Differentiation of hepatocellular adenoma by subtype and hepatocellular carcinoma in non-cirrhotic liver by fractal analysis of perfusion MRI

Background: To investigate whether fractal analysis of perfusion differentiates hepatocellular adenoma (HCA) subtypes and hepatocellular carcinoma (HCC) in non-cirrhotic liver by quantifying perfusion chaos using four-dimensional dynamic contrast-enhanced magnetic resonance imaging (4D-DCE-MRI). Results: A retrospective population of 63 patients (47 female) with histopathologically characterized HCA and HCC in non-cirrhotic livers was investigated. Our population consisted of 13 hepatocyte nuclear factor (HNF)-1 alpha-inactivated (H-HCAs), 7 beta-catenin-exon-3-mutated (b(ex3)-HCAs), 27 inflammatory HCAs (I-HCAs), and 16 HCCs. Four-dimensional fractal analysis was applied to arterial, portal venous, and delayed phases of 4D-DCE-MRI and was performed in lesions as well as remote liver tissue. Diagnostic accuracy of fractal analysis was compared to qualitative MRI features alone and their combination using multi-class diagnostic accuracy testing including kappa-statistics and area under the receiver operating characteristic curve (AUC). Fractal analysis allowed quantification of perfusion chaos, which was significantly different between lesion subtypes (multi-class AUC = 0.90, p < 0.001), except between I-HCA and HCC. Qualitative MRI features alone did not allow reliable differentiation between HCA subtypes and HCC (kappa = 0.35). However, combining qualitative MRI features and fractal analysis reliably predicted the histopathological diagnosis (kappa = 0.89) and improved differentiation of high-risk lesions (i.e., HCCs, b(ex3)-HCAs) and low-risk lesions (H-HCAs, I-HCAs) from sensitivity and specificity of 43% (95% confidence interval [CI] 23-66%) and 47% (CI 32-64%) for qualitative MRI features to 96% (CI 78-100%) and 68% (CI 51-81%), respectively, when adding fractal analysis. Conclusions: Combining qualitative MRI features with fractal analysis allows identification of HCA subtypes and HCCs in patients with non-cirrhotic livers and improves differentiation of lesions with high and low risk for malignant transformation

Initiative on Superselective Conventional Transarterial Chemoembolization Results (INSPIRE)

Several publications show that superselective conventional TransArterial ChemoEmbolization (cTACE), meaning cTACE performed selectively with a microcatheter positioned as close as possible to the tumor, improves outcomes, maximizing the anti-tumoral effect and minimizing the collateral damages of the surrounding liver parenchyma. Recent recommendations coming from the European Association for the Study of the Liver (EASL) and European Society of Medical Oncology (ESMO) highlighted that TACE must be used in Hepatocellular Carcinoma (HCC) "selectively targetable" and "accessible to supraselective catheterization." The goal of the manuscript is to better define such population and to standardize superselective cTACE (ss-cTACE) technique. An expert panel with extensive clinical-procedural experience in TACE, have come together in a virtual meeting to generate recommendations and express their consensus. Experts recommend that anytime cTACE is proposed, it should be ss-cTACE, preferably with a 1.5-2.0 Fr microcatheter. Ideally, ss-cTACE should be proposed to patients with less than five lesions and a maximum number of two segments involved, with largest tumor smaller than 5 cm. Angio Cone-Beam Computed Tomography (CBCT) should be used to detect enhancing tumors, tumor feeders and guide tumor targeting. Whole tumor volume should be covered to obtain the best response. Adding peritumoral margins is encouraged but not mandatory. The treatment should involve a water-in-oil emulsion, whose quality is assessable with the "drop test." Additional particulate embolization should be systematically performed, as per definition of cTACE procedure. Non-contrast CBCT or Multi-Detector Computed Tomography (MDCT) combined with angiography has been considered the gold standard for imaging during TACE, and should be used to assess tumor coverage during the procedure. Experts convene that superselectivity decreases incidence of adverse effects and improves tolerance. Experts recommend contrast-enhanced Computed Tomography (CT) as initial imaging on first follow-up after ss-cTACE, and Magnetic Resonance Imaging (MRI) if remaining tumor viability cannot be confidently assessed on CT. If no response is obtained after two ss-cTACE sessions within six months, patient must be considered unsuitable for TACE and proposed for alternative therapy. Patients are best served by multidisciplinary decision-making, and Interventional Radiologists should take an active role in patient selection, treatment allocation, and post-procedural care

Specificities and challenges of imaging response in pancreatic neuroendocrine tumors treated with targeted therapies

Les tumeurs neuroendocrines pancréatiques bien différenciées (pNET) sont richement vascularisées et ont une imagerie caractéristique au scanner. Lorsque ces tumeurs sont traitées par une thérapie ciblée, en particulier un antiangiogénique tel que le sunitinib, ces lésions présentent peu de changement de taille, mais des modifications de la densité tumorale. Les faibles taux de réponse objective (< 10 %) rapportés dans les 2 études randomisées ayant permis l’AMM pour le sunitinib et l’évérolimus dans les pNET, confirment que les critères RECIST sont insuffisants à évaluer ces thérapies ciblées, nécessitant l’exploration de nouveaux critères tels que ceux de Choi, qui intègrent les variations de densité tumorale.Well-differentiated pancreatic neuroendocrine tumors (pNET) are highly vascularized and display specific imaging patterns on CT-scans. When treated with targeted therapies such as the VEGFR inhibitor sunitinib, target lesions show limited if any variation in dimensions, but modifications in tumor density. The low rates of objective response (< 10%) reported in the 2 randomized trials leading to the approval of sunitinib and everolimus in pNET highlight the limits of RECIST criteria to evaluate the effects of targeted therapies, warranting to explore new endpoints involving variation of tumor density, such as Choi criteria

Automated Assessment of T2-Weighted MRI to Differentiate Malignant and Benign Primary Solid Liver Lesions in Noncirrhotic Livers Using Radiomics

Rationale and Objectives: Distinguishing malignant from benign liver lesions based on magnetic resonance imaging (MRI) is an important but often challenging task, especially in noncirrhotic livers. We developed and externally validated a radiomics model to quantitatively assess T2-weighted MRI to distinguish the most common malignant and benign primary solid liver lesions in noncirrhotic livers. Materials and Methods: Data sets were retrospectively collected from three tertiary referral centers (A, B, and C) between 2002 and 2018. Patients with malignant (hepatocellular carcinoma and intrahepatic cholangiocarcinoma) and benign (hepatocellular adenoma and focal nodular hyperplasia) lesions were included. A radiomics model based on T2-weighted MRI was developed in data set A using a combination of machine learning approaches. The model was internally evaluated on data set A through cross-validation, externally validated on data sets B and C, and compared to visual scoring of two experienced abdominal radiologists on data set C. Results: The overall data set included 486 patients (A: 187, B: 98, and C: 201). The radiomics model had a mean area under the curve (AUC) of 0.78 upon internal validation on data set A and a similar AUC in external validation (B: 0.74 and C: 0.76). In data set C, the two radiologists showed moderate agreement (Cohen's κ: 0.61) and achieved AUCs of 0.86 and 0.82. Conclusion: Our T2-weighted MRI radiomics model shows potential for distinguishing malignant from benign primary solid liver lesions. External validation indicated that the model is generalizable despite substantial MRI acquisition protocol differences. Pending further optimization and generalization, this model may aid radiologists in improving the diagnostic workup of patients with liver lesions.</p

The clinical spectrum of Fontan-associated liver disease: results from a prospective multimodality screening cohort

AIMS: Liver fibrosis and cirrhosis are a consequence of a Fontan physiology, and determine prognosis. It is unclear whether non-invasive assessment of liver pathology is helpful to provide clinically relevant information. The aims of this study were to assess the spectrum of Fontan-associated liver disease (FALD) and usefulness of non-invasive methods to assess biopsy confirmed liver fibrosis. METHODS AND RESULTS: Hepatic screening of consecutive patients consisted of a blood panel, ultrasonography, elastography, contrast-enhanced magnetic resonance imaging (MRI)/computed tomography (CT) scan, and liver biopsy (scored with Fontan specific fibrosis scores and collagen proportionate area; CPA). Fibrosis parameters, varices, ascites, and splenomegaly were measured on imaging. Thirty-eight of 49 referred patients (27 +/- 6.6 years, 73.7% male) underwent the complete screening protocol. Liver fibrosis on biopsy was present in all patients, and classified as severe (Stages 3-4) in 68%. Median CPA was 22.5% (16.9-29.5) and correlated with individual fibrosis scores. ELF(R) and liver stiffness were elevated, but MELD-XI scores were low in all patients. Fibrosis severity neither correlated to ELF(R) and liver stiffness, nor to (semi-) quantitative fibrosis parameters on MRI/CT. Varices were present in 50% and hyperenhancing nodules in 25% of patients, both independent of fibrosis stage, but varices were associated with higher CPA values. CONCLUSION: The FALD spectrum includes both hepatic congestion and severe fibrosis, with signs of portal hypertension and hyperenhancing nodules as significant manifestations. Routine imaging, transient elastography, and serum biomarkers are unable to accurately assess severity of liver fibrosis in this cohort. Future research should focus on validating new diagnostic tools with biopsy as the reference standard

Individual participant data meta-analysis of LR-5 in LI-RADS version 2018 versus revised LI-RADS for hepatocellular carcinoma diagnosis

Background A simplification of the Liver Imaging Reporting and Data System (LI-RADS) version 2018 (v2018), revised LI-RADS (rLI-RADS), has been proposed for imaging-based diagnosis of hepatocellular carcinoma (HCC). Single-site data suggest that rLI-RADS category 5 (rLR-5) improves sensitivity while maintaining positive predictive value (PPV) of the LI-RADS v2018 category 5 (LR-5), which indicates definite HCC. Purpose To compare the diagnostic performance of LI-RADS v2018 and rLI-RADS in a multicenter data set of patients at risk for HCC by performing an individual patient data meta-analysis. Materials and Methods Multiple databases were searched for studies published from January 2014 to January 2022 that evaluated the diagnostic performance of any version of LI-RADS at CT or MRI for diagnosing HCC. An individual patient data meta-analysis method was applied to observations from the identified studies. Quality Assessment of Diagnostic Accuracy Studies version 2 was applied to determine study risk of bias. Observations were categorized according to major features and either LI-RADS v2018 or rLI-RADS assignments. Diagnostic accuracies of category 5 for each system were calculated using generalized linear mixed models and compared using the likelihood ratio test for sensitivity and the Wald test for PPV. Results Twenty-four studies, including 3840 patients and 4727 observations, were analyzed. The median observation size was 19 mm (IQR, 11–30 mm). rLR-5 showed higher sensitivity compared with LR-5 (70.6% [95% CI: 60.7, 78.9] vs 61.3% [95% CI: 45.9, 74.7]; P < .001), with similar PPV (90.7% vs 92.3%; P = .55). In studies with low risk of bias (n = 4; 1031 observations), rLR-5 also achieved a higher sensitivity than LR-5 (72.3% [95% CI: 63.9, 80.1] vs 66.9% [95% CI: 58.2, 74.5]; P = .02), with similar PPV (83.1% vs 88.7%; P = .47). Conclusion rLR-5 achieved a higher sensitivity for identifying HCC than LR-5 while maintaining a comparable PPV at 90% or more, matching the results presented in the original rLI-RADS study

Performance de l imagerie et de la biopsie hépatique dans le diagnostic et la classification des adénomes hépatocellulaires

PARIS7-Xavier Bichat (751182101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Feasibility, safety and accuracy of a CT-guided robotic assistance for percutaneous needle placement in a swine liver model

International audienceAbstract Evaluate the feasibility, safety and accuracy of a CT-guided robotic assistance for percutaneous needle placement in the liver. Sixty-six fiducials were surgically inserted into the liver of ten swine and used as targets for needle insertions. All CT-scan acquisitions and robotically-assisted needle insertions were coordinated with breath motion using respiratory monitoring. Skin entry and target points were defined on planning CT-scan. Then, robotically-assisted insertions of 17G needles were performed either by experienced interventional radiologists or by a novice. Post-needle insertion CT-scans were acquired to assess accuracy (3D deviation, ie. distance from needle tip to predefined target) and safety. All needle insertions (43/43; median trajectory length = 83 mm (interquartile range [IQR] 72–105 mm) could be performed in one (n = 36) or two (n = 7) attempts (100% feasibility). Blinded evaluation showed an accuracy of 3.5 ± 1.3 mm. Accuracy did not differ between novice and experienced operators (3.7 ± 1.3 versus 3.4 ± 1.2 mm, P = 0.44). Neither trajectory angulation nor trajectory length significantly impacted accuracy. No complications were encountered. Needle insertion using the robotic device was shown feasible, safe and accurate in a swine liver model. Accuracy was influenced neither by the trajectory length nor by trajectory angulations nor by operator’s experience. A prospective human clinical trial is recruiting