Extensive tumor thrombus of hepatocellular carcinoma in the entire portal venous system detected on fluorodeoxyglucose positron emission tomography computed tomography

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.

Tumor in the veins: an abdominal perspective with an emphasis on CT and MR imaging

Endovenous tumor thrombus in abdomen should be accurately diagnosed as it is a significant finding that may change medical and surgical treatment approaches. As some underlying reasons for endovenous tumor thrombi are relatively rare and imaging findings may be quite subtle, they can be easily overlooked which may have important clinical consequences. In this paper, we described the various imaging aspects of endovenous tumor thrombi originating from various tumor types in different venous structures of the abdomen.

FDG-Avid Portal Vein Tumor Thrombosis from Hepatocellular Carcinoma in Contrast-Enhanced FDG PET/CT

OBJECTIVES

In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT), complicating hepatocellular carcinoma (HCC) in contrast-enhanced FDG PET/CT scan.

METHODS

In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis.

RESULTS

Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%). PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8 ± 0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001). FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001). PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6%) had no extrahepatic metastasis, 3 cases (33.3%) had metastasis of regional lymph nodes, and 1 case (11.1%) presented with distant metastasis. The median estimated survival time of patients was 5 months.

CONCLUSION

The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are findings of FDG-avid PVTT from HCC in contrast-enhanced FDG PET/CT.