To investigate the ability of contrast-enhanced ultrasound (CEUS) to predict transarterial chemoembolization (TACE) efficacy within 1 week of treating hepatocellular carcinoma (HCC).

We evaluated CEUS shortly after 38 TACE procedures that were performed on 29 patients (M:19, F:10). Multiple bolus injections of US contrast were given IV. Phase-inversion low MI real-time and intermittent phase-inversion imaging was performed with a Siemens Elegra using a curved 3.5 MHz transducer.

There were no adverse events. Real-time imaging at low MI allowed the detection of arterial blood flow in the viable portions of tumors while intermittent imaging allowed the detection of persistent tumor parenchymal blood flow. Pre TACE, CEUS and CT and/or MRI showed similar tumor enhancement in all cases (15/15). To date, 27 of 38 tumors have reached final outcome (histology, angiography, tumor growth, or CT/MR imaging more than 6 months after TACE). Of the 23 tumors that recurred, CEUS detected flow in all 23 tumors without any false negative cases. Of the four tumors that were completely treated without evidence of recurrence, CEUS detected no flow in 3 and detected subtle enhancement in 1 tumor one day after TACE that was not detected on an MRI performed 1 year later. CT performed in 18 patients post treatment that had follow-up resulted in 5 false negative and one false positive cases as subtle enhancement was difficult to detect due to tumor accumulation of radiopaque ethiodol. There were 8 MRIs performed post treatment with follow-up, MRI had no false negative or false positive in this small number of patients.

Residual tumor blood flow on CEUS performed within 1 week after TACE is predictive of tumor outcome that currently requires 3 months to be reliably detected by CT/MRI. CEUS can therefore be used to determine the need for additional treatment within 1 week after TACE.