The technical development described herein was undertaken to create a tumor ablation treatment system that consists of a software component and a robotic hardware component. First, the software treatment planning system enables applicator placement planning before tumor ablation. For example, it allows creation of overlapping ablations with the goal of treating larger tumors. Second, the robotic hardware system allows accurate applicator placement. The combined treatment system integrates treatment planning with treatment execution by taking the coordinates dictated by the planning system and feeding them to the robotic system for implementation. The feasibility of this system was tested in two patients with large hepatic metastases that required overlapping ablations.