Ultimate performance of microwave tissue ablation

Microwave ablation is a therapeutic procedure to eliminate abnormal tissue within a body selectively. There are two types of ablation; thermal ablation aims to raise the temperature at the target, while nonthermal ablation induces a temporarily high electric field at the target to disrupt cellular membrane integrity. This work identifies the fundamental bounds of the efficiency for each type of ablation and the sources to achieve them. For both types, the bounds exceed the performance of existing solutions tenfold, showing large room for improvement. Finally, the optimal source for thermal ablation is physically realized with an $11\times 11$ dipole array, the performance of which closely approaches the bound.