Prevalence and clinical significance of discordant LI-RADS® observations on multiphase contrast-enhanced MRI in patients with cirrhosis

LI-RADS-based hepatocellular carcinoma risk mapping using contrast-enhanced MRI and self-configuring deep learning

BACKGROUND

Hepatocellular carcinoma (HCC) is often diagnosed using gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI). Standardized reporting according to the Liver Imaging Reporting and Data System (LI-RADS) can improve Gd-MRI interpretation but is rather complex and time-consuming. These limitations could potentially be alleviated using recent deep learning-based segmentation and classification methods such as nnU-Net. The study aims to create and evaluate an automatic segmentation model for HCC risk assessment, according to LI-RADS v2018 using nnU-Net.

METHODS

For this single-center retrospective study, 602 patients at risk for HCC were included, who had dynamic EOB-MRI examinations between 05/2005 and 09/2022, containing ≥ LR-3 lesion(s). Manual lesion segmentations in semantic segmentation masks as LR-3, LR-4, LR-5 or LR-M served as ground truth. A set of U-Net models with 14 input channels was trained using the nnU-Net framework for automatic segmentation. Lesion detection, LI-RADS classification, and instance segmentation metrics were calculated by post-processing the semantic segmentation outputs of the final model ensemble. For the external evaluation, a modified version of the LiverHccSeg dataset was used.

RESULTS

The final training/internal test/external test cohorts included 383/219/16 patients. In the three cohorts, LI-RADS lesions (≥ LR-3 and LR-M) ≥ 10 mm were detected with sensitivities of 0.41-0.85/0.40-0.90/0.83 (LR-5: 0.85/0.90/0.83) and positive predictive values of 0.70-0.94/0.67-0.88/0.90 (LR-5: 0.94/0.88/0.90). F1 scores for LI-RADS classification of detected lesions ranged between 0.48-0.69/0.47-0.74/0.84 (LR-5: 0.69/0.74/0.84). Median per lesion Sørensen-Dice coefficients were between 0.61-0.74/0.52-0.77/0.84 (LR-5: 0.74/0.77/0.84).

CONCLUSION

Deep learning-based HCC risk assessment according to LI-RADS can be implemented as automatically generated tumor risk maps using out-of-the-box image segmentation tools with high detection performance for LR-5 lesions. Before translation into clinical practice, further improvements in automatic LI-RADS classification, for example through large multi-center studies, would be desirable.

Clinical impact of CEUS on non-characterizable observations and observations with intermediate probability of malignancy on CT/MRI in patients at risk for HCC

BACKGROUND

Hepatocellular carcinoma (HCC) is a unique cancer allowing tumor diagnosis with identification of definitive patterns of enhancement on contrast-enhanced imaging, avoiding invasive biopsy. However, it is still unclear to what extent Contrast-Enhanced Ultrasound (CEUS) is a clinically useful additional step when Computed tomography (CT) or Magnetic resonance imaging (MRI) are inconclusive.

METHODS

A prospective international multicenter validation study for CEUS Liver Imaging Reporting and Data System (LI-RADS) was conducted between January 2018 and August 2021. 646 patients at risk for HCC with focal liver lesions were enrolled. CEUS was performed using an intravenous ultrasound contrast agent within 4 weeks of CT/MRI. Liver nodules were categorized based on LI-RADS (LR) criteria. Histology or one-year follow-up CT/MRI imaging results were used as the reference standard. The diagnostic performance of CEUS was evaluated for inconclusive CT/MRI scan in two scenarios for which the AASLD recommends repeat imaging or imaging follow-up: observations deemed non-characterizable (LR-NC) or with indeterminate probability of malignancy (LR-3).

RESULTS

75 observations on CT or MRI were categorized as LR-3 (n = 54) or LR-NC (n = 21) CEUS recategorization of such observations into a different LR category (namely, into one among LR-1, LR-2, LR-5, LR-M, or LR-TIV) resulted in management recommendation changes in 33.3% (25/75) and in all but one (96.0%, 24/25) observation, the new management recommendations were correct.

CONCLUSION

CEUS LI-RADS resulted in management recommendations change in substantial number of liver observations with initial indeterminate CT/MRI characterization, identifying both non-malignant lesions and HCC, potentially accelerating the diagnostic process and alleviating the need for biopsy or follow-up imaging.

CLINICALTRIALS

gov number, NCT03318380.

The clinical and financial burden of nonhepatocellular carcinoma focal lesions detected during the surveillance of patients with cirrhosis

BACKGROUND AND AIMS

HCC surveillance is challenged by the detection of hepatic focal lesions (HFLs) of other types. This study aimed to describe the incidence, characteristics, outcomes, and costs of non-HCC HFL detected during surveillance.

APPROACH AND RESULTS

We retrospectively analyzed nonstandardized workup performed in French patients included in HCC surveillance programs recruited in 57 French tertiary centers (ANRS CirVir and CIRRAL cohorts, HCC 2000 trial). The overall cost of workup was evaluated, with an estimation of an average cost per patient for the entire population and per lesion detected. A total of 3295 patients were followed up for 59.8 months, 391 (11.9%) patients developed HCCs (5-year incidence: 12.1%), and 633 (19.2%) developed non-HCC HFLs (5-year incidence: 21.8%). Characterization of non-HCC HFL required a median additional of 0.7 exams per year. A total of 11.8% of non-HCC HFLs were not confirmed on recall procedures, and 19.6% of non-HCC HFLs remained undetermined. A definite diagnosis of benign liver lesions was made in 65.1%, and malignant tumors were diagnosed in 3.5%. The survival of patients with benign or undetermined non-HCC HFL was similar to that of patients who never developed any HFL (5-year survival 92% vs. 88%, p = 0.07). The average cost of the diagnostic workup was 1087€ for non-HCC HFL and €1572 for HCC.

CONCLUSIONS

Non-HCC HFLs are frequently detected in patients with cirrhosis, and do not impact prognosis, but trigger substantial costs. This burden must be considered in cost-effectiveness analyses of future personalized surveillance strategies.

Radiological-histopathological discordance in patients transplanted for HCC and its impact on post-transplant outcomes

BACKGROUND AND AIMS

Contrast-enhanced cross-sectional imaging is the cornerstone in the diagnosis, staging, and management of HCC, including eligibility for liver transplantation (LT). Radiological-histopathological discordance may lead to improper staging and may impact patient outcomes. We aimed to assess the radiological-histopathological discordance at the time of LT in HCC patients and its impact on the post-LT outcomes.

METHODS

We analyzed further the effect of 6-month waiting policy on the discordance. Using United Network for Organ Sharing-Organ Procurement and Transplantation Network (UNOS-OPTN) database, we examined the discordance between pre-LT imaging and explant histopathology for all adult HCC patients who received liver transplants from deceased donors between April 2012 and December 2017. Kaplan-Meier methods and Cox regression analyses were used to evaluate the impact of discordance on 3-year HCC recurrence and mortality.

RESULTS

Of 6842 patients included in the study, 66.7% were within Milan criteria on both imaging and explant histopathology, and 33.3% were within the Milan based on imaging but extended beyond Milan on explant histopathology. Male gender, increasing numbers of tumors, bilobar distribution, larger tumor size, and increasing AFP are associated with increased discordance. Post-LT HCC recurrence and death were significantly higher in patients who were discordant, with histopathology beyond Milan (adj HR 1.86, 95% CI 1.32-2.63 for mortality and 1.32, 95% CI 1.03-1.70 for recurrence). Graft allocation policy with 6-month waiting time led to increased discordance (OR 1.19, CI 1.01-1.41), although it did not impact post-LT outcome.

CONCLUSION

Current practice for staging of HCC based on radiological imaging features alone results in underestimation of HCC burden in one out of three patients with HCC. This discordance is associated with a higher risk of post-LT HCC recurrence and mortality. These patients will need enhanced surveillance to optimize patient selection and aggressive LRT to reduce post-LT recurrence and increase survival.

Multidisciplinary care for patients with HCC: a systematic review and meta-analysis

BACKGROUND

Given the complexity of managing HCC, professional society guidelines advocate multidisciplinary care (MDC) for patients with HCC. However, implementation of MDC programs requires a significant investment of time and resources. We conducted a systematic review and meta-analysis to enumerate potential benefits of MDC for patients with HCC.

METHODS

We conducted a search of the PubMed/MEDLINE and EMBASE databases and national conference abstracts to identify studies published after January 2005 that reported early-stage presentation, treatment receipt, or overall survival among patients with HCC, stratified by MDC status. We calculated pooled risk ratios and HRs for clinical outcomes according to MDC receipt using the DerSimonian and Laird method for random effects models.

RESULTS

We identified 12 studies (n = 15,365 patients with HCC) with outcomes stratified by MDC status. MDC was associated with improved overall survival (HR = 0.63, 95% CI: 0.45-0.88); however, its association with curative treatment receipt was not statistically significant (risk ratio = 1.60, 95% CI: 0.89-2.89) and pooled estimates were limited by high heterogeneity (I2 > 90% for both). Studies (n = 3) were discordant regarding an association between MDC and time-to-treatment initiation. MDC was associated with early-stage HCC (risk ratio = 1.60, 95% CI: 1.12-2.29), suggesting possible referral bias contributing to improved outcomes. Limitations of studies also included risk of residual confounding, loss to follow-up, and data preceding the availability of immune checkpoint inhibitors.

CONCLUSION

MDC for patients with HCC is associated with improved overall survival, underscoring the likely benefit of managing patients with HCC in a multidisciplinary care setting.

Dynamic Changes in Ultrasound Quality for Hepatocellular Carcinoma Screening in Patients With Cirrhosis

BACKGROUND & AIMS

Identifying patients in whom ultrasound may be inadequate to exclude the presence of hepatocellular carcinoma (HCC) can inform interventions to improve screening effectiveness. We aimed to characterize correlates of suboptimal ultrasound quality and changes in ultrasound quality over time in patients with cirrhosis undergoing HCC screening.

METHODS

We performed a retrospective cohort study of patients with cirrhosis who underwent ultrasound examination at 2 large health systems between July 2016 and July 2019. Exam adequacy was graded by radiologists using the LI-RADS Visualization Score (A, B, C); we evaluated changes in visualization over time among patients with >1 ultrasound exams. We performed multivariable logistic regression to identify characteristics associated with limited ultrasound visualization (scores B or C).

RESULTS

Of 2053 cirrhosis patients, 1685 (82.1%) had ultrasounds with score A, 262 (12.8%) had score B, and 106 (5.2%) had score C. Limited visualization was associated with alcohol-related or nonalcoholic fatty liver disease cirrhosis and presence of class II-III obesity. Among 1546 patients with >1 ultrasounds, 1129 (73.0%) had the same visualization score on follow-up (1046 score A, 60 score B, 23 score C). However, 255 (19.6%) of 1301 with score A at baseline had limited visualization when repeated (230 score B, 25 score C), and 130 (53.1%) of 245 patients with baseline limited visualization had good visualization when repeated.

CONCLUSIONS

Nearly 1 in 5 patients with cirrhosis had moderately-severely limited ultrasound visualization for HCC nodules, particularly those with obesity or alcohol-related or nonalcoholic fatty liver disease cirrhosis. Ultrasound quality can change between exams, including improvement in many patients with limited visualization.

Overdiagnosis of hepatocellular carcinoma: Prevented by guidelines?

Overdiagnosis refers to detection of disease that would not otherwise become clinically apparent during a patient's lifetime. Overdiagnosis is common and has been reported for several cancer types, although there are few studies describing its prevalence in HCC surveillance programs. Overdiagnosis can have serious negative consequences including overtreatment and associated complications, financial toxicity, and psychological harms related to being labeled with a cancer diagnosis. Overdiagnosis can occur for several different reasons including inaccurate diagnostic criteria, detection of premalignant or very early malignant lesions, detection of indolent tumors, and competing risks of mortality. The risk of overdiagnosis is partly mitigated, albeit not eliminated, by several guideline recommendations, including definitions for the at-risk population in whom surveillance should be performed, surveillance modalities, surveillance interval, recall procedures, and HCC diagnostic criteria. Continued research is needed to further characterize the burden and trends of overdiagnosis as well as identify strategies to reduce overdiagnosis in the future.

LI-RADS treatment response algorithm after first-line DEB-TACE: reproducibility and prognostic value at initial post-treatment CT/MRI

PURPOSE

To evaluate the inter-reader reproducibility and prognostic accuracy of the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (LR-TR) at the time of initial post-treatment evaluation following drug-eluting beads transarterial chemoembolization (DEB-TACE) for hepatocellular carcinoma (HCC).

METHODS

This retrospective study included patients with HCC who underwent first-line DEB-TACE between January 2011 and December 2015. Six readers (three fellowship-trained radiologists and three radiology trainees) independently assessed lesion-level response in up to two treated lesions per LR-TR and modified Response Evaluation Criteria in Solid Tumors (mRECIST)-target criteria, as well as patient-level response per mRECIST-overall criteria, on the initial post-treatment CT/MRI. Inter-reader agreement was calculated by Fleiss' multi-reader κ. We tested whether LR-TR, mRECIST-target, and mRECIST-overall response were associated with overall survival using Kaplan-Meier and Cox proportional hazard model analyses.

RESULTS

A total of 82 patients with 113 treated target lesions were included. Inter-reader agreement was moderate for LR-TR and mRECIST-overall (κ range 0.42-0.57), and substantial for mRECIST-target (κ range 0.62-0.66), among all three reader-groups: all readers, experienced readers, and less-experienced readers. LR-TR and mRECIST-target response were not significantly associated with overall survival regardless of reader experience (P > 0.05). In contrast, mRECIST-overall response was significantly associated with overall survival when assessed by all readers (P = 0.02) and experienced readers (P = 0.03), but not by the less-experienced readers (P = 0.35).

CONCLUSION

Although LR-TR algorithm has moderate inter-reader reproducibility, it alone may not predict overall survival on the initial post-treatment CT/MRI after first-line DEB-TACE for HCC.

Role of the radiologist at HCC multidisciplinary conference and use of the LR-TR algorithm for improving workflow

Multidisciplinary conferences (MDCs) play a major role in management and care of oncology patients. Hepatocellular carcinoma (HCC) is a complex disease benefiting from multidisciplinary discussions to determine optimal patient management. A multitude of liver-directed locoregional therapies have emerged allowing for more options for treatment of HCC. A radiologist dedicated to HCC-MDC is an important member of the team contributing to patient care in multiple ways. The radiologist plays a key role in image interpretation guiding initial therapy discussions as well as interpreting post-treatment imaging following liver-directed therapy. Standardization of image interpretation can lead to more consistent treatment received by the patient as well as accurate assessment of transplant eligibility. The radiologist can facilitate this process using structured reporting that is also supported by stakeholders involved in interdisciplinary management of liver diseases. The Liver Imaging Reporting and Data System (LI-RADS), is a living document which offers a standardized reporting algorithm for consistent communication of radiologic findings for HCC screening and characterization of liver observations in patients at risk for HCC. The LI-RADS post-treatment algorithm (LR-TR algorithm) has been developed to standardize liver observations following liver-directed locoregional therapy. This review article focuses on the role of the radiologist at HCC-MDC and implementation of the LR-TR algorithm for improving workflow.

Role of Multidisciplinary Care in the Management of Hepatocellular Carcinoma

Despite advances in treatment options for hepatocellular carcinoma (HCC), 5-year survival for HCC remains below 20%. This poor survival is multifactorial but is partly related to underuse of curative treatment in clinical practice. In light of growing treatment options, delivered by different types of providers, optimal management requires input from multiple specialties. A multidisciplinary approach has been evolving over the past couple of decades, bringing different specialists together to develop a therapeutic plan to treat and manage HCC, which significantly increases timely guideline-concordant treatment and improves overall survival. The present review attempts to highlight the need for such a multimodal approach by providing insights on its potential structure and impact on the various aspects of HCC management.

Expert radiologist review at a hepatobiliary multidisciplinary tumor board: impact on patient management

PURPOSE

To identify the frequency, source, and management impact of discrepancies between the initial radiology report and expert reinterpretation occurring in the context of a hepatobiliary multidisciplinary tumor board (MTB).

METHODS

This retrospective study included 974 consecutive patients discussed at a weekly MTB at a large tertiary care academic medical center over a 2-year period. A single radiologist with dedicated hepatobiliary imaging expertise attended all conferences to review and discuss the relevant liver imaging and rated the concordance between original and re-reads based on RADPEER scoring criteria. Impact on management was based on the conference discussion and reflected changes in follow-up imaging, recommendations for biopsy/surgery, or liver transplant eligibility.

RESULTS

Image reinterpretation was discordant with the initial report in 19.9% (194/974) of cases (59.8%, 34.5%, 5.7% RADPEER 2/3/4 discrepancies, respectively). A change in LI-RADS category occurred in 59.8% of discrepancies. Most common causes of discordance included re-classification of a lesion as benign rather than malignant (16.0%) and missed tumor recurrence (13.9%). Impact on management occurred in 99.0% of discordant cases and included loco-regional therapy instead of follow-up imaging (19.1%), follow-up imaging instead of treatment (17.5%), and avoidance of biopsy (12.4%). 11.3% received OPTN exception scores due to the revised interpretation, and 8.8% were excluded from listing for orthotopic liver transplant.

CONCLUSION

Even in a sub-specialized abdominal imaging academic practice, expert radiologist review in the MTB setting identified discordant interpretations and impacted management in a substantial fraction of patients, potentially impacting transplant allocation. The findings may impact how abdominal imaging sections best staff advanced MTBs.