2026 Korean Association for the Study of the Liver Guidelines for Chronic Hepatitis B Management: A Radiological Perspective

INTRODUCTION

Chronic hepatitis B (CHB) remains represents a major public health challenge in South Korea, where it is a leading cause of liver cirrhosis and hepatocellular carcinoma (HCC). Approximately 1.2 million individuals are affected by CHB, with a persistent prevalence of 3%–4% among adults aged 40–60 years [1,2]. Although treatment with safe and effective oral antiviral therapies significantly reduce HCC development and liver-related mortality, the treatment rate in South Korea remains suboptimal, at only 22.2% [1].

To address the limitations of the prior guidelines, which restricted antiviral treatment to patients in the immune-active phase with elevated alanine aminotransferase levels, in 2026 the Korean Association for the Study of the Liver (KASL) released updated clinical practice guidelines for CHB management [3]. These revised guidelines introduced a redefined framework for the natural history of CHB infection, centered on serum HBV DNA levels, reflecting the accumulating evidence indicating that viral load is a more reliable predictor of long-term clinical outcomes and linking disease phases directly to treatment indications.

The updated guidelines further incorporated several key changes regarding the role of radiological examinations. As radiologists play a central role in the diagnosis, staging, surveillance, and treatment of patients with CHB, familiarity with these updates is essential. This article summarizes the key revisions from a radiological perspective.

METHODOLOGY IN BRIEF

The 2026 KASL Clinical Practice Guidelines for CHB Management were developed by a revision committee comprising 19 experts. A systematic literature review was conducted using domestic and international databases, including PubMed, MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, KoreaMed, and KMbase, emphasizing evidence published in the past decade.

The updated guidelines adopted a modified version of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system [4,5,6] to classify the quality of evidence (high [A], moderate [B], low [C]) and strength of recommendations (strong: 1 or weak: 2) according to clinical efficacy, safety, cost-effectiveness, and patient acceptability (Supplementary Table 1). Following an independent review by an external advisory committee and a public hearing in 2026, the final guidelines, comprising 22 key clinical questions and 72 recommendations, were approved by the KASL Board of Directors. The Korean version is available on the KASL website (http://www.kasl.org), and the English version was published in Clinical and Molecular Hepatology [3].

RECOMMENDATIONS AND KEY UPDATES

Among the 72 recommendations, those most relevant to radiological practice are summarized in Table 1.

Table 1. Radiology-related recommendations from the 2026 KASL guidelines.

Category	Recommendation	Recommendation strength	Level of evidence
Initial evaluation	Liver ultrasonography should be performed in patients with CHB to assess for the presence of cirrhosis and HCC	Strong	High
	Non-invasive liver fibrosis tests should be performed to evaluate fibrosis in patients with CHB	Strong	Moderate
Monitoring of patients not eligible for antiviral therapy	In patients with CHB aged 40 years or older, or those younger than 40 years who are at high risk for HCC development, such as those with cirrhosis, HCC surveillance consisting of serum AFP testing and ultrasonography should be performed at 6-month intervals	Strong	High
Monitoring during antiviral therapy	Regular surveillance for HCC using serum AFP measurement and liver ultrasonography should be performed every 6 months during antiviral therapy	Strong	High
	Even after achieving a virologic response, serum HBV DNA may be monitored every 3–6 months, and non-invasive fibrosis assessment may be performed every 12–24 months	Strong	Moderate

KASL = Korean Association for the Study of the Liver, CHB = chronic hepatitis B, HCC = hepatocellular carcinoma, AFP = alpha-fetoprotein, HBV = hepatitis B virus

Initial Evaluation

Liver ultrasonography to evaluate cirrhosis and to screen for HCC remains the primary imaging modality for the initial assessment of patients with CHB. When ultrasonographic visualization or findings are inadequate or inconclusive, liver protocol CT or MRI may be performed as an alternative.

For the initial assessment of hepatic fibrosis, noninvasive modalities are now preferred over traditional liver biopsies owing to their relative invasiveness, risk of complications, sampling errors, and inter-observer variability [7]. The clinical applications and recommendations for these techniques have been described in detail in the 2024 KASL Practice Guidelines [8].

Among the available techniques, vibration-controlled transient elastography (VCTE) remains the most extensively validated modality with a high diagnostic accuracy for fibrosis staging. Recent meta-analyses have established the following optimal liver stiffness measurement (LSM) cutoff values [9,10]:

• • Significant fibrosis (≥F2): 7.0 kPa

  • Advanced fibrosis (≥F3): 8.0–9.5 kPa

  • Liver cirrhosis (F4): 11.0–12.5 kPa

Shear wave elastography (SWE), including point SWE and two-dimensional SWE, has demonstrated diagnostic performance comparable with that of VCTE. In particular, two-dimensional SWE shows highly concordant stage-specific LSM cutoff values [8]. MR elastography offers an excellent diagnostic performance for the staging of hepatic fibrosis in patients with CHB [8].

Monitoring Patients not Eligible for Antiviral Therapy

For HCC surveillance in patients with CHB not eligible for antiviral treatment, liver ultrasonography combined with serum alpha-fetoprotein (AFP) testing should be performed every 6 months in patients aged ≥40 years and in younger patients with high-risk features, such as cirrhosis. Surveillance should continue even after achieving HBsAg seroclearance in patients with underlying cirrhosis, a family history of HCC, or HBsAg loss occurring at an older age (≥40 for males, ≥50 for females) [11,12].

Longitudinal non-invasive fibrosis assessment is further recommended for monitoring disease progression in untreated patients. Assessment every 2–3 years is appropriate for clinically stable patients, while an annual evaluation is recommended for patients with borderline treatment indications or uncertain disease status [13].

Monitoring During Antiviral Therapy

Although long-term antiviral therapy substantially reduces the risk of HCC, this risk has not yet been eliminated. Therefore, surveillance with liver ultrasonography and serum AFP measurements every 6 months in patients undergoing antiviral therapy remains essential throughout treatment [14,15].

As antiviral therapy may slow or reverse hepatic fibrosis, serial LSM assessment provides valuable information for monitoring treatment responses and predicting long-term prognosis [16,17,18]. Risk-prediction models that incorporate on-treatment LSM outperform conventional models in estimating future HCC risk [17,19,20]. In patients with mild to moderate fibrosis, assessment every 24 months may be considered. However, active hepatic inflammation may transiently increase liver stiffness values; therefore, LSM findings should always be interpreted in an appropriate clinical context [21].

CONCLUSION

The 2026 KASL Clinical Practice Guidelines introduce important updates for understanding the natural history and clinical management of CHB. Several revisions have directly influenced the role of imaging in disease evaluation, surveillance, and treatment monitoring. Given the central role of radiologists in the multidisciplinary care of patients with CHB, familiarity with these updated recommendations may facilitate evidence-based imaging practices and optimize patient management.

Supplement

The Supplement is available with this article at https://doi.org/10.3348/kjr.2026.1224.