Differences in temperature distribution along the symmetry axis for tumour models of variable size. Tumour models with varying length and thickness are compared to the only fat case 2. Only temperature dependent conductivity was used. The electrode tip was located at Z = 0.09. The only spatial variable that had any significant effect on the temperature distribution was the tumour width W. Increased width enlarged the thermal lesion and pushed the maximum temperature further from the electrode. Interestingly, very thin tumours generated smaller thermal lesions (50° margin) than the original fat model.