Radiomics on Gadoxetic Acid-Enhanced Magnetic Resonance Imaging for Prediction of Postoperative Early and Late Recurrence of Single Hepatocellular Carcinoma

Purpose: To evaluate the usefulness of the radiomic model in predicting early (<= 2 years) and late (> 2 years) recurrence after curative resection in cases involving a single hepatocellular carcinoma (HCC) 2-5 cm in diameter using preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI), in comparison with the clinicopathologic model. Experimental Design: This retrospective study included 167 patients with surgically resected and pathologically confirmed single HCC 2-5 cm in diameter (n = 167, training set: validation set = 128: 39) who underwent preoperative gadoxetic acid-enhanced MRI between January 2010 and December 2015. A radiomic model, a clinicopathologic model, and a combined clinicopatho-logic-radiomic (CCR) model were built using a random survival forest to predict disease-free survival (DFS) in the following conditions: early DFS versus late DFS, dynamic phases, and the peritumoral area included in the segmentation. Results: The radiomic model showed a prognostic performance comparable with the clinicopathologic model only with 3-mm peritumoral border extension [c-index difference (radiomic-clinicopathologic), -0.021, P = 0.758]. The CCR model with the 3-mm border extension showed the highest c-index value but no statistically significant improvement over the clinicopathologic model [CCR, 0.716 (0.627-0.799); clinicopathologic model, 0.696 (0.557-0.799)]. Conclusions: The prognostic value of the preoperative radiomic model with 3-mm border extension showed comparable performance with that of the postoperative clinicopathologic model for predicting DFS of early recurrence of HCC using gadoxetic acid-enhanced MRI. This suggests the importance of including peritumoral changes in the radiomic analysis of HCC.