OBJECTIVETo investigate the feasibility and safety of ultrasound-guided transrectal microwave ablation in reducing the prostate volume.

METHODSUltrasound-guided transrectal microwave ablation of both sides of the prostate was conducted on experimental dogs with the output volume of 30W for 120 seconds. The dogs were sacrificed on the very day of the ablation, and the prostate and its surrounding tissues were excised for observation of the thermal lesions and pathological examination.

RESULTSA total of 12 thermal lesions were achieved on the two sides of the prostate. The ultrasonogram manifested dense echo and increasing extent in the ablated area, and then an irregular heterogeneous echogenic area and clearly differentiated margin. Pathological examination of the gross specimen showed a little stagnant blood under the rectal mucous, the urethra and bladder not injured, and the thermal lesions elliptical, clearly margined and with the mean size of (0.94 +/- 0.30) cm3.

CONCLUSIONUltrasound-guided transrectal microwave ablation of the prostate can effectively cause coagulative necrosis of the local tissue without inflicting thermal injury upon the surrounding tissues. Conventional grayscale ultrasound can give a real-time'display of the extent of thermal lesion and the whole process of the ablation.