Prediction of Posttransplantation Recurrence of Hepatocellular Carcinoma Using Metabolic and Volumetric Indices of 18F-FDG PET/CT

The role of 18F-FDG PET in predicting the pathological response and prognosis to unresectable HCC patients treated with lenvatinib and PD-1 inhibitors as a conversion therapy

Purpose

To investigate the diagnostic value of ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET), as an imaging biomarker, for predicting pathological response and prognosis of unresectable hepatocellular carcinoma (HCC) patients treated with Lenvatinib and programmed cell death protein 1 (PD-1) inhibitors as a conversion therapy.

Methods

A total of 28 unresectable HCC patients with BCLC stage B or C were treated with Lenvatinib and PD-1 inhibitors before surgery. The ¹⁸F-FDG PET/CT scans were acquired before pre- (scan-1) and post-conversion therapy (scan-2). The maximum standardized uptake value (SUVmax), TLR (tumor-to-normal liver standardized uptake value ratio), and the percentages of post-treatment changes in metabolic parameters (ΔSUVmax [%] and ΔTLR [%]) were calculated. Major pathological response (MPR) was identified based on the residual viable tumor in the resected primary tumor specimen (≤10%). Differences in the progression-free survival (PFS) and overall survival (OS) stratified by ΔTLR were examined by the Kaplan-Meier method.

Results

11 (11/28, 39.3%) patients were considered as MPR responders and 17 (17/28, 60.7%) patients as non-MPR responders after conversion therapy. ΔSUVmax (-70.0 [-78.8, -48.8] vs. -21.7 [-38.8, 5.7], respectively; P<0.001) and ΔTLR (-67.6 [-78.1, -56.8] vs. -18.6 [-27.9, 4.0], respectively; P<0.001) were reduced in the responder group than those in the non-responder group. According to the results of the receiver operating characteristic curve analysis, ΔTLR showed an excellent predictive value for the MPR of primary HCC lesions (area under curve=0.989, with the optimal diagnostic threshold of -46.15). When using ΔTLR of -21.36% as a threshold, patients with ΔTLR-based metabolic response had superior PFS (log-rank test, P=0.001) and OS (log-rank test, P=0.016) compared with those without ΔTLR-based metabolic response.

Conclusion

¹⁸F-FDG PET is a valuable tool for predicting pathological response and prognosis of unresectable HCC patients treated by Lenvatinib combined with PD-1 as a conversion therapy.

Impact of metabolic indices of 18F-fluorodeoxyglucose positron emission tomography/computed tomography on post transplantation recurrence of hepatocellular carcinoma

BACKGROUND

Tumor recurrence is the leading cause of death after liver transplantation in patients with hepatocellular carcinoma. There is an ongoing debate as to whether metabolic indices such as tumor to liver standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography of the primary tumor can identify patients outside the Milan criteria with as low recurrence rates as patients inside Milan and thus should be added to the established prognostic factors.

METHODS

This retrospective study analyzes 103 consecutive patients who underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography before liver transplantation for hepatocellular carcinoma using data of clinical tumor registry. Primary endpoints were overall survival and 10-year cumulative recurrence rates.

RESULTS

Tumor to liver standardized uptake value ratio of the primary tumor was statistically significant higher in Milan out tumors, "up-to-seven" out tumors, grade 3 tumors, α- fetoprotein level >400 ng/ml and lesions > 5cm in diameter. Factors with statistically significant influence on the 10- year overall survival in the univariate analysis were Milan, up-to-seven" criteria, number of lesions and pT-category. COX regression analysis did not show independently statistically significant factors for 10-year overall survival. Milan, "up-to-seven" criteria, grade, pV, number of lesions, size of lesion, pT-category, tumor to liver standardized uptake value ratio influenced 10-year cumulative recurrence rates statistically significant. Tumor to liver standardized uptake value ratio, grade and pT-category proved to be independently statistically significant factors for 10-year cumulative recurrence rates.

CONCLUSIONS

Our study suggests that tumor to liver standardized uptake value standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography is an independent prognostic factor in transplanted patients with hepatocellular carcinoma. If we focus on preoperative findings, such as tumor size, tumor number and AFP value adding the information given by TLR of ¹⁸F-FDG PET/CT allows to estimate the risk of tumor recurrence more accurate than the established classifications Milan and UTS. Therefore, it may add valuable information to other preoperative findings, such as tumor size, tumor number and AFP level.

Total Lesion Glycolysis on 18F-FDG PET/CT Is a Better Prognostic Factor Than Tumor Dose on 90Y PET/CT in Patients With Hepatocellular Carcinoma Treated With 90Y Transarterial Radioembolization

PURPOSE

This study aimed to evaluate the prognostic value of metabolic parameters on 18F-FDG PET/CT and tumor dose (TD) on posttreatment 90Y PET/CT in patients with hepatocellular carcinoma (HCC) who underwent 90Y transarterial radioembolization (TARE).

PATIENTS AND METHODS

Forty-seven HCC patients treated with 90Y TARE were retrospectively enrolled between January 2013 and October 2018. 18F-FDG PET/CT was performed before treatment. Maximum tumor SUV-to-mean normal liver SUV ratio (TLR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured for each patient. Voxel dosimetry was performed on 90Y PET/CT images to measure TD. The prognostic significance of metabolic parameters on 18F-FDG PET/CT, TD on 90Y PET/CT, and clinical factors for overall survival (OS) was evaluated. In addition, TD on 90Y PET/CT was analyzed in relation to the administered dose of 90Y-labeled microspheres and metabolic parameters on 18F-FDG PET/CT.

RESULTS

The median patient age was 57 years, and 37 patients (78.7%) were men. During the follow-up period, 25 patients (53.2%) died. In univariable analysis, Barcelona Clinic Liver Cancer stage C, Child-Pugh score, TD on 90Y PET/CT, TLR, MTV, and TLG were significant prognostic factors affecting OS (P < 0.05). In multivariable analysis, Barcelona Clinic Liver Cancer stage C and high TLG on 18F-FDG PET/CT were independent prognostic factors for OS (P < 0.05). The 1-year OS rates were 72.9% in patients with low TLG and 33.3% in patients with high TLG (P < 0.05). We also found that TD on 90Y PET/CT was not correlated with the administered dose of 90Y-labeled microspheres, but negatively correlated with TLG on pretreatment 18F-FDG PET/CT (P < 0.05).

CONCLUSIONS

TLG, a parameter incorporating both the degree of 18F-FDG uptake and amount of metabolically active tumor volume on pretreatment 18F-FDG PET/CT, is a better prognostic factor than TD on 90Y PET/CT for predicting OS in HCC patients treated with 90Y TARE.

PET-Based Radiogenomics Supports mTOR Pathway Targeting for Hepatocellular Carcinoma

PURPOSE

This work aimed to explore in depth the genomic and molecular underpinnings of hepatocellular carcinoma (HCC) with increased 2[18F]fluoro-2-deoxy-d-glucose (FDG) uptake in PET and to identify therapeutic targets based on this imaging-genomic surrogate.

EXPERIMENTAL DESIGN

We used RNA sequencing and whole-exome sequencing data obtained from 117 patients with HCC who underwent hepatic resection with preoperative FDG-PET/CT imaging as a discovery cohort. The primary radiogenomic results were validated with transcriptomes from a second cohort of 81 patients with more advanced tumors. All patients were allocated to an FDG-avid or FDG-non-avid group according to the PET findings. We also screened potential drug candidates targeting FDG-avid HCCs in vitro and in vivo.

RESULTS

High FDG avidity conferred worse recurrence-free survival after HCC resection. Whole transcriptome analysis revealed upregulation of mTOR pathway signals in the FDG-avid tumors, together with higher abundance of associated mutations. These clinical and genomic findings were replicated in the validation set. A molecular signature of FDG-avid HCCs identified in the discovery set consistently predicted poor prognoses in the public-access datasets of two cohorts. Treatment with an mTOR inhibitor resulted in decreased FDG uptake followed by effective tumor control in both the hyperglycolytic HCC cell lines and xenograft mouse models.

CONCLUSIONS

Our PET-based radiogenomic analysis indicates that mTOR pathway genes are markedly activated and altered in HCCs with high FDG retention. This nuclear imaging biomarker may stimulate umbrella trials and tailored treatments in precision care of patients with HCC.

Correlation between Tissue Cellularity and Metabolism Represented by Diffusion-Weighted Imaging (DWI) and 18F-FDG PET/MRI in Head and Neck Cancer (HNC)

Simple Summary

We report on the correlation between the diffusion-weighted imaging (DWI) and the metabolic volume parameters derived from a PET scan, to determine the correlation between these parameters and the tumor cellularity in head and neck primary tumors. Our findings implied that there was no correlation between the information derived from the DWI and the information derived from the FDG metabolic parameters. Thus, both imaging techniques might play a complementary role in HNC diagnosis and assessment. This is significant because the treatment plan of patients with HNC should be well evaluated by using all the available diagnosis techniques, for a better understanding of how the tumor will react.

Abstract

Background: This study aimed to assess the association of 18F-Fluorodeoxyglucose positron-emission-tomography (18F-FDG/PET) and DWI imaging parameters from a primary tumor and their correlations with clinicopathological factors. Methods: We retrospectively analyzed primary tumors in 71 patients with proven HNC. Primary tumor radiological parameters: DWI and FDG, as well as pathological characteristics were analyzed. Spearman correlation coefficient was used to assess the correlation between DWI and FDG parameters, ANOVA or Kruskal–Wallis, independent sample t-test, Mann–Whitney test, and multiple regression were performed on the clinicopathological features that may affect the 18F- FDG and apparent-diffusion coefficient (ADC) of the tumor. Results: No significant correlations were observed between DWI and any of the 18F-FDG parameters (p > 0.05). SUVmax correlated with N-stages (p = 0.023), TLG and MTV correlated with T-stages (p = 0.006 and p = 0.001), and ADC correlated with tumor grades (p = 0.05). SUVmax was able to differentiate between N+ and N− groups (p = 0.004). Conclusions: Our results revealed a non-significant correlation between the FDG-PET and ADC-MR parameters. FDG-PET-based glucose metabolic and DWI-MR-derived cellularity data may represent different biological aspects of HNC.

Prognostic Value of Intratumor Metabolic Heterogeneity Parameters on 18F-FDG PET/CT for Patients with Colorectal Cancer

Purpose

Intratumor metabolic heterogeneity parameters on ¹⁸F-2-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography-computed tomography (PET-CT) have been proven to be predictors of the clinical prognosis of cancer patients. The study aimed to examine the correlation between ¹⁸F-FDG PET-CT-defined heterogeneity parameters and the prognostic significance in patients with colorectal cancer.

Methods

The study included 188 patients with colorectal cancer who received surgery and ¹⁸F-FDG PET/CT examinations. Preoperative ¹⁸F-FDG PET/CT conventional and metabolic heterogeneity parameters were collected, including maximum, peak, and mean standardized uptake value (SUVmax, SUVpeak, and SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), heterogeneity index-1 (HI-1) and heterogeneity index-2 (HI-2), and clinicopathological information. Correlations between these parameters and patient survival outcomes were inferred.

Results

The associations between ¹⁸F-FDG PET/CT parameters and clinical outcomes were analyzed. Tumor thrombus (P < 0.001), tumor stage (P=0.001), MTV (P=0.003), HI-1 (P=0.032), and HI-2 (P=0.001) differed between the two groups with and without recurrence. Multivariate analysis showed that, in the radical surgery group, HI-2 (HR = 1.10, 95% CI: 1.04–1.17, P=0.001), tumor stage (HR = 20.65, 95% CI: 4.81–88.62, P < 0.001), and regional lymph nodes status (HR = 0.16, 95% CI: 0.04–0.57, P=0.005) were independent variables significantly correlated with progression-free survival (PFS) and HI-2 (HR = 1.16, 95% CI: 1.07–1.26, P < 0.001) was an independent variable affecting overall survival (OS). In the palliative surgery group, HI-2 (HR = 1.03, 95% CI: 1.01–1.06, P=0.020) was an independent variable affecting PFS, and all the parameters were not statistically significant for OS.

Conclusion

HI-2, tumor stage, and regional lymph nodes status might predict the outcomes of colorectal cancer more effectively than other ¹⁸F-FDG PET/CT defined parameters.

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.

The value of preoperative 18F-FDG PET metabolic and volumetric parameters in predicting microvascular invasion and postoperative recurrence of hepatocellular carcinoma

BACKGROUND

Microvascular invasion (MVI) is very important in the evaluation of hepatocellular carcinoma (HCC), but diagnosis is determined by postoperative pathology; thus, preoperative noninvasive methods will play an active role. The purpose of the study was to assess the performance of metabolic parameters of preoperative 18F-fluorodeoxyglucose PET/computerized tomography (18F-FDG PET/CT) in the prediction of MVI and postoperative recurrence in primary hepatocellular carcinoma.

METHODS

We retrospectively collected 72 patients with HCC who have performed 18F-FDG PET/CT scan before partial hepatectomy between 2016 and 2019. We used both normal liver tissue and inferior vena cava as the reference background and combined with clinicopathological features, 18F-FDG PET/CT metabolic and volumetric indices to predict MVI and postoperative recurrence of primary HCC before surgery.

RESULTS

Twenty-one of the 72 patients recurred, in recurrent cases showed higher maximum standard uptake value (SUVmax), TNR (ratio of tumor SUVmax to mean SUV [SUVmean] of the background tissue), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) than nonrecurrence cases (P < 0.001). All 18F-FDG PET metabolic and volumetric indices for predicting postoperative HCC recurrence were significant on receiver-operating-characteristic (ROC) curve analyses (P < 0.05). TNRIVC, TNRNL, MTVIVC, MTVNL TLGIVC and TLGNL were significant factors for predicting MVI in HCC (P < 0.05). On multivariate analyses, MVI, SUVmax, TNRIVC, TNRNL, MTVIVC, MTVNL, TLGIVC and TLGNL (P < 0.05) are independent risk factors for predicting postoperative HCC recurrence. TNRIVC is the most relevant PET/CT parameter for predicting MVI in HCC, and MTVIVC is the most valuable for predicting postoperative HCC recurrence. Moreover, the PET/CT parameters are more accurate for prognosis with inferior vena cava as a reference background than with normal liver tissue.

CONCLUSION

18F-FDG PET/CT metabolic and volumetric indices are effective predictors, and could noninvasively provide more comprehensive predictive information on MVI and postoperative recurrence of primary HCC before surgery.

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.

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.

Expression of TIGAR and its correlation with clinicopathology, prognosis, and 18F-FDG PET/CT parameters in patients with resectable pancreatic ductal adenocarcinoma

OBJECTIVE

The aim of this study was to investigate the expression of TP53-inducible glycolysis and apoptosis regulator (TIGAR) and its relationship with clinical pathology and prognosis; and to analyze the correlation between TIGAR expression and 18F-labeled fluoro-2-deoxyglucose (18F-FDG) PET/computed tomography (CT) parameters in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

We retrospectively analyzed the data of 23 patients who underwent preoperative 18F-FDG PET/CT examinations and were confirmed to have PDAC by postoperative pathology. TIGAR was detected using immunohistochemistry. The relationships between TIGAR expression and clinicopathology and its value in predicting the prognosis of patients with PDAC were analyzed. The correlations between TIGAR expression and 18F-FDG PET/CT parameters [standard uptake value (SUV) max, SUVmean, SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis (TLG)] were analyzed.

RESULTS

The expression of TIGAR was low in 34.8% of patients and high in 65.2% of patients. There was no correlation between TIGAR expression and clinicopathology. The overall survival of patients with high TIGAR expression was significantly shorter than that of patients with low TIGAR expression (11.2 vs. 35.4 months). The 18F-FDG PET/CT parameters: SUVmax, SUVmean, SUVpeak, MTV, and TLG were positively correlated with TIGAR expression, but only the MTV correlation with TIGAR expression was statistically significant.

CONCLUSION

TIGAR is highly expressed in PDAC. Its expression is independent of clinicopathological data and can be used as an independent prognostic factor. TIGAR expression was significantly positively correlated with the 18F-FDG PET/CT parameter MTV.

An FDG PET/CT metabolic parameter-based nomogram for predicting the early recurrence of hepatocellular carcinoma after liver transplantation

PURPOSE

To construct an FDG PET/CT metabolic parameter-based model to predict early recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT).

METHODS

A total of 62 patients with HCC after LT were enrolled with a follow-up period of 1 year. Basic clinical, pathology, and laboratory data, CT features (CPLC), and PET metabolic parameters (CPLCP) were collected for model construction. A CPLC nomogram without metabolic parameters and a CPLCP nomogram with metabolic parameters were established. The net reclassification index (NRI) and integrated discrimination improvement (IDI) of the two models were calculated. The constructed model was compared with Milan criteria and University of California San Francisco (UCSF) criteria. The time-dependent area under the receiver operating characteristic curve (time-AUC) was used to compare the efficiency of the models, and the bootstrap method was used to for verification. Harrell's concordance index (C-index) was used to evaluate the performance of these models. Decision curve analysis (DCA) was used to evaluate the clinical practicability of each model.

RESULTS

Thirty out of 62 patients experienced a recurrence during the 1-year follow-up. BCLC stage (P = 0.009), MVI (P = 0.032), AFP (P = 0.004), CTdmax (P = 0.033), and MTV (P = 0.039) were the independent predictors. The CPLC nomogram and the CPLCP nomogram were established. Compared with the CPLC nomogram, the NRI of the CPLCP nomogram increased by 38.98% (95% CI = -18.77-60.43%) and the IDI increased by 4.40% (95% CI = -1.00-16.62%). The AUC value of the CPLCP nomogram was higher than those of Milan criteria and UCSF criteria in the time-AUC curve. Moreover, the CPLCP nomogram had a higher C-index (0.774) than other models. Finally, the DCA curve showed that clinical practicability of the CPLCP nomogram outperformed the Milan criteria and UCSF criteria.

CONCLUSIONS

The CPLCP nomogram combining basic clinical data, pathology data, laboratory data, CT features, and PET metabolic parameters showed good efficacy and high clinical practicability in predicting the early recurrence of HCC after LT.

Prognostic Significance of Pretreatment 18F-FDG PET/CT Volumetric Parameters in Patients With Colorectal Liver Metastasis: A Systematic Review and Meta-analysis

PURPOSE

Colorectal liver metastasis (CRLM) remains a clinical challenge due to the lack of reliable prognostic parameters. We performed a systematic review and meta-analysis of the prognostic value of pretreatment 18F-FDG PET/CT volumetric parameters for hepatic metastatic lesions (HMLs) in patients with CRLM.

METHODS

A systematic search was performed using the following combination of keywords: CRLM, FDG, PET, and prognosis. The inclusion criteria were studies using 18F-FDG PET/CT as an imaging tool before treatment, including volumetric parameters (metabolic tumor volume [MTV] and total lesion glycolysis [TLG]) for HMLs, and reported survival data. Event-free survival and overall survival were considered as survival markers. The effect on survival was determined by the effect size of the hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Our systematic search identified 668 records, and a total of 10 studies comprising 494 patients were included. The pooled HRs of the prognostic value of the MTV and TLG for event-free survival were 1.55 (95% CI, 1.21-1.99; P = 0.0006) and 1.64 (95% CI, 1.23-2.19; P = 0.0009) with significance, respectively. The pooled HRs of the prognostic value of the MTV and TLG for overall survival were 1.72 (95% CI, 1.32-2.23; P < 0.0001) and 2.09 (95% CI, 1.48-2.96; P < 0.0001) with significance, respectively.

CONCLUSIONS

Higher MTV and TLG for HMLs before treatment were identified as worse prognostic parameters in patients with CRLM. The MTV and TLG of 18F-FDG PET/CT could be used as predictors of prognosis.

Preoperative 18F-FDG PET/computed tomography predicts survival following resection for colorectal liver metastases

OBJECTIVE

The liver is the most frequent metastatic site from colorectal cancer and about 20% of these patients are treated by surgical resection. However, the 5-year disease-free survival (DFS) following resection is only about 25% and 5-year overall survival (OS) about 38%. The aim of the study was to evaluate the ability of metabolic and volumetric measurements from fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) prior to resection for colorectal liver metastases (CLM) to predict survival.

PATIENTS AND METHODS

Preoperative F-FDG PET/CT examinations were assessed. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), maximum, mean and peak standardized uptake values and tumor to background ratio, were obtained for all CLM. Cutoff values were determined for each of these parameters by using receiver operating characteristic analysis dividing the patients into two groups. DFS, liver recurrence-free survival (LRFS), OS and cancer-specific survival (CSS) for patients over and under the cutoff value were compared by using the Kaplan-Meier method and log-rank test.

RESULTS

Twenty-seven patients who underwent F-FDG PET/CT prior to resection for CLM were included. Low values of total MTV and TLG were significantly correlated to improved 5-year LRFS (P = 0.016 and 0.006) and CSS (P = 0.034 and 0.008). Patients who developed liver recurrence had significantly higher total MTV and TLG compared to patients without liver recurrence (P = 0.042 and 0.047).

CONCLUSION

Low values of total MTV and TLG were significantly correlated to improved LRFS and CSS and may improve the risk stratification of patients considered for resection for CLM.

Predicting tumor recurrence using metabolic indices of 18F-FDG PET/CT prior to orthotopic liver transplantationfor hepatocellular carcinoma

The present study analyzed the ability of metabolic burden indices from ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) to predict tumor recurrence following orthotopic liver transplantation (OLT) in patients with hepatocellular carcinoma (HCC). Seven major metabolic indices were measured by ¹⁸F-FDG PET/CT in 93 patients with HCC, prior to OLT. The Mann-Whitney U test was then used to predict the association of metabolic indices, including the maximum standardized uptake value (SUVmax), tumor-to-mediastinum SUV ratio, tumor-to-normal-liver SUV ratio, SUV normalized to lean body mass metabolic tumor volume (MTV), total lesion glycolysis (TLG) and uptake-volume product (UVP), with the recurrence risk. The Deauville-like scoring system was used to quantify the recurrence risk. Univariate and multivariable Cox regression models were performed to determine survival rate. The results showed that Deauville-like score (PET-negative vs. -positive), MTV (cutoff value, 13.36), TLG (cutoff value, 62.21) and UVP (cutoff value, 66.60) had high prediction performance for tumor recurrence (P<0.05). TLG had the highest receiver operating characteristics area under the curve of 0.725. Among the clinical factors, high level of α-fetoprotein (AFP, ≥144 ng/ml), Milan criteria, tumor number (>3), involvement of both right and left lobes, and tumor size (>5 cm) were found to be significant predictors of tumor recurrence. Patients in the low metabolic group had longer recurrence-free survival (RFS) times compared with those in the high metabolic group, regardless of whether they met the Milan criteria or not. AFP, uptake-volume product according the SUV mean of mediastinum (UVP-M), Milan criteria, lymph node metastasis, and the number of tumors were significant prognostic factors for RFS (P<0.05) in both univariate and multivariate survival analyses. Additionally, the MVI was a significant prognostic factor based on univariate survival analyses. Overall, the present study demonstrated the metabolic burden indices measured by PET/CT, Deauville-like score, MTV, TLG and UVP as significant prognostic factors in patients with HCC following OLT. The combination of metabolic indices measured by PET/CT and the existing criteria, such as the Milan criteria, may play an important role in evaluating the suitability of OLT in specific patients.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Positron-emission tomography for hepatocellular carcinoma: Current status and future prospects

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality worldwide. Various imaging modalities provide important information about HCC for its clinical management. Since positron-emission tomography (PET) or PET-computed tomography was introduced to the oncologic setting, it has played crucial roles in detecting, distinguishing, accurately staging, and evaluating local, residual, and recurrent HCC. PET imaging visualizes tissue metabolic information that is closely associated with treatment. Dynamic PET imaging and dual-tracer have emerged as complementary techniques that aid in various aspects of HCC diagnosis. The advent of new radiotracers and the development of immuno-PET and PET-magnetic resonance imaging have improved the ability to detect lesions and have made great progress in treatment surveillance. The current PET diagnostic capabilities for HCC and the supplementary techniques are reviewed herein.

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.

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.

Prognostic Value of the Metabolic and Volumetric Parameters of 11C-Methionine Positron-Emission Tomography for Gliomas: A Systematic Review and Meta-Analysis

BACKGROUND

Several studies have demonstrated that ¹¹C-methionine positron-emission tomography provides information on prognosis.

PURPOSE

We performed a systematic review and meta-analysis of the prognostic value of the metabolic and volumetric parameters of ¹¹C-methionine-PET for gliomas.

DATA SOURCES

A systematic search was performed using the following combination of keywords: "methionine," "PET," "glioma," and "prognosis."

STUDY SELECTION

The inclusion criteria were the use of ¹¹C-methionine-PET as an imaging tool, studies limited to gliomas, studies including metabolic parameters (tumor-to-normal ratio) and/or volumetric parameters (metabolic tumor volume), and studies reporting survival data. The electronic search first identified 181 records, and 14 studies were selected.

DATA ANALYSIS

Event-free survival and overall survival were the outcome measures of interest. The effect of the tumor-to-normal ratio and metabolic tumor volume on survival was determined by the effect size of the hazard ratio. Hazard ratios were extracted directly from each study when provided or determined by analyzing the Kaplan-Meier curves.

DATA SYNTHESIS

The combined hazard ratios of the tumor-to-normal ratio for event-free survival was 1.74 with no significance and that of the tumor-to-normal ratio for overall survival was 2.02 with significance. The combined hazard ratio of the metabolic tumor volume for event-free survival was 2.72 with significance and that of the metabolic tumor volume for overall survival was 3.50 with significance.

LIMITATIONS

The studies selected were all retrospective, and there were only 4 studies involving the metabolic tumor volume.

CONCLUSIONS

The present meta-analysis of ¹¹C-methionine-PET suggests that the tumor-to-normal ratio for overall survival and the metabolic tumor volume for event-free survival and overall survival are significant prognostic factors for patients with gliomas.

Prognostic value of simultaneous 18F-FDG PET/MRI using a combination of metabolo-volumetric parameters and apparent diffusion coefficient in treated head and neck cancer

Background

The aim of this study was to determine the usefulness of combined positron emission tomography (PET)/magnetic resonance imaging (MRI) parameters provided by simultaneous ¹⁸F-fluorodeoxyglucose (FDG) PET/MRI for the prediction of treatment failure in surgically resected head and neck cancer. We hypothesized that PET parameters corrected by tumor cellularity (combined PET/MRI parameters) could predict the prognosis. On regional PET, maximum standardized uptake value (SUVmax) was measured as metabolic parameters. In addition, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were checked as metabolo-volumetric parameters. Mean apparent diffusion coefficient (ADCmean) of tumor was evaluated as the MRI parameter on the ADC map. Ratios between metabolic/metabolo-volumetric parameters and ADC were calculated as combined PET/MRI parameters. PET, MRI, and combined PET/MRI parameters were compared with clinicopathologic parameters in terms of treatment failure.

Results

Seventy-two patients (mean age = 55.9 ± 14.6 year, M: F = 45: 27) who underwent simultaneous ¹⁸F-FDG PET/MRI before head and neck cancer surgery were retrospectively enrolled. Twenty-two patients (30.6%) showed tumor treatment failure after head and neck cancer surgery (mean treatment failure = 13.0 ± 7.0 months). In the univariate analysis, MTV (P = 0.044) and ratios between metabolo-volumetric parameters and ADC (MTV/ADCmean, P = 0.022; TLG/ADCmean, P = 0.044) demonstrated significance among ¹⁸F-FDG PET/MRI parameters. Lymphatic invasion (P = 0.044) and perineural invasion (P = 0.046) revealed significance among clinicopathologic parameters. In the multivariate analysis, MTV (P = 0.026), MTV/ADCmean (P = 0.011), and TLG/ADCmean (P = 0.002) with lymphatic invasion (P = 0.026, 0.026, and 0.044, respectively) showed significance.

Conclusions

Combined PET/MRI parameters (PET metabolo-volumetric parameters corrected by tumor cellularity) could be effective predictors of tumor treatment failure after head and neck cancer surgery in addition to MTV and clinicopathologic parameter.

Electronic supplementary material

The online version of this article (10.1186/s13550-018-0357-9) contains supplementary material, which is available to authorized users.

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.

Volumetric parameters on FDG PET can predict early intrahepatic recurrence-free survival in patients with hepatocellular carcinoma after curative surgical resection

PURPOSE

This study assessed the prognostic values of volumetric parameters on ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in predicting early intrahepatic recurrence-free survival (RFS) after curative resection in patients with hepatocellular carcinoma (HCC).

METHODS

A retrospective analysis was performed on 242 patients with HCC who underwent staging FDG PET and subsequent curative surgical resection. The tumor-to-non-tumorous liver uptake ratio, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the HCC lesions on PET were measured. The prognostic values of clinical factors and PET parameters for predicting overall RFS, overall survival (OS), extrahepatic RFS, and early and late intrahepatic RFS were assessed.

RESULTS

The median follow-up period was 54.7 months, during which 110 patients (45.5%) experienced HCC recurrence and 62 (25.6%) died. Patients with extrahepatic and early intrahepatic recurrence showed worse OS than did those with no recurrence or late intrahepatic recurrence (p < 0.001). Serum bilirubin level, MTV, and TLG were independent prognostic factors for overall RFS and OS (p < 0.05). Only MTV and TLG were prognostic for extrahepatic RFS (p < 0.05). Serum alpha-fetoprotein and bilirubin levels, MTV, and TLG were prognostic for early intrahepatic RFS (p < 0.05) and hepatitis C virus (HCV) positivity and serum albumin level were independently prognostic for late intrahepatic RFS (p < 0.05).

CONCLUSION

Intrahepatic recurrence showed different prognoses according to the time interval of recurrence in which early recurrence had as poor survival as extrahepatic recurrence. MTV and TLG on initial staging PET were significant independent factors for predicting early intrahepatic and extrahepatic RFS in patients with HCC after curative resection. Only HCV positivity and serum albumin level were significant for late intrahepatic RFS, which is mainly attributable to the de novo formation of new primary HCC.

Heterogeneity index evaluated by slope of linear regression on 18F-FDG PET/CT as a prognostic marker for predicting tumor recurrence in pancreatic ductal adenocarcinoma

PURPOSE

¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been investigated as a method to predict pancreatic cancer recurrence after pancreatic surgery. We evaluated the recently introduced heterogeneity indices of ¹⁸F-FDG PET/CT used for predicting pancreatic cancer recurrence after surgery and compared them with current clinicopathologic and ¹⁸F-FDG PET/CT parameters.

METHODS

A total of 93 pancreatic ductal adenocarcinoma patients (M:F = 60:33, mean age = 64.2 ± 9.1 years) who underwent preoperative ¹⁸F-FDG PET/CT following pancreatic surgery were retrospectively enrolled. The standardized uptake values (SUVs) and tumor-to-background ratios (TBR) were measured on each ¹⁸F-FDG PET/CT, as metabolic parameters. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were examined as volumetric parameters. The coefficient of variance (heterogeneity index-1; SUVmean divided by the standard deviation) and linear regression slopes (heterogeneity index-2) of the MTV, according to SUV thresholds of 2.0, 2.5 and 3.0, were evaluated as heterogeneity indices. Predictive values of clinicopathologic and ¹⁸F-FDG PET/CT parameters and heterogeneity indices were compared in terms of pancreatic cancer recurrence.

RESULTS

Seventy patients (75.3%) showed recurrence after pancreatic cancer surgery (mean recurrence = 9.4 ± 8.4 months). Comparing the recurrence and no recurrence patients, all of the ¹⁸F-FDG PET/CT parameters and heterogeneity indices demonstrated significant differences. In univariate Cox-regression analyses, MTV (P = 0.013), TLG (P = 0.007), and heterogeneity index-2 (P = 0.027) were significant. Among the clinicopathologic parameters, CA19-9 (P = 0.025) and venous invasion (P = 0.002) were selected as significant parameters. In multivariate Cox-regression analyses, MTV (P = 0.005), TLG (P = 0.004), and heterogeneity index-2 (P = 0.016) with venous invasion (P < 0.001, 0.001, and 0.001, respectively) demonstrated significant results.

CONCLUSIONS

The heterogeneity index obtained using the linear regression slope, could be an effective predictor of pancreatic cancer recurrence after pancreatic cancer surgery, in addition to ¹⁸F-FDG PET/CT volumetric parameters and clinicopathologic parameters.

Prognostic Value of Metabolic Parameters of 18F-FDG PET/CT and Apparent Diffusion Coefficient of MRI in Hepatocellular Carcinoma

BACKGROUND

The aim of this study was to predict the survival of patients with hepatocellular carcinoma (HCC) by examining metabolic PET parameters, apparent diffusion coefficients (ADCs), and clinical parameters.

METHODS

We retrospectively reviewed 52 patients with pathologically confirmed HCC (age, 57.9 ± 10.7 years; 43 men) who underwent MRI and F-FDG PET/CT. The tumor-to-normal liver SUV ratio (TLR), the mean ADC of each tumor, and other clinical data were obtained. Survival analysis was performed.

RESULTS

Thirty-two patients died during the follow-up period. There was an inverse correlation between the mean SUV and the mean ADC of a tumor (r = -0.402, P = 0.020). Among HCC patients, disease-specific survival was significantly associated with each of the following factors: high TLR (TLR ≥ 2; hazard ratio [HR], 3.78; P = 0.001), high mean ADC (mean ADC ≥ 1.250 × 10 mm/s; HR, 0.45; P = 0.028), AFP ≥ 400 ng/mL (HR, 3.48; P = 0.001), PIVKA-II ≥ 100mAU/mL (HR, 6.39; P = 0.011), tumor size (HR, 1.13; P < 0.001), number of tumors (HR, 2.16; P = 0.031), tumor stage (HR, 3.08; P < 0.001), and surgery for initial treatment (HR, 0.06; P < 0.001). The results of multivariate analysis show that DSS was significantly associated with each of the following factors: TLR ≥ 2 (HR, 2.46; P = 0.044), PIVKA-II ≥ 100mAU/mL (HR, 5.11; P = 0.037), tumor stage (HR, 3.01; P < 0.001), and surgery for initial treatment (HR, 0.04; P < 0.001).

CONCLUSIONS

High TLRs and low mean ADCs were associated with poor outcomes. The TLR was an independent prognostic factor in patients with HCC, but the mean ADC was not. A negative correlation was found between the mean ADC and the mean SUV of a tumor.

Prognostic value of pre-treatment F-18-FDG PET-CT in patients with hepatocellular carcinoma undergoing radioembolization

AIM

To evaluate the value of pre-treatment 18F-FDG PET/CT in patients with HCC following liver radioembolization.

METHODS

We identified 34 patients with HCC who underwent an FDG PET/CT scan prior to hepatic radioembolization at our institution between 2009 and 2013. Patients were seen in clinic one month after radioembolization and then at 2-3 mo intervals. We assessed the influence of FDG tumor uptake on outcomes including local liver control (LLC), distant liver control (DLC), time to distant metastases (DM), progression free survival (PFS) and overall survival (OS).

RESULTS

The majority of patients were males (n = 25, 74%), and had Child Pugh Class A (n = 31, 91%), with a median age of 68 years (46-84 years). FDG-avid disease was found in 19 (56%) patients with SUVmax ranging from 3 to 20. Female patients were more likely to have an FDG-avid HCC (P = 0.02). Median follow up of patients following radioembolization was 12 months (1.2-62.8 mo). FDG-avid disease was associated with a decreased 1 year LLC, DLC, DM and PFS (P < 0.05). Using multivariate analysis, FDG avidity predicted for LLC, DLC, and PFS (all P < 0.05).

CONCLUSION

In this retrospective study, pre-treatment HCC FDG-avidity was found to be associated with worse LLC, DLC, and PFS following radioembolization. Larger studies are needed to validate our initial findings to assess the role of F-18-FDG PET/CT scans as biomarker for patients with HCC following radioembolization.

Role of positron emission tomography/computed tomography in living donor liver transplantation for hepatocellular carcinoma

Living donor liver transplantation (LDLT) becomes an important option for treatment for patients with hepatocellular carcinoma (HCC). With the advance of imaging modalities such as computed tomography (CT) and magnetic resonance image (MRI), preoperative staging and diagnosis for HCC was improved in LDLT. However, morphological characteristics based on the tumor number and size do not represent the tumor pathology and prognosis clearly. Therefore, many criteria using various markers have been reported, but still have limitation to predict the pathology and prognosis. Recently, 18F-fluorodeoxyglucose-positron emission tomography/CT (18F-FDG PET/CT) was introduced to have the usefulness for detection of extrahepatic metastases and prediction of post-transplant prognosis in liver transplantation (LT). Furthermore, the hybrid concept with both biologic activity using PET/CT and morphologic tumor characteristics using CT and MRI was reported to be selection criteria for the patient with HCC waiting LDLT. We will discuss the role of 18F-FDG PET/CT in LDLT as various aspects including tumor detection, pathology prediction, prognosis prediction, and possibility of selecting criteria.