Prediction of Tumor Recurrence by 18F-FDG PET in Liver Transplantation for Hepatocellular Carcinoma

Micro-Nano Convergence-Driven Radiotheranostic Revolution in Hepatocellular Carcinoma

Radiotherapy, as an important means of treating hepatocellular carcinoma (HCC), has shown unique therapeutic advantages, especially in patients who are unable to undergo surgery or transplantation. It mainly includes external radiotherapy, transarterial radioembolization and intratumoral radioactive particle implantation. However, under the influence of factors such as the hypoxic characteristics of the liver tumor microenvironment and the radioresistance of tumor cells, the effect of radiotherapy may be unstable and may cause side effects, affecting the quality of life of patients. In recent years, with the development of nanotechnology, drug delivery systems based on micro-nanomaterials have provided new solutions for improving the effect of radiotherapy for HCC. Despite this, the application of micro-nano drug delivery systems in the treatment of HCC still faces some challenges, mainly including the in vivo safety and in vivo metabolism of micro-nano materials. This article reviews the latest progress of micro-nano materials in the treatment of HCC, especially their application in radiosensitization and their clinical translation potential. This article systematically analyzes the role of micro-nanomaterials in external or internal radiotherapy sensitization and radioimmunotherapy and explores the advantages of micro-nanomaterials in improving the treatment effect of HCC.

Criteria and prognostic models for patients with hepatocellular carcinoma undergoing liver transplantation

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated death globally. Liver transplantation (LT) has emerged as a key treatment for patients with HCC, and the Milan criteria have been adopted as the cornerstone of the selection policy. To allow more patients to benefit from LT, a number of expanded criteria have been proposed, many of which use radiologic morphological characteristics with larger and more tumors as surrogates to predict outcomes. Other groups developed indices incorporating biological variables and dynamic markers of response to locoregional treatment. These expanded selection criteria achieved satisfactory results with limited liver supplies. In addition, a number of prognostic models have been developed using clinicopathological characteristics, imaging radiomics features, genetic data, and advanced techniques such as artificial intelligence. These models could improve prognostic estimation, establish surveillance strategies, and bolster long-term outcomes in patients with HCC. In this study, we reviewed the latest findings and achievements regarding the selection criteria and post-transplant prognostic models for LT in patients with HCC.

A review of F-18 fluorodeoxyglucose PET/CT in the evaluation and treatment of hepatobiliary tumors

Hepatocellular carcinoma (HCC) and biliary tract cancers (BTC) pose significant diagnostic and therapeutic challenges. Magnetic resonance imaging (MRI) and multiphase computed tomography (CT) have been the preferred imaging modalities for diagnosis, staging, and surveillance of patients with these malignancies. The best clinical outcomes depend on the appropriate selection of treatment options from the tools available in neo-adjuvant therapy, surgical resection, locoregional therapy, liver transplantation, and adjuvant therapy. While not a part of the routine diagnostic work-up or follow-up, F-18 fluorodeoxyglucose positron emission tomography (FDG PET/CT) can inform therapeutic decision making and help avoid futile surgeries by detecting unsuspected distant metastases. Additionally, metabolic information obtained with FDG PET/CT has prognostic value, predicting treatment response and survival. In patients with HCC metabolic parameters obtained by FDG PET/CT have been shown to correlate with microvascular invasion and predict recurrence in orthotopic transplant recipients. This article will highlight studies that have evaluated the role of FDG PET/CT in diagnosis, staging and therapeutic response assessment in patients with hepatobiliary cancers.

Correlation between 18 F-FDG PET/CT metabolic parameters and microvascular invasion before liver transplantation in patients with hepatocellular carcinoma

BACKGROUND

Microvascular infiltration (MVI) before liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) is associated with postoperative tumor recurrence and survival. MVI is mainly assessed by pathological analysis of tissue samples, which is invasive and heterogeneous. PET/computed tomography (PET/CT) with 18 F-labeled fluorodeoxyglucose ( 18 F-FDG) as a tracer has been widely used in the examination of malignant tumors. This study investigated the association between 18 F-FDG PET/CT metabolic parameters and MVI before LT in HCC patients.

METHODS

About 124 HCC patients who had 18 F-FDG PET/CT examination before LT were included. The patients' clinicopathological features and 18 F-FDG PET/CT metabolic parameters were recorded. Correlations between clinicopathological features, 18 F-FDG PET/CT metabolic parameters, and MVI were analyzed. ROC curve was used to determine the optimal diagnostic cutoff value, area under the curve (AUC), sensitivity, and specificity for predictors of MVI.

RESULT

In total 72 (58.06%) patients were detected with MVI among the 124 HCC patients. Univariate analysis showed that tumor size ( P  = 0.001), T stage ( P  < 0.001), maximum standardized uptake value (SUV max ) ( P  < 0.001), minimum standardized uptake value (SUV min ) ( P  = 0.031), mean standardized uptake value (SUV mean ) ( P  = 0.001), peak standardized uptake value (SUV peak ) ( P  = 0.001), tumor-to-liver ratio (SUV ratio ) ( P  = 0.010), total lesion glycolysis (TLG) ( P  = 0.006), metabolic tumor volume (MTV) ( P  = 0.011) and MVI were significantly different. Multivariate logistic regression showed that tumor size ( P  = 0.018), T stage ( P  = 0.017), TLG ( P  = 0.023), and MTV ( P  = 0.015) were independent predictors of MVI. In the receiver operating characteristic curve, TLG predicted MVI with an AUC value of 0.645. MTV predicted MVI with an AUC value of 0.635. Patients with tumor size ≥5 cm, T3-4, TLG > 400.67, and MTV > 80.58 had a higher incidence of MVI.

CONCLUSION

18 F-FDG PET/CT metabolic parameters correlate with MVI and may be used as a noninvasive technique to predict MVI before LT in HCC patients.

Combined Hounsfield units of hepatocellular carcinoma on computed tomography and PET as a noninvasive predictor of early recurrence after living donor liver transplantation: Time-to-recurrence survival analysis

BACKGROUND

Liver transplantation is an effective treatment for preventing hepatocellular carcinoma (HCC) recurrence. This retrospective study aimed to quantitatively evaluate the attenuation in Hounsfield units (HU) on contrast-enhanced computed tomography (CECT) as a prognostic factor for hepatocellular carcinoma (HCC) following liver transplantation as a treatment. Our goal is to optimize its predictive ability for early tumor recurrence and compare it with the other imaging modality-positron emission tomography (PET).

METHODS

In 618 cases of LDLT for HCC, only 131 patients with measurable viable HCC on preoperative CECT and preoperative positron emission tomography (PET) evaluations were included, with a minimum follow-up period of 6 years. Cox regression models were developed to identify predictors of postoperative recurrence. Performance metrics for both CT and PET were assessed. The correlation between these two imaging modalities was also evaluated. Survival analyses were conducted using time-dependent receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) to assess accuracy and determine optimized cut-off points.

RESULTS

Univariate and multivariate analyses revealed that both arterial-phase preoperative tumor attenuation (HU) and PET were independent prognostic factors for recurrence-free survival. Both lower arterial tumor enhancement (Cut-off value = 59.2, AUC 0.88) on CT and PET positive (AUC 0.89) increased risk of early tumor recurrence 0.5-year time-dependent ROC. Composites with HU < 59.2 and a positive PET result exhibited significantly higher diagnostic accuracy in detecting early tumor recurrence (AUC = 0.96).

CONCLUSION

Relatively low arterial tumor enhancement values on CECT effectively predict early HCC recurrence after LDLT. The integration of CT and PET imaging may serve as imaging markers of early tumor recurrence in HCC patients after LDLT.

The potential of 18F-FDG PET/CT metabolic parameter-based nomogram in predicting the microvascular invasion of hepatocellular carcinoma before liver transplantation

PURPOSE

Microvascular invasion (MVI) is a critical factor in predicting the recurrence and prognosis of hepatocellular carcinoma (HCC) after liver transplantation (LT). However, there is a lack of reliable preoperative predictors for MVI. The purpose of this study is to evaluate the potential of an 18F-FDG PET/CT-based nomogram in predicting MVI before LT for HCC.

METHODS

83 HCC patients who obtained 18F-FDG PET/CT before LT were included in this retrospective research. To determine the parameters connected to MVI and to create a nomogram for MVI prediction, respectively, Logistic and Cox regression models were applied. Analyses of the calibration curve and receiver operating characteristic (ROC) curves were used to assess the model's capability to differentiate between clinical factors and metabolic data from PET/CT images.

RESULTS

Among the 83 patients analyzed, 41% were diagnosed with histologic MVI. Multivariate logistic regression analysis revealed that Child-Pugh stage, alpha-fetoprotein, number of tumors, CT Dmax, and Tumor-to-normal liver uptake ratio (TLR) were significant predictors of MVI. A nomogram was constructed using these predictors, which demonstrated strong calibration with a close agreement between predicted and actual MVI probabilities. The nomogram also showed excellent differentiation with an AUC of 0.965 (95% CI 0.925-1.000).

CONCLUSION

The nomogram based on 18F-FDG PET/CT metabolic characteristics is a reliable preoperative imaging biomarker for predicting MVI in HCC patients before undergoing LT. It has demonstrated excellent efficacy and high clinical applicability.

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.

Can 18F-FDG PET/CT findings be used to predict orbital tumor histology?

PURPOSE

To investigate whether 18F-FDG PET/CT might be useful to predict the histology of various orbital tumors based on the maximum standard uptake value (SUVmax) and the OMSUV (orbital max SUV)/MLSUV (mean liver SUV) ratio.

PATIENTS AND METHODS

A retrospective single-center study was conducted between May 2019 and December 2020. Patients with an orbital mass who underwent preoperative 18F-FDG PET/CT followed by an orbital biopsy were included. Tumor histology was classified as follows: orbital inflammation, solid tumor, low-grade lymphoid tumor, and high-grade lymphoid tumor. Orbital tumors were also classified as indolent or aggressive. Data recorded included the orbital SUVmax, OMSUV/MLSUV ratio and additional extra-orbital SUV sites.

RESULTS

Forty-five patients (24 men) were included. There were 15 (33.3%), 14 (31.1%), 9 (20%), and 7 (15.5%) cases of orbital inflammation, solid tumor, low-grade lymphoid tumor, and high-grade lymphoid tumor, respectively. No correlation was found between the OMSUV/MLSUV ratio and orbital SUVmax and tumor histology (Z = -0.77, Z = -0.6, Z = -1.6, and Z = 0.94, all P > 0.05, respectively). No correlation was found between the OMSUV/MLSUV ratio (Z = -1.42, P > 0.05) and orbital SUVmax (Z = -0.82, P > 0.05) and tumor aggressiveness (indolent versus aggressive). Subgroup analyses showed that SUVmax was predictive of lymphoma aggressiveness (P = 0.05) and was able to distinguish orbital cancers (all lymphomas+solid tumors) from benign tumors (P = 0.02).

CONCLUSION

18F-FDG PET/CT could not be used to predict the underlying orbital tumor histology. However, more aggressive tumors, especially high-grade lymphomas and cancers, tended to have a higher orbital SUVmax compared to indolent lesions.

Head-to-head comparison of 18F-FAPI and 18F-FDG PET/CT in staging and therapeutic management of hepatocellular carcinoma

BACKGROUND

Fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has limitations in staging hepatocellular carcinoma (HCC). The recently introduced 18F-labeled fibroblast-activation protein inhibitor (FAPI) has shown promising prospects in detection of HCC lesions. This study aimed to investigate the initial staging and restaging performance of 18F-FAPI PET/CT compared to 18F-FDG PET/CT in HCC.

METHODS

This prospective study enrolled histologically confirmed HCC patients from March 2021 to September 2022. All patients were examined with 18F-FDG PET/CT and 18F-FAPI PET/CT within 1 week. The maximum standard uptake value (SUVmax), tumor-to-background ratio (TBR), and diagnostic accuracy were compared between the two modalities.

RESULTS

A total of 67 patients (57 men; median age, 57 [range, 32-83] years old) were included. 18F-FAPI PET showed higher SUVmax and TBR values than 18F-FDG PET in the intrahepatic lesions (SUVmax: 6.7 vs. 4.3, P < 0.0001; TBR: 3.9 vs. 1.7, P < 0.0001). In diagnostic performance, 18F-FAPI PET/CT had higher detection rate than 18F-FDG PET/CT in intrahepatic lesions [92.2% (238/258) vs 41.1% (106/258), P < 0.0001] and lymph node metastases [97.9% (126/129) vs 89.1% (115/129), P = 0.01], comparable in distant metastases [63.6% (42/66) vs 69.7% (46/66), P > 0.05]. 18F-FAPI PET/CT detected primary tumors in 16 patients with negative 18F-FDG, upgraded T-stages in 12 patients and identified 4 true positive findings for local recurrence than 18F-FDG PET, leading to planning therapy changes in 47.8% (32/67) of patients.

CONCLUSIONS

18F-FAPI PET/CT identified more primary lesions, lymph node metastases than 18F-FDG PET/CT in HCC, which is helpful to improve the clinical management of HCC patients.

TRIAL REGISTRATION

Clinical Trials, NCT05485792 . Registered 1 August 2022, Retrospectively registered.

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.

Predicting Overall Survival with Deep Learning from 18F-FDG PET-CT Images in Patients with Hepatocellular Carcinoma before Liver Transplantation

Positron emission tomography and computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET-CT) were used to predict outcomes after liver transplantation in patients with hepatocellular carcinoma (HCC). However, few approaches for prediction based on 18F-FDG PET-CT images that leverage automatic liver segmentation and deep learning were proposed. This study evaluated the performance of deep learning from 18F-FDG PET-CT images to predict overall survival in HCC patients before liver transplantation (LT). We retrospectively included 304 patients with HCC who underwent 18F-FDG PET/CT before LT between January 2010 and December 2016. The hepatic areas of 273 of the patients were segmented by software, while the other 31 were delineated manually. We analyzed the predictive value of the deep learning model from both FDG PET/CT images and CT images alone. The results of the developed prognostic model were obtained by combining FDG PET-CT images and combining FDG CT images (0.807 AUC vs. 0.743 AUC). The model based on FDG PET-CT images achieved somewhat better sensitivity than the model based on CT images alone (0.571 SEN vs. 0.432 SEN). Automatic liver segmentation from 18F-FDG PET-CT images is feasible and can be utilized to train deep-learning models. The proposed predictive tool can effectively determine prognosis (i.e., overall survival) and, thereby, select an optimal candidate of LT for patients with HCC.

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.

Preoperative clinical-radiomics nomogram for microvascular invasion prediction in hepatocellular carcinoma using 18 F-FDG PET/CT

PURPOSE

To develop a clinical-radiomics nomogram by incorporating radiomics score and clinical predictors for preoperative prediction of microvascular invasion in hepatocellular carcinoma.

METHODS

A total of 97 HCC patients were retrospectively enrolled from Shanghai Universal Medical Imaging Diagnostic Center and Changhai Hospital Affiliated to the Second Military Medical University. 909 CT and 909 PET slicers from 97 HCC patients were divided into a training cohort (N = 637) and a validation cohort (N = 272). Radiomics features were extracted from each CT or PET slicer, and features selection was performed with least absolute shrinkage and selection operator regression and radiomics score was also generated. The clinical-radiomics nomogram was established by integrating radiomics score and clinical predictors, and the performance of the models were evaluated from its discrimination ability, calibration ability, and clinical usefulness.

RESULTS

The radiomics score consisted of 45 selected features, and age, the ratio of maximum to minimum tumor diameter, and18 F-FDG uptake status were independent predictors of microvascular invasion. The clinical-radiomics nomogram showed better performance for MVI detection (0.890 [0.854, 0.927]) than the clinical nomogram (0.849 [0.804, 0.893]) (p < 0.05 ). Both nomograms showed good calibration and the clinical-radiomics nomogram's clinical practicability outperformed the clinical nomogram.

CONCLUSIONS

With the combination of radiomics score and clinical predictors, the clinical-radiomics nomogram can significantly improve the predictive efficacy of microvascular invasion in hepatocellular carcinoma (p < 0.05 ) compared with clinical nomogram.

[18F]FDG PET/MRI in the follow-up of hepatocellular carcinoma after liver transplantation

BACKGROUND

There is limited evidence regarding the application of [18F] fluorodeoxyglucose (FDG)-PET/MRI in patients with a suspected clinical recurrence, who underwent liver transplantation for hepatocellular carcinoma (HCC). Therefore, we compared the accuracy of PET/MR and standard-of-care (SOC) imaging in these patients.

METHODS

We retrospectively reviewed 26 patients, whose liver were transplanted for HCC and were suspected of disease relapse based on biochemical analysis or SOC follow-up imaging, and carried out PET/MRI with diffusion-weighted imaging sequences on them. All patients underwent SOC imaging within the 2 months prior to the PET/MRI examination and had follow-up data for at least 12 months after. Reference standards were histopathology, clinical and imaging follow-up data.

RESULTS

Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for PET/MRI were 100, 94, 91, 100 and 96%, whereas for SOC imaging were 80, 69, 61, 85 and 73%. The accuracy of PET/MRI was higher with respect to SOC imaging, although not significantly.

CONCLUSIONS

PET/MRI is useful for oncological surveillance of patients who have undergone liver transplantation for HCC, particularly in cases of allergy to contrast media, renal failure or persistently elevated alpha-fetoprotein levels, and with no identification of metastatic/relapsing foci at standard-of-care imaging.

Metabolism-Associated Gene Signatures for FDG Avidity on PET/CT and Prognostic Validation in Hepatocellular Carcinoma

Introduction

The prognostic value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in hepatocellular carcinoma (HCC) was established in previous reports. However, there is no evidence suggesting the prognostic value of transcriptomes associated with tumor FDG uptake in HCC. It was aimed to elucidate metabolic genes and functions associated with FDG uptake, followed by assessment of those prognostic value.

Methods

Sixty HCC patients with Edmondson–Steiner grade II were included. FDG PET/CT scans were performed before any treatment. RNA sequencing data were obtained from tumor and normal liver tissue. Associations between each metabolism-associated gene and tumor FDG uptake were investigated by Pearson correlation analyses. A novel score between glucose and lipid metabolism-associated gene expression was calculated. In The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset, the prognostic power of selected metabolism-associated genes and a novel score was evaluated for external validation.

Results

Nine genes related to glycolysis and the HIF-1 signaling pathway showed positive correlations with tumor FDG uptake; 21 genes related to fatty acid metabolism and the PPAR signaling pathway demonstrated negative correlations. Seven potential biomarker genes, PFKFB4, ALDOA, EGLN3, EHHADH, GAPDH, HMGCS2, and ENO2 were identified. A metabolic gene expression balance score according to the dominance between glucose and lipid metabolism demonstrated good prognostic value in HCC.

Conclusions

The transcriptomic evidence of this study strongly supports the prognostic power of FDG PET/CT and indicates the potential usefulness of FDG PET/CT imaging biomarkers to select appropriate patients for metabolism-targeted therapy in HCC.

Liver Transplantation for Hepatocellular Carcinoma: How Should We Improve the Thresholds?

Simple Summary

The ideal treatment for hepatocellular carcinoma (HCC) is liver transplantation (LT), which both eliminates the HCC and cures the diseased liver. Once considered an experimental treatment with dismal survival rates, LT for HCC entered a new era with the establishment of the Milan criteria over 20 years ago. However, over the last two decades, the Milan criteria, which are based on tumor morphology, have come under intense scrutiny and are now largely regarded as too restrictive, and limit the access of transplantation for many patients who would otherwise achieve good clinical outcomes. The liver transplant community has been making every effort to reach a goal of establishing more reliable selection criteria. This article addresses how the criteria have been extended, as well as the concept of pre-transplant down-staging to maximize the eligibility.

Abstract

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related mortality, and liver transplantation is the ideal treatment for this disease. The Milan criteria provided the opportunity for HCC patients to undergo LT with favorable outcomes and have been the international gold standard and benchmark. With the accumulation of data, however, the Milan criteria are not regarded as too restrictive. After the implementation of the Milan criteria, many extended criteria have been proposed, which increases the limitations regarding the morphological tumor burden, and incorporates the tumor’s biological behavior using surrogate markers. The paradigm for the patient selection for LT appears to be shifting from morphologic criteria to a combination of biologic, histologic, and morphologic criteria, and to the establishment of a model for predicting post-transplant recurrence and outcomes. This review article aims to characterize the various patient selection criteria for LT, with reference to several surrogate markers for the biological behavior of HCC (e.g., AFP, PIVKA-II, NLR, 18F-FDG PET/CT, liquid biopsy), and the response to locoregional therapy. Furthermore, the allocation rules in each country and the present evidence on the role of down-staging large tumors are addressed.

Predicting the Recurrence of Hepatocellular Carcinoma after Primary Living Donor Liver Transplantation Using Metabolic Parameters Obtained from 18F-FDG PET/CT

This study evaluated the prognostic value of metabolic parameters based on the standardized uptake value (SUV) normalized by total body weight (bwSUV) and by lean body mass (SUL) measured on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for predicting tumor recurrence after primary living donor liver transplantation (LDLT) in patients with hepatocellular carcinoma (HCC) without transplantation locoregional therapy. This retrospective study enrolled 49 patients with HCC. The maximum tumor bwSUV (T-bwSUVmax) and SUL (T-SULmax) were measured on PET. The maximum bwSUV (L-bwSUVmax), mean bwSUV (L-bwSUVmean), maximum SUL (L-SULmax), and mean SUL (L-SULmean) were measured in the liver. All metabolic parameters were evaluated using survival analyses and compared to clinicopathological factors. Tumor recurrence occurred in 16/49 patients. Kaplan–Meier analysis revealed that all metabolic parameters were significant (p < 0.05). Univariate analysis revealed that prothrombin-induced by vitamin K absence or antagonist-II; T-stage; tumor number; tumor size; microvascular invasion; the Milan criteria, University of California, San Francisco (UCSF), and up-to-seven criteria; T-bwSUVmax/L-bwSUVmean; T-SULmax; T-SULmax/L-SULmax; and T-SULmax/L-SULmean were significant predictors. Multivariate analysis revealed that the T-SULmax/L-SULmean (hazard ratio = 115.6; p = 0.001; cut-off, 1.81) and UCSF criteria (hazard ratio = 172.1; p = 0.010) were independent predictors of tumor recurrence. SUL-based metabolic parameters, especially T-SULmax/L-SULmean, were significant, independent predictors of HCC recurrence post-LDLT.

KSNM60 in Clinical Nuclear Oncology

Since the foundation of the Korean Society of Nuclear Medicine in 1961, clinical nuclear oncology has been a major part of clinical nuclear medicine in Korea. There are several important events for the development of clinical nuclear oncology in Korea. First, a scintillating type gamma camera was adopted in 1969, which enabled to perform modern oncological gamma imaging. Second, Tc-99 m generator was imported to Korea since 1979, which promoted the wide clinical use of gamma camera imaging by using various kinds of Tc-99 m labeled radiopharmaceuticals. Third, a gamma camera with single photon emission tomography (SPECT) capability was first installed in 1980, which has been used for various kinds of tumor SPECT imaging. Fourth, in 1994, clinical positron emission tomography (PET) scanner and cyclotron with a production of F-18 fluorodeoxyglucose were first installed in Korea. Fifth, Korean Board of Nuclear Medicine was established in 1995, which contributed in the education and manpower training of dedicated nuclear medicine physicians in Korea. Finally, an integrated PET/CT scanner was first installed in 2002. Since that, PET/CT imaging has been a major imaging tool in clinical nuclear oncology in Korea. In this review, a brief history of clinical nuclear oncology in Korea is described.

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.

Investigating the value of pre-treatment 18F-FDG PET/CT in predicting the pathological characteristic of hepatocellular carcinoma and recurrence after liver transplantation

PURPOSE

The aim of this study is to investigate the value of pre-treatment ¹⁸F-FDG PET/CT in predicting the pathological characteristic of HCC and recurrence after liver transplantation (LT).

METHODS

A total of 34 patients who underwent ¹⁸F-FDG PET/CT before LT for HCC and did not receive any other treatment were retrospectively enrolled in the study. The maximal standard uptake value of the tumor (T-SUVmax), normal liver tissues (L-SUVmax), and mediastinal blood pool (B-SUVmax) were derived, followed by the calculations of the T-SUVmax/L-SUVmax (T/L) and the T-SUVmax/B-SUVmax (T/B) ratios. Combined with the post-transplantation pathological results and ROC curve, the performance in predicting the pathological characteristic and the recurrence after LT were evaluated.

RESULTS

The AUCs for T-SUVmax, T/L, and T/B in predicting the pathological grade of tumors were 0.820, 0.784, and 0.806, respectively. Alternatively, the AUCs for T-SUVmax, T/L, and T/B in predicting the recurrence after LT were 0.865, 0.899, and 0.931, respectively. The individual cutoff values were 5.0, 1.7, and 2.2, corresponding to a predication accuracy of 88.2%, 85.3%, and 88.2%, respectively. In addition, the AUCs for T/B in predicting microvascular invasion (mVI) and liver capsular invasion (LCI) were 0.825 and 0.788, respectively.

CONCLUSION

The pre-treatment ¹⁸F-FDG PET/CT is effective for predicting recurrence of HCC after LT. In addition, it demonstrates values for predicting the pathological characteristic of HCC such as pathological grade, mVI, and LCI.

Expanding the Limits of Liver Transplantation for Hepatocellular Carcinoma: Is There a Limit?

Liver transplantation is a treatment option for hepatocellular carcinoma within Milan criteria. With careful selection practices, patients with larger tumors can do well with successful downstaging followed by liver transplantation and should not be excluded based on tumor size or number alone. When considering expanded criteria for hepatocellular carcinoma, however, survival outcomes after liver transplantation should be comparable with patients without hepatocellular carcinoma. Surrogate measures of tumor biology, such as α-fetoprotein, other biomarkers, and dynamic tumor behavior including response to locoregional therapy can aid in risk stratification of patients before liver transplantation.

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.

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.

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.

Selecting patients with hepatocellular carcinoma for liver transplantation: incorporating tumor biology criteria

Liver transplantation (LT) is the optimal therapeutic option for patients with liver cirrhosis and hepatocellular carcinoma (HCC). Due to universal donor shortage, only the patients with limited tumor burden (under the so-called Milan criteria) are considered as potential candidates for LT in most institutions. It is expected that in the near future, more liver grafts will be available for patients with HCC due to the implementation of new direct antivirals against hepatitis C, leaving a prone scenario to consider expanding Milan criteria. A moderate expansion of Milan criteria could be implemented without increasing the risk of tumor recurrence if patients with favorable biological behavior are carefully selected. Incorporating information regarding tumor biology in the decision-making algorithm would result in a more rational use of LT in patients with HCC. In the present review, surrogate markers of tumor biology are critically evaluated as potential tools to be combined with existing radiological criteria. In addition, the current state of liquid biopsy is discussed, as this cutting-edge technology may reshape the management of HCC in the upcoming years.

Efficacy of contrast-enhanced FDG PET/CT in patients awaiting liver transplantation with rising alpha-fetoprotein after bridge therapy of hepatocellular carcinoma

OBJECTIVE

To assess the diagnostic accuracy and illustrate positive findings of contrast-enhanced fluorine-18 fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) image in patients awaiting liver transplantation (LT) with rising alpha-fetoprotein (AFP) after bridge therapy of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This prospective study included 100 patients who were waiting for LT and who previously underwent locoregional therapy (LRT) of HCC. These patients had rising AFP levels on a routine follow-up examination awaiting LT. All patients underwent a contrast-enhanced 18F-FDG PET/CT examination. We calculated for each patient the maximum standardised uptake value (SUVmax) of the tumour and the ratio of the tumoral SUVmax to the normal-liver SUVmax. The diagnostic accuracy and positive contrast-enhanced findings of 18F-FDG PET/CT were established by histopathology and clinical and imaging follow-up as the reference standards.

RESULTS

Contrast-enhanced 18F-FDG PET/CT detected tumour relapse in 78 patients (13 patients had intrahepatic lesions, 10 patients had extrahepatic metastases and 55 patients with combined lesions). The sensitivity, specificity and accuracy values of contrast-enhanced 18F-FDG PET/CT examination in the detection of HCC recurrence were 92.8%, 94.1% and 93%, respectively. A significant correlation was found between the AFP level and SUVmax ratio (r = 0.2283; p = 0.0224). The best threshold for 18F-FDG PET positivity was >1.21.

CONCLUSION

Contrast-enhanced 18F-FDG PET/CT is a valuable tool for the detection of intrahepatic HCC recurrence or extrahepatic metastasis following rising AFP levels after LRT of HCC, and should be incorporated during routine workup awaiting LT.

KEY POINTS

• 18F-FDG PET/CT is a valuable tool for the detection of HCC recurrence • 18 F-FDG PET/CT should be incorporated during routine workup awaiting liver transplantation • Significant correlation was found between AFP level and SUVmax ratio • The best threshold for 18 F-FDG PET positivity was >1.21 • The ideal cut-off value for AFP was >202.

Role of pre-transplant 18F-FDG PET/CT in predicting hepatocellular carcinoma recurrence after liver transplantation

The last two decades have seen a paradigm shift in the selection of patients with hepatocellular carcinoma (HCC) for liver transplantation. Microvascular invasion and differentiation have been the most significant factors affecting post-transplant recurrence; however, because of inherent disadvantages of pre-transplant biopsy, histological criteria never gained popularity. Recently, the selection criteria evolved from morphological to biological criteria, such as biomarkers and response to loco-regional therapy. With the introduction of multimodality imaging, combination of computed tomography with nuclear medicine imaging, particularly, 18F-fluorodeoxyglucose positron emission tomography fulfilled an unmet need and rapidly became a critical component of HCC management. This review article will focus on the use of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography in the pre-transplant evaluation of HCC patients with special discussion on its ability to predict HCC recurrence after liver transplantation.

PET/MRI for Gastrointestinal Imaging: Current Clinical Status and Future Prospects

Positron emission tomography (PET)/computed tomography (CT) with 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment for numerous gastrointestinal malignancies. However, it is often supplemented by magnetic resonance imaging (MRI) for local tumor staging. Hybrid PET/MRI scanners, which acquire PET data and MRI data simultaneously, have the potential to provide accurate whole-body staging in a single examination. Furthermore, to address certain limitations of FDG, many new PET tracers have been developed to probe distinctive aspects of tumor biology.

Patient Selection by Tumor Markers in Liver Transplantation for Advanced Hepatocellular Carcinoma

Although far advanced hepatocellular carcinoma (HCC) is generally considered a contraindication for liver transplantation (LT), biologically favorable tumors among them could show acceptable results. However, it is still unclear which tumors can be treated with LT. Data were collected on adult patients who underwent LT for HCC beyond the Milan criteria in 8 Korean LT centers between January 2000 and June 2013. Far advanced HCC was defined as HCC with the largest tumor ≥ 10 cm, 10 or more tumor nodules, or accompanying macrovascular invasion. A total of 688 patients, including 169 with far advanced HCC, were enrolled in this study. The 5-year overall and recurrence-free survival rates were 60.4% and 55.1%, respectively, for all patients but only 28.7% and 24.8%, respectively, for patients with far advanced HCC (P < 0.001). Both preoperative alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist II (PIVKA-II) were significant risk factors for HCC recurrence after LT. In particular, AFP + PIVKA-II combined was a better predictor than either marker alone. Of all far advanced HCC patients with available AFP and PIVKA-II levels, 45 (30.8%) had low AFP + PIVKA-II (≤300) and their 5-year overall and recurrence-free survival rate were 47.8% and 53.4%, respectively, which were acceptable and significantly superior to those of patients with AFP (ng/mL) + PIVKA-II (nAU/mL) > 300 (21.0% and 10.8%, respectively; P < 0.001). In conclusion, patients with favorable HCC had acceptable outcomes after LT even when their tumors were extremely advanced. AFP + PIVKA-II gave reliable information about the tumor biology of far advanced HCC. Liver Transplantation 00 000-000 2018 AASLD.

11C-acetate and 18F-fluorodeoxyglucose positron emission tomography/computed tomography dual imaging for the prediction of response and prognosis after transarterial chemoembolization

The aim of the present study was to evaluate the clinical significance of dual radiotracer studies, C-acetate and F-fluoro-D-glucose positron emission tomography/computed tomography (F-FDG PET/CT), for the prediction of response and recurrence after transarterial chemoembolization (TACE).This study retrospectively included a total 42 hepatoceullar carcinoma (HCC) patients (median age, 59; range, 34-85 years old) who underwent C-acetate and F-FDG PET/CT concurrently. Tumor uptake normalized by liver uptake (TNR; maximum tumor SUV to mean normal liver SUV ratio) was obtained first. Then, FAratio, which is the ratio of F-FDG TNR (TNR_FDG) to C-acetate TNR, was obtained and correlated with response after TACE and recurrence-free survival (RFS), using a Cox multivariate proportional-hazard model.Among clinical factors, including the Hepatoma Arterial Embolization Prognostic score and positron emission tomography (PET) parameters, multiple regression analysis revealed FAratio and tumor size to be the only significant factors. As a PET parameter, FAratio exhibited the largest area under the curve in the prediction of response after TACE. In the Cox multivariate proportional-hazard model, TNR_FDG was the only significant predictive factor for RFS. In subgroup analysis, TNR_FDG was the only significant predictive factor for recurrence in intermediate stage patients. However, FAratio was the only significant predictive factor for recurrence in advanced stage patients.Dual radiotracer use of C-acetate and F-FDG PET/CT contributed to the prediction of response and recurrence after TACE. Used in addition to F-FDG, C-acetate PET/CT could give additional information in advanced stage patients. Based on the characteristics of tumor metabolism assessed by dual radiotracer PET/CT, treatment plans could be more personalized and optimized.

Evolutionary Distance Predicts Recurrence After Liver Transplantation in Multifocal Hepatocellular Carcinoma

Background

Liver transplantation (LTx) is a potentially curative treatment option for hepatocellular carcinoma (HCC) in cirrhosis. However, patients, where HCC is already a systemic disease, LTx may be individually harmful and has a negative impact on donor organ usage. Thus, there is a need for improved selection criteria beyond nodule morphology to select patients with a favorable outcome for LTx in multifocal HCC. Evolutionary distance measured from genome-wide single-nucleotide polymorphism data between tumor nodules and the cirrhotic liver may be a prognostic marker of survival after LTx for multifocal HCC.

Methods

In a retrospective multicenter study, clinical data and formalin-fixed paraffin-embedded specimens of the liver and 2 tumor nodules were obtained from explants of 30 patients in the discovery and 180 patients in the replication cohort. DNA was extracted from formalin-fixed paraffin-embedded specimens followed by genome wide single-nucleotide polymorphism genotyping.

Results

Genotype quality criteria allowed for analysis of 8 patients in the discovery and 17 patients in the replication set. DNA concentrations of a total of 25 patients fulfilled the quality criteria and were included in the analysis. Both, in the discovery (P = 0.04) and in the replication data sets (P = 0.01), evolutionary distance was associated with the risk of recurrence of HCC after transplantation (combined P = 0.0002). In a univariate analysis, evolutionary distance (P = 7.4 × 10⁻⁶) and microvascular invasion (P = 1.31 × 10⁻⁵) were significantly associated with survival in a Cox regression analysis.

Conclusions

Evolutionary distance allows for the determination of a high-risk group of recurrence if preoperative liver biopsy is considered.

The authors of this multicenter retrospective study assess whether the evolutionary distance measured from genome-wide single nucleotide polymorphism (SNP) data between tumor nodules and the cirrhotic liver may be a prognostic marker of survival after liver transplantation for multifocal hepatocellular carcinoma. Supplemental digital content is available in the text.

18F-fluorodeoxyglucose uptake of hepatocellular carcinoma as a prognostic predictor in patients with sorafenib treatment

PURPOSE

Sorafenib, an oral multikinase inhibitor, is a recommended treatment option available for patients with Barcelona Clinic Liver Cancer (BCLC)-C stage hepatocellular carcinoma (HCC). This study aimed to evaluate the performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) for predicting tumour progression during sorafenib treatment.

METHODS

We formed a retrospective cohort comprising patients treated with sorafenib for at least 30 days and undergoing 18F-FDG PET/CT within 1 month before treatment. For statistical analyses, the tumour-to-liver standardised uptake value (SUV) ratio (TLR) of the most hypermetabolic lesion was measured.

RESULTS

Among a total of 35 patients, two obtained partial remission, and 11 showed stable disease after the first response evaluation. Patients with a TLR ≥ 2.9 (n = 17) had a median overall survival (OS) of 3.7 months after sorafenib treatment, whereas patients with a TLR < 2.9 (n = 18) had median OS of 12.2 months (P < 0.001), although the disease control rate was not significantly different between the two groups. Pretreatment TLR ≥ 2.9 (hazard ratio [HR] = 6.318, P = 0.002) and Child-Pugh class B (HR = 4.316, P = 0.044) were poor prognostic factors for OS, and a TLR ≥ 2.9 (HR = 2.911, P = 0.024) was the only poor prognostic factor for progression-free survival in a multivariate analysis.

CONCLUSION

Pretreatment tumour metabolic activity assessed by 18F-FDG PET is an independent prognostic factor for survival in patients with BCLC-C stage HCC receiving sorafenib monotherapy, although it may not predict tumour response to the treatment.

Signature of survival: a 18F-FDG PET based whole-liver radiomic analysis predicts survival after 90Y-TARE for hepatocellular carcinoma

Purpose

To generate a predictive whole-liver radiomics scoring system for progression-free survival (PFS) and overall survival (OS) in patients undergoing transarterial radioembolization using Yttrium-90 (⁹⁰Y-TARE) for unresectable hepatocellular carcinoma (uHCC).

Results

The generated pPET-RadScores were significantly correlated with survival for PFS (median of 11.4 mo [95% confidence interval CI: 6.3–16.5 mo] in low-risk group [PFS-pPET-RadScore < 0.09] vs. 4.0 mo [95% CI: 2.3–5.7 mo] in high-risk group [PFS-pPET-RadScore > 0.09]; P = 0.0004) and OS (median of 20.3 mo [95% CI: 5.7–35 mo] in low-risk group [OS-pPET-RadScore < 0.11] vs. 7.7 mo [95% CI: 6.0–9.5 mo] in high-risk group [OS-pPET-RadScore > 0.11]; P = 0.007). The multivariate analysis confirmed PFS-pPET-RadScore (P = 0.006) and OS-pPET-RadScore (P = 0.001) as independent negative predictors.

Conclusion

Pretreatment ¹⁸F-FDG PET whole-liver radiomics signature appears as an independent negative predictor for PFS and OS in patients undergoing ⁹⁰Y-TARE for uHCC.

Methods

Pretreatment ¹⁸F-FDG PET of 47 consecutive patients undergoing ⁹⁰Y-TARE for uHCC (31 resin spheres, 16 glass spheres) were retrospectively analyzed. For each patient, based on PET radiomics signature from whole-liver semi-automatic segmentation, PFS and OS predictive PET-radiomics scores (pPET-RadScores) were obtained using LASSO Cox regression. Using X-tile software, the optimal score to predict PFS (PFS-pPET-RadScore) and OS (OS-pPET-RadScore) served as cutoff to separate high and low-risk patients. Survival curves were estimated using the Kaplan-Meier method. The prognostic value of PFS and OS-pPET-RadScore, Barcelona-Clinic Liver Cancer staging system and serum alpha-fetoprotein level was analyzed to predict PFS and OS in multivariate analysis.

Preoperative prediction of microvascular invasion of hepatocellular carcinoma using 18F-FDG PET/CT: a multicenter retrospective cohort study

PURPOSE

The aim of this study was to assess the potential of tumor ¹⁸F-fluorodeoxyglucose (FDG) avidity as a preoperative imaging biomarker for the prediction of microvascular invasion (MVI) of hepatocellular carcinoma (HCC).

METHODS

One hundred and fifty-eight patients diagnosed with Barcelona Clinic Liver Cancer stages 0 or A HCC (median age, 57 years; interquartile range, 50-64 years) who underwent ¹⁸F-FDG positron emission tomography with computed tomography (PET/CT) before curative surgery at seven university hospitals were included. Tumor FDG avidity was measured by tumor-to-normal liver standardized uptake value ratio (TLR) of the primary tumor on FDG PET/CT imaging. Logistic regression analysis was performed to identify significant parameters associated with MVI. The predictive performance of TLR and other clinical variables was assessed using receiver operating characteristic (ROC) curve analysis.

RESULTS

MVI was present in 76 of 158 patients with HCCs (48.1%). Multivariable logistic regression analysis revealed that TLR, serum alpha-fetoprotein (AFP) level, and tumor size were significantly associated with the presence of MVI (P < 0.001). Multinodularity was not significantly associated with MVI (P = 0.563). The area under the ROC curve (AUC) for predicting the presence of MVI was best with TLR (AUC = 0.704), followed by tumor size (AUC = 0.685) and AFP (AUC = 0.670). We were able to build an improved prediction model combining TLR, tumor size, and AFP by using multivariable logistic regression modeling (AUC = 0.756).

CONCLUSIONS

Tumor FDG avidity measured by TLR on FDG PET/CT is a preoperative imaging biomarker for the prediction of MVI in patients with HCC.

Combining 18F-FDG positron emission tomography with Up-to-seven criteria for selecting suitable liver transplant patients with advanced hepatocellular carcinoma

The Up-to-seven (UTS) criteria (sum of tumor size and number not exceeding 7) for indicating liver transplantation (LT) in hepatocellular carcinoma (HCC) were originally based on explant pathology features and absence of microvascular invasion (MVI). ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) was shown to indicate the risk of MVI and tumor recurrence. The aim of this study was to analyze the prognostic significance of the clinical UTS criteria when being combined with PET-status of the tumor. Data of 116 liver transplant patients were subject to retrospective analysis. Five-year recurrence-free survival (RFS) rates in patients meeting (n = 85) and exceeding (n = 21) the radiographic UTS criteria were 81% and 55.1%, respectively (p = 0.014). In the UTS In subset, RFS was significantly better in PET-negative (94.9%) than in PET-positive patients (48.3%; p < 0.001). In the UTS Out subset, 5-year RFS rates were 87.1% and 19% in patients with non- ¹⁸F-FDG-avid and ¹⁸F-FDG-avid tumors (p < 0.001), respectively. Positive PET-status was identified as the only independent clinical predictor of tumor recurrence in beyond UTS patients (Hazard ratio [HR] 19.25; p < 0.001). Combining radiographic UTS criteria with FDG-PET may safely expand the HCC selection criteria for LT.

18F-FDG-PET for Assessing Biological Viability and Prognosis in Liver Transplant Patients with Hepatocellular Carcinoma

Liver transplantation (LT) has become standard of care in patients with non-resectable early stage hepatocellular carcinoma (HCC) in liver cirrhosis. Currently, patient selection for LT is strictly based on tumor size and number, provided by the Milan criteria. This may, however, exclude patients with advanced tumor load but favourable biology from a possibly curative treatment option. It became clear in recent years that biological tumor viability rather than tumor macromorphology determines posttransplant outcome. In particular, microvascular invasion and poor grading reflect tumor aggressiveness and promote the risk of tumor relapse. Pretransplant biopsy is not applicable due to tumor heterogeneity and risk of tumor cell seeding. ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), an established nuclear imaging device in oncology, was demonstrated to non-invasively correlate with unfavorable histopathologic features. Currently, there is an increasing amount of evidence that ¹⁸F-FDG-PET is very useful for identifying eligible liver transplant patients with HCC beyond standard criteria but less aggressive tumor properties. In order to safely expand the HCC selection criteria and the pool of eligible liver recipients, tumor evaluation with ¹⁸F-FDG-PET should be implemented in pretransplant decision process.

Living donor liver transplantation for hepatocellular cancer: an (almost) exclusive Eastern procedure?

Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer and it is linked with chronic liver disease. Liver transplantation (LT) is the best curative treatment modality, since it can cure simultaneously the underlying liver disease and HCC. Milan criteria (MC) are the benchmark for selecting patients with HCC for LT, achieving up to 91% 1-year survival post transplantation. However, when considering intention-to-treat (ITT) rates are substantially lower, mainly due dropout. Additionally, Milan criteria (MC) are too restrictive and more inclusive criteria have been reported with good outcomes. Mainly, in Eastern countries, deceased donors are scarce, therefore Asian centers have developed living-donor liver transplantation (LDLT) to a state-of-art status. There are many eastern centers reporting huge numbers of LDLT with outstanding results. Regarding HCC patients, they have reported many criteria including more advanced tumors achieving reasonable outcomes. Western countries have well-established deceased-donor liver transplantation (DDLT) programs. However, organ shortage and restrictive criteria for listing patients with HCC endorses LDLT as a good option to offer curative treatment to more HCC patients. However, there are some controversial reports claiming higher rates of HCC recurrence after LDLT than DDLT. An extensive review included 30 studies with cohorts of HCC patients who underwent LDLT in both East and West countries. We reported also the results of our Institution, in Brazil, where it was performed the first LDLT. This review also addresses the eligibility criteria for transplanting patients with HCC developed in Western and Eastern countries.

Elevated tumor-to-liver uptake ratio (TLR) from 18F-FDG-PET/CT predicts poor prognosis in stage IIA colorectal cancer following curative resection

Purpose

The prognostic value of the tumor-to-liver uptake ratio (TLR) from 18-fluoro-2-deoxyglucose positron emission tomography/computed tomography (¹⁸F–FDG-PET/CT) in the early stage of colorectal cancer (CRC) is unclear. Notably, some stage IIA CRC patients experience early recurrence even after curative resection and might benefit from neoadjuvant or adjuvant chemotherapy. This study aims to evaluate whether elevated TLR from ¹⁸F–FDG-PET/CT can predict poor prognosis in stage IIA CRC patients undergoing curative resection.

Methods

From April 2010 to December 2013, 504 consecutive CRC patients with different TNM stages (I-IV) underwent ¹⁸F–FDG-PET/CT scans at the 6th Affiliated Hospital of Sun Yat-Sen University. Among the patients, 118 with stage IIA CRC who accepted preoperative ¹⁸F–FDG-PET/CT scanning and were treated with curative surgery alone were reviewed retrospectively. The maximum standardized uptake value (SUVmax) in the primary tumor, TLR, and demographic, clinical, histopathological, and laboratory data were analyzed. Receiver operating characteristic (ROC) curve, univariate and multivariate analyses were performed to identify prognostic factors associated with patient disease-free survival (DFS) and overall survival (OS).

Results

ROC curve analysis demonstrated that TLR was superior to primary tumor SUVmax in predicting the risk of recurrence in stage IIA CRC. The optimal TLR cutoff was 6.2. Univariate analysis indicated that elevated TLR, tumor size, and lymphovascular/neural invasion correlated with DFS (P = 0.001, P = 0.002, and P = 0.001, respectively) and OS (P = 0.001, P = 0.003, and P < 0.001, respectively). The 1-, 3-, and 5-year DFS rates were 98.4%, 96.9%, and 96.9% for stage IIA CRC patients with lower TLR (≤6.2) versus 77.8%, 60.6%, and 60.6% for those with elevated TLR (>6.2), respectively. The 1-, 3-, and 5-year OS rates were 100.0%, 100.0%, and 98.3% for the patients with lower TLR versus 98.1%, 83.3%, and 74.3% for those with elevated TLR. Cox regression analysis showed that elevated TLR [>6.2; hazard ratio (HR): 3.109–57.463; P < 0.001] and tumor size (>4.4 cm; HR: 1.636–19.155; P = 0.006) were independent risk factors for DFS. Meanwhile, elevated TLR (>6.2; HR: 1.398–84.945; P = 0.023) and lymphovascular/neural invasion (positive; HR: 1.278–12.777; P = 0.017) were independent risk factors for OS.

Conclusion

Elevated TLR predicted worse DFS and OS for stage IIA CRC patients and might serve as a potential radiological index to identify candidates for neoadjuvant or adjuvant chemotherapy. Stage IIA CRC patients with elevated TLR should be monitored carefully for early detection of possible recurrence.

The value of [11C]-acetate PET and [18F]-FDG PET in hepatocellular carcinoma before and after treatment with transarterial chemoembolization and bevacizumab

Purpose

This prospective study was to investigate the value of [¹¹C]-acetate PET and [¹⁸F]-FDG PET in the evaluation of hepatocellular carcinoma (HCC) before and after treatment with transarterial chemoembolization (TACE) and vascular endothelial growth factor (VEGF) antibody (bevacizumab).

Methods

Twenty-two patients (three women, 19 men; 62 ± 8 years) with HCC verified by histopathology were treated with TACE and bevacizumab (n = 11) or placebo (n = 11). [¹¹C]-acetate PET and [¹⁸F]-FDG PET were performed before and after TACE with bevacizumab or placebo. Comparisons between groups were performed with t-tests and Chi-squared tests, where appropriate. Overall survival (OS) was defined as the time from start of bevacizumab or placebo until the date of death/last follow-up, respectively.

Results

The patient-related sensitivity of [¹¹C]-acetate PET, [¹⁸F]-FDG PET, and combined [¹¹C]-acetate and [¹⁸F]-FDG PET was 68%, 45%, and 73%, respectively. There was a significantly higher rate of conversion from [¹¹C]-acetate positive lesions to negative lesions in patients treated with TACE and bevacizumab as compared with that in patients with TACE and placebo (p < 0.05). In patients with negative acetate PET, the mean OS in patients treated with TACE and bevacizumab was 259 ± 118 days and was markedly shorter as compared with that (668 ± 217 days) in patients treated with TACE and placebo (p < 0.05). In patients treated with TACE and placebo, there was significant difference in mean OS in patients with positive FDG PET as compared with that in patients with negative FDG PET (p < 0.05). The HCC lesions had different tracer avidities showing the heterogeneity of HCC.

Conclusions

Our study suggests that combining [¹⁸F]-FDG with [¹¹C]-acetate PET could be useful for the management of HCC patients and might also provide relevant prognostic and molecular heterogeneity information.

Combination of FDG-PET and UCSF Criteria for Predicting HCC Recurrence After Living Donor Liver Transplantation

BACKGROUND

F-18 fluorodeoxyglucose (FDG) uptake in hepatocellular carcinoma (HCC) is related to tumor biology and has predictive value for tumor recurrence after liver transplantation. This retrospective study assessed whether the degree of FDG uptake in positron emission tomography (PET) can be used to predict HCC recurrence after living donor liver transplantation (LDLT).

METHODS

One hundred forty-seven patients with HCC underwent FDG-PET studies before LDLT. The semiquantification of FDG uptake in FDG-positive HCC was done with maximum standardized uptake value (SUVmax) and tumor to nontumor ratio (TNR). Recurrence-free survivals (RFS) were calculated using the Kaplan-Meier method.

RESULTS

In univariable analysis, T stage, presence of microvascular invasion, being FDG-positive, SUVmax, and TNR were significant predictors for worse RFS. The optimal cutoff values of SUVmax and TNR were 4.8 and 2.0, respectively. The high FDG uptake HCC (TNR ≥ 2) was a strong predictor for worse RFS (hazard ratio, 13.52; 95% confidence interval, 4.77-38.29; P < 0.001). Using a combination of FDG-PET and University of California San Francisco (UCSF) criteria, the patients can be divided into low-risk (within UCSF criteria and FDG-negative), intermediate-risk (beyond UCSF criteria and FDG-negative; FDG-positive and TNR < 2), and high-risk (FDG-positive and TNR ≥ 2) groups. The estimated 5-year RFS in these groups were 85.5%, 83.9%, and 29.6% according to the combination of FDG-PET and clinical UCSF criteria, and 94.0%, 75.8%, and 29.6% according to the combination of FDG-PET and pathologic UCSF criteria, respectively.

CONCLUSIONS

Combination of FDG-PET and UCSF criteria can be used to predict the risk of HCC recurrence after LDLT.