An interstitial ultrasound thermal ablation applicator for conformal treatment of an inhomogeneous tumor lesion includes: a body having a longitudinal axis； and a plurality of array transducers mounted on the body, arranged side by side and having azimuth directions parallel to the longitudinal axis of the body, and having outer faces disposed in a polygonal arrangement； the plurality of array transducers having predetermined elevation dimensions defined for directing emitted ultrasonic energy to obtain a conformal volume treatment of the tumor lesions. An electronic driving method for driving an applicator having multiple independent transducer elements arranged in rows and columns includes: controlling focal parameters of each row and column of transducer elements； and controlling a contribution of each row and column of transducer elements in a manner to provide a conformal ablated volume.
