Clinical usefulness of FDG-PET in patients with hepatocellular carcinoma undergoing surgical resection

Quarter-Century PET/Computed Tomography Transformation of Oncology: Hepatobiliary and Pancreatic Cancer

[18F] Fluorodeoxyglucose (18F-FDG) PET/CT can improve the staging accuracy and clinical management of patients with hepatobiliary and pancreatic cancers, by detection of unsuspected metastases. 18F-FDG PET/CT metabolic parameters are valuable in predicting treatment response and survival. Metabolic response on 18F-FDG PET/CT can predict preoperative pathologic response to neoadjuvant therapy in patients with pancreatic cancer and determine prognosis. Several novel non-FDG tracers, such as 68Ga prostate-specific membrane antigen (PSMA) and 68Ga-fibroblast activation protein inhibitor (FAPI) PET/CT, show promise for imaging hepatobiliary and pancreatic cancers with potential for radioligand therapy.

Predicting Outcome after Percutaneous Ablation for Early-Stage Hepatocellular Carcinoma Using Various Imaging Modalities

Percutaneous ablation is a low-invasive, repeatable, and curative local treatment that is now recommended for early-stage hepatocellular carcinoma (HCC) that is not suitable for surgical resection. Poorly differentiated HCC has high-grade malignancy potential. Microvascular invasion is frequently seen, even in tumors smaller than 3 cm in diameter, and prognosis is poor after percutaneous ablation. Biopsy has a high risk of complications such as bleeding and dissemination; therefore, it has limitations in determining HCC tumor malignancy prior to treatment. Advances in diagnostic imaging have enabled non-invasive diagnosis of tumor malignancy. We describe the usefulness of ultrasonography, computed tomography, magnetic resonance imaging, and 18F-fluorodeoxyglucose positron emission tomography for predicting outcome after percutaneous ablation for HCC.

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.

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.

PET-guided attention for prediction of microvascular invasion in preoperative hepatocellular carcinoma on PET/CT

PURPOSE

To achieve PET/CT-based preoperative prediction of microvascular invasion in hepatocellular carcinoma by combining the advantages of PET and CT.

METHODS

This retrospective study included a total of 100 patients from two institutions who underwent PET/CT imaging. The above patients were divided into a training cohort (n = 70) and a validation cohort (n = 30). This study was based on PET/CT images to evaluate the possibility of microvascular invasion (MVI) of patients. In this study, we proposed a two-branch PET-guided attention network to predict MVI. The model used a two-branch network to extract image features from PET and CT, respectively. The PET-guided attention module aimed to enable the model to focus on the lesion region and reduce the disturbance of irrelevant and redundant information. Model performance was evaluated by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

RESULTS

The method outperformed the single-modality prediction model for preoperative hepatocyte microvascular invasion, achieving an AUC of 0.907. On the validation set, accuracy reached 0.846, precision reached 0.881, recall 0.793, and F1-score 0.835.

CONCLUSION

The model exploits the particularities of the molecular metabolic function of PET and the anatomical structure of CT and can strongly improve the accuracy of clinical diagnosis of MVI.

Role of preoperative prediction of microvascular invasion in hepatocellular carcinoma based on the texture of FDG PET image: A comparison of quantitative metabolic parameters and MRI

Objective: To investigate the role of prediction microvascular invasion (mVI) in hepatocellular carcinoma (HCC) by ¹⁸F-FDG PET image texture analysis and hybrid criteria combining PET/CT and multi-parameter MRI.

Materials and methods: Ninety-seven patients with HCC who received the examinations of MRI and ¹⁸F-FDG PET/CT were retrospectively included in this study and were randomized into training and testing cohorts. The lesion image texture features of ¹⁸F-FDG PET were extracted using MaZda software. The optimal predictive texture features of mVI were selected, and the classification procedure was conducted. The predictive performance of mVI by radiomics classier in training and testing cohorts was respectively recorded. Next, the hybrid model was developed by integrating the ¹⁸F-FDG PET image texture, metabolic parameters, and MRI parameters to predict mVI through logistic regression. Furthermore, the diagnostic performance of each time was recorded.

Results: The ¹⁸F-FDG PET image radiomics classier showed good predicted performance in both training and testing cohorts to discriminate HCC with/without mVI, with an AUC of 0.917 (95% CI: 0.824–0.970) and 0.771 (95% CI: 0.578, 0.905). The hybrid model, which combines radiomics classier, SUVmax, ADC, hypovascular arterial phase enhancement pattern on contrast-enhanced MRI, and non-smooth tumor margin, also yielded better predictive performance with an AUC of 0.996 (95% CI: 0.939, 1.000) and 0.953 (95% CI: 0.883, 1.000). The differences in AUCs between radiomics classier and hybrid classier were significant in both training and testing cohorts (DeLong test, both p < 0.05).

Conclusion: The radiomics classier based on ¹⁸F-FDG PET image texture and the hybrid classier incorporating ¹⁸F-FDG PET/CT and MRI yielded good predictive performance, which might provide a precise prediction of HCC mVI preoperatively.

Radiomics for the detection of microvascular invasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, accounting for about 90% of liver cancer cases. It is currently the fifth most common cancer in the world and the third leading cause of cancer-related mortality. Moreover, recurrence of HCC is common. Microvascular invasion (MVI) is a major factor associated with recurrence in postoperative HCC. It is difficult to evaluate MVI using traditional imaging modalities. Currently, MVI is assessed primarily through pathological and immunohistochemical analyses of postoperative tissue samples. Needle biopsy is the primary method used to confirm MVI diagnosis before surgery. As the puncture specimens represent just a small part of the tumor, and given the heterogeneity of HCC, biopsy samples may yield false-negative results. Radiomics, an emerging, powerful, and non-invasive tool based on various imaging modalities, such as computed tomography, magnetic resonance imaging, ultrasound, and positron emission tomography, can predict the HCC-MVI status preoperatively by delineating the tumor and/or the regions at a certain distance from the surface of the tumor to extract the image features. Although positive results have been reported for radiomics, its drawbacks have limited its clinical translation. This article reviews the application of radiomics, based on various imaging modalities, in preoperative evaluation of HCC-MVI and explores future research directions that facilitate its clinical translation.

Current Trends in Non-Invasive Imaging of Interactions in the Liver Tumor Microenvironment Mediated by Tumor Metabolism

Simple Summary

Deregulated tumor metabolism is known to shape the tumor microenvironment and directly affect the local immune response, promoting tumor growth, metastasis, and resistance to treatment. However, the metabolic profile or tumor cells, and therefore, the composition of their microenvironment, are highly variable among patients and even within the same tumor, resulting in heterogeneous response rates to oncologic therapies, making patient selection a key issue. This review article focuses on non-invasive imaging techniques that aim to visualize the crosstalk between tumor cells and their microenvironment in liver cancer mediated by tumor metabolism. In addition to improved tumor detection, such imaging tools may be able to provide a more accurate characterization of the individual tumor and ultimately improve understanding, as well as guide personalized treatment regimens for patients with liver cancer.

Abstract

With the increasing understanding of resistance mechanisms mediated by the metabolic reprogramming in cancer cells, there is a growing clinical interest in imaging technologies that allow for the non-invasive characterization of tumor metabolism and the interactions of cancer cells with the tumor microenvironment (TME) mediated through tumor metabolism. Specifically, tumor glycolysis and subsequent tissue acidosis in the realms of the Warburg effect may promote an immunosuppressive TME, causing a substantial barrier to the clinical efficacy of numerous immuno-oncologic treatments. Thus, imaging the varying individual compositions of the TME may provide a more accurate characterization of the individual tumor. This approach can help to identify the most suitable therapy for each individual patient and design new targeted treatment strategies that disable resistance mechanisms in liver cancer. This review article focuses on non-invasive positron-emission tomography (PET)- and MR-based imaging techniques that aim to visualize the crosstalk between tumor cells and their microenvironment in liver cancer mediated by tumor metabolism.

2-[18F]FDG PET/CT as a Predictor of Microvascular Invasion and High Histological Grade in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) generally presents a low avidity for 2-deoxy-2-[18F]fluoro-d-glucose (FDG) in PET/CT although an increased FDG uptake seems to relate to more aggressive biological factors. To define the prognostic value of PET/CT with FDG in patients with an HCC scheduled for a tumor resection, forty-one patients were prospectively studied. The histological factors of a poor prognosis were determined and FDG uptake in the HCC lesions was analyzed semi-quantitatively (lean body mass-corrected standardized uptake value (SUL) and tumor-to-liver ratio (TLR) at different time points). The PET metabolic parameters were related to the histological characteristics of the resected tumors and to the evolution of patients. Microvascular invasion (MVI) and a poor grade of differentiation were significantly related to a worse prognosis. The SULpeak of the lesion 60 min post-FDG injection was the best parameter to predict MVI while the SULpeak of the TLR at 60 min was better for a poor differentiation. Moreover, the latter parameter was also the best preoperative variable available to predict any of these two histological factors. Patients with an increased TLRpeak60 presented a significantly higher incidence of poor prognostic factors than the rest (75% vs. 28.6%, p = 0.005) and a significantly higher incidence of recurrence at 12 months (38% vs. 0%, p = 0.014). Therefore, a semi-quantitative analysis of certain metabolic parameters on PET/CT can help identify, preoperatively, patients with histological factors of a poor prognosis, allowing an adjustment of the therapeutic strategy for those patients with a higher risk of an early recurrence.

The development of a Glypican-3-specific binding peptide using in vivo and in vitro two-step phage display screening for the PET imaging of hepatocellular carcinoma

Glypican-3 (GPC3) is a diagnostic biomarker for hepatocellular carcinoma (HCC). Although numerous designs targeting GPC3 have been reported, the HCC diagnostic agents with specific tumor accumulation and low background, particularly in normal liver tissue, are still in need. Peptides have attracted considerable attention as an imaging probe due to their low immunogenicity, short in vivo circulation time, and acceptable production cost. Herein, a two-step phage display screening approach was performed against GPC3-high expression tumor xenografts in vivo, followed by human recombinant GPC3 protein in vitro. A GPC3-specific binding peptide, named TJ12P2, with the sequence of Ser-Asn-Asp-Arg-Pro-Pro-Asn-Ile-Leu-Gln-Lys-Arg (SNDRPPNILQKR) was identified. The apparent Kd value between TJ12P2 and the GPC3 protein was measured as 158.2 ± 26.25 nM. After 18F labeling, 18F-AlF-NOTA-TJ12P2 was found accumulated in the tumors by positron emission tomography (PET) imaging in two HCC subcutaneous tumor models (HepG2 and SMMC-7721) with high GPC3 expression. Static PET imaging revealed that 18F-AlF-NOTA-TJ12P2 accumulation in the HepG2 and SMMC-7721 tumors reached 1.825 ± 0.296 %ID g-1 and 1.575 ± 0.520 %ID g-1, with tumor-to-muscle ratios of 4.14 ± 0.50 and 4.25 ± 0.25, respectively, at 30 min post-injection (p.i.). Much less accumulation (0.533 ± 0.078 %ID g-1) of the 18F-AlF-NOTA-TJ12P2 was found in the control PC3 tumors with low GPC3 expression. More importantly, no obvious normal liver uptake of TJ12P2 was observed in the abovementioned animal models. As a result, a novel peptide targeting GPC3, TJ12P2, with strong affinity and specificity was identified using a two-step phage display screening technique in the present study. The 18F-AlF-NOTA-TJ12P2 may be a promising PET imaging probe with translational potential for accurate HCC diagnosis.

Pembrolizumab Exacerbates Thyroid Diseases Shown on FDG PET/CT

A 51-year-old woman with a history of sarcomatoid hepatocellular carcinoma, status post resection, underwent FDG PET/CT. In addition to abnormal activity elsewhere, the images showed focal activity in the isthmus of the thyroid, suggestive of malignant involvement, and diffuse mild activity in the left lobe of the thyroid, suggestive of thyroiditis. After a 10-week anti-PD-1 pembrolizumab therapy, the follow-up FDG PET/CT scan demonstrated much more intense activity in both the isthmus and the left lobe of the thyroid. Pathological examination revealed papillary thyroid cancer in the isthmus and thyroiditis in the left lobe of the thyroid.

Role of PET/CT in patients with unexplained rising alpha fetoprotein post HCC interventional management

Background

Positron emission tomography–computed tomography (PET/CT) is considered a powerful modality in the follow-up of hepatocellular carcinoma (HCC) patients. In this study, PET/CT was done in an evaluation of patients with unexplained rising alpha fetoprotein (AFP) post hepatocellular carcinoma (HCC) interventional management in 40 patients (16 females and 24 males); their age ranged from 25 to 82 years, had undergone interventional management for HCC and underwent PET/CT follow-up within an 8-month duration from their intervention. Whole-body PET/CT was performed after injection of (18)-FDG, and the results were read in a masked manner by two specialists, and diagnostic performance was assessed from the results of consensus masked reading. All the results were evaluated with the Barcelona criteria and biopsy correlation.

Results

During the follow-up PET/CT, 24 patients had complete response and 8 patients showed focal residual while the rest 8 patients showed newly developed lesions.

Conclusion

PET/CT is an excellent method for the evaluation of HCC patients with equivocal results after interventional management.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

PET and MRI based RT treatment planning: Handling uncertainties

Imaging provides the basis for radiotherapy. Multi-modality images are used for target delineation (primary tumor and nodes, boost volume) and organs at risk, treatment guidance, outcome prediction, and treatment assessment. Next to anatomical information, more and more functional imaging is being used. The current paper provides a brief overview of the different applications of imaging techniques used in the radiotherapy process, focusing on uncertainties and QA. The paper mainly focuses on PET and MRI, but also provides a short discussion on DCE-CT. A close collaboration between radiology, nuclear medicine and radiotherapy departments provides the key to improve the quality of radiotherapy. Jointly developed imaging protocols (RT position setup, immobilization tools, lasers, flat table…), and QA programs are mandatory. For PET, suitable windowing in consultation with a Nuclear Medicine Physician is crucial (differentiation benign/malignant lesions, artifacts…). A basic knowledge of MRI sequences is required, in such a way that geometrical distortions are easily recognized by all members the RT and RT physics team. If this is not the case, then the radiologist should be introduced systematically in the delineation process and multidisciplinary meetings need to be organized regularly. For each image modality and each image registration process, the associated uncertainties need to be determined and integrated in the PTV margin. When using functional information for dose painting, response assessment or outcome prediction, collaboration between the different departments is even more important. Limitations of imaging based biomarkers (specificity, sensitivity) should be known.

Hepatocellular carcinoma - time to take the ticket

Hepatocellular carcinoma is one of the leading malignancies worldwide. Early detection of hepatocellular carcinoma and its management in the form of liver transplantation offers an attractive treatment option. The Milan criteria, proposed by Mazzaferro et al, have been the standard for selecting patients with hepatocellular carcinoma for transplantation. Recently, several studies have shown that even patients selected outside the Milan criteria can undergo transplantation with a relatively good outcome. This article examines the currently existing criteria other than the Milan criteria and also evaluates use of alpha-fetoprotein and positron emission tomography scans to predict the chance of recurrence.

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.

Emerging role of 18F-fluorodeoxyglucose positron emission tomography for guiding management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of major causes of cancer mortality worldwide. For decades, ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been widely used for staging, predicting prognosis, and detecting cancer recurrence in various types of malignant diseases. Due to low sensitivity of FDG PET for detecting intrahepatic HCC lesions, the clinical value of FDG PET in HCC patients has been limited. However, recent studies with diverse analytic methods have shown that FDG PET has promising role in aiding management of HCC patients. In this review, we will discuss the clinical role of FDG PET for staging, predicting prognosis, and evaluating treatment response in HCC. Further, we will focus on recent clinical studies regarding implication of volumetric FDG PET parameters, the significance of FDG uptake in HCC for selecting treatment and predicting treatment response, and the use of radiomics of FDG PET in HCC.

18F-fludeoxyglucose positron emission tomography for diagnosis of HCC: implications for therapeutic strategy in curative and non-curative approaches

Hepatocellular carcinoma (HCC) is a global health issue with increasing incidence and high mortality rate. Depending on the tumor load and extent of underlying liver cirrhosis, aggressive surgical treatment by hepatectomy or liver transplantation (LT) may lead to cure, whereas different modalities of liver-directed locoregional or systemic tumor treatments are currently available for a noncurative approach. Apart from tumor burden and grade of liver dysfunction, assessment of prognostic relevant biological tumor aggressiveness is vitally important for establishing a promising multimodal therapeutic strategy and improving the individual treatment-related risk/benefit ratio. In recent years, an increasing body of clinical evidence has been presented that ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), which is a standard nuclear imaging device in oncology, may serve as a powerful surrogate for tumor invasiveness and prognosis in HCC patients and, thereby, impact individual decision making on most appropriate therapy concept. This review describes the currently available data on the prognostic value of ¹⁸F-FDG PET in patients with early and advanced HCC stages and the resulting implications for treatment strategy.