Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid (Gd-EOB-DTPA)-Enhanced Magnetic Resonance Imaging and Multidetector-Row Computed Tomography for the Diagnosis of Hepatocellular Carcinoma

The purpose of this meta-analysis was to compare the diagnostic accuracy of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and multidetector-row computed tomography (MDCT) for hepatocellular carcinoma (HCC). Medline, Cochrane, EMBASE, and Google Scholar databases were searched until July 4, 2014, using combinations of the following terms: gadoxetic acid disodium, Gd-EOB-DTPA, multidetector CT, contrastenhanced computed tomography, and magnetic resonance imaging. Inclusion criteria were as follows: confirmed diagnosis of primary HCC by histopathological examination of a biopsy specimen; comparative study of MRI using Gd-EOB-DTPA and MDCT for diagnosis of HCC; and studies that provided quantitative outcome data. The pooled sensitivity and specificity of the 2 methods were compared, and diagnostic accuracy was assessed with alternative-free response receiver-operating characteristic analysis. Nine studies were included in the meta-analysis, and a total of 1439 lesions were examined. The pooled sensitivity and specificity for 1.5T MRI were 0.95 and 0.96, respectively, for 3.0T MRI were 0.91 and 0.96, respectively, and for MDCT were 0.74 and 0.93, respectively. The pooled diagnostic odds ratio for 1.5T and 3.0T MRI was 242.96, respectively, and that of MDCT was 33.47. To summarize, Gd-EOBDTPA-enhanced MRI (1.5T and 3.0T) has better diagnostic accuracy for HCC than MDCT. (Medicine 94(32):e1157) d Han Ouyang, MD carcinoma, MDCT = multidetector-row computed tomography, MRI = magnetic resonance imaging, QUADAS = quality summary receiver-operating characteristic, TN = true negative, TP = true positive. INTRODUCTION H epatocellular carcinoma (HCC) is the fifth most common cancer, and the third most common cause of cancer deaths worldwide. Early detection and accurate assessment of HCC are therefore very important, as early stages of HCC are potentially curable, with diagnostic imaging playing a major role in the detection, characterization, staging, and treatment monitoring of patients with HCC or liver metastases. Computed tomography (CT) and magnetic resonance imaging (MRI) are both commonly used imaging modalities for diagnosis and evaluation of liver lesions. Compared with regular single-detector CT, multidetector-row computed tomography (MDCT) has advantages of providing greater speed, thinner slices, and multiphasic scanning, which improve spatial and temporal resolution, and provide a more precise evaluation of liver tumor’s hemodynamics thereby improving the overall diagnostic accuracy. On the contrary, dynamic MRI using a fast 3-dimensional T1-weighted gradient echoimaging sequence with a nonspecific contrast medium can also be highly sensitive in detecting hypervascular HCC. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA; gadoxetic acid disodium; Primovist, Bayer Schering Pharma, Berlin, Germany) is a liver-specific contract agent for MRI imaging. Approximately 50% of injected GD-EOB-DTPA is taken up by functioning hepatocytes and excreted in the bile, thus enabling hepatobiliary phase imaging to begin approximately 10 to 20 minutes after injection. Studies have shown that GD-EOB-DTPA MRI provides excellent diagnostic accuracy for both HCC and incidental lesions in the liver. Some even suggested that GD-EOB-DTPA-enhanced MRI may replace CT arterial portography (CTAP) and CT hepatic arteriography (CTHA). Although a number of studies have suggested that GDEOB-DTPA-enhanced MRI provides a better diagnostic performance than MDCT for HCC, there has been no in-depth meta-analysis performed to compare the 2 methods with respect to their diagnostic accuracies. Thus, the purpose of this study eta-analysis comparing the diagnostic -DTPA-enhanced MRI and MDCT for www.md-journal.com | 1 MATERIALS AND METHODS Ethic Statement Meta-analyses do not involve human subjects and do not require Institutional Review Board review (J Grad Med Educ. 2011 March; 3(1): 5–6.). Literature Search Strategy This systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. We have searched various databases including Medline, Cochrane, EMBASE, and Google Scholar until July 4, 2014, using the following terms or their combinations: gadoxetic acid disodium, Gd-EOB-DTPA, multidetector CT, contrast-enhanced computed tomography, and magnetic resonance imaging. The inclusion criteria of our study were as follows: confirmed diagnosis of primary HCC by histopathological examination of a biopsy or resected specimen; comparative study of MRI using Gd-EOB-DTPA as the contrast agent and MDCT for diagnosis of HCC; and studies that provided quantitative data for the outcomes. Non-English publications, letters, comments, editorials, case reports, proceedings, and personal communications were excluded. We also excluded studies that did not provide sufficient data for the outcomes to be analyzed. Reference lists of relevant studies or reviews were also manually searched for additional records that might qualify for inclusion. The quality assessment of diagnostic studies (QUADAS) tool was used by 2 independent reviewers to assess diagnostic accuracy and rate the quality of each study included in this meta-analysis. Data Extraction Studies were identified via the search strategy by 2 independent reviewers, and a third reviewer was consulted when disagreement arose. Data extracted from studies that met the inclusion criteria include name of the first author, year of publication, study design, number of patients in each imaging group and their age and sex, locations and stages of tumors, and the numbers of lesions that were true positive (TP), false positive (FP), true negative (TN), and false negative (FN) for each imaging modality. Outcome Measures and Data Analysis The primary outcomes were the sensitivity and specificity of GD-EOB-DTPA-enhanced MRI and MDCT for the diagnosis of primary HCC. The sensitivity and specificity with corresponding 95% confidence intervals (95% CIs) were calculated and presented by a forest plot. A x-based test of homogeneity was performed using Cochran Q test and I statistics. I statistic indicates the percentage of the total variability in the effect estimates among trials due to heterogeneity rather than chance. Random-effects models of analysis were used if heterogeneity was detected (Cochran Q test P< 0.1 or I> 50%), and the pooled sensitivity and specificity were derived using the DerSimonian–Laird method. Otherwise, fixed-effects models were used and the pooled sensitivity and specificity were derived using the Mantel–Haenszel method instead. Summary receiver-operating characteristic (SROC) curves for MRI and MDCT were constructed using the false-positive rate (FPR1⁄4 1-specificity) and true positive rate (TPR1⁄4 sensiYe et al sensitivity). The area under the SROC curve (AUC) with standard error (SE) was estimated for the diagnostic accuracy of each imaging method. An AUC that is >0.5 and closer to 1.0 2 | www.md-journal.com implies better accuracy. Moreover, a diagnostic odds ratio (DOR) and index Q value with SE were calculated for the discriminating ability of the imaging methods. A higher DOR value indicates better discriminatory performance for a diagnostic test. Both the DOR and the Q values were used to compare the diagnostic performance of MRI and MDCT based on the z-statistic test. In addition, the Moses model was used to examine the symmetry of data according to the coefficient b of the model, and the results were reported as either asymmetric or symmetric. A coefficient b1⁄4 0 would indicate the SROC curve’s being symmetric. All the statistical analyses were performed using MetaDiSc version 1.4 (Clinical Biostatistics Unit, Ramón y Cajal Hospital, Madrid, Spain).