Metabolic restaging of hepatocellular carcinoma using whole-body 18F-FDG PET/CT

Advancements in hepatocellular carcinoma management: the role of 18F-FDG PET-CT in diagnosing portal vein tumor thrombosis

Portal vein thrombosis, a relatively frequent complication associated with hepatocellular carcinoma (HCC) and liver cirrhosis, is recognized as a significant global health concern. This is mainly due to these conditions' high prevalence and potentially severe outcomes. The aim of our study was to conduct a comprehensive literature review to evaluate the efficacy, accuracy, and clinical implications of 18F-FDG PET-CT in diagnosing and managing portal vein tumor thrombosis (PVTT) in patients with HCC. HCC, which accounts for 80% of liver malignancies, ranks as the fourth most prevalent cancer globally and is a significant contributor to cancer-related mortality. The majority of HCC patients are diagnosed at an advanced stage, leading to a deterioration in patient outcomes. Involvement of the portal vein is also a significant negative factor. This review analyzes the application of 18F-FDG PET-CT in the detection and management of PVTT in patients with HCC, with an emphasis on the importance of the maximum standardized uptake value as an essential diagnostic and prognostic marker. 18F-FDG PET-CT is invaluable for detecting recurrence and guiding management strategies, particularly in patients with high-grade HCC, and plays a pivotal role in differentiating malignant portal vein thrombi from their benign counterparts.

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

Background

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

Results

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

Conclusion

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

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

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

Efficiency of whole-body 18F-FDG PET CT in detecting the cause of rising serum AFP level in post-therapeutic follow-up for HCC patients

PURPOSE

The goal of this study was to assess the value of whole-body ¹⁸F-FDG PET/CT in detecting the cause of rising serum alpha-fetoprotein (AFP) level after the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

¹⁸F-FDG PET/CT studies were performed for 100 patients (76 men and 24 women), ranged in age from 40 to 76 years who had underwent either surgical resection or interventional therapy for HCC, but were subsequently noted to have rising AFP serum level on routine follow-up examinations. The ¹⁸F-FDG PET/CT results were correlated with histological findings or radiological and clinical follow-up.

RESULTS

According to patient-based analysis, ¹⁸F-FDG PET/CT demonstrated 74 true-positives, four false-negatives, 16 true-negative, and 6 false-positive results, with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 95%, 72.7%, 92.5%, 80%, and 90%, respectively. According to Lesion-based analysis, ¹⁸F-FDG PET/CT demonstrated 202 true-positive lesions, 8 false-negatives, and 16 true-negative and 6 false-positive results, with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 98%, 72.7%, 97%, 80%, and 95.6%, respectively.

CONCLUSION

¹⁸F-FDG PET/CT is a valuable imaging tool investigating patients who have a rising serum AFP level after HCC treatment. It accurately detects residual or recurrent tumor as well as extrahepatic metastasis.

18F-FDG PET with or without CT in the diagnosis of extrahepatic metastases or local residual/recurrent hepatocellular carcinoma

The aim of the present study was to meta-analyze the literature on the diagnostic value of 18-fluorodeoxyglucose (F-FDG) positron emission tomography (PET) with or without computed tomography (CT) in detecting extrahepatic metastases or local residual/recurrent hepatocellular carcinoma (HCC).Systematic review of literature in MEDLINE, Embase, and Cochrane databases was conducted in March 2017, and relevant studies analyzing the diagnostic performance of F-FDG PET with or without CT were meta-analyzed.Meta-analysis was carried out on data from 11 studies involving 572 patients. F-FDG PET, with or without CT, showed pooled sensitivity of 64% and pooled specificity of 95%. Pooled sensitivity was similar with CT (74%) or without (52%; P = .279). Similarly, pooled specificity was comparable with CT (93%) or without 95% (P = .481).F-FDG PET, with or without CT, shows relatively low sensitivity but high specificity for diagnosing extrahepatic metastases or local residual/recurrent HCC. Adding CT to F-FDG PET may improve diagnostic performance, but the available evidence suggests that the improvement is not statistically significant.

[Combined PET-MRI of the abdomen]

The first fully integrated combined positron emission tomography-magnetic resonance imaging (PET-MRI) scanners have been clinically available since 2010. Large prospective studies regarding indications and diagnostic accuracy of this new modality are not yet available; however, preliminary studies have shown a higher diagnostic accuracy and confidence compared to PET-computed tomography (PET-CT) in regions where MRI is known to be superior to CT, such as the liver. The benefit of MRI in accurate lesion characterization and the additional value of diffusion-weighted imaging (DWI) as a complementary functional modality by means of the apparent diffusion coefficient (ADC) is apparent in entities with low tracer uptake (e.g. due to small size) and a decreased or absent accumulation pattern on PET.

Clinical utility and limitations of FDG PET in detecting recurrent hepatocellular carcinoma in postoperative patients

BACKGROUND

The clinical usefulness of positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) for the detection of recurrent hepatocellular carcinoma (HCC) is controversial because HCC displays varying FDG avidity. The purposes of this study were to re-evaluate the utility of FDG PET for the detection of recurrent HCC, and to assess its prognostic value in a large series of postoperative patients.

METHODS

We retrospectively reviewed 113 scans in 86 patients undergoing FDG PET after curative surgery for HCC. These scans were performed for suspected recurrence on radiologic imaging (group A: n = 44) because of an elevated tumor marker level with negative prior imaging results (group B: n = 32) or with no suspicion of recurrence (group C: n = 37). FDG PET's accuracy for recurrence detection and its value as a predictor of survival were assessed.

RESULTS

The sensitivity, specificity, and diagnostic accuracy were 53, 100, and 55 % for group A; 34, 100, and 41 % for group B; and 11, 100, and 78 % for group C, respectively. A change in therapy resulted from the scan results in 7, 9, and 8 % in groups A, B, and C, respectively. The combined sensitivities for intra- and extrahepatic recurrence were 30 and 42 %, respectively. Histopathological features at initial surgery did not affect the sensitivity. The overall survival of patients with positive scans was significantly poorer than that of patients with negative scans (P = 0.008).

CONCLUSIONS

The sensitivity of FDG PET for recurrent HCC was low, with little change in treatment resulting. However, it can predict prognosis in postoperative patients.

Usefulness of F-18 FDG PET/CT in the Evaluation of Early Treatment Response After Interventional Therapy for Hepatocellular Carcinoma

PURPOSE

This retrospective study investigated the usefulness of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after interventional therapy for hepatocellular carcinoma (HCC).

METHODS

Between March 2007 and November 2010, 31 patients (24 men, 7 women; mean age, 61.8 ± 11.0 years) with 45 lesions underwent PET/CT within 1 month after interventional therapy for HCC. Twenty-six patients with 40 lesions underwent transcatheter arterial chemoembolization (TACE), two patients with 2 lesions underwent radiofrequency ablation (RFA), and three patients with 3 lesions underwent percutaneous ethanol injection therapy (PEIT). Patients with a history of previous interventional therapy were excluded. Visual analysis was graded as positive when FDG was observed as an eccentric, nodular, or infiltrative pattern, and negative in case of isometabolic, hypometabolic, or rim-shaped uptake. For quantitative analysis, the standardized uptake value (SUV) was measured by region of interest technique. Maximum SUV (SUVmax) was assessed, and the ratio of SUVmax of tumor to mean SUV of normal liver (TNR) was calculated. The patients were divided into two groups, with and without residual tumor, based on 6-month clinical follow-up with serum alpha-fetoprotein and contrast-enhanced abdominal CT.

RESULTS

Of the 45 lesions, 24 were classified in the residual tumor group and the other 21 lesions in the no residual tumor group. No residual tumor was detected after RFA or PEIT. By visual analysis, the respective values for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.5, 71.4, 77.8, 83.3, and 80.0 %. However, there were no significant differences in the SUVmax and TNR between the two groups.

CONCLUSIONS

It is suggested that FDG PET/CT may play a role in the evaluation of early treatment response after interventional therapy for HCC. The results indicate that FDG PET/CT visual analysis may be more useful than quantitative analysis. Further prospective studies with a large number of patients and established protocol are needed to substantiate our results.

18F-FDG PET or PET/CT for detecting extrahepatic metastases or recurrent hepatocellular carcinoma: a systematic review and meta-analysis

AIM

Positron emission tomography (PET) using F18-flurodeoxy-glucose (FDG) has been widely used for reflecting cellular metabolism. However, the feasibility of FDG PET in the diagnosis of hepatocellular carcinoma (HCC) is limited. The aim of the study was to assess the ability of FDG PET (PET/CT) in the detection of extrahepatic metastases or recurrent HCC.

MATERIALS AND METHODS

We conducted MEDLINE, EMBASE and COCHRANE searches (last update, April 2011). Eight eligible articles were identified evaluating F18-FDG PET (PET/CT) in extrahepatic metastases or recurrent HCC. Two authors independently evaluated the methodological quality of each study. We estimated pooled sensitivities, specificities, summary receiver-operating-characteristic (SROC) curves, and summary likelihood ratios.

RESULTS

Eight eligible studies were enrolled in this study. The pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FDG PET (PET/CT) in the detection of metastatic HCC were 76.6%, 98.0%, 14.68, and 0.28, respectively. The pooled estimates of sensitivity, specificity, LR+ and LR- of FDG PET (PET/CT) in the detection of recurrent HCC were 81.7%, 88.9%, 4.72, and 0.19, respectively.

CONCLUSION

Based on the results of this systematic review, F-18 FDG PET (PET/CT) was useful in ruling in extrahepatic metastases of HCC and valuable for ruling out the recurrent HCC.

Evaluation of Bone Metastasis from Hepatocellular Carcinoma Using (18)F-FDG PET/CT and (99m)Tc-HDP Bone Scintigraphy: Characteristics of Soft Tissue Formation

PURPOSE

Bone metastasis from hepatocellular carcinoma (HCC) can present with soft tissue formation, resulting in oncologic emergency. Contrast-enhanced FDG PET/CT and bone scintigraphy were compared to evaluate characteristics of bone metastases with or without soft tissue formation from HCC.

METHODS

Of 4,151 patients with HCC, 263 patients had bone metastases. Eighty-five patients with bone metastasis from HCC underwent contrast-enhanced FDG PET/CT. Fifty-four of the enrolled subjects had recent (99m)Tc-HDP bone scintigraphy available for comparison. Metastatic bone lesions were identified with visual inspection on FDG PET/CT, and maximum standardized uptake value (SUVmax) was used for the quantitative analysis. Confirmation of bone metastasis was based on histopathology, combined imaging modalities, or serial follow-up studies.

RESULTS

Forty-seven patients (55%) presented with soft tissue formation, while the remaining 38 patients presented without soft tissue formation. Frequent sites of bone metastases from HCC were the spine (39%), pelvis (19%), and rib cage (14%). The soft-tissue-formation group had more frequent bone pain (77 vs. 37%, p < 0.0001), higher SUVmax (6.02 vs. 3.52, p < 0.007), and higher incidence of photon defect in bone scintigraphy (75 vs. 0%) compared to the non-soft-tissue-formation group. FDG PET/CT had higher detection rate for bone metastasis than bone scintigraphy both in lesion-based analysis (98 vs. 53%, p = 0.0015) and in patient-based analysis (100 vs. 80%, p < 0 .001).

CONCLUSIONS

Bone metastasis from HCC showed a high incidence of soft tissue formation requiring emergency treatment. Although the characteristic findings for soft tissue formation such as photon defect in bone scintigraphy are helpful in detection, overall detectability of bone metastasis is higher in FDG PET/CT. Contrast-enhanced PET/CT will be useful in finding and delineating soft-tissue-forming bone metastasis from HCC.