A radiation detector disposed on a microwave antenna assembly to receive unintended field exposure in an insufflated abdomen. The radiation detector includes a receiving antenna made up of at least two pieces of metal externally attached to the microwave antenna within the abdomen. The radiation detector is adapted to receive errant microwave energy that resonates in the abdomen. A rectifier is coupled between the two pieces of metal, where the pieces of metal are strips, rings, patches, or other geometric combinations. The rectifier is adapted to rectify at least a portion of the errant microwave energy. A filter is coupled to the rectifier and is adapted to convert the rectified microwave energy into a detection signal. An inflatable stop is located on a distal end of the microwave antenna and the inflatable stop is inflated when inserted within the abdomen. The inflated stop prevents inadvertent removal of the microwave antenna.