The prediction of microvascular invasion of hepatocellular carcinoma using multiple imaging modalities

Abstract

To implement an adequate treatment strategy for solitary hepatocellular carcinoma (HCC), the prediction of microvascular invasion (MVI) is crucial. Metastatic recurrences after curative treatments can result from occult metastasis derived from invisible MVI. For predicting MVI, poorly differentiated or non-singular nodular HCC with a high risk of MVI should be evaluated by common imaging modalities such as ultrasound, contrast enhanced computed tomography (CECT), or magnetic resonance imaging (MRI). Summarizing these predictabilities in previous reports, the accuracies for predicting MVI were 78% in contrast enhanced ultrasonography (CEUS), 76%-89% in CECT, and 62%-77% in MRI. Those for predicting poor differentiation were 69%-92% in CEUS, 52%-90% in CECT, and 71%-75% in MRI. Those for predicting non-singular nodular type were 92%-95% in CEUS, 81%-89% in MRI, and 91%-93% in the combination of MRI and CECT. Among common imaging modalities, MRI can provide tissue characterization of the HCC using signal intensity. Gadolinium-ethoxybenzyl diethylenetriamine penta-acetic acid-enhanced MRI including diffusion imaging is the most informative imaging modality to predict MVI. Combination of MRI with other imaging modalities or tumor markers may provide a more accurate predicting for MVI. HCC with a high risk of MVI should be treated as advanced HCC even after curative treatment.

Feeding artery ablation before radiofrequency ablation for hepatocellular carcinoma may reduce critical recurrence

“…The reduction in risk of critical recurrence by the prior feeding artery ablation method may be due to decreased metastasis or dissemination due to RFA by avoiding excessive intratumor pressure by blocking tumor blood flow before tumor ablation. Based on the above, this method should be applied to poorly differentiated HCC with microvascular invasion regardless of tumor diameter, such as HCC with high levels of tumor markers or irregular tumor margins 23 . To validate our results, whether this method can reduce the risk of critical recurrence after RFA for HCC with high‐grade malignancy should be investigated.…”

“…Based on the above, this method should be applied to poorly differentiated HCC with microvascular invasion regardless of tumor diameter, such as HCC with high levels of tumor markers or irregular tumor margins. 23 To validate our results, whether this method can reduce the risk of critical recurrence after RFA for HCC with high-grade malignancy should be investigated.…”

Risk Score Model for Microvascular Invasion in Hepatocellular Carcinoma: The Role of Tumor Burden and Alpha-Fetoprotein

“…AFP level, histological grade, and the presence of multiple tumors have also been found to be common predictors for MVI [12,25]. Using ultrasound CT, MRI, and PET, multiple image features, including irregular tumor margin, incomplete capsule, typical dynamical pattern, low apparent diffusion coefficient (ADC) values and peri-tumor hypo-intensity in MRI, and a high tumor/liver activity ratio (RSUVmax) in PET, have been found to correlate with MVI [26,27]. Liver imaging reporting and data system (LI-RADS) 5 subclass in LI-RADS classification was found to associated with a higher frequency of microvascular invasion [28].…”