A Radiomics-Based Biomarker for Cytokeratin 19 Status of Hepatocellular Carcinoma with Gadoxetic Acid-Enhanced MRI

Abstract

Background: We aimed to develop and validate a radiomics-based model derived from gadoxetic acid-enhanced MR images to preoperatively identify cytokeratin (CK) 19 status of hepatocellular carcinoma (HCC). Methods: A cohort of 227 patients with single HCC was classified into a training set (n=159) and a time-independent validated set (n=68). A total of 647 radiomic features were extracted from multi-sequence MR images separately. The least absolute shrinkage and selection operator regression and decision tree methods were utilized for feature selection and radiomics signature construction. A further multivariable-based model was built for predicting CK19 status of HCC. Findings: By combining 11 and 6 radiomics features extracted in arterial phase and hepatobiliary phase images, respectively, a fusion radiomics signature achieved a satisfying performance for CK19 stratification. The final combined model integrated serum a-fetoprotein levels, arterial rim enhancement pattern, irregular tumor margin and the fusion radiomics signature, with a sensitivity of 0.818 and specificity of 0.974 in the training cohort and that of 0.769 and 0.818 in the validated cohort. The nomogram based on the combined model showed satisfactory prediction performance in training (C-index: 0.959) and validation (C-index: 0.846) dataset. Interpretations: The combined model based on a fusion radiomics signature derived from arterial phase and hepatobiliary phase images of gadoxetic acid-enhanced MRI can be a reliable biomarker for identifying CK19 status of HCC. Funding: This paper is supported by National Natural Science Foundation of China; Ministry of Science and Technology of China; Chinese Academy of Sciences; the Strategic Priority Research Program of Chinese Academy of Science; the Shanghai Sailing Program. Declaration of Interest: All authors declare no potential conflict of interest. Ethical Approval: The retrospective study was approved by our Institutional Review Board (approval number B2018-236) and the requirement for informed consent was waived.