Abstract: A minimally-invasive fluid-cooled insertion sleeve assembly, with an attached balloon and distally-located penetrating tip, into which sleeve any of a group comprising a rigid rod, a microwave-radiator assembly and an ultrasonic-imaging transducer assembly may be inserted, constitutes a probe of the system. The sleeve assembly comprises spaced inner and outer plastic tubes with two fluid channels situated within the coaxial lumen between the inner and outer tubes. The fluid coolant input flows through the fluid channels into the balloon, thereby inflating the balloon, and then exits through that coaxial lumen. An alternative embodiment has no balloon. The method employs the probe for piercing sub-cutaneous tissue and then ablating deep-seated tumor tissue with microwave-radiation generated heat.

Abstract: In a first embodiment, the antenna cooperatively situated with respect to an external surface of the balloon of a balloon catheter has a spiral configuration, which renders this external antenna highly directional. This first embodiment of balloon catheter is shown inserted in the urethra of a patient in a system for irradiating his prostatic tumor and measuring the tumor's temperature with a radiometer. In a second embodiment, the antenna cooperatively situated with respect to an external surface of the balloon of a balloon catheter has a helical configuration, which renders this external antenna omnidirectional.