EXTRACORPOREAL LIVER ABLATION USING SONOGRAPHY-GUIDED HIGH-INTENSITY FOCUSED ULTRASOUND

RATIONALE AND OBJECTIVES. High-intensity focused ultrasound (HIFU) is the only radiation beam that can remotely destroy deep-seated tissue targets without causing damage to the intervening tissues. This study evaluates the ability of sonography-guided HIFU to extracorporeally induce liver ablation in a rabbit model. METHODS. Under sonographic guidance, the HIFU beam was transcutaneously focused at the target tissue in the liver through a subcostal approach. A computer controlled the HIFU exposure and transducer movement to destroy a preselected tissue volume. Simultaneous sonography monitored the tissue response. Ten insonated rabbits were killed from days 0 to 10, and the liver and intervening tissues were examined histologically. RESULTS. A sharply demarcated sonolesion of coagulation necrosis was produced in the liver in 9 of 10 animals. No damage was found in the intervening tissues (n = 6) when adequate acoustic coupling and proper beam path was applied. CONCLUSION. Sonography-guided HIFU might be a potential new modality for extracorporeal inducement of liver cancer ablation without resorting to laparatomy.