A microwave spacer for guiding and positioning microwave energy delivery devices during a surgical procedure includes a spacer including a body forming a plurality of device apertures defined therein. The plurality of device apertures includes at least two lumens and at least one arcuate slot. The lumens are configured to receive an energy delivery device therethrough. The arcuate slot includes a length, a width and a radius of curvature and is configured to receive an additional energy delivery device therethrough.
