A system for use with a microwave antenna includes a microwave antenna configured to deliver microwave energy from a power source to tissue and a sensor module in operative communication with the power source and configured to detect a reflectance parameter. The system further includes a jacket adapted to at least partially surround the microwave antenna to define a fluid channel between the jacket and the microwave antenna. A plurality of fluid distribution ports are defined through the jacket and are in fluid communication with the fluid channel to permit the flow of fluid through the jacket. The system further includes a fluid pumping system operably coupled to the power source and configured to selectively provide cooling fluid to the fluid channel for distribution through the fluid distribution ports based on the reflectance parameter.