Comparison of acoustic radiation force impulse elastography and transient elastography for prediction of hepatocellular carcinoma recurrence after radiofrequency ablation

Can Liver Ultrasound Elastography Predict the Risk of Hepatocellular Carcinoma Recurrence After Radiofrequency Ablation? A Systematic Review and Meta-Analysis

PURPOSE

The role of liver stiffness (LS) on ultrasound elastography in the prediction of hepatocellular carcinoma (HCC) recurrence after treatment with radiofrequency ablation (RFA) is still unclear. Our aim was to perform a systematic review and meta-analysis to assess whether LS can predict the recurrence of HCC after RFA.

MATERIALS AND METHODS

Medline via PubMed, Embase, Scopus, and Cochrane Library databases, and abstracts of international conference proceedings were searched up to June 30, 2020. Cohort studies were included if they assessed the association between LS values measured by ultrasound elastography before RFA and HCC recurrence.

RESULTS

9 studies including 1373 patients with HCC treated by RFA, 643 of whom developed HCC recurrence, were identified. The mean value of LS before RFA was significantly higher in patients who developed HCC recurrence than in those who did not (weighted mean difference=11.98 kPa, 95%CI: 7.60-16.35, I2=63.8%). There was a significant positive association between LS value and HCC recurrence both at univariate (unadjusted HR=1.03, 95%CI: 1.00-1.07, I2=72.7%) and multivariate analysis (adjusted HR=1.03, 95%CI: 1.02-1.04, I2=0). Patients with LS value ≥13-14 kPa or >1.5 m/s have a higher risk of both HCC recurrence (unadjusted HR=2.18, 95%CI: 1.46-3.25, I2=49.7%; adjusted HR=2.41, 95%CI: 1.53-3.79, I2=0) and overall mortality (adjusted HR=4.38; 95%CI: 2.33-8.25, I2=0) in comparison with those with LS below these cutoffs.

CONCLUSION

Liver ultrasound elastography appears to be a reliable tool to predict HCC recurrence and overall survival after RFA. This technique may be useful for the management of patients with HCC treated by RFA.

Prognostic value of liver stiffness measurement in patients with hepatocellular carcinoma (HCC) treated by radiofrequency ablation: a meta-analysis

BACKGROUND

In patients with stage 0-A (as per Milan criteria) hepatocellular carcinoma (HCC) image-guided ablation is less invasive and requires shorter hospitalization than resection, but long-term prognosis is poorer. This meta-analysis was conducted to investigate whether liver stiffness measurement (LSM) could be used to predict prognosis in HCC patients after tumor ablation.

METHODS

A literature search was conducted for all studies published till July 2020 in PubMed, Web of Science, Cochrane Library and EMBASE. Studies were included if they investigated the association between pretreatment LSM and prognosis in HCC patients treated with ablation. Subgroup analysis, meta-regression, publication bias assessment and sensitivity were conducted.

RESULTS

Eight studies (with a total of 1276 HCC patients) were included in this meta-analysis. All patients were treated with radiofrequency ablation. Pooled results showed that high pretreatment LSM were associated with poor overall survival (OS) (hazard ratio [HR] = 4.31, 95% confidence interval [CI]: 2.27-8.20, p < .001) and recurrence-free survival (RFS), regardless of whether LSM was considered as a categorical variable (HR = 2.63, 95% CI = 1.63-4.22, p < .001) or as a continuous variable (HR = 1.02, 95% CI = 1.01-1.04, p = .003). Among studies treating LSM value as a categorical variable, liver stiffness measured using acoustic radio force impulse (ARFI) or transient elastography (TE) was significantly associated with RFS, but not liver stiffness measured using two-dimensional shear wave elastography (SWE).

CONCLUSIONS

High baseline LSM value appears to be associated with poor prognosis in HCC patients treated with radiofrequency ablation.

Quantitative Ultrasound Elastography Methods in Focal Liver Lesions Including Hepatocellular Carcinoma: From Diagnosis to Prognosis

ABSTRACT

The ability of ultrasound elastography to diagnose focal liver lesions and determine their prognoses including hepatocellular carcinoma (HCC) is unclear. At present, radiofrequency ablation and liver resection are the most common treatments for HCC. However, the survival rate remains disappointing because of recurrences and postoperative liver failure, necessitating the development of noninvasive approaches. There is currently no systematic definition of an elastic technique for measuring liver stiffness to predict the recurrence of HCC after radiofrequency ablation and postoperative liver failure. In this review, recent advances in ultrasound elastography for the diagnosis and prognosis of focal liver lesions are discussed including HCC.

The role of liver and spleen elastography in advanced chronic liver disease

Portal hypertension is the main driver of complications in patients with advanced chronic liver disease (ACLD). In the last decade, many non-invasive tests, such us liver and spleen elastography, have been proposed and validated for the identification of patients with clinically significant portal hypertension (CSPH) and its complications, mainly hepatic decompensation and liver-related morbidity and mortality. Moreover, elastography accurately stratifies for the risk of HCC development, HCC recurrence and decompensation after liver surgery. Recent studies suggest a role of SSM in monitoring response to treatments and interventions in ACLD, such as viral eradication, non-selective beta-blockers and transjugular intrahepatic portosystemic shunt placement. However, one of the most indications to perform elastography in ACLD still remains the screening for esophageal varices. In fact, according to the Baveno VI consensus, liver stiffness measurement (LSM) <20 kPa and platelet count >150,000/mm³ can safely identify patients at low risk of varices requiring treatment (VNT) and could therefore avoid invasive upper invasive endoscopy; LSM>20-25 kPa can accurately rule-in CSPH in patients with viral etiology. Spleen stiffness measurement (SSM) is a direct surrogate of portal hypertension and has been demonstrated more accurate in predicting portal hypertension severity and VNT. A combined model including Baveno VI Criteria and SSM (≤46 kPa) can significantly increase the number of spared endoscopies (>40-50%), maintaining a low (<5%) of missed VNT.

Clinical value of artificial intelligence in hepatocellular carcinoma: Current status and prospect

Hepatocellular carcinoma (HCC) is the most commonly diagnosed type of liver cancer and the fourth leading cause of cancer-related mortality worldwide. The early identification of HCC and effective treatments for it have been challenging. Due to the sufficient compensatory ability of early patients and its nonspecific symptoms, HCC is more likely to escape diagnosis in the incipient stage, during which patients can achieve a more satisfying overall survival if they undergo resection or liver transplantation. Patients at advanced stages can profit from radical therapies in a limited way. In order to improve the unfavorable prognosis of HCC, diagnostic ability and treatment efficiency must be improved. The past decade has seen rapid advancements in artificial intelligence, underlying its unique usefulness in almost every field, including that of medicine. Herein, we sought and reviewed studies that put emphasis on artificial intelligence and HCC.

Liver stiffness measured by acoustic radiation force impulse elastography predicted prognoses of hepatocellular carcinoma after radiofrequency ablation

The prognostic factors of patients who undergo radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) is not fully elucidated. We aimed to investigate the role of liver stiffness (LS) and spleen stiffness (SS) measured by acoustic radiation force impulse (ARFI) elastography in determining the prognoses of patients with HCC after RFA. We prospectively enrolled 173 patients with HCC who underwent ARFI elastography for measurement of LS and SS on the same day of RFA. Overall survival (OS), recurrence-free survival (RFS) after adjusting for competing mortality, and presence of hepatic decompensation were investigated. Patients with LS > 1.5 m/s had significantly shorter OS and RFS than their counterparts. Anti-viral treatment (hazard ratio [HR]: 0.396, p = 0.015) and LS > 1.5 m/s (HR 4.105, p = 0.028) correlated with OS by a multivariate analysis. Besides, serum alpha fetoprotein >10 ng/mL and LS > 1.5 m/s independently predicted poorer RFS. On the other hand, anti-viral treatment (HR: 0.315, p = 0.010), creatinine > 1.5 mg/dL (HR: 9.447, p = 0.006), and SS > 2.7 m/s (HR: 2.869, p = 0.044) predicted a higher risk of hepatic decompensation. In conclusion, LS but not SS measured by ARFI elastography predicted tumor recurrence and OS in RFA-treated HCC; whereas, SS predicted development of hepatic decompensation in these patients.

Comparison of 2 curative treatment options for very early hepatocellular carcinoma: Efficacy, recurrence pattern, and retreatment

Curative treatments for very early-stage hepatocellular carcinoma (HCC), defined as single HCC with a maximum diameter of <2 cm in patients with well-preserved liver function, consist of surgical resection or radiofrequency ablation (RFA). In this retrospective study, we compared the efficacy of both treatments in 154 patients with very early-stage HCCs who underwent resection or RFA as initial therapy and were followed up for a median of 56.8 months. Propensity score matching analysis was also conducted. Overall survival was comparable between treatment groups (median survival time of 143 vs 97 months for resection and RFA, respectively; P = .132). Resection group; however, demonstrated a significantly lower recurrence rate after initial therapy than RFA group (42.3% vs 65.7%; P = .006) with a longer median recurrence-free survival time (66.7 vs 33.8 months; P = .002), which was confirmed even after matching (P = .04). In contrast, the recurrence pattern in advanced-stage (9.6% vs 1.0%; P = .01) or incurable recurrences (19% vs 13%; P = .04) was more frequent following resection than RFA. Recurrent lesions were comparatively more curable in RFA group than in resection group (80% vs 54.5%; P = .02). The recurrence of HCC was independently associated with lower serum albumin level (P = .027), the presence of comorbid diabetes mellitus (P = .010), and RFA (P = .034). In conclusion, in patients with very early-stage HCC, surgical resection has achieved significantly better recurrence-free survival than RFA. A closer follow-up is required after resection.