 Our group has developed a novel, interstitial induction coil device that has been designed to coagulate large tumours 3cm through a single needle insertion using heat in the range 55-90 C. 31Our system consists of a helical coil that is loosely wound inside the tumour tissue or phantom and excited with radiofrequency energy at 27.12 MHz. The coil is constructed from Nitinol, a shape memory alloy, to permit percutaneous deployment of the device from a cannulating delivery needle into the tumor target. This novel monopolar device has the potential to treat larger tumours with larger ablation zones 6cm x 4cm with shorter treatment time, in both ex vivo and in vivo settings. In our previous pig studies our group has not seen a decrease in ablation volume compared to the ex vivo studies. The intent of this research proposal is to determine the safety and efficacy of the application of a unique interstitial coil electrode RF thermal therapy device for ablating large human renal and hepatic tumors under US or CT guidance. 