Predictive factors of contrast-enhanced ultrasonography for the response to transarterial chemoembolization in hepatocellular carcinoma

Background/Aims: The predictive role of contrast-enhanced ultrasonography (CEUS) before performing transarterial chemoembolization (TACE) has not been determined. We assessed the possible predictive factors of CEUS for the response to TACE. Methods: Seventeen patients with 18 hepatocellular carcinoma (HCC) underwent TACE. All of the tumors were studied with CEUS before TACE using a second-generation ultrasound contrast agent (SonoVue (R), Bracco, Milan, Italy). The tumor response to TACE was classified with a score between 1 and 4 according to the remaining enhancing-tumor percentage based on modified response evaluation criteria in solid tumors (mRECIST): 1, enhancing tumor <25%; 2, 25%<= enhancing tumor<50%; 3, 50%<= enhancing tumor<75%; and 4, enhancing tumor >= 75%). A score of 1 was defined as a "good response" to TACE. The predictive factors for the response to TACE were evaluated during CEUS based on the maximum tumor diameter, initial arterial enhancing time, arterial enhancing duration, intensity of arterial enhancement, presence of a hypoenhanced pattern, and the feeding artery to the tumor. Results: The median tumor size was 3.1 cm. The distribution of tumor response scores after TACE in all tumors was as follows: 1, n=11; 2, n=4; 3, n=2; and 4, n=1. Fifteen tumors showed feeding arteries. The presence of a feeding artery and the tumor size (<= 5 cm) were the predictive factors for a good response (P=0.043 and P=0.047, respectively). Conclusions: The presence of a feeding artery and a tumor size of less than 5 cm were the predictive factors for a good response of HCC to TACE on CEUS.