Dear Editor,
We read with great interest the authors’ study on the clinical utility of non-contrast magnetic resonance imaging (NC-MRI) in the surveillance of recurrent hepatocellular carcinoma (HCC) [
1]. Conducted across multiple centers, the study systematically evaluates the diagnostic performance of NC-MRI compared to contrast-enhanced computed tomography (CE-CT), providing valuable insights to inform postoperative imaging follow-up strategies. We commend the authors for the methodological rigor and clinical relevance of this work and would like to offer several constructive comments that may further support future research in this area.
While we highly appreciate the contribution of this study, it is worth noting that a systematic assessment of the costeffectiveness between NC-MRI and CE-CT for follow-up in late-stage recurrent HCC is lacking. Although NC-MRI avoids radiation exposure and contrast-related risks and demonstrated superior diagnostic accuracy in this study, its real-world application may be constrained by higher costs, longer examination times, and increased demands on equipment and radiological expertise. These factors are particularly relevant in primary care settings or resourcelimited regions, where the accessibility and scalability of such imaging strategies warrant further consideration [
2]. Future studies incorporating health economic evaluationstaking into account diagnostic cost per case, accessibility, and patient throughput-would be instrumental in determining the real-world value of NC-MRI and guiding the development of stratified follow-up imaging protocols.
Another point of concern is the absence of inter-reader agreement analysis. Given that NC-MRI primarily relies on T2-weighted imaging and diffusion-weighted imaging sequences, lesion detection may be somewhat subjective, especially in the absence of contrast enhancement. This can lead to discrepancies in the identification of small or perivascular lesions. In a multicenter study such as this, variation in radiologist training, experience, and interpretive criteria could introduce heterogeneity. Without independent, blinded double readings and statistical measures such as kappa coefficients or intraclass correlation coefficients to quantify agreement, the reproducibility and generalizability of the results across clinical settings may be limited [
3]. Strengthening inter-reader consistency assessments would enhance the applicability and reliability of this imaging strategy in real-world scenarios.
In addition, serum biomarkers such as alpha-fetoprotein (AFP) and PIVKA-II play a complementary role in the surveillance of HCC recurrence, particularly when imaging findings are atypical or inconclusive. Although the current study briefly mentions AFP elevation in some recurrent cases, it lacks a systematic analysis of the correlation between biomarker trends and imaging results [
4]. Integrating serological markers with imaging data to construct a multimodal risk stratification model could further improve the sensitivity and accuracy of follow-up strategies, enhancing their utility in clinical practice.
The selection criteria for study participants also merit further reflection. Important subpopulations with significant clinical relevance-such as patients who had undergone liver transplantation, those with concurrent primary or metastatic malignancies, or those with severe extrahepatic comorbidities-were excluded. While this improves internal validity by reducing potential confounding, it also limits the external validity and real-world applicability of the findings. For high-risk or clinically complex patients, the performance of NC-MRI in follow-up remains to be systematically evaluated [
5].
Lastly, the absence of a systematic analysis of “interval cancers” represents a significant limitation. Interval cancers are defined as recurrent lesions that were missed on prior imaging but diagnosed between two surveillance time points, serving as a critical indicator of both imaging modality sensitivity and the appropriateness of follow-up intervals. Studies by Tzartzeva et al. [
6] and Kim et al. [
7] have emphasized that analyzing interval cancers can expose the limitations of imaging techniques and inform improvements in surveillance strategies, while Rhee et al. [
8] further highlighted the potential blind spots of non-contrast-enhanced MRI. Identifying and characterizing such cases-including the time of detection, imaging features, tumor size, and differentiation status-can guide the optimization of surveillance intervals and screening protocols, ultimately strengthening risk management [
6-
8].
In conclusion, this study provides important preliminary evidence supporting the use of NC-MRI in the surveillance of recurrent HCC. Incorporating cost-effectiveness analysis, inter-reader agreement evaluation, integration of serological biomarkers, validation in broader patient populations, and dedicated interval cancer analysis in future research would offer a more comprehensive understanding of the clinical feasibility and implementation potential of this imaging strategy.
FOOTNOTES
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Authors’ contributions
Conceptualization, Writing – original draft: Lu Sun; Writing – review & editing, Supervision, Validation: Xin Zhang. All authors have read and agreed to the published version of the manuscript.
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Conflicts of Interest
The authors have no conflicts to disclose.
Abbreviations
contrast-enhanced computed tomography
non-contrast magnetic resonance imaging
REFERENCES
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Citations
Citations to this article as recorded by
- Correspondence to letter to the editor on “Non-contrast magnetic resonance imaging for detection of late recurrent hepatocellular carcinoma after curative treatment: a prospective multicenter comparison to contrast-enhanced computed tomography”
Dong Ho Lee
Clinical and Molecular Hepatology.2026; 32(2): e251. CrossRef
