To the Editor:
We thank Dr Choi and colleagues for their interest in our work and their generous appraisal of our article. They have also made valuable comments, which we would like to respond to.
Dr. Choi and colleagues have first focused on the timing of “washout” using hepatobiliary contrast agent-enhanced MRI (HBA-MRI). We have evaluated the presence of washout on all phases: portal venous phase, transitional (“delayed”) phase, and the hepatobiliary phase. Using the most restrictive criteria (2018 EASL)
[1]
that only consider the washout on portal venous phase, HBA-MRI achieved similar specificity to MRI with extracellular contrast agents (ECA-MRI) but with a significant decrease in sensitivity; while HBA-MRI had a similar sensitivity to ECA-MRI but significantly decreased specificity when extended washout was used (portal venous phase, or transitional phase, or hepatobiliary phase). These results were suggested by other studies. We agree with Dr. Choi and colleagues that the drop in sensitivity of HBA-MRI with EASL guidelines is not satisfactory but the drop in specificity using extended “washout” is also of concern, in particular when non-invasive imaging-based diagnosis of hepatocellular carcinoma (HCC) is sufficient for patient management.The second comment regards ancillary imaging features. Indeed, we agree that MRI is multiparametric and we should take advantage of additional findings. Some findings have been incorporated in guidelines such as those from the AASLD.
[2]
While these ancillary findings may increase or decrease the likelihood of a lesion being HCC, they do not enable a definitive diagnosis of HCC or non-HCC. If the role of ancillary imaging features is further confirmed in large and prospective studies, guidelines might consider them as major features for the diagnosis of HCC.We thank Dr. Choi and colleagues for their comment regarding the registration of the study in ClinicalTrials.gov and we have clarified this issue. This institutional study was built in 2008 and patient enrollment started in 2010, aiming at comparing the performances of EASL criteria for the diagnosis of small HCC using contrast-enhanced ultrasound (CEUS), CT and MRI. During this time HBA-MRI took on a growing importance and we decided to complete the study and to amend the study protocol. Therefore, this study has 2 parts. The first part (2008–2013) compared CT, ECA-MRI and CEUS in patients at risk of HCC
[3]
and the second part (2014–2017) compared ECA-MRI and HBA-MRI.[4]
The patients included in the 2 studies were different.Last, Dr. Choi and colleagues highlighted their recent study
[5]
showing that CT plus gadoxetic acid-enhanced MRI was associated with better survival than CT plus non-gadoxetic acid-enhanced MRI in patients with HCC and localized disease. This large nationwide retrospective cohort study from Korea is extremely interesting. Yet, the better performance of HBA-MRI is much more related to the improvement of HBA-MRI in tumor staging over ECA-MRI than the diagnostic performance itself.In conclusion, we do not think that a single MR contrast agent is best for the diagnosis and staging of HCC. The diagnostic performance of HCC using MRI varies according to the contrast agent and the criteria used. The sensitivity/specificity expectations are clearly different around the world. Eastern countries prioritize a high sensitivity while Western countries consider a high specificity to be very important. Such differences are largely explained by the priority given to different therapeutic options around the world.
Financial support
The authors received no financial support to produce this reply.
Authors' contributions
This manuscript was co-written by Anita Paisant, Christophe Aubé and Valérie Vilgrain.
Conflicts of interest
The authors declare no conflicts of interest.
Please refer to the accompanying ICMJE disclosure forms for further details.
Supplementary data
- disclosures.pdf
References
- EASL clinical practice guidelines: management of hepatocellular carcinoma.J Hepatol. 2018; 69: 182-236
- Diagnosis, staging, and management of hepatocellular carcinoma: 2018 practice guidance by the American Association for the Study of Liver Diseases.Hepatology. 2018; 68: 723-750
- EASL and AASLD recommendations for the diagnosis of HCC to the test of daily practice.Liver Int. 2017; 37: 1515-1525
- Comparison of extracellular and hepatobiliary MR contrast agents for the diagnosis of small HCCs.J Hepatol. 2020; 72: 937-945
- Use of gadoxetic acid-enhanced liver MRI and mortality in more than 30 000 patients with hepatocellular carcinoma: a nationwide analysis.Radiology. 2020; 295: 114-124
Article info
Publication history
Published online: June 13, 2020
Accepted:
April 28,
2020
Received:
April 27,
2020
Identification
Copyright
© 2020 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
