A device is for thermal treatment of tissue. The device includes (a) an elongated member extending from a proximal end to a distal end insertable to a target position within a body; (b) a housing coupled to the distal end of the elongated member sized and shaped for insertion to a target organ within a living body, the housing including an opening permitting fluid surrounding the housing to enter the housing, the housing further including first and second deflecting elements shaped to diffuse pulses of fluid directed thereagainst; and © a piezoelectric element mounted within the housing between the first and second deflecting elements. The piezoelectric element is oriented to generate pulses in liquid received within the housing toward the first and second deflecting elements.