scheme (using different TL-Vin concentrations). Twenty-four hours after the treatment the tumor specimens were collected, the necrotic areas were measured separately, and the optimal TL-Vin concentration was determined. At the second experimental period, 13 mice were randomly selected to receive treatment. Half an hour after the treatment the tumor tissues were collected and the TL-Vin concentration within the tumor was determined. At the third experimental period, 32 mice were randomly and equally divided into 4 groups, and 90 days after treatment the tumor growth curve was drawn. The survival rate was compared between each other of the groups. Results Compared with pure RFA group, TL-Vin + RFA significantly increased tumor coagulation extent (P0.05). Tumor coagulation area in TL-Vin + RFA group was bigger than that in free-VIN + RFA group at the concentration of 10 mg/kg [(341.8 ± 65.4)mm2 vs (225.3 ± 25.4)mm2, P < 0.01]. In TL-Vin group the coagulation margin was clear. The mean intratumoral Vinorelbine accumulation in TL-Vin + RFA group was 10 folds of that in free-Vin group [(1 156.5 ± 158.3)ng/ml vs (194.5 ± 52.3)ng/ml, P = 0.005]. TL-Vin +RFA had better survival result than that of RFA alone (37.6 ± 20.1 days vs. 23.4 ± 5.0 days, P=0.015), as well as than that of free-Vin + RFA [(37.6 ± 20.1)days vs (23.3 ± 1.2)days, P = 0.016]. Conclusion Thermosensitive liposomal chemotherapies (Vinorelbine) can be selectively delivered at the edge of RFA coagulation area and thus effectively increase RFA-induced tumor coagulation and prolong the end-point survival in experimental mice.