Accuracy of Pretransplant Imaging Diagnostic for Hepatocellular Carcinoma: A Retrospective German Multicenter Study

External Validation of the RETREAT Score for Prediction of Hepatocellular Carcinoma Recurrence after Liver Transplantation

Simple Summary

Liver transplantation (LT) is a potentially curative treatment option for hepatocellular carcinoma (HCC), but is frequently complicated by HCC recurrence. In order to estimate the recurrence risk a novel risk score was developed in the United States: the Risk Estimation of Tumor Recurrence After Transplant (RETREAT). External validation of this novel risk score, in a different patient population with other LT selection criteria, is needed. In this study we demonstrate that the RETREAT score is able to predict the risk of HCC recurrence after liver transplantation in a European population. These findings may be used to inform patients of recurrence risk and as a basis for studies on surveillance strategies.

Abstract

Background. We aimed to externally validate the performance of the RETREAT score in a European population. Methods. This single center retrospective cohort study enrolled all consecutive patients with HCC who underwent LT between 1989 and 2019. The performance of RETREAT was assessed in the overall population and after stratification between being within or beyond the Milan criteria based on the explant pathology report. Recurrence probabilities were estimated by using the Kaplan–Meier method and compared by log-rank test. Results. We studied 203 patients; 42 patients were beyond the Milan criteria based on explant pathology. The median follow-up was 26.8 months (IQR 7.2–60.7). Overall cumulative HCC recurrence rates were 10.6%, 21.3%, and 23.0% at 2, 5, and 10 years, with the majority of recurrences extrahepatic and at multiple sites. Higher RETREAT scores were associated with higher recurrence rates, with a 10-year recurrence rate of 60.5% in patients with RETREAT ≥ 3 (n = 65), compared to 6.2% in those with RETREAT ≤2 (n = 138; p < 0.001). HCC recurrence rates were even lower in patients within the Milan criteria who also had a low RETREAT score (n = 122; 2.7% at 10 years). Conclusion. Low RETREAT scores identify patients at low risk of HCC recurrence after LT in patients within the Milan criteria based on explant pathology.

Prognostic role of selection criteria for liver transplantation in patients with hepatocellular carcinoma: a network meta-analysis

BACKGROUND

Patients with hepatocellular carcinoma (HCC) are selected for transplantation if they have a low tumour burden and low risk of recurrence. The morphometric Milan criteria have been the cornerstone for patient selection, but dynamic morphological and biological tumour characteristics surfaced as an encouraging tool to refine the selection of patients with HCC and to support the expansion of the Milan criteria. The outcomes of the most prevalent models that select patients with HCC for liver transplantation were analysed in this study, which aimed to identify the selection model that offered the best recurrence-free and overall survival after transplantation.

METHODS

Studies that compared Milan, University of California San Francisco (UCSF), up-to-seven (UPTS), alpha-fetoprotein (AFP), and MetroTicket 2.0 (MT2) models were included. One-year, 3-year, and 5-year recurrence-free and overall survival rates of patients selected for transplantation using different models were analysed.

RESULTS

A total of 60 850 adult patients with HCC selected for liver transplantation using Milan, UCSF, UPTS, AFP, or MT2 criteria were included. Patients selected for transplantation using the MT2 model had the highest 1-, 3-, and 5-year recurrence-free survival. In addition, patients selected for transplantation using MT2 criteria had the best 1- and 3-year overall survival, whereas patients selected for transplantation using the Milan criteria had the best 5-year overall survival rates.

CONCLUSION

The MT2 model offered the best post-transplant outcomes in patients with HCC, highlighting the importance of considering tumour morphology and biology when selecting patients with HCC for liver transplantation.

LI-RADS in the year 2020 - Are you already using it or still considering?

PURPOSE

 The working group for gastrointestinal and abdominal imaging within the German Radiological Society performed a nationwide online survey in order to assess the current status regarding the awareness and application of LI-RADS, a classification for evaluation of liver lesions in patients at risk.

MATERIALS AND METHODS

 Using the website www.deutsches-krankenhausverzeichnis.de a list of hospitals was generated meeting the criteria internal medicine, gastroenterology, general and visceral surgery and radiology (n = 391). Randomly, 102 department directors were contacted, and asked to name one consultant and one resident from their department in order to participate in the survey. 177 potential participants were invited to fill out an approximately 10-minute online survey in the form of 17 questions regarding the awareness and application of LI-RADS. The results of the survey were analyzed by means of descriptive statistics.

RESULTS

 77 participants were registered, which corresponds to a response rate of 43.5 %. 47 % of all participants were radiologists, 30 % surgeons and 23 % internal doctors/gastroenterologists, respectively, many with more than 13 years of professional experience (37.2 %). The majority of participants worked in a hospital with a focus (37.2 %) or a university hospital (29.1 %). Even though the majority of participants knows about or has heard of LI-RADS (73.2 %), only a minority uses the classification themselves (26 %) or within the context of tumor boards (19.2 %).

CONCLUSION

 The results of our survey demonstrate that LI-RADS is relatively known in Germany, the application however quite sparse. This is in contrast to the general desire and endeavor for more standardized reporting in radiology.

KEY POINTS

· LI-RADS is not yet broadly implemented in clinical routine in Germany. · The sparse application is in contrast to the general desire for more standardized reporting in radiology. · Interdisciplinary education may support the propagation and use of the LI-RDAS classification.

CITATION FORMAT

· Ringe KI, Gut A, Grenacher L et al. LI-RADS in the year 2020 - Are you already using it or still considering? Fortschr Röntgenstr 2021; 193: 186 - 193.

Milan criteria in the MELD era-is it justifiable to extend the limits for orthotopic liver transplantation?

Background

The Milan criteria (MC) are widely used for the indication of liver transplantation (LTx) in hepatocellular carcinoma (HCC). Good long-term results have also been reported following LTx for patients exceeding the MC. In this article, we compare the overall and recurrence-free survival of our patients fulfilling and exceeding the MC according to the post-transplant histopathological results.

Patients and methods

Data from 120 patients with HCC (22 females and 98 males) were analyzed. The median patient age was 61 years (Q1, Q3 54.7, 65.4), and the median MELD score was 11 (Q1, Q3 8, 15). The median follow-up period was 53 months (Q1, Q3 16.6, 78). Patients were categorized into established criteria (MC, up-to-seven (UTS), Asan criteria, AFP score), and the outcome of the individual groups was compared.

Results

Seventy-four of 120 patients fulfilled the MC, 86 patients met the UTS criteria, 85 patients fulfilled the Asan criteria, and 79 patients had an AFP score less than or equal to 2. The 1- and 5-year survival rates of all patients were 76.7% and 55.6%, respectively. In total, 14.2% of all patients (5.4% of patients who met the MC, 7% of patients who met the UTS criteria, 5.9% of patients who met the Asan criteria, and 6.3% of patients who had an AFP score less than 2) experienced recurrence.

Conclusions

The outcomes of the patients were comparable to those reported in the current literature. In our population, similar recurrence and survival rates of the patients were noted for patients fulfilling the UTS criteria irrespective of fulfilling or exceeding the MC. Consequently, we consider using UTS criteria as the extended criterion for LTx indication.

Combined DCE-MRI- and FDG-PET enable histopathological grading prediction in a rat model of hepatocellular carcinoma

PURPOSE

To test combined dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and 18F-FDG positron emission tomography (FDG-PET)-derived parameters for prediction of histopathological grading in a rat Diethyl Nitrosamine (DEN)-induced hepatocellular carcinoma (HCC) model.

METHODS

15 male Wistar rats, aged 10 weeks were treated with oral DEN 0.01 % in drinking water and monitored until HCCs were detectable. DCE-MRI and PET were performed consecutively on small animal scanners. 38 tumors were identified and manually segmented based on HCC-specific contrast enhancement patterns. Grading (G2/3: 24 tumors, G1:14 tumors) alongside other histopathological parameters, tumor volume, contrast agent and 18F-FDG uptake metrics were noted. Class imbalance was addressed using SMOTE and collinearity was removed using hierarchical clustering and principal component analysis. A logistic regression model was fit separately to the individual parameter groups (DCE-MRI-derived, PET-derived, tumor volume) and the combined parameters.

RESULTS

The combined model using all imaging-derived parameters achieved a mean ± STD sensitivity of 0.88 ± 0.16, specificity of 0.70 ± 0.20 and AUC of 0.90 ± 0.03. No correlation was found between tumor grading and tumor volume, morphology, necrosis, extracellular matrix, immune cell infiltration or underlying liver fibrosis.

CONCLUSION

A combination of DCE-MRI- and 18F-FDG-PET-derived parameters provides high accuracy for histopathological grading of hepatocellular carcinoma in a relevant translational model system.