An ablation system for directing energy to a target volume of tissue, comprising:an ablation antenna probe including at least one radiating portion configured to output electromagnetic radiation; andat least one electromagnetic shielding reflector configured for removable positioning on the antenna probe, wherein the at least one electromagnetic shielding reflector is configured to block electromagnetic radiation from the at least one radiating portion through the at least one electromagnetic shielding reflector such that a particular directionality of the electromagnetic radiation from the at least one radiating portion to a target volume of tissue is achieved.