Quantitative evaluation of CT-perfusion map as indicator of tumor response to transarterial chemoembolization and radiofrequency ablation in HCC patients

Purpose: To assess if radiofrequency ablation (RFA) and transarterial chemoembolization (TACE) may influence the evaluation of perfusion parameters obtained with CT-perfusion (CT-p) in HCC treated patients. Materials and methods: Thirty-three consecutive cirrhotic patients with biopsy-proven diagnosis of HCC lesions and candidates to TACE or RFA were included. The CT-p study of hepatic parenchyma and of treated lesions was performed about 1 month after treatment on 16 multidetector CT after injection of 50 mL of non ionic contrast agent (350 mg l/mL) at a flow rate of 6 mL/s acquiring 40 dynamic scans. A dedicated perfusion software which generated a quantitative map of arterial and portal perfusion by means of colour scale was employed. The following perfusion parameters were assessed before and after RFA or TACE treatment: hepatic perfusion (HP), arterial perfusion (AP), blood volume (BV), time to peak (TTP), hepatic perfusion index (HPI). Results: A complete treatment was obtained in 16 cases and incomplete treatment in the 17 remaining cases. The perfusion data of completely treated lesions were: HP 10.2 +/- 6.3; AP 10.4 +/- 7; BV 4.05 +/- 4.8; UP 38.9 +/- 4.2; HPI 9.9 +/- 9.2, whereas in partially treated lesions were: HP 43.2 +/- 15.1 mL/s/100 g; AP 38.7 +/- 8.8 mL/min; BV 20.7 +/- 9.5 mL/100 mg; TTP 24 +/- 3.7s; HPI 61.7 +/- 7.5%. In adjacent cirrhotic parenchyma, the parameters of all evaluated patients were: HP 13.2 +/- 4; AP 12.3 +/- 3.4; BV 11.8 +/- 2.8; TTP 43.9 +/- 2.9; and HPI 17.1 +/- 9.8. A significant difference (P < 0.001) was found for all parameters between residual viable tumor tissue (P < 0.001) compared to successfully treated lesion due to the presence of residual arterial vascular structure in viable portion of treated HCC. Conclusion: According to our results, CT-p evaluation is not influenced by TACE or RFA treatments, thus representing a feasible technique that allows a reproducible quantitative evaluation of treatment response in HCC patients. (C) 2014 Elsevier Ireland Ltd. All rights reserved.