Division of Abdominal Imaging and Intervention, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, White 270, Boston, MA 02114, USA. firstname.lastname@example.org
To investigate the hypothesis that MRI derived diffusion-weighted imaging (DWI) and perfusion (MRP) parameters are sensitive image biomarkers for monitoring early antiangiogenic effects and predicting progression free survival (PFS) in advanced hepatocellular carcinoma (HCC).
In this phase II clinical trial, 23 of 34 patients were included in the imaging and circulating biomarker study. DWI and MRP were performed at the baseline and at 2-weeks after initiation of sunitinib. The imaging protocol included an axial DWI sequence using b values of 50, 400 and 800 sec/mm2, and MRP using a series of coronal 3D-VIBE following 20 ml of Gd-DTPA at 2 ml/sec. These parameters were compared with clinical outcome and PFS at 6-months. Correlation between changes in MRI parameters and plasma biomarkers was also evaluated.
After 2-week of sunitinib, substantial Ktrans changes in HCC were observed from median baseline value 2.15 min⁻¹ to 0.94 min⁻¹ (P = 0.0001) with increases in median apparent diffusion coefficient (ADC) from 0.88 × 10⁻³ mm²/s to 0.98 × 10⁻³ mm²/s (P = 0.0001). Tumor size remained unchanged by RECIST and mRECIST (both P > 0.05). Patients who showed larger drop in Ktrans and Kep at 2 weeks correlated with favorable clinical outcome, and higher baseline Ktrans and larger drop in EVF correlated with longer PFS (all P < 0.05). There was a significant association between a decrease in sVEGFR2 and the drop in Ktrans and Kep (P = 0.044, P = 0.030), and a significant and borderline association between decrease in TNF-α and the drop in Ktrans and Kep, respectively (P = 0.051, P = 0.035).
In HCC, MRP may be a more sensitive biomarker in predicting early response and PFS following sunitinib than RECIST and mRECIST.