An interstitial ultrasound thermal ablation applicator for conformal treatment of inhomogeneous tumor lesions includes: a body having a longitudinal axis, the body defining a hollow central channel along the longitudinal axis； and a plurality of CMUT array transducers mounted on the body, arranged side by side to form a cylindrical shape, having azimuth plans parallel to a longitudinal axis of the body, each of the plurality of CMUT array transducers having elevation dimensions predetermined to steer emitted ultrasonic waves 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.
