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

LINC01004/hsa-mir-125b-2-3p axis restrains ferroptosis in hepatocellular carcinoma by targeting HSPA4 via ceRNA mechanism

BackgroundHepatocellular carcinoma (HCC) is a primary cancer, accounting for 90% of primary liver cancer, mainly occurring in patients with cirrhosis and chronic liver disease.ObjectiveTo investigate the latent mechanisms of hepatocellular carcinoma (HCC) and find therapeutic targets.MethodsDifferentially expressed and overall survival related genes of HCC, and cell death related genes were intersected to obtain latent target genes. These genes were analyzed using ROC curve for diagnosing HCC. RT-qPCR and Western blot were performed to detect the expression level of genes. Wound healing tests were performed with or without si-HSPA4. Potential ceRNA axis was forecasted using TargetScan and miRanda and the dual luciferase reporter gene assay was used to verify the results. Finally, the images of H&E dye liquor-stained HCC tissue section, the CT images for patients in different tumor stage.ResultsLINC01004/hsa-miR-125b-2-3p/HSPA4 axis was forecasted and then was verified using dual-luciferase reporter assay. HSPA4 knockdown caused significant reduction of cell proliferation and ferroptosis. Si-HSPA4 related ferroptosis was generated through impairing iron transport via targeting restrain GPX4. For human subjects, the RT-qPCR analysis revealed the that the larger the tumor diameter, the higher the LINC01004, HSPA4, and GPX4 expression, and the lower the hsa-miR-125b-2-3p expression.ConclusionLINC01004/hsa-miR-125b-2-3p/HSPA4 regulatory axis involved in the ferroptosis of the progression of HCC via GPX4 dependent method, providing new therapeutic targets for HCC patients.

Early prediction of microvascular invasion (MVI) occurrence in hepatocellular carcinoma (HCC) by 18F-FDG PET/CT and laboratory data

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the deadliest malignant tumors in China. Microvascular invasion (MVI) often indicates poor prognosis and metastasis in HCC patients. 18F-FDG PET-CT is a new imaging method commonly used to screen for tumor occurrence and evaluate tumor stage.

PURPOSE

This study attempted to predict the occurrence of MVI in early-stage HCC through 18F-FDG positron emission tomography (PET)/computed tomography (CT) imaging findings and laboratory data.

PATIENTS AND METHODS

A total of 113 patients who met the inclusion criteria were divided into two groups based on postoperative pathology: the MVI-positive group and MVI-negative group. We retrospectively analyzed the imaging findings and laboratory data of 113 patients. Imaging findings included tumor size, tumor maximum standard uptake value (SUVmaxT), and normal liver maximum standard uptake value (SUVmaxL). The ratios of SUVmaxT to SUVmaxL (SUVmaxT/L) and an SUVmaxT/L > 2 were defined as active tumor metabolism. The tumor size was indicated by the maximum diameter of the tumor, and a diameter greater than 5 cm was defined as a mass lesion. The laboratory data included the alpha-fetoprotein (AFP) level and the HBeAg level. An AFP concentration > 20 ng/mL was defined as a high AFP level. A HBeAg concentration > 0.03 NCU/mL was defined as HB-positive.

RESULTS

The SUVmaxT/L (p = 0.003), AFP level (p = 0.008) and tumor size (p = 0.015) were significantly different between the two groups. Patients with active tumor metabolism, mass lesions and high AFP levels tended to be MVI positive. Binary logistic regression analysis verified that active tumor metabolism (OR = 4.124, 95% CI, 1.566-10.861; p = 0.004) and high AFP levels (OR = 2.702, 95% CI, 1.214-6.021; p = 0.015) were independent risk factors for MVI. The sensitivity of the combination of these two independent risk factors predicting HCC with MVI was 56.9% (29/51), the specificity was 83.9% (52/62) and the accuracy was 71.7% (81/113).

CONCLUSION

Active tumor metabolism and high AFP levels can predict the occurrence of MVI in HCC patients.

Prostate-Specific Membrane Antigen Positron Emission Tomography Oncological Applications beyond Prostate Cancer in Comparison to Other Radiopharmaceuticals

BACKGROUND

Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein overexpressed on the surface of tumor cells in most of the patients affected by prostate adenocarcinoma (PCa). However, PSMA expression has also been demonstrated in the endothelial cells of newly formed vessels of various solid tumors, suggesting a role for PSMA in neoangiogenesis. In this scenario, gallium-68 (68Ga) or fluoro-18 (18F)-labeled PSMA positron emission tomography (PET) may play a role in tumors other than PCa, generally evaluated employing other radiopharmaceuticals targeting different pathways. This review aims to investigate the detection rate of PSMA-PET compared to other radiopharmaceuticals (especially [18F]FDG) in non-prostate tumors to identify patients who may benefit from the use of such a theragnostic agent.

METHODS

We performed a bibliographic search on three different databases until February 2024 using the following terms: "positron emission tomography", "PET", "PET/CT", "Prostate-specific membrane antigen", "PSMA", "non-prostate", "not prostate cancer", "solid tumor", "FDG", "Fluorodeoxyglucose", "FAPi", "FET", "MET", "DOPA", "choline", "FCH", "FES", "DOTATOC", "DOTANOC", and "DOTATATE". Only original articles edited in English with at least 10 patients were included.

RESULTS

Out of a total of 120 articles, only 25 original articles comparing PSMA with other radiotracers were included in this study. The main evidence was demonstrated in renal cell carcinoma, where PSMA showed a higher detection rate compared to [18F]FDG PET/CT, with implications for patient management. PSMA PET may also improve the assessment of other entities, such as gliomas, in defining regions of early neoangiogenesis. Further data are needed to evaluate the potential role of PSMA-PET in triple-negative breast cancer as a novel therapeutic vascular target. Finally, unclear applications of PSMA-PET include thyroid and gastrointestinal tumors.

CONCLUSIONS

The present review shows the potential use of PSMA-labeled PET/CT in solid tumors beyond PCa, underlining its value over other radiopharmaceuticals (mainly [18F]FDG). Prospective clinical trials with larger sample sizes are crucial to further investigate these possible clinical applications.

Bench to Bedside Development of [18F]Fluoromethyl-(1,2-2H4)choline ([18F]D4-FCH)

Malignant transformation is characterised by aberrant phospholipid metabolism of cancers, associated with the upregulation of choline kinase alpha (CHKα). Due to the metabolic instability of choline radiotracers and the increasing use of late-imaging protocols, we developed a more stable choline radiotracer, [18F]fluoromethyl-[1,2-2H4]choline ([18F]D4-FCH). [18F]D4-FCH has improved protection against choline oxidase, the key choline catabolic enzyme, via a 1H/2D isotope effect, together with fluorine substitution. Due to the promising mechanistic and safety profiles of [18F]D4-FCH in vitro and preclinically, the radiotracer has transitioned to clinical development. [18F]D4-FCH is a safe positron emission tomography (PET) tracer, with a favourable radiation dosimetry profile for clinical imaging. [18F]D4-FCH PET/CT in lung and prostate cancers has shown highly heterogeneous intratumoral distribution and large lesion variability. Treatment with abiraterone or enzalutamide in metastatic castrate-resistant prostate cancer patients elicited mixed responses on PET at 12-16 weeks despite predominantly stable radiological appearances. The sum of the weighted tumour-to-background ratios (TBRs-wsum) was associated with the duration of survival.

Emerging theragnostic radionuclide applications for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major global health problem. Theragnostic is a term that refers to the integration of diagnostic and therapeutic modalities into a single system for personalized medicine. Theragnostic care in HCC involves the use of imaging techniques to diagnose the cancer and assess its characteristics, such as size, location, and extent of spread. Theragnostics involves the use of molecular and genetic tests to identify specific biomarkers that can help guide treatment decisions and, post-treatment, assess the dosimetry and localization of the treatment, thus guiding future treatment. This can be done through either positron emission tomography (PET) scanning or single photon emission tomography (SPECT) using radiolabeled tracers that target specific molecules expressed by HCC cells or radioembolization. This technique can help identify the location and extent of the cancer, as well as provide information on the tumor's metabolic activity and blood supply. In summary, theragnostics is an emerging field that holds promise for improving the diagnosis and treatment of HCC. By combining diagnostic and therapeutic modalities into a single system, theragnostics can help guide personalized treatment decisions and improve patient outcomes.

A dual-tracer approach using [11C]CH and [18F]FDG in HCC clinical decision making

BACKGROUND

Early detection of recurrent or progressive HCC remains the strongest prognostic factor for survival. Dual tracer PET/CT imaging with [11C]CH and [18F]FDG can further increase detection rates as both tracers entail different metabolic pathways involved in HCC development. We investigated dual-tracer PET/CT in clinical decision making in patients suspected of recurrent or progressive HCC. All HCC patients who underwent both [11C]CH and [18F]FDG PET/CT in our institute from February 2018 to December 2021 were included. Both tracer PET/CT were within 4 weeks of each other with at least 6-month follow-up. Patients underwent dual tracer PET/CT because of unexplained and suspicious CT/MRI or sudden rise of serum tumour markers. A detected lesion was considered critical when the finding had prognostic consequences leading to treatment changes.

RESULTS

Nineteen patients who underwent [11C]CH and [18F]FDG PET/CT were included of which all but six patients were previously treated for HCC. Dual-tracer critical finding detection rate was 95%, with [18F]FDG 68%, and [11C]CH 84%. Intrahepatic HCC recurrence finding rate was 65% for both tracers. [18F]FDG found more ablation site recurrences (4/5) compared to [11C]CH (2/5). Only [11C]CH found two needle tract metastases. Both tracers found 75% of the positive lymph nodes. Two new primary tumours were found, one by [18F]FDG and both by [11C]CH.

CONCLUSIONS

Our study favours a dual-tracer approach in HCC staging in high-risk patients or when conventional imaging is non-conclusive.

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.

Imaging Diagnosis of Hepatocellular Carcinoma: A State-of-the-Art Review

Hepatocellular carcinoma (HCC) remains not only a cause of a considerable part of oncologic mortality, but also a diagnostic and therapeutic challenge for healthcare systems worldwide. Early detection of the disease and consequential adequate therapy are imperative to increase patients' quality of life and survival. Imaging plays, therefore, a crucial role in the surveillance of patients at risk, the detection and diagnosis of HCC nodules, as well as in the follow-up post-treatment. The unique imaging characteristics of HCC lesions, deriving mainly from the assessment of their vascularity on contrast-enhanced computed tomography (CT), magnetic resonance (MR) or contrast-enhanced ultrasound (CEUS), allow for a more accurate, noninvasive diagnosis and staging. The role of imaging in the management of HCC has further expanded beyond the plain confirmation of a suspected diagnosis due to the introduction of ultrasound and hepatobiliary MRI contrast agents, which allow for the detection of hepatocarcinogenesis even at an early stage. Moreover, the recent technological advancements in artificial intelligence (AI) in radiology contribute an important tool for the diagnostic prediction, prognosis and evaluation of treatment response in the clinical course of the disease. This review presents current imaging modalities and their central role in the management of patients at risk and with 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.

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.

Can PSMA-Targeting Radiopharmaceuticals Be Useful for Detecting Hepatocellular Carcinoma Using Positron Emission Tomography? An Updated Systematic Review and Meta-Analysis

BACKGROUND

Several studies proposed the use of positron emission tomography (PET) with Prostate-Specific Membrane Antigen (PSMA)-targeting radiopharmaceuticals in hepatocellular carcinoma (HCC). Our aim is to calculate the detection rate (DR) of this examination in HCC with a meta-analysis.

METHODS

A comprehensive literature search of studies on the DR of PET/CT or PET/MRI with PSMA-targeting radiopharmaceuticals in HCC was performed. Original articles evaluating these imaging examinations both in newly diagnosed HCC patients and HCC patients with disease relapse were included. Pooled DR including 95% confidence intervals (95% CI) was calculated. Statistical heterogeneity was also assessed using the I2 test.

RESULTS

The meta-analysis of six selected studies (126 patients) provided a DR of 85.9% for PET imaging with PSMA-targeting radiopharmaceuticals in the diagnosis of HCC. Moderate statistical heterogeneity among the included studies was found (I2 = 56%).

CONCLUSIONS

The quantitative data provided demonstrate the high DR of PET/CT or PET/MRI with PSMA-targeting radiopharmaceuticals for HCC lesion detection. However, more studies are needed to confirm the promising role of PSMA-targeted PET in 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.