Feasibility of nanoparticle of Fe2O3 combination with microwave for ablation of renal VX2 tumor / 中华放射学杂志

ABSTRACT

Objective To evaluate the application of embolic material, iron oxide nanoparticles?lipiodol?gelatin in the improvement of therapeutic effect of microwave ablation in vitrogelatin phantom model and in vivo VX2 renal tumors model. Methods After preparing new embolic material containing nano Fe2O3, in vitro model experiment was firstly conducted to verify the temperature distribution of the microwave ablation. Further verification was performed in bilateral renal VX2 tumors in rabbit model. A total of 10 (20 kidneys) New Zealand White rabbits bearing renal VX2 tumors were treated by renal artery embolization and CT guided microwave ablation, in which left kidneys were treated by material containing nano Fe2O3 in iodized oil and right kidneys were treated by renal embolization with super liquid iodized oil as a control. The same microwave ablation time and power were used for both kidneys. CT perfusion and histopathological examinations were performed to determine the renal perfusion parameters, tumor histopathology and tumor?related angiogenesis. Results In vitro experiments, when nano Fe2O3 was present in the local area at 1cm from the microwave needle at 20 and 60, the temperature reached(59.1 ± 1.7)° C, (95.5 ± 4.5)° C vs.(31.1 ± 2.5)and(45.6 ± 3.5)° C in the controls. Our present results strongly suggested that local nano Fe2O3 particles absorbed microwave and shielded microwave energy transferring to the surrounding tissue. Before and immediately after renal VX2 tumor embolization, blood flow significantly reduced from (31.4 ± 10.6) to (6.1 ± 9.9) ml · 100 ml-1 · min-1. Our pathology findings indicated nano Fe2O3?lipiodol-gelatin embolic agent stored in endovascular regions, while no penetration into the renal parenchyma happened. Conclusions This in vitro model and in vivo experiment suggest that the new embolic material containing nano Fe2O3 may help to improve heat efficiency of MWA microwave, and it is feasible to administer it through transcatheter arterial embolization approach for the microwave ablation therapy of kidney cancer.