MWA is a technique with properties that challenge RFA. MWA has the potential to create larger zones of active heating due to an improved convection profile. It has a broader field of power density up to 2 cm surrounding a single probe, with a corresponding larger zone of active heating. The active zone leads to more uniform tumor ablation and subsequent tumor kill both within the targeted zone and next to the blood vessels. While RFA is limited by an increase in impedance with tissue boiling and charring because water vapor and char act as electrical insulators, MWA is not subject to this limitation.