RESUMO
BACKGROUND: The purpose of this study was to assess the value of functional MRI (fMRI) of post-doxorubicin drug-eluting beads transcatheter arterial chemoembolization (DEB-TACE) for hepatocellular carcinoma (HCC) as an early imaging biomarker of response to therapy. METHODS: This prospective analysis included 21 consecutive patients undergoing fMRI before and after DEB-TACE at a single medical center from January 2013 to December 2014. Functional MRI, including relative changes in apparent diffusion coefficient (ADC) and choline levels measured at hydrogen-1 magnetic resonance spectroscopy (MRS) of treated lesions, was recorded at baseline before DEB-TACE, and at 1, 2, and 4 weeks after DEB-TACE therapy. Assessment of tumor response was based on dynamic contrast-enhanced computer tomography imaging response according to modified response evaluation criteria in solid tumors. RESULTS: At post-therapy, 76% (n = 16) of patients demonstrated objective tumor response, 10% (n = 2) had stable disease, and 3 (14%) had progressive disease. Stable disease and progressive disease were designated as non-response. At week 2, the mean change in ADC value of responsive tumors was 0.35 ± 0.24 mm2/s, which was greater than that of non-response tumors (mean 0.01 ± 0.13 × 10-3 mm2/s) (P = 0.006). Significant differences were found in mean choline/water ratio between responsive (7.8 ± 4.9 × 10-3) and non-responsive (17.2 ± 4.9 × 10-3) tumors (P = 0.005). Composite scores of choline/water ratio and relative change of ADC showed significantly better diagnostic accuracy in non-responsive tumors than responsive tumors (area under the curve = 1.0; P < 0.001). CONCLUSIONS: Combined DWI and MRS may be used as an early imaging biomarker of therapy response in HCC patients after chemoembolization therapy.