Contrast-enhanced ultrasound for guidance of local tumor ablation

The objective was to assess the efficacy of sonography with and without con trast medium enhancement in guiding and monitoring percutaneous ethanol abl ation of tumors in an animal model. VX-2 carcinoma was implanted into the t highs of New Zealand white rabbits and examined by grey-scale ultrasound, c olor, power, and pulse Doppler, before and after injection of 95% ethanol i nto the tumors. Injections of ethanol were guided by ultrasound to sites of tumor vascularity, until all tumor vascularity had been obliterated. Micro bubble contrast medium or saline was injected IV prior to each of the ultra sonic interrogations. Arteriography was performed before and after ablation , Selected tumor samples were submitted for histologic examination. Contras t enhanced tumor vascularity over saline controls in all cases. In some, in completely ablated foci of tumor could only be identified with contrast med ium enhancement. Arteriography showed complete ablation of all but 1 tumor, We conclude that ultrasound enhanced by contrast better shows the presence or absence of tumor vascularity. Ultrasound enhanced by contrast might off er an accurate means of guiding and monitoring percutaneous ethanol injecti on for tumor ablation, (C) 1999 World Federation for Ultrasound in Medicine & Biology.