Advanced Hepatocellular Carcinoma: Early evaluation of response to targeted therapy and prognostic value of Perfusion CT and Dynamic Contrast Enhanced-Ultrasound. Preliminary results

Purpose: To investigate whether there is any correlation between standard endpoints and tumor perfusion measurements with Perfusion CT and Dynamic Contrast-Enhanced Ultrasonography (DCE-US) in patients with advanced Hepatocellular Carcinoma (HCC) treated with targeted therapy. Materials and methods: Nineteen patients were evaluated during targeted therapy (sorafenib n = 16, sunitinib n = 3). Changes in tumor perfusion measurements between baseline and month 1 were assessed and compared using RECIST progression criteria at month 2. Results: Median time to progression according to RECIST was 117 days and median time to death was 208 days. Perfusion CT values before treatment were significantly increased in HCC compared to the surrounding liver (n = 17, P <.02). Eleven patients received complete examinations with both techniques at baseline and month 1. A non-significant decrease was found in all Perfusion CT values between RECIST nonprogressors (n = 7) and progressors (n = 4): mean Blood Volume: -27.9 vs. -11.1% and mean Blood Flow: -25.0 vs. -11.7% respectively. With DCE-US, opposite changes were found (mean Area Under the Curve AUC: -38.3 vs. 436.3%). RECIST progression at month 2 was significantly correlated with a threshold 40% decrease in AUC (P =.015). None of the patients with a decrease in AUC ≥ 40% was a progressor at month 2. Conclusion: Despite perfusion changes with both Perfusion CT and DCE-US in patients receiving treatment, only DCE-US at month 1 (with a decrease in the AUC of more than 40%) predicted non-progression at month 2 and may be a potential surrogate marker of tumor response during targeted therapy.