Positron emission tomography/computed tomography with 18F-fluorocholine improve tumor staging and treatment allocation in patients with hepatocellular carcinoma

Hepato-Biliary Imaging in an Acute Setting: Is There a Role for Nuclear Medicine?

Nuclear medicine (NM) is not commonly considered as a first-line imaging modality in hepato-biliary (HB) emergencies. The aim of this review is to provide an update on the potential of NM for the imaging of HB emergencies. 99mTc-HIDA scintigraphy showed high diagnostic accuracy for acute cholecystitis, thus being particularly useful in patients at high-risk for surgery due to comorbidities and with no clear findings at US or CT. Although limitedly explored, White blood cell (WBC) scan might have a role in case of acute pancreatitis, especially for the imaging of pancreatic leukocyte infiltration and the prediction of pancreatic necrosis. Scientific literature on 18F-FDG-PET/CT in HB acute disease mainly consists of case reports or case series, describing incidental findings in oncological PET/CT scans. In patients with obstructive jaundice, PET/CT has been proposed to disclose and characterize occult tumoral etiology. Further studies are needed to evaluate the clinical usefulness of the various NM approaches in HB acute settings, particularly with respect to the emerging new technologies (eg, PET/MRI) and radiopharmaceuticals.

Additional value of interleukin-6 level to predict histopathological features of hepatocellular carcinoma before liver transplantation

BACKGROUND & AIMS

Inflammatory biomarkers are increasingly used as outcome predictors in the field of oncology and liver transplantation for HCC, but no study has shown the prognostic value of IL6 after LT. The goal of this study was to evaluate the predictive value of IL-6 on histopathological features of HCC on explant, its predictive value on recurrence risk and its additional value to other scores and inflammatory markers at the time of transplantation.

METHODS

From 2009 to 2019, all adults transplanted with a first liver graft and diagnosed with HCC on the explant analysis were retrospectively included (n = 229). Only patients who had a pre-LT IL6 level determination were analysed in this study (n = 204).

RESULTS

High IL-6 level at transplantation was associated with a significantly higher risk of vascular invasion (15% vs 6%; p = 0.023), microsatellitosis (11% vs 3%; p = 0.013), lower rate of histological response both in terms of complete response (2% vs 14%, p = 0.004) and of necrosis (p = 0.010). Patients with pre-LT IL-6 level > 15 ng/ml had a lower overall and cancer-specific survival (p = 0.013). Recurrence-free survival was lower in patients with IL-6 > 15 ng/ml with a 3-year recurrence-free survival of 88% versus 78% (p = 0.034). IL6 levels were significantly higher in patients with early recurrence compared to patients without (p = 0.002) or with late recurrence (p = 0.044).

CONCLUSIONS

IL6 level at transplantation is an independent predictor of pejorative histological features of HCC and is associated to the risk of recurrence.

Towards refining the utility of dual (18F-FDG / 18F-Choline) PET/CT for the management of hepatocellular carcinoma: a tertiary center study

BACKGROUND

The role of positron emission tomography/computed tomography (PET/CT) in hepatocellular carcinoma (HCC) management is not clearly defined. Our objective was to analyze the utility of dual-PET/CT (18F-FDG + 18F-Choline) imaging findings on the BCLC staging and treatment decision for HCC patients.

METHODS

Between January 2011 and April 2019, 168 consecutive HCC patients with available baseline dual-PET/CT imaging data were retrospectively analyzed. To identify potential refinement criteria for surgically-treated patients, survival Kaplan-Meier curves of various standard-of-care and dual-PET/CT baseline parameters were estimated. Finally, multivariate cox proportional hazard ratios of the most relevant clinico-biological and/or PET parameters were estimated.

RESULTS

Dual-PET/CT findings increased the score of BCLC staging in 21 (12.5%) cases. In 24.4% (N.=41) of patients, the treatment strategy was modified by the PET findings. Combining AFP levels at a threshold of 10 ng/mL with 18F-FDG or 18F-Choline N status significantly impacted DFS (P<0.05). In particular, the combined criteria of the N+ status assessed by 18F-Choline with AFP threshold of 10 ng/mL provided a highly predictive composite parameter for estimation of DFS according to multivariate analysis (HR=10.6, P<0.05).

CONCLUSIONS

The 18F-Choline / AFP composite parameter appears promising, and further prospective studies are mandatory to validate its oncological impact.

Chromatographic method development using multivariate approaches for organic solvents optimized analysis in [18F]fluorocholine

A fast and simple method using Gas Chromatography combined with Flame Ionization Detection (GC-FID) was developed for the determination of ethanol, acetonitrile, dibromomethane, dimethylaminoethanol, and dimethyl sulfoxide in [¹⁸F]fluorocholine. The combination of fractional factorial design, Doehlert design, and Desirability function was used to evaluate the operational parameters and to establish the best working condition. The validation results revealed that the proposed method has good recovery (85.1-104.1%) and repeatability (RSD ≤8.1%). Correlation coefficients (R ≥ 0.983) indicated good linearity over a wide range. The limit of detection (≤2.5 ppm) and the limit of quantification (≤7.5 ppm) were satisfactory. The proposed method is based on minimum manual operation, sample preparation free, direct injection technique, and short chromatographic separation time. This method is useful for routine analysis of organic solvents in [¹⁸F]fluorocholine, feasible for the modernization of specific monograph, and was therefore successfully implemented to assess samples manufactured by Nuclear Technology Development Center (CDTN).

Is 18 F-FDG/ 18 F-Choline Dual-Tracer PET Behavior a Surrogate of Tumor Differentiation in Hepatocellular Carcinoma : A Tertiary Center Dedicated Study

BACKGROUND

In hepatocellular carcinoma (HCC) setting, 18 F-FDG and 18 F-choline PET/CT radiotracers are classically considered surrogates of the degree of differentiation, a strong predictor of disease recurrence after curative treatment. Because the corresponding level of evidence has never been assessed as primary end point, the aim of this retrospective study was to specifically assess the relevance of 18 F-FDG combined to 18 F-choline PET imaging as a surrogate of tumor differentiation in HCC.

PATIENTS AND METHODS

A total of 49 histologically proven HCCs (46 patients treated by surgery or liver transplantation) with available baseline 18 F-FDG and 18 F-choline PET/CT, dedicated liver contrast-enhanced CT scan, and histological key features were retrospectively reviewed. Hepatocellular carcinoma tumors with well, moderately, and poorly differentiation (grades I, II, and III of the World Health Organization classification) were compared on their PET findings (double-blinded visual analysis and 8 usual semiquantitative metrics) by using nonparametric Kruskal-Wallis analyses of variance. In the case of statistical significance, pairwise post hoc tests with family-wise error rate adjustment were performed.

RESULTS

No statistical difference between the grades was observed for any of the patients' or lesions' characteristics ( P > 0.05), except for the macrovascular invasion between the grades I and II (adjusted P = 0.03). None of the PET findings showed statistical difference between the grades, except the tumor-to-background ratio of 18 F-FDG, higher for the grade III compared with grades I (adjusted P = 0.02) and II (adjusted P = 0.01). For less than one third of cases (14 lesions; 28.5%), the regional uptake was judged visually heterogeneous, but none of the related semiquantitative PET metrics were statistically discriminant ( P > 0.05).

CONCLUSIONS

Contrary to a common belief, 18 F-FDG/ 18 F-choline dual-tracer PET behavior is not a relevant surrogate of tumor differentiation in HCC. Future multitracer PET studies are mandatory to refine our knowledges of their deep biological meaning in this field.

Update on PET Radiopharmaceuticals for Imaging Hepatocellular Carcinoma

Numerous positron emission tomography (PET) targets for detection and staging of hepatocellular cancer have been developed in recent years. Hepatocellular carcinomas (HCCs) are clinically and pathologically heterogeneous tumours with a high tendency to be aggressive and unresponsive to chemotherapy. Early detection is essential, and the need for an adequate imaging biomarker, which can overcome some of the limitations of conventional radiological imaging, is persistent. Flourine-18 (18F) flourodeoxyglucose (FDG), the most widely used PET radiopharmaceutical, has proven disappointing as a possible staple in the evaluation of HCC. This disappointment had led to experimentation with carious radiotracers, such as the choline derivatives, acetate, and prostate-specific membrane antigen, which appear to complement and/or enhance the role of FDG. In this study, we look at the various PET radiopharmaceuticals that have been used for imaging HCC and the particular pathways that they target in HCC and liver cancers.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Influence of key histological characteristics on 18F-fluorodeoxyglucose /18F-choline positron emission tomography positivity in hepatocellular carcinoma: A machine learning study

Purpose

To determine the characteristics influence of key histological on 18F-fluorodeoxyglucose (18F-FDG) and 18F-choline positron emission tomography (PET) positivity in hepatocellular carcinoma (HCC).

Materials and methods

The 18F-FDG/18F-choline PET imaging findings of 103 histologically proven HCCs (from 62 patients, of which 47 underwent hepatectomy and 15 received liver transplantation) were retrospectively examined to assess the following key histological parameters: Grade, capsule, microvascular invasion (mVI), macrovascular invasion (MVI), and necrosis. Using a ratio of 70/30 for training and testing sets, respectively, a penalized classification model (Elastic Net) was trained using 100 repeated cross-validation procedures (10-fold cross-validation for hyperparameter optimization). The contribution of each histological parameter to the PET positivity was determined using the Shapley Additive Explanations method. Receiver operating characteristic curves with and without dimensionality reduction were finally estimated and compared.

Results

Among the five key histological characteristics of HCC (Grade, capsule, mVI, MVI, and necrosis), mVI and tumor Grade (I-III) showed the highest relevance and robustness in explaining HCC uptake of 18F-FDG and 18F-choline. MVI and necrosis status both showed high instability in outcome predictions. Tumor capsule had a minimal influence on the model predictions. On retaining only mVI and Grades I-III for the final analysis, the area under the receiver operating characteristic (ROC) curve values were maintained (0.68 vs. 0.63, 0.65 vs. 0.64, and 0.65 vs. 0.64 for 18F-FDG, 18F-choline, and their combination, respectively).

Conclusion

18F-FDG/18F-choline PET positivity appears driven by both the Grade and mVI components in HCC. Consideration of the tumor microenvironment will likely be necessary to improve our understanding of multitracer PET positivity.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

PET/CT with 18F-choline or 18F-FDG in Hepatocellular Carcinoma Submitted to 90Y-TARE: A Real-World Study

Our aim was to assess the role of positron emission computed tomography (PET/CT) with 18F-choline (18F-FCH) or 18F-fluorodeoxyglucose (18F-FDG) in hepatocellular carcinoma (HCC) submitted to 90Y-radioembolization (90Y-TARE). We retrospectively analyzed clinical records of 21 HCC patients submitted to PET/CT with 18F-fluorocholine (18F-FCH) or 18F-fluodeoxyglucose (18F-FDG) before and 8 weeks after 90Y-TARE. On pre-treatment PET/CT, 13 subjects (61.9%) were 18F-FCH-positive, while 8 (38.1%) resulted 18F-FCH-negative and 18F-FDG-positive. At 8-weeks post 90Y-TARE PET/CT, 13 subjects showed partial metabolic response and 8 resulted non-responders, with a higher response rate among 18F-FCH-positive with respect to 18F-FDG-positive patients (i.e., 76.9% vs. 37.5%, p = 0.46). Post-treatment PET/CT influenced patients’ clinical management in 10 cases (47.6%); in 8 subjects it provided indication for a second 90Y-TARE targeting metabolically active HCC remnant, while in 2 patients it led to a PET-guided radiotherapy on metastatic nodes. By Kaplan−Meier analysis, patients’ age (≤69 y) and post 90Y-TARE PET/CT’s impact on clinical management significantly correlated with overall survival (OS). In Cox multivariate analysis, PET/CT’s impact on clinical management remained the only predictor of patients’ OS (p < 0.001). In our real-world study, PET/CT with 18F-FCH or 18F-FDG influenced clinical management and affected the final outcome for HCC patients treated with 90Y-TARE.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Current Imaging Diagnosis of Hepatocellular Carcinoma

Simple Summary

The role of imaging in the management of hepatocellular carcinoma (HCC) has significantly evolved and expanded beyond the plain radiological confirmation of the tumor based on the typical appearance in a multiphase contrast-enhanced CT or MRI examination. The introduction of hepatobiliary contrast agents has enabled the diagnosis of hepatocarcinogenesis at earlier stages, while the application of ultrasound contrast agents has drastically upgraded the role of ultrasound in the diagnostic algorithms. Newer quantitative techniques assessing blood perfusion on CT and MRI not only allow earlier diagnosis and confident differentiation from other lesions, but they also provide biomarkers for the evaluation of treatment response. As distinct HCC subtypes are identified, their correlation with specific imaging features holds great promise for estimating tumor aggressiveness and prognosis. This review presents the current role of imaging and underlines its critical role in the successful management of patients with HCC.

Abstract

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer related death worldwide. Radiology has traditionally played a central role in HCC management, ranging from screening of high-risk patients to non-invasive diagnosis, as well as the evaluation of treatment response and post-treatment follow-up. From liver ultrasonography with or without contrast to dynamic multiple phased CT and dynamic MRI with diffusion protocols, great progress has been achieved in the last decade. Throughout the last few years, pathological, biological, genetic, and immune-chemical analyses have revealed several tumoral subtypes with diverse biological behavior, highlighting the need for the re-evaluation of established radiological methods. Considering these changes, novel methods that provide functional and quantitative parameters in addition to morphological information are increasingly incorporated into modern diagnostic protocols for HCC. In this way, differential diagnosis became even more challenging throughout the last few years. Use of liver specific contrast agents, as well as CT/MRI perfusion techniques, seem to not only allow earlier detection and more accurate characterization of HCC lesions, but also make it possible to predict response to treatment and survival. Nevertheless, several limitations and technical considerations still exist. This review will describe and discuss all these imaging modalities and their advances in the imaging of HCC lesions in cirrhotic and non-cirrhotic livers. Sensitivity and specificity rates, method limitations, and technical considerations will be discussed.

Targeted Multifunctional Nanoplatform for Imaging-Guided Precision Diagnosis and Photothermal/Photodynamic Therapy of Orthotopic Hepatocellular Carcinoma

Background

Effective theranostic of hepatocellular carcinoma (HCC) in an early-stage is imminently demanded to improve its poor prognosis. Combination of the near-infrared (NIR) photoacoustic imaging (PAI) and fluorescence imaging (FLI) can provide high temporospatial resolution, outstanding optical contrast, and deep penetration and thus is promising for accurate and sensitive HCC diagnosis.

Methods

A versatile CXCR4-targeted Indocyanine green (ICG)/Platinum (Pt)-doped polydopamine melanin-mimic nanoparticle (designated ICG/Pt@PDA-CXCR4, referred to as IPP-c) is synthesized as an HCC-specific contrast agent for high-resolution precise diagnostic PAI/FLI and optical imaging-guided targeted photothermal therapy (PTT)/photodynamic therapy (PDT) of orthotopic small hepatocellular carcinoma (SHCC).

Results

The multifunctional targeted nanoparticle yields superior HCC specificity, high imaging contrast in both PAI and FLI, good stability, reliable biocompatibility, effective singlet oxygen generation and superior photothermal conversion efficiency (PCE, 58.7%) upon 808-nm laser irradiation. The targeting ability of IPP-c was validated in in vitro experiments on selectively killing the CXCR4-overexpressing HCC cells. Moreover, we test the efficient dual-modal optical precision diagnosis properties of IPP-c via in vivo experiments on targeted particle accumulation in an early-stage SHCC mouse model (tumor diameter about 1.2 mm). Then, under the guidance of real-time optical imaging, effective and mini-invasive PTT/PDT of orthotopic SHCCs were demonstrated without damaging adjacent liver tissues or other major organs.

Conclusion

This study presented a multifunctional CXCR4-targeted nanoparticle to conduct effective and mini-invasive phototherapeutics of orthotopic SHCCs via the real-time quantitative guidance by optical imaging, which provided a new perception for building a versatile targeted nanoplatform for phototheranostics of early-stage HCC.

18F-FDG /18F-Choline Dual-Tracer PET Behavior and Tumor Differentiation in HepatoCellular Carcinoma. A Systematic Review

Background

Post-operative recurrence remains the strongest prognostic factor of resected hepatocellular carcinoma (HCC), making the accurate selection of patients with curable HCC a crucial issue. PET imaging combining both 18F-FDG and fatty acid synthase (FAS) radiotracers—such as Choline—has shown its interest for the initial staging and therapeutic management of patients with HCC, but its use is still not consensual. Importantly, the very first dual-tracer PET studies suggested 18F-FDG/FAS PET behavior be linked to the degree of differentiation of HCC, a major predictive factor of post-operative recurrence. Although this key molecular imaging concept may impact how dual-tracer PET will be used in early-stage HCC, its level of evidence remains largely unexplored. In this study, we conducted a systematic review of the available evidence-based data to clarify the relevance of dual 18F-FDG/18F-Choline PET in characterizing the degree of differentiation of HCC tumors.

Methods

A systematic search of the PubMed/Medline and Embase databases was performed up to November 2021. A systematic review of the dual-tracer 18F-FDG/18F-Choline PET behavior of histology-proven HCC according to their degree of differentiation was conducted. The overall quality of the included studies was critically assessed based on the STROBE guidelines. Information on study date, design, patient cohort characteristics, grade of differentiation of HCC tumors, and the dual-tracer PET behavior per HCC was independently extracted and summarized.

Results

From 440 records initially available, 6 full-text articles (99 histology-proven HCC) provided dual-tracer 18F-FDG/18F-Choline PET behavior per HCC tumor grade were included in the systematic review. Based on our analysis, 43/99 HCCs were reported to be well-differentiated, and 56/99 HCCs were reported to be less-differentiated tumors. In the well-differentiated subgroup, more than half were exclusively positive for 18F-Choline (51%), whereas 39% were positive for both 18F-FDG and 18F-Choline. In the less-differentiated subgroup, 37% of HCC patients were positive exclusively for FDG, 36% were positive for both 18F-FDG and 18F-Choline, and 25% were positive exclusively for 18F-Choline.

Conclusion

The 18F-FDG/18F-Choline dual-tracer PET behavior of uptake shows high overlap between well- and less differentiated HCC, making the characterization of tumors challenging based on such PET combination alone. Given our growing knowledge of the molecular complexity of HCC, further studies are necessary to refine our understanding of radiotracers’ behavior in this field and improve the usefulness of PET imaging in the clinical decision process of HCC.

Morphomolecular Classification Update on Hepatocellular Adenoma, Hepatocellular Carcinoma, and Intrahepatic Cholangiocarcinoma

Hepatocellular adenomas (HCAs), hepatocellular carcinomas (HCCs), and intrahepatic cholangiocarcinomas (iCCAs) are a highly heterogeneous group of liver tumors with diverse pathomolecular features and prognoses. High-throughput gene sequencing techniques have allowed discovery of distinct genetic and molecular underpinnings of these tumors and identified distinct subtypes that demonstrate varied clinicobiologic behaviors, imaging findings, and complications. The combination of histopathologic findings and molecular profiling form the basis for the morphomolecular classification of liver tumors. Distinct HCA subtypes with characteristic imaging findings and complications include HNF1A-inactivated, inflammatory, β-catenin-activated, β-catenin-activated inflammatory, and sonic hedgehog HCAs. HCCs can be grouped into proliferative and nonproliferative subtypes. Proliferative HCCs include macrotrabecular-massive, TP53-mutated, scirrhous, clear cell, fibrolamellar, and sarcomatoid HCCs and combined HCC-cholangiocarcinoma. Steatohepatitic and β-catenin-mutated HCCs constitute the nonproliferative subtypes. iCCAs are classified as small-duct and large-duct types on the basis of the level of bile duct involvement, with significant differences in pathogenesis, molecular signatures, imaging findings, and biologic behaviors. Cross-sectional imaging modalities, including multiphase CT and multiparametric MRI, play an essential role in diagnosis, staging, treatment response assessment, and surveillance. Select imaging phenotypes can be correlated with genetic abnormalities, and identification of surrogate imaging markers may help avoid genetic testing. Improved understanding of morphomolecular features of liver tumors has opened new areas of research in the targeted therapeutics and management guidelines. The purpose of this article is to review imaging findings of select morphomolecular subtypes of HCAs, HCCs, and iCCAs and discuss therapeutic and prognostic implications. Online supplemental material is available for this article. ^©RSNA, 2022.

Pathophysiological mechanisms of ALPPS: experimental model

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a two-stage strategy that may increase hepatic tumour resectability and reduce postoperative liver failure rate by inducing rapid hypertrophy of the future liver remnant (FLR). Pathophysiological mechanisms after the first stage of ALPPS are poorly understood.

METHODS

An ALPPS model was established in rabbits with liver VX2 tumour. The pathophysiological mechanisms after the first stage of ALPPS in the FLR and tumour were assessed by multiplexed positron emission tomography (PET) tracers, dynamic contrast-enhanced MRI (DCE-MRI) and histopathology.

RESULTS

Tumour volume in the ALPPS model differed from post-stage 1 ALPPS at day 14 compared to control animals. 18F-FDG uptake of tumour increased from day 7 onwards in the ALPPS model. Valid volumetric function measured by 18F-methylcholine PET showed good values in accurately monitoring dynamics and time window for functional liver regeneration (days 3 to 7). DCE-MRI revealed changes in the vascular hyperpermeability function, with a peak on day 7 for tumour and FLR.

CONCLUSION

Molecular and functional imaging are promising non-invasive methods to investigate the pathophysiological mechanisms of ALPPS with potential for clinical application.

Non-invasive diagnosis and follow-up of primary malignant liver tumours

Among a wide range of malignant liver tumours, hepatocellular carcinoma (HCC) developed on a background of cirrhosis represents the most frequent clinical situation. In this setting, HCC is one of the rare solid tumours for which histological confirmation is not mandatory. The convergence of multiple arguments obtained by non-invasive parameters using radiological findings allows to avoid liver biopsy in a large proportion of patients when a diagnosis of underlying cirrhosis is ascertained. Conversely, in case of atypical presentation or in order to exclude other rare malignant tumours mostly developed in the absence of cirrhosis, liver biopsy will then be essential. Based on typical radiological patterns described by contrast-enhanced imaging, numerous clinical guidelines have endorsed non-invasive diagnosis, staging and monitoring of HCC patients under treatment since 20 years. These algorithms have evolved over the years, taking into account progress in radiological technology and advances in curative or palliative procedures. Large cohort studies have also helped to refine diagnostic criteria and prognostication in the setting of complex therapeutic strategy. Unsupervised multi-analysis approaches both at the biological and radiological levels will in the future enrich the panel of non-invasive markers useful in clinical practice to manage HCC and other malignant tumours.

Utility of Early Posttreatment PET/CT Evaluation Using FDG or 18F-FCH to Predict Response to 90Y Radioembolization in Patients With Hepatocellular Carcinoma

Background: Assessment of hepatocellular carcinoma (HCC) treatment response after transarterial radioembolization (TARE) is challenging, as response by conventional imaging criteria may not become apparent until 6 months after treatment. Though HCC exhibits variability avidity for FDG, some cases of HCC without avidity for FDG show avidity for 18F-FCH. Objectives: To evaluate the utility of early posttreatment evaluation by PET/CT using FDG or 18F-FCH to predict 6-month treatment response and survival after TARE in patients with HCC. Methods: This retrospective study included 37 patients (mean age 67 years; 34 men, 3 women) with documented HCC treated by TARE who underwent both pretreatment FDG PET/CT and 18F-FCH PET/CT, as well as early FDG PET/CT and/or 18F-FCH PET/CT 4-8 weeks after treatment; FDG PET/CT and 18F-FCH PET/CT examinations were performed on separate dates. Only one of 73 initially identified potentially eligible patients was excluded due to lack of HCC avidity for both FDG and 18F-FCH. Response assessment by mRECIST on multiphase CT or MRI was performed at one-month and six-months in 23 patients. Early PET/CT response and one-month mRECIST response were assessed as predictors of six-month mRECIST response. Univariable and multivariable predictors of overall survival (OS) were identified. Results: On pretreatment PET/CT, 28 (76%) patients were FDG-positive, 15 (41%) FCH-positive 6 (16%) both FDG-positive and FCH-positive. Twelve of 28 FDG-positive HCCs exhibited early response by FDG PET/CT; 7 of 15 FCH-positive HCCs exhibited early response by 18F-FCH PET/CT. Twelve (52%) patients exhibited six-month mRECIST response. Early posttreatment PET/CT response exhibited 100% (12/12) sensitivity and 100% (11/11) specificity for six-month mRECIST response, whereas one-month mRECIST response exhibited 67% (8/12) sensitivity and 100% (11/11) specificity for six-month mRECIST response. Early postteatment PET/CT response was a significant independent predictor of OS on univariable (hazard ratio: 0.37, 95% CI: 0.15-0.93, p=.03) and multivariable analyses (hazard ratio: 0.24, 95% CI: 0.08-0.76, p=.01). Conclusion: Early post-TARE evaluation by PET/CT using FDG or 18F-FCH may predict six-month response and OS in patients with HCC. Clinical Impact: Early posttreatment evaluation with PET/CT could help more reliably identify true nonresponders after TARE, which in turn could prompt early adapted therapeutic management.

68Ga-PSMA-11 PET/CT Improves Tumor Detection and Impacts Management in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the sixth most prevalent cancer and the third most frequent cause of cancer-related death. A growing number of local and systemic therapies are available, and accurate staging is critical for management decisions. We assessed the impact of neovasculature imaging by ⁶⁸Ga-PSMA-11 PET/CT on disease staging, prognostic groups, and management of patients with HCC compared with staging with CT. Methods: Forty patients who received imaging with ⁶⁸Ga-PSMA-11 PET/CT for HCC staging between September 2018 and September 2019 were retrospectively included. Management before and after PET scanning was assessed by standardized surveys. The presence of HCC was evaluated by 3 masked readers on a per-patient and per-region basis for PET/CT (PET criteria) and multiphase contrast-enhanced CT (CT criteria) in separate sessions. Lesions were validated by follow-up imaging or histopathology, and progression-free survival was recorded. Endpoints were detection rate and positive predictive value for ⁶⁸Ga-PSMA-11 PET versus CT, interreader reproducibility, and changes in stage, prognostic groups, and management plans. Results: Median age was 65 y (range, 37-81 y), and median Child-Pugh score was 5 (range, 5-9). Most patients were treatment-naïve (27/40, 67.5%). The sensitivity of PET versus CT to identify liver lesions for patients with lesion validation was 31 of 32 (97%) for both modalities, whereas it was 6 of 6 (100%) versus 4 of 6 (67%), respectively, for extrahepatic lesions. PET and CT each had a positive predictive value of 100% at the liver level. PET versus CT stage was congruent in 30 of 40 (75%) patients; upstaging was seen in 8 of 40 patients (20%), whereas 2 of 40 (5%) had downstaging by PET. Intended management changed in 19 of 40 patients (47.5%); 9 of 19 of these patients were found to have detectable distant metastases (47.4%) and assigned stage 4 disease, most of whom were shifted to systemic therapy (8/9, 89%). Two patients underwent ¹⁷⁷Lu-PSMA-617 radioligand therapy. Median progression-free survival was 5.2 mo for the entire cohort; 5.3 mo for PET M0, and 4.7 mo for PET M1 patients, respectively. Conclusion: ⁶⁸Ga-PSMA-11 PET demonstrated higher accuracy than CT in the detection of HCC metastases and was associated with a management change in about half the patient cohort.

A pH-triggered fluorescence-switchable extracellular vesicle for tracing drug release and improving drug delivery

Extracellular vesicles have shown great potential in drug delivery for clinical applications. However, some obstacles still need to be overcome before their clinical translation, including on demand release of drugs to improve the efficacy and monitoring of the drug release process to ascertain drug dosage. Herein, a pH-triggered fluorescence-switchable extracellular vesicle as a smart nanocarrier is fabricated by loading zwitterionic fluorescent carbon dots (CDs) into macrophage cell-secreted vesicles to achieve improved drug delivery and real-time monitoring of drug release. When circulating in the blood, the zwitterionic CDs loaded in the vesicles can tightly bind the chemotherapeutic drug DOX through electrostatic interactions to avoid premature drug unload. The nanocarriers have a long blood circulation half-life of 15.12 h and a high tumor accumulation of 9.88% ID/g. Meanwhile, the fluorescence of the CDs is in the "off" state due to the fluorescence inner filter effect (IFE) between the DOX and the CDs. When the nanocarriers enter the tumor cells, the low pH of the lysosome leads to charge reversal of the CDs. DOX can be quickly released through electrostatic repulsion and the fluorescence of the CDs turns "on" after the release of the drugs, thus enabling an improved drug delivery and real-time tracking of the drug release process.

Non-cirrhotic hepatocellular carcinoma in chronic viral hepatitis: Current insights and advancements

Primary liver cancers carry significant morbidity and mortality. Hepatocellular carcinoma (HCC) develops within the hepatic parenchyma and is the most common malignancy originating from the liver. Although 80% of HCCs develop within background cirrhosis, 20% may arise in a non-cirrhotic milieu and are referred to non-cirrhotic-HCC (NCHCC). NCHCC is often diagnosed late due to lack of surveillance. In addition, the rising prevalence of non-alcoholic fatty liver disease and diabetes mellitus have increased the risk of developing HCC on non-cirrhotic patients. Viral infections such as chronic Hepatitis B and less often chronic hepatitis C with advance fibrosis are associated with NCHCC. NCHCC individuals may have Hepatitis B core antibodies and occult HBV infection, signifying the role of Hepatitis B infection in NCHCC. Given the effectiveness of current antiviral therapies, surgical techniques and locoregional treatment options, nowadays such patients have more options and potential for cure. However, these lesions need early identification with diagnostic models and multiple surveillance strategies to improve overall outcomes. Better understanding of the NCHCC risk factors, tumorigenesis, diagnostic tools and treatment options are critical to improving prognosis and overall outcomes on these patients. In this review, we aim to discuss NCHCC epidemiology, risk factors, and pathogenesis, and elaborate on NCHCC diagnosis and treatment strategies.

Noninvasively visualize the expression of LAPTM4B protein using a novel 18F-labeled peptide PET probe in hepatocellular carcinoma

OBJECTIVE

Lysosomal protein transmembrane 4 beta (LAPTM4B) is selectively expressed in hepatocellular carcinoma (HCC) cells and thus a potential biomarker for diagnosing HCC. In this study, we designed a novel ¹⁸F-labeled PET probe to non-invasively visualize LAPTM4B expression in mouse model of HCC tumor.

METHODS

A PET targeting tracer named [¹⁸F]FP-LAP2H was radio-synthesized using a LAPTM4B targeting peptide, LAP2H, coupled with 4-nitrophenyl-2-[¹⁸F]fluoropropionate ([¹⁸F]NFP). Radio-stability, cell uptake, micro PET/CT imaging and ex vivo biodistribution were performed for determining its stability, cell binding specificity, and tumor targeting in vivo.

RESULTS

[¹⁸F]FP-LAP2H was successfully synthesized with radiochemical yields of 6-14% (decay-corrected yield) and molar activity of 10-44 GBq/μmol. The tracer showed stable (~90%) in phosphate-buffered saline, pH 7.4, and in human serum (~80%) for 2 h. In vitro cell uptake studies indicated the radioactivity accumulation in HCC cells was LAPTM4B protein-specific. Micro PET/CT demonstrated that implanted LAPTM4B positive HepG2 and BEL7402 tumors could be clearly visualized. The ex vivo biodistribution studies demonstrated that the tumor/liver ratio were 1.80 ± 0.65 and 2.09 ± 0.68 in implanted HepG2 and BEL7402 tumors respectively. Negative control and blocking experiments revealed that the radioactivity uptake in the HCC tumor was LAPTM4B protein-specific.

CONCLUSIONS

[¹⁸F]FP-LAP2H appears to be a potential PET tracer for imaging LAPTM4B-positive HCC tumor. Further endeavors need to do to improve tumor/liver ratio.

18F-choline PET-computed tomography for the prediction of early treatment responses to transarterial radioembolization in patients with hepatocellular carcinoma

BACKGROUND

Transarterial radioembolization (TARE) is widely used for the treatment of hepatocellular carcinoma (HCC), but early treatment response can be very difficult to assess. The aim was to evaluate 18F-fluorocholine PET/computed tomography (CT) to assess the treatment response in patients with intermediate or locally advanced HCC.

METHODS

Between March 2019 and July 2020, nine HCC patients treated with TARE, who underwent PET/CT at baseline and 1 month after treatment, were enrolled. The maximum, mean (SUVmean), and peak (SUVpeak) standardized uptake value (SUV), SUV normalized by lean body mass (SUL), and total lesion glycolysis (TLG) were measured. Statistical analysis used the Mann-Whitney test to evaluate the differences in parameters between responders (partial and complete response) and nonresponders (stable or progressive disease) at the 6-month follow-up, according to the modified Response Evaluation Criteria in Solid Tumors.

RESULTS

Three patients were nonresponders (progressive disease and stable disease) and six were responders. Delta SUVmean, delta SUL, and delta TLG could predict an early response (P = 0.02, P = 0.04, and P = 0.02, respectively). None of the pre-therapeutic parameters were correlated with the response. Post-therapeutic SUL, SUVmean, TLG, and SUVpeak were also predictive of the response.

CONCLUSIONS

Our preliminary results showed that changes in certain metabolic parameters (from baseline PET to 1-month PET) are predictive of the response to TARE in HCC (Delta SUVmean, delta TLG, and delta SUL). The absence of post-treatment inflammation could lead to a better prediction than MRI evaluation. This study suggests that 1-month 18F-choline PET/CT could modify the clinical management predicting responders.Video Abstract: http://links.lww.com/NMC/A193.

From congestive hepatopathy to hepatocellular carcinoma, how can we improve patient management?

Heart failure and liver disease often coexist because of systemic disorders and diseases that affect both organs as well as complex cardio-hepatic interactions. Heart failure can cause acute or chronic liver injury due to ischaemia and passive venous congestion, respectively. Congestive hepatopathy is frequently observed in patients with congenital heart disease and after the Fontan procedure, but also in older patients with chronic heart failure. As congestive hepatopathy can evolve into cirrhosis and hepatocellular carcinoma, screening for liver injury should be performed in patients with chronic cardiac diseases and after Fontan surgery. Fibrosis starts in the centro-lobular zone and will extend progressively to the portal area. Chronic liver injury can be reversible if heart function improves. However, in the case of terminal heart failure, uncontrolled by medical resources or by assistive device support, the combination of heart and liver transplants must be discussed in patients with chronic advanced liver fibrosis. In this review of the literature, we will focus on congestive hepatopathy and its complications, such as liver fibrosis and hepatocellular carcinoma, with the aim of improving the management and surveillance of patients experiencing these complications.

Hepatocellular carcinoma: French Intergroup Clinical Practice Guidelines for diagnosis, treatment and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, AFEF, SIAD, SFR/FRI)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of hepatocellular carcinoma (HCC) published in March 2019.

METHOD

It is a collaborative work under the auspices of most of the French medical societies involved in the management of HCC. It is based on the previous guidelines published in 2017. Recommendations are graded in 3 categories according to the level of evidence of data found in the literature.

RESULTS

The diagnosis and staging of HCC is essentially based on clinical, biological and imaging features. A pathological analysis obtained by a biopsy of tumoral and non-tumoral liver is recommended. HCCs can be divided into 2 groups, taking into account not only the tumor stage, but also liver function. HCCs accessible to curative treatments are tumors that are in Milan criteria or with an AFP score ≤ 2, mainly treated by surgical resection, local ablation or liver transplantation. Intermediate and advanced HCCs with no liver insufficiency, accessible only to palliative treatments, benefit from TACE, SIRT or systemic therapy according to the presence or absence of macrovascular invasion or extrahepatic spread.

CONCLUSION

Such recommendations are in permanent optimization and each individual case must be discussed in a multidisciplinary expert board.

Mortality after Transplantation for Hepatocellular Carcinoma: A Study from the European Liver Transplant Registry

BACKGROUND AND AIMS

Prognosis after liver transplantation differs between hepatocellular carcinoma (HCC) arising in cirrhotic and non-cirrhotic livers and aetiology is poorly understood. The aim was to investigate differences in mortality after liver transplantation between these patients.

METHODS

We included patients from the European Liver Transplant Registry transplanted due to HCC from 1990 to November 2016 and compared cirrhotic and non-cirrhotic patients using propensity score (PS) calibration of Cox regression estimates to adjust for unmeasured confounding.

RESULTS

We included 22,787 patients, of whom 96.5% had cirrhosis. In the unadjusted analysis, non-cirrhotic patients had an increased risk of overall mortality with a hazard ratio (HR) of 1.37 (95% confidence interval [CI] 1.23-1.52). However, the HR approached unity with increasing adjustment and was 1.11 (95% CI 0.99-1.25) when adjusted for unmeasured confounding. Unadjusted, non-cirrhotic patients had an increased risk of HCC-specific mortality (HR 2.62, 95% CI 2.21-3.12). After adjustment for unmeasured confounding, the risk remained significantly increased (HR 1.62, 95% CI 1.31-2.00).

CONCLUSIONS

Using PS calibration, we showed that HCC in non-cirrhotic liver has similar overall mortality, but higher HCC-specific mortality. This may be a result of a more aggressive cancer form in the non-cirrhotic liver as higher mortality could not be explained by tumour characteristics or other prognostic variables.

Addition of [18 F]Fluorodeoxyglucose Positron Emission Tomography With Computed Tomography to Cross-Sectional Imaging Improves Staging and Alters Management in Hepatocellular Carcinoma

In this work, we characterize the value of positron emission tomography (PET) with computed tomography (CT) in combination with cross-sectional imaging for staging and prognostication of hepatocellular carcinoma (HCC) patients. In this retrospective cohort study, HCC patients underwent PET-CT after initial staging with contrast-enhanced CT or magnetic resonance imaging (MRI). The benefit of PET-CT was measured by the identification of new HCC lesions, and potential harm was quantified by the number of false positives and subsequent diagnostic evaluation. We used multivariate Cox regression analysis to evaluate the association between the highest grade on PET-CT with the risk of extrahepatic metastasis, progression-free, and overall survival. Among 148 patients, PET-CT detected additional extrahepatic metastasis in 11.9% of treatment-naïve and 13.8% of treatment-experienced patients. PET-CT changed the Barcelona Clinic Liver Cancer (BCLC) staging in 5.9% of treatment-naïve and 18.8% of treatment-experienced patients compared with CT/MRI alone, changing HCC management in 9.9% and 21.3% of patients, respectively. Of the patients, 5% (n = 8) experienced severe physical harm requiring additional procedures to evaluate extrahepatic findings. High tumor grade on PET-CT was independently associated with a higher likelihood of extrahepatic metastasis (hazard ratio [HR], 17.1; 95% confidence interval [CI], 3.6-81.5) and worse overall survival (HR, 2.4; 95% CI, 1.4-4.3). Treatment-experienced patients (versus treatment-naïve patients; HR, 9.7; 95% CI, 1.9-49.4) and BCLC stage A (HR, 8.2; 95% CI, 1.5-45.9; P < 0.01) and BCLC stage B (HR, 20.6; 95% CI, 1.5-282.2; P < 0.05) were more likely to have an upstaging with PET-CT compared with BCLC stage C (reference). PET-CT provides prognostic information and improves tumor staging beyond CT/MRI alone, with subsequent changes in management for patients with HCC.

Hepatobiliary MR contrast agent uptake as a predictive biomarker of aggressive features on pathology and reduced recurrence-free survival in resectable hepatocellular carcinoma: comparison with dual-tracer 18F-FDG and 18F-FCH PET/CT

OBJECTIVES

To compare the performance of the quantitative analysis of the hepatobiliary phase (HBP) tumor enhancement in gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI and of dual-tracer 18F-FDG and 18F-fluorocholine (FCH) PET/CT for the prediction of tumor aggressiveness and recurrence-free survival (RFS) in resectable hepatocellular carcinoma (HCC).

METHODS

This retrospective, IRB approved study included 32 patients with 35 surgically proven HCCs. All patients underwent Gd-BOPTA-enhanced MRI including delayed HBP images, 18F-FDG PET/CT, and (for 29/32 patients) 18F-FCH PET/CT during the 2 months prior to surgery. For each lesion, the lesion-to-liver contrast enhancement ratio (LLCER) on MRI HBP images and the SUV_max tumor-to-liver ratio (SUV_T/L) for both tracers were calculated. Their predictive value for aggressive pathological features-including the histological grade and microvascular invasion (MVI)-and RFS were analyzed and compared using area under receiver operating characteristic (AUROC) curves and Cox regression models, respectively.

RESULTS

The AUROCs for the identification of aggressive HCCs on pathology with LLCER, 18F-FDG SUV_T/L, and 18F-FCH SUV_T/L were 0.92 (95% CI 0.78, 0.98), 0.89 (95% CI 0.74, 0.97; p = 0.70), and 0.64 (95% CI 0.45, 0.80; p = 0.035). At multivariate Cox regression analysis, LLCER was identified as an independent predictor of RFS (HR (95% CI) = 0.91 (0.84, 0.99), p = 0.022). LLCER - 4.72% or less also accurately predicted moderate-poor differentiation grade (Se = 100%, Sp = 92.9%) and MVI (Se = 93.3%, Sp = 60%) and identified patients with poor RFS after surgical resection (p = 0.030).

CONCLUSIONS

HBP tumor enhancement after Gd-BOPTA injection may help identify aggressive HCC pathological features, and patients with reduced recurrence-free survival after surgical resection.

KEY POINTS

• In patients with resectable HCC, the quantitative analysis of the HBP tumor enhancement in Gd-BOPTA-enhanced MRI (LLCER) accurately identifies moderately-poorly differentiated and/or MVI-positive HCCs. • After surgical resection for HCC, patients with LLCER - 4.72% or less had significantly poorer recurrence-free survival than patients with LLCER superior to - 4.72%. • Gd-BOPTA-enhanced MRI with delayed HBP images may be suggested as part of pre-surgery workup in patients with resectable HCC.

Baseline and Post-treatment 18F-Fluorocholine PET/CT Predicts Outcomes in Hepatocellular Carcinoma Following Locoregional Therapy

BACKGROUND AND AIMS

¹⁸F-fluorocholine positron emission tomography/computed tomography (¹⁸F-FCH PET/CT) is an emerging functional imaging technique in the diagnosis and management of hepatocellular carcinoma (HCC). The aim of this study was to assess the ability of a pre- and post-treatment ¹⁸F-FCH PET/CT to predict prognosis and treatment response in early-stage HCC.

METHODS

Patients with early- or intermediate-stage HCC planned for locoregional therapy were prospectively enrolled. Baseline demographic and tumor information was collected and baseline and post-treatment ¹⁸F-FCH PET/CT performed. Maximum standardized uptake values (SUVmax) were determined for each HCC lesion, and the difference between baseline and post-treatment SUVmax values were compared with progression-free survival outcomes.

RESULTS

A total of 29 patients with 39 confirmed HCC lesions were enrolled from a single clinical center. Patients were mostly men (89.7%) with hepatitis C or alcohol-related cirrhosis (65.5%) and early-stage disease (89.7%). Per-patient and per-lesion sensitivity of ¹⁸F-FCH PET/CT was 72.4% and 59.0%, respectively. A baseline SUVmax < 13 was associated with a superior median progression-free survival compared with an SUVmax of > 13 (17.7 vs. 5.1 months; p = 0.006). A > 45% decrease in SUVmax between baseline and post-treatment ¹⁸F-FCH PET/CT ("responders") was associated with a superior mean progression-free survival than a percentage decrease of < 45% ("non-responders," 36.1 vs. 11.6 months; p = 0.034).

CONCLUSIONS

Baseline and post-treatment ¹⁸F-FCH PET/CT predicts outcomes in early-stage HCC undergoing locoregional therapy. This technique may identify patients with an objective response post-locoregional therapy who would benefit from further therapy.

[18 F]-Fluoro-2-deoxy-D-galactose positron emission tomography/computed tomography as complementary imaging tool in patients with hepatocellular carcinoma

BACKGROUND & AIMS

Positron emission tomography (PET) with the liver-specific tracer [¹⁸ F]-fluoro-2-deoxy-D-galactose (¹⁸ F-FDGal) can be used for imaging of hepatocellular carcinoma (HCC). Curative intended and locoregional treatments of HCC require absence of extrahepatic disease. The aim of this prospective study was to determine whether adding ¹⁸ F-FDGal PET/CT to standard work-up changes the planned treatment in patients with HCC deemed suitable for curative or locoregional treatment.

METHODS

Fifty patients with HCC were included at our tertiary liver centre. The primary study outcome was a change in treatment strategy. A subgroup of 29 patients was also examined with [¹⁸ F]-fluoro-2-deoxy-D-glucose (¹⁸ F-FDG) PET/CT for comparison.

RESULTS

¹⁸ F-FDGal PET/CT detected eight extrahepatic HCC metastases in six patients (12%), which were primarily not detected by ceCT or MRI. These findings led to a change in treatment in five patients (10%). One of the eight extrahepatic HCC foci was also detected by ¹⁸ F-FDG PET/CT. A total of 85 malignant intrahepatic foci were examined, 12 of these were new findings by ¹⁸ F-FDGal PET/CT which had a sensitivity of 71%, highest for large foci. None of the additional intrahepatic foci found by ¹⁸ F-FDGal PET changed the planned treatment.

CONCLUSIONS

For the detection of extrahepatic HCC metastases, ¹⁸ F-FDGal PET/CT was superior both to standard clinical work-up with contrast-enhanced CT, and/or MRI, and to ¹⁸ F-FDG PET/CT in patients deemed suitable for locoregional treatment. ¹⁸ F-FDGal PET/CT led to a change in the planned treatment in 10% of the patients whereas ¹⁸ F-FDG PET/CT did not change the planned treatment in any patient.

Advances in resection and transplantation for hepatocellular carcinoma

It would be impossible to summarise all of the significant developments in the surgical management of hepatocellular carcinoma (HCC), even just over the past year, in a manuscript of this scope. Thus, we have selected topics for discussion that are the subject of current controversy and have attempted to present balanced points of view. Hepatic resection and transplantation are both mature modalities, and for the most part technical advances and improvements in candidate selection are incremental. The ability to readily cure hepatitis C stands out as the most impactful development in the field over recent years, especially in Western countries where hepatitis C has long been the chief aetiology underlying HCC and a predictor of poor outcomes after surgery, but its full implications remain to be clarified. The rising incidence of non-alcoholic steatohepatitis-related HCC and what it means with regard to surgical HCC management is an area of great current interest. With advancing technology, non-surgical locoregional treatments are gaining increasing application as potentially curative therapies. In addition, the advances in molecular and genomic assessment of HCC hold promise for personalising treatment and prognostication. The possible role of immunotherapy as an adjuvant to resection is being aggressively investigated. While liver surgery maintains an important role, the care of patients with HCC is more and more a team effort and needs to take place in the context of a well-integrated interdisciplinary programme to achieve the best outcomes for patients.

Hypoxia-induced modulation of glucose transporter expression impacts 18F-fluorodeoxyglucose PET-CT imaging in hepatocellular carcinoma

PURPOSE

To investigate the molecular mechanisms underlying the variable standard uptake value (SUV) of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET-CT) imaging in hepatocellular carcinoma (HCC) and whether hypoxia-induced glucose transporter expression contributes to the progression of HCC and the rate of glycolysis in HCC cells.

MATERIALS AND METHODS

Sixteen HCC specimens obtained from patients who underwent pre-treatment staging with ¹⁸F-FDG PET-CT imaging were divided into high maximum SUV (SUV_max > 8) and low SUV_max (SUV_max < 5) groups and employed for whole-genome gene expression profiling using GeneChip Human Genome U133 Plus 2.0 Arrays. The relationship between SUV_max and the expression of glucose transporters 1 and 3 (GLUT1 and GLUT3) was further validated using immunohistochemical analysis. The expression of GLUT1 and GLUT3 in different HCC cells under hypoxia and normoxia conditions were monitored by quantitative reverse transcription PCR (RT-qPCR). Glycolysis and FDG uptake by HCC cells were measured using the Seahorse XF glycolysis stress test and ¹⁸F-FDG PET-CT imaging. The effect of GLUT1 and GLUT3 on glucose uptake in HCC cells was examined using the fluorescent D-glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) followed by detection of fluorescence produced by the cells using flow cytometry.

RESULTS

Glucose transporters are differentially expressed between samples from HCC patients with high and low SUV_max. In particular, over-expression of GLUT1 and GLUT3 in high SUV_max patients was correlated with high glucose uptake and overall survival. The expression of GLUT1 and GLUT3 was significantly induced by hypoxia in different HCC cells. High expression of GLUT1 and GLUT3 in HCC cells were correlated with high rates of glycolysis and 18F-FDG uptake. Therefore, our data suggested that hypoxia-induced glucose transporters expression could result in the variations of ¹⁸F-FDG PET-CT imaging and progression of HCC, contributing to more aggressive disease phenotypes like large tumor size, recurrence, and poor survival.

CONCLUSION

Over-expression of GLUT1 and GLUT3 significantly increase glucose uptake in HCC cells. Hypoxia-induced glucose transporters expression may therefore be a contributing variable in ¹⁸F-FDG PET-CT imaging and progression in HCC.

18F-Fluorocholine Uptake by a Head and Neck Meningeal Inflammatory Pseudotumor

F-Fluoro-ethyl-choline (F-FCH) PET/CT is widely used to study patients affected by prostate cancer. However, F-FCH may be taken-up by other neoplastic diseases, infections, and non-infective inflammatory processes. While this behavior may be an opportunity to study different diseases, on the other hand, this condition brings with it the source of error in the evaluation of the images. Here we present the case of a meningeal inflammatory pseudotumor evidenced by F-FCH.

18F-FDG PET/CT predicts microvascular invasion and early recurrence after liver resection for hepatocellular carcinoma: A prospective observational study

BACKGROUND

This study assessed the prognostic value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in the prediction of MVI and early recurrence following resection.

METHOD

This prospective study (ClinicalTrials.gov ID: NCT02145013) included 78 consecutive HCC patients who underwent 18F-FDG PET/CT before curative-intent resection from 2014 to 2017. Prognostic factors available before surgery for predicting MVI and early recurrence (≤2 years) were identified by univariate and multivariate analyses.

RESULTS

The 18F-FDG PET/CT result was positive in 30 (38%) patients. MVI was present in 33% (26/78) of specimens. Early recurrence occurred in 19% (14/74) of surviving patients. PET/CT positivity was the sole independent predictor of MVI (odds ratio [OR] = 3.6, 95% confidence interval [CI] = 1.1-11.2; p = 0.03), with a specificity and sensitivity for predicting MVI of 73% and 62%, respectively. Analysis of variables available before surgery showed that PET/CT positivity (hazard ratio [HR] = 5.8, 95% CI = 1.6-20.4; p = 0.006) and the male sex (HR = 6.6; 95% CI = 1.8-24.2; p = 0.005) were independent predictors of early recurrence.

CONCLUSION

18F-FDG PET/CT predicts MVI and early recurrence after surgery for HCC and could be used to select patients for neoadjuvant treatment.

Early-Stage Supraglottic "In Situ" Squamous Cell Carcinoma of the Larynx Incidentally Detected by 18F-Fluorocholine PET/CT

F-fluorocholine (F-FCH) PET/CT is widely used to study patients affected by prostate cancer. Despite its specificity, however, F-FCH may be taken up by other neoplasms such as multiple myeloma, lymphomas, lung, bladder, and colon cancer; brain tumors; and renal and hepatocellular carcinoma. This is due to its ability to evaluate the cell proliferation, which is typical of neoplastic cells. While this behavior may be an opportunity to image more neoplasms, on the other hand it could represent a source of error in the evaluation of the images. Here we present the case of a laryngeal squamous cell carcinoma detected by F-FCH.

Transcriptomics Associates Molecular Features with 18F-Fluorocholine PET/CT Imaging Phenotype and Its Potential Relationship to Survival in Hepatocellular Carcinoma

Studies involving transcriptomics have revealed multiple molecular subtypes of hepatocellular carcinoma (HCC). Positron emission tomography/computed tomography (PET/CT) has also identified distinct molecular imaging subtypes, including those with increased and decreased choline metabolism as measured by the tissue uptake of the radiopharmaceutical ¹⁸F-fluorocholine. Gene signatures reflecting the molecular heterogeneity of HCC may identify the biological and clinical significance of these imaging subtypes. In this study, 41 patients underwent ¹⁸F-fluorocholine PET/CT, followed by tumor resection and gene expression profiling. Over- and underexpressed components of previously published gene signatures were evaluated for enrichment between tumors with high and low ¹⁸F-fluorocholine uptake using gene set analysis. Significant gene sets were enumerated by FDR based on phenotype permutation. Associations with overall survival were analyzed by univariate and multivariate proportional hazards regression. Ten gene sets related to HCC were significantly associated with high tumor ¹⁸F-fluorocholine uptake at FDR q < 0.05, including those from three different clinical molecular classification systems and two prognostic signatures for HCC that showed predictive value in the study cohort. Tumor avidity for ¹⁸F-fluorocholine was associated with favorable characteristics based on these signatures with lower mortality based on survival analysis (HR 0.36; 95% confidence interval, 0.14-0.95). Tumors demonstrating high ¹⁸F-fluorocholine uptake were also enriched for genes involved in oxidative phosphorylation, fatty acid metabolism, peroxisome, bile acid metabolism, xenobiotic metabolism, and adipogenesis. These results provide a pathobiological framework to further evaluate ¹⁸F-fluorocholine PET/CT as a molecular and prognostic classifier in HCC. SIGNIFICANCE: A pathobiological framework for HCC brings together multiple prognostically relevant gene signatures via convergence with ¹⁸F-fluorocholine PET/CT imaging phenotype.