Hepatocellular carcinoma enhancement on contrast-enhanced CT and MR imaging: response assessment after treatment with sorafenib: preliminary results.

PURPOSE: This study was undertaken to compare response evaluation criteria in solid tumours (RECIST) 1.1 and modified RECIST (mRECIST) in patients with unresectable hepatocellular carcinoma (HCC) on sorafenib, and to describe HCC enhancement changes before and after sorafenib treatment. METHODS AND MATERIALS: Seventeen patients (12 men, 5 women; mean age 69 years; age range 58-79 years) were included. Tumour response was assessed according to RECIST and mRECIST. Two readers placed a region of interest (ROI) within each target lesion, on the portion showing enhancement during the arterial phase. The lesion attenuation values measured within the ROIs on computed tomography or the signal intensity measured on magnetic resonance imaging, during the unenhanced phase, hepatic arterial phase and venous phase were recorded. Changes in arterial and venous contrast enhancement before and after treatment were compared among the mRECIST groups using Mann-Whitney U test. RESULTS: Agreement between mRECIST and RECIST was good (Cohen's k coefficient, 0.791). Patients with partial response had a greater decrease in arterial enhancement (-79.8%) than did patients with stable disease (SD) (-24.8%; p = 0.011) or progressive disease (PD) (-32.9%; p = 0.034). No statistically significant difference in arterial enhancement variation was found among patients with SD and PD. No statistically significant difference in venous enhancement was found among the mRECIST groups. CONCLUSIONS: mRECIST showed a more favourable response compared to RECIST 1.1 in patients with unresectable HCC receiving sorafenib.