The role of 18F-FDG PET/CT in differentiating malignant from benign portal vein thrombosis

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.

Mesorectal thromboembolism with increased 18F-fluorodeoxyglucose uptake during positron emission tomography/computed tomography in a patient with non-small cell lung cancer

This study presents a case of a 72-year-old man diagnosed with non-small cell lung cancer (cT4N0M0) referred to our hospital for possible surgical treatment of a solitary nodule detected in the mesorectum. The patient had received combined chemoradiotherapy and achieved a complete response 13 months before the presentation. On examination, the mesorectal nodule was incidentally detected during surveillance computed tomography, and the maximum standardized uptake value of the nodule was 10.3. Because of the potential malignancy and need for en-bloc resection of the nodule, we performed laparoscopically assisted high anterior resection of the rectum. The postoperative course was uneventful. Notably, while pathological examination revealed that the mesorectal nodule comprised an intravenous organized thromboembolism, malignancy was not observed. These findings suggest that although positron emission tomography/computed tomography with 18F-fluorodeoxyglucose is useful for the diagnosis of malignant diseases, surgical resection might be the most reliable option for complex cases such as ours.

Liver transplantation for advanced hepatocellular carcinoma: Controversy over portal vein tumor thrombosis

Liver transplantation (LT) is considered the ideal treatment for hepatocellular carcinoma (HCC) concurrent with underlying cirrhotic liver disease. As well-known, LT for HCC based on the Milan criteria has shown satisfactory outcomes. However, numerous expanded transplantation criteria were proposed to benefit more patients for LT and showed comparable survivals as well. In addition, a modest expansion of transplantation criteria for HCC may be acceptable on the basis of the consensus within the transplantation community. Nonetheless, LT in patients with advanced HCC and portal vein tumor thrombosis (PVTT) recently has received attention and has been reported by many transplantation centers despite being contraindicated. Of those, the LT outcomes in certain HCC patients with PVTT were favorable. Additionally, the advancement of multimodality treatments and the evolution of systemic therapies have emerged as promising therapeutic options for downstaging advanced HCC prior to LT. Somehow, advanced HCC with PVTT could be downstaged to become eligible for LT through these multidisciplinary approaches. Although the available evidence of LT for HCC with PVTT is limited, it is hoped that LT may soon be more widely indicated for these patients. Nevertheless, several unknown factors associated with LT for HCC remain to be explored. Herein, this review aimed to update the developments in LT for patients with advanced HCC.

The Role of Contrast-Enhanced Ultrasound (CEUS) in the Detection of Neoplastic Portal Vein Thrombosis in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the principal primary liver cancer and one of the most frequent malignant tumors worldwide in patients with chronic liver disease. When diagnosed at an advanced stage, it is often associated with portal vein tumor thrombosis (PVTT), which heavily affects patients' prognosis. Imaging evaluation is crucial in PVTT detection and staging; computed tomography and magnetic resonance are the principal diagnostic tools. Contrast-enhanced ultrasound (CEUS) is a non-invasive and easily repeatable method that can also be used in patients with impaired renal function. It represents an important means for the identification of PVTT, particularly differentiating neoplastic and non-neoplastic thrombosis through the analysis of ultrasound enhancement characteristics of the thrombosis (arterial hyperenhancement and portal washout), thus allowing more refined disease staging, appropriate treatment planning, and response evaluation, along with prognosis assessment.

Breaking down tumor thrombus: Current strategies for medical management

Tumor thrombus, the intravascular extension of tumor into adjacent blood vessels, is frequently encountered in patients with renal cell carcinoma and hepatocellular carcinoma, and often involves the abdominal vasculature including the renal vein, portal vein, and the inferior vena cava. While a bland thrombus is composed of platelets and fibrin, in contrast, a tumor thrombus refers to an organized collection of tumor cells. Though oftentimes detected incidentally on imaging, tumor thrombus may have significant clinical implications and can be challenging to differentiate from bland thrombus. Additionally, the optimal management of tumor thrombus, including the use of anticoagulation, remains poorly described. This review summarizes common causes of tumor thrombus, as well as its impact on staging, prognosis, and treatment.

FDG PET/CT Depicting Right Iliac Vein Tumor Thrombosis following Low Anterior Resection in Rectal Cancer Patient: A Case Report and Literature Review

Venous tumor thrombus is a rare complication of rectal cancer but is more common in other types of cancer, like renal cell carcinoma and hepatocellular carcinoma. The usual site of tumor thrombus in rectal cancer patients is the inferior mesenteric vein (IMV), which is seldom seen in the common iliac vein, with only a few cases reported till now. We present a case of fluorodeoxyglucose (FDG) avid right iliac vein tumor thrombosis after low anterior resection in a patient with rectal cancer and review the literature.

68 Ga-FAPI PET/MRI and 18 F-FDG PET/CT in a Case With Extensive Portal Vein Tumor Thrombus

ABSTRACT

18 F-FDG PET/CT has been reported to be useful in differentiating tumor thrombus and bland thrombus. There are few reports on 68 Ga-FAPI PET imaging features of tumor thrombus. Herein, we report a 46-year-old man with extensive tumor thrombus in the portal vein due to hepatic malignancy on 18 F-FDG PET/CT and 68 Ga-FAPI PET/MRI.

Prognostic value and morphological findings of overexpression of glypican-3 in hepatocellular carcinoma

OBJECTIVES

Hepatocellular carcinoma (HCC) is the seventh most common cancer all worldwide and is second in cancer-related deaths. In HCC, whose prognosis is still not good despite current treatments, there is a need for prognostic markers as well as early diagnosis. Glypican (GPC)-3 has been proposed as a potential serologic and histochemical marker specific to HCC. This study aimed to determine the relationship between GPC3 overexpression and HCC prognosis and clinicomorphologic features.

MATERIALS AND METHODS

In total 152 patients who were diagnosed as a result of hepatectomy, lobectomy or liver transplantation were enrolled. The patients were divided into two groups, GPC3-positive (overexpression) (>10%) and GPC3-negative (<10%). The demographic data of the patients, tumor characteristics and survival times were recorded.

RESULTS

Survival was significantly lower in the GPC3+ group. In the multivariate analysis, hepatitis C, AFP, tumor number, tumor focality, portal vein tumor thrombosis and GLP3 positivity were found to be independent risk factors for survival.

CONCLUSION

Our study shows that GPC3 overexpression is a poor prognostic factor in HCC. GPC3 positivity were found to be an independent risk factor for survival.

Diagnostic performance and prognostic value of preoperative 18F-FDG PET/CT in renal cell carcinoma patients with venous tumor thrombus

Background

To observe the diagnostic efficacy of preoperative fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) upon venous tumor thrombus (VTT) in patients with renal cell carcinoma (RCC), and investigate the prognostic value of imaging parameters integrated with clinicopathological characteristics in patients with VTT after nephrectomy with tumor thrombectomy.

Methods

Patients with newly diagnosed RCC who underwent 18F-FDG PET/CT were reviewed retrospectively. The diagnostic efficacy of 18F-FDG PET/CT in VTT was analyzed. Logistic regression analysis was carried out to identify the clinical variables and PET/CT variables (including maximum standardized uptake value (SUVmax) of primary tumor, VTT SUVmax and primary tumor size) for differentiating early VTT (Mayo 0-II) from advanced VTT (Mayo III-IV). Cox proportional hazard analyses were used to evaluate clinicopathological factors and PET/CT factors (including distant metastasis, primary tumor SUVmax, VTT SUVmax and primary tumor size) for disease-free survival (DFS) in patients with VTT after operation.

Results

A total of 174 eligible patients were included in this study, including 114 men (65.5%) and 60 women (34.5%), with a median age of 58 years (range, 16–81 years). The distribution of pathological tumor stage (T stage) was 56 (T1), 17 (T2), 95 (T3), and 6 cases (T4), respectively. According to WHO/ISUP grade, except for 4 cases of chromophobe cell RCC, there were 14 patients (8.0%) of grade 1, 59 patients (33.9%) of grade 2, 74 patients (42.5%) of grade 3 and 23 patients (13.2%) of grade 4. The median maximum diameter of the primary tumor on PET/CT was 7.3 cm (5.0–9.5 cm). The distal metastasis was observed in 46 patients (26.4%). Sixty-one cases (35.1%) were confirmed with VTT by pathology. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 18F-FDG PET/CT imaging were 96.7, 99.1, 98.3, 98.3, and 98.2%, in detecting VTT, respectively, and 70.0, 100.0, 94.9, 100.0, and 94.2%, in evaluating the level of VTT, respectively. Elevated VTT SUVmax (≥5.20) could significantly distinguish the early VTT group and advanced VTT group (P = 0.010). In the prognosis analysis, elevated VTT SUVmax (≥4.30) (P = 0.018, HR 3.123, 95% CI 1.212–8.044) and distant metastasis (P = 0.013, HR 3.344, 95% CI 1.293–8.649) were significantly independent predictors for DFS.

Conclusion

Preoperative 18F-FDG PET/CT has a high diagnostic efficacy in detecting VTT and evaluating its level in RCC patients. Those patients with elevated VTT SUVmax should be carefully monitored to detect the possibility of disease progression after operation.

Prognostic factors of elderly patients with hepatocellular carcinoma: should we be more courageous in treatment?

OBJECTIVES

Hepatocellular carcinoma (HCC) is a cancer with a poor prognosis, its incidence increases with age. The risk of developing HCC is highest in the seventh decade. In this study, we aimed to determine the clinicopathological differences, treatment choices, survival times, and effective prognostic factors of HCC in the elderly and young populations.

METHODS

All patients aged ≥18 years who were diagnosed histologically between 2016 and 2020 were included in the study. Patients were divided into two groups: <70 years and ≥70 years. The clinicopathological differences, treatment choices, survival times, and effective prognostic factors of HCC were compared in the elderly and young populations.

RESULTS

A total of 407 patients were evaluated. There were 164 patients (40.3%) in the geriatric age group. There was no significant difference in the female/male ratio, the laboratory values, survival time between the two groups. There was no significant difference between the two groups in terms of tumor focality and portal vein invasion ( P > 0.05). The presence of NAFLD, maximal tumor diameter (MTD), and portal invasion were found to be significant for survival according to the univariate analysis in elderly group ( P < 0.05). In the multivariate analysis, presence of NAFLD etiologically, and MTD independent risk factors were observed in elderly group ( P < 0.05).

CONCLUSION

If the clinicomorphological features of the tumor and prognostic risk factors can be determined by examining the patients in detail, all treatments can be easily applied in the geriatric group.

Anormal uterin kanama ile seyreden tümör trombüsünün nadir bir nedeni olarak uterin leiomyomatozis

Anormal uterin kanama ile seyreden tümör trombüsünün nadir bir nedeni olarak uterin leiomyomatozis

Differentiation of malignant from non-malignant portal vein thrombosis in liver cirrhosis: the challenging dilemma

Background

PVT is an ultrasonographic finding in up to 8% of patients with liver cirrhosis. Once hepatocellular carcinoma has occurred as the final station in liver cirrhosis, the risk of PVT rises to 40%. Benign and malignant PVT can occur in patients with liver cirrhosis, and it is important to differentiate the nature of PVT as it has a great impact on patient’s management and outcome.

Diagnosis

Confirming portal vein thrombosis and extension by abdominal ultrasound, contrast-enhanced USG, CT, or MRI. Malignant criteria of PVT are pulsatile pattern in Doppler and heterogeneous contrast enhancement, which are especially seen at the arterial phase, neovascularity within PVT, portal vein thrombus with a diameter of > 23 mm while in benign thrombus, PV diameter does not exceed 20 mm. Visible hypervascular tumor is in close proximity to PVT.

Conclusion

It is not uncommon to find portal vein thrombosis in patients with liver cirrhosis, despite the fact that malignant variant is the most frequent, but efforts should be gathered to exclude benign PVT which may change the management of the patients dramatically.

Predictors of Macrovascular Invasion and Extrahepatic Metastasis in Treatment Naive Hepatocellular Carcinoma: When Is [18F] FDG PET/CT Relevant?

Purpose

Hypermetabolic macrovascular invasion (MVI) and extrahepatic metastasis (EHM) occur in aggressive hepatocellular carcinoma (HCC) and carry unfavorable prognosis. [¹⁸F] FDG PET/CT, despite having low sensitivity in primary HCC, is valuable in patients with aggressive HCC for detection of hypermetabolic MVI and EHM. The study aimed at identifying the parameters that could predict hypermetabolic MVI and/or EHM in treatment naive HCC patients for tailored approach to utilize [¹⁸F] FDG PET/CT.

Methods

Data of 131 treatment naive HCC patients (median age, 60 years; range, 21-80 years; 90.8% males) who underwent [¹⁸F] FDG PET/CT were retrospectively analyzed to determine the proportion of patients with hypermetabolic MVI and/or EHM. Logistic regression analysis was performed to define independent predictors of hypermetabolic MVI and/or EHM.

Results

78/131 (59.5%) patients had hypermetabolic MVI and/or EHM. 52/131 (39.7%) patients had EHM. 56/131 (42.7%) patients had hypermetabolic MVI of which, 30 had concomitant EHM with majority (90%; 27/30) having distant metastasis. 26/131 (19.8%) patients had hypermetabolic MVI without EHM while 22/131 (16.8%) patients had EHM without hypermetabolic MVI of which, majority (95.5%; 21/22) had distant metastasis. Hypermetabolic MVI was associated with EHM (χ² = 7.868; p value = 0.007). AFP > 93.7 ng/ml, SUVmax > 3.5, and maximum tumor size > 5.0 cm were the independent predictors of hypermetabolic MVI and/or EHM.

Conclusion

In treatment naive HCC patients with AFP > 93.7 ng/ml or maximum tumor size > 5.0 cm, [¹⁸F] FDG PET/CT can be valuable.

Portal Vein Tumor Thrombosis and Hepatocellular Carcinoma - The Changing Tides

Portal vein involvement is considered one of the most fearful complications of hepatocellular carcinoma (HCC). Portal vein tumor thrombosis (PVTT) is associated with aggressive tumor biology (high grade), high tumor burden (number and size of lesions), high levels of serum markers (AFP), poor liver function (deranged LFT), and poor performance status of patients. The Barcelona Clinic Liver Cancer staging system places HCC patients with PVTT in advanced stage (BCLC Stage-C). This group contains a fairly heterogeneous patient population, previously considered candidates for palliative systemic therapy with sorafenib. However, this provided modest overall survival (OS) benefit. The results of a recent Phase III (IMbrave150) trial favor the combination of atezolizumab and bevacizumab over sorafenib as a standard of care in advanced unresectable HCC. While only lenvatinib proved to be non-inferior against sorafenib in a phase III (REFLECT trial), regorafenib (RESORCE trial), ramucirumab (REACH-2), and cabozantinib (CELESTIAL) have been approved second-line therapy in phase III clinical trials. Recently, the data on the prospect of other modalities in the management of HCC with PVTT is mounting with favorable results. Targeting multiple pathways in the HCC cascade using a combination of drugs and other modalities such as RT, TACE, TARE, and HAIC appear effective for systemic and loco-regional control. The quest for the ideal combination therapy and the sequence set is still widely unanswered and prospective trials are lacking. With the armament of available therapeutic options and the advances and refinements in the delivery system, down-staging patients to make them eligible for curative resection has been reported. In a rapidly evolving treatment landscape, performing surgery when appropriate, in the form of LR and even LT to achieve cure does not seem farfetched. Likewise, adjuvant therapy and prompt management of the recurrences holds the key to prolong OS and DFS. This review discusses the management options of HCC patients with PVTT.

Liver transplantation for hepatocellular carcinoma with portal vein tumor thrombosis

Traditionally, liver transplantation for hepatocellular carcinoma with portal vein tumor thrombosis is not recommended. However, with recent developments in locoregional therapies for hepatocellular carcinoma, more aggressive treatments have been attempted for advanced hepatocellular carcinoma. Recently, various studies on locoregional therapies for downstaging followed by living donor liver transplantation reported inspiring overall survival and recurrence-free survival of patients. These downstaging procedures included three-dimensional conformal radiation therapy, trans-arterial chemoembolization, stereotactic body radiation therapy, trans-arterial radioembolization, hepatic arterial infusion chemotherapy and combinations of these therapies. Selection of the optimal downstaging protocol should depend on tumor location, biology and background liver status. The risk factors affecting outcome include pre-downstaging alpha-fetoprotein values, delta alpha-fetoprotein values, disappearance of portal vein tumor thrombosis on imaging and meeting the Milan criteria or not after downstaging. For hepatocellular carcinoma with portal vein tumor thrombosis, downstaging procedure with liver transplantation in mind would be helpful. If the reaction of the downstaged tumor is good, liver transplantation may be performed.

Metastatic Infiltration of Anaplastic Carcinoma of the Pancreas Into the Portal Venous System: A Masquerading Cause of Expansive Portal Venous Thrombosis

BACKGROUND The portal vein thrombosis caused by a carcinoma of the pancreas or liver could be a diagnostic challenge. There are some cases which could be diagnosed only by observing changes in patients' clinical manifestations or imaging studies over time. CASE REPORT A 63-year-old man experienced exacerbation of chronic low back pain for 1 month, with abdominal distention. He was admitted to our hospital because abdominal ultrasonography and abdominal contrast-enhanced computed tomography performed at another hospital revealed an extensive thrombus in the portal, splenic, and superior mesenteric veins. Anticoagulation therapy with warfarin was started immediately on admission. Although no baseline disease, such as malignancies, coagulopathies, infections, or collagen diseases were revealed during the 12 days of his hospitalization, the thrombus gradually expanded, with the appearance of obstructive jaundice 8 months after admission. He was readmitted at that time for biopsy of intrahepatic tumors detected by abdominal computed tomography, which diagnosed metastasis of a carcinoma of unknown origin. Although chemotherapy was started, he died 11 months after his initial admission to our hospital. Autopsy revealed a tumorous lesion in the pancreatic head with almost complete replacement of the portal venous thrombus with a similar-appearing tumor. We confirmed the diagnosis of portal venous metastatic infiltration by undifferentiated pancreatic carcinoma, using histopathological examinations. CONCLUSIONS It is essential to consider portal venous metastatic infiltration of undiagnosed malignancy inducing local hypercoagulopathy as a possible cause of expansive portal venous thrombosis.

Isolated Malignant Portal Vein Thrombus in Colon Carcinoma: A Rare Finding on 18F-FDG PET/CECT

In the absence of hepatic metastasis in abdominal cancers, an isolated malignant portal vein thrombus is very rare. The presence of a malignant thrombus has clinical significance for determining the stage, treatment, and prognosis. ¹⁸F-FDG PET/CECT is a noninvasive modality for discriminating between malignant and benign thrombi. We present a case of primary sigmoid colon carcinoma for which ¹⁸F-FDG PET/CT showed, in addition to the ¹⁸F-FDG-avid primary lesion, an ¹⁸F-FDG-avid filling defect in the portal vein, likely malignant thrombus.

Multimodality Imaging of Abdominopelvic Tumors with Venous Invasion

A broad range of abdominal and pelvic tumors can manifest with or develop intraluminal venous invasion. Imaging features at cross-sectional modalities and contrast-enhanced US that allow differentiation of tumor extension within veins from bland thrombus include the expansile nature of tumor thrombus and attenuation and enhancement similar to those of the primary tumor. Venous invasion is a distinctive feature of hepatocellular carcinoma and renal cell carcinoma with known prognostic and treatment implications; however, this finding remains an underrecognized characteristic of multiple other malignancies-including cholangiocarcinoma, adrenocortical carcinoma, pancreatic neuroendocrine tumor, and primary venous leiomyosarcoma-and can be a feature of benign tumors such as renal angiomyolipoma and uterine leiomyomatosis. Recognition of tumor venous invasion at imaging has clinical significance and management implications for a range of abdominal and pelvic tumors. For example, portal vein invasion is a strong negative prognostic indicator in patients with hepatocellular carcinoma. In patients with rectal cancer, diagnosis of extramural venous invasion helps predict local and distant recurrence and is associated with worse survival. The authors present venous invasion by vascular distribution and organ of primary tumor origin with review of typical imaging features. Common pitfalls and mimics of neoplastic thrombus, including artifacts and anatomic variants, are described to help differentiate these findings from tumor in vein. By accurately diagnosing tumor venous invasion, especially in tumors where its presence may not be a typical feature, radiologists can help referring clinicians develop the best treatment strategies for their patients. ^©RSNA, 2020.

Hepatocellular carcinoma with macrovascular invasion: multimodality imaging features for the diagnosis

Hepatocellular carcinoma (HCC) is frequently associated with macrovascular invasion of the portal vein or hepatic veins in advanced stages. The accurate diagnosis of macrovascular invasion and the differentiation from bland non-tumoral thrombus has significant clinical and management implications, since it narrows the therapeutic options and it represents a mandatory contraindication for liver resection or transplantation. The imaging diagnosis remains particularly challenging since the imaging features of HCC with macrovascular invasion may be subtle, especially in lesions showing infiltrative appearance. However, each radiologic imaging modality may provide findings suggesting the presence of tumor thrombus rather than bland thrombus. The purpose of this paper is to review the current guidelines and imaging appearance of HCC with macrovascular invasion. Knowledge of the most common imaging features of HCC with macrovascular invasion may improve the diagnostic confidence of tumor thrombus in clinical practice and help to guide patients' management.

Different patterns of hepatocellular carcinoma-related malign thrombosis in 18F-FDG PET/CT

Tumor thrombus is an intravascular malign tumor extension that may occur in various types of cancer. Hepatocellular carcinomas (HCC) are common causes of malign thrombus. The presence of a malign thrombus due to HCC has a dismal prognosis, which affects treatment choices. We present three cases of tumor thrombi due to advanced HCC detected by ¹⁸F-FDG PET/CT.

Treatment of hepatocellular carcinoma in patients with portal vein tumor thrombosis: Beyond the known frontiers

Hepatocellular carcinoma is one of the most frequent malignant tumors worldwide: Portal vein tumor thrombosis (PVTT) occurs in about 35%-50% of patients and represents a strong negative prognostic factor, due to the increased risk of tumor spread into the bloodstream, leading to a high recurrence risk. For this reason, it is a contraindication to liver transplantation and in several prognostic scores sorafenib represents its standard of care, due to its antiangiogenetic action, although it can grant only a poor prolongation of life expectancy. Recent scientific evidences lead to consider PVTT as a complex anatomical and clinical condition, including a wide range of patients with different prognosis and new treatment possibilities according to the degree of portal system involvement, tumor biological aggressiveness, complications caused by portal hypertension, patient's clinical features and tolerance to antineoplastic treatments. The median survival has been reported to range between 2.7 and 4 mo in absence of therapy, but it can vary from 5 mo to 5 years, thus depicting an extremely variable scenario. For this reason, it is extremely important to focus on the most adequate strategy to be applied to each group of PVTT patients.

Value of 18F-FDG PET/CT in the diagnosis of portal vein tumor thrombus in patients with hepatocellular carcinoma

OBJECTIVE

The aim of this study was to evaluate the usefulness of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for the diagnosis of a portal vein tumor thrombus (PVTT) in patients with hepatocellular carcinoma (HCC).

METHODS

One hundred fifty-four patients with histologically proven HCC underwent ¹⁸F-FDG PET/CT imaging. The maximum standardized uptake value (SUVmax) was calculated, and the change in SUVmax (retention index, RI) was defined as the ratio of the increase in SUVmax between early and delayed scans to the SUVmax in the early scan. The circular region of interest was placed on the transaxial images according to the corresponding CT images. The final diagnoses of a PVTT were confirmed by histopathology.

RESULTS

Of the patients examined, 101 (65.6%) had no confirmed instances of a PVTT, whereas 53 (34.4%) had a confirmed PVTT. The sensitivity of ¹⁸F-FDG PET/CT imaging was 62.3%, the specificity was 97.0%, the accuracy was 85.1%, the positive predictive value was 91.7%, and the negative predictive value was 83.1%. The SUVmax of the PVTT was 4.32 ± 1.96 and the SUVmax of the HCC lesions for these patients was 5.38 ± 2.79, but these differences were insignificant (t = 1.78, p = 0.08). For dual-time-point imaging, the SUV1 of the PVTT lesions was 3.75 ± 1.48, and SUV2 was 3.63 ± 1.41, but these differences were insignificant (t = 0.82, p = 0.42). The SUV1 of the HCC lesions was 4.47 ± 2.03, and the SUV2 was 4.90 ± 2.07, which were both also insignificant (t = - 1.81, p = 0.09). The RI of the PVTT lesions was - 2.05 ± 19.96%, and the RI of the HCC lesions was 11.87 ± 26.20%, with no significant differences between them (t = 1.58, p = 0.13).

CONCLUSIONS

¹⁸F-FDG PET/CT may potentially improve the accurate diagnoses of a PVTT in patients with HCC.

A hypothesis on paradoxical privileged portal vein metastasis of hepatocellular carcinoma. Can organ evolution shed light on patterns of human pathology, and vice versa?

Unlike other carcinomas, hepatocellular carcinoma (HCC) metastasizes to distant organs relatively rarely. In contrast, it routinely metastasizes to liver vasculature/liver, affecting portal veins 3-10 times more often than hepatic veins. This portal metastatic predominance is traditionally rationalized within the model of a reverse portal flow, due to accompanying liver cirrhosis. However, this intuitive model is not coherent with facts: 1) reverse portal flow occurs in fewer than 10% of cirrhotic patients, while portal metastasis occurs in 30-100% of HCC cases, and 2) portal vein prevalence of HCC metastasis is also characteristic of HCC in non-cirrhotic livers. Therefore, we must assume that the route for HCC metastatic dissemination is the same as for other carcinomas: systemic dissemination via the draining vessel, i.e., via the hepatic vein. In this light, portal prevalence versus hepatic vein of HCC metastasis appears as a puzzling pattern, particularly in cases when portal HCC metastases have appeared as the sole manifestation of HCC. Considering that other GI carcinomas (colorectal, pancreatic, gastric and small bowel) invariably disseminate via portal vein, but very rarely form portal metastasis, portal prevalence of HCC metastasis appears as a paradox. However, nature does not contradict itself; it is rather our wrong assumptions that create paradoxes. The 'portal paradox' becomes a logical event within the hypothesis that the formation of the unique portal venous system preceded the appearance of liver in evolution of chordates. The analysis suggests that the appearance of the portal venous system, supplying hormones and growth factors of pancreatic family, which includes insulin, glucagon, somatostatin, and pancreatic polypeptide (HGFPF) to midgut diverticulum in the early evolution of chordates (in an Amphioxus-like ancestral animal), promoted differentiation of enterocytes into hepatocytes and their further evolution to the liver of vertebrates. These promotional-dependent interactions are conserved in the vertebrate lineage. I hypothesize that selective homing and proliferation of malignant hepatocytes (i.e., HCC cells) in the portal vein environment are due to a uniquely high concentration of HGFPF in portal blood. HGFPF are also necessary for liver function and renewal and are significantly extracted by hepatocytes from passing blood, creating a concentration gradient of HGFPF between the portal blood and hepatic vein outflow, making post-liver vasculature and remote organs less favorable spaces for HCC growth. It also suggested that the portal vein environment (i.e., HGFPF) promotes the differentiation of more aggressive HCC clones from already-seeded portal metastases, explaining the worse outcome of HCC with the portal metastatic pattern. The analysis also offers new hypothesis on the phylogenetic origin of the hepatic diverticulum of cephalochordates, with certain implications for the modeling of the chordate phylogeny.

Venous invasion by hepatic tumors: imaging appearance and implications for management

Venous invasion by hepatic tumors most commonly occurs with hepatocellular carcinoma and is associated with worse patient prognosis. Imaging plays an important role in the diagnosis of tumor thrombus in the liver. Moreover, differentiating between bland and tumor thrombus in the liver has important diagnostic, staging, therapeutic, and prognostic implications and may require a multimodal imaging approach including ultrasound, computed tomography, and/or magnetic resonance imaging. Treatment of hepatic malignancies with associated tumor thrombus is dependent on tumor type, disease extent within the liver, liver hemodynamics, and underlying liver function. Treatment of such tumors may involve surgical, locoregional and/or systemic therapies. The current review will focus on the imaging characteristics of venous invasion by hepatic tumors. The imaging findings most useful for differentiating hepatic venous tumor thrombus and bland thrombus will be highlighted and demonstrated with imaging examples. Imaging findings with implications for subsequent patient management will be described.

Differentiation of Malignant Thrombus From Bland Thrombus of the Portal Vein in Patient With Hepatocellular Carcinoma on 18F-FDG PET CT

Hepatocellular carcinoma carries a high risk of invasion of the portal vein. Neoplastic and bland portal vein thrombi discrimination is of great clinical significance for determining the therapeutic approach, predicting survival, and assessing candidates for liver transplantation. F-FDG PET/CT may be helpful in discriminating between malignant and portal vein thrombi. We present the case of a 61-year old man who presented with hepatocellular carcinoma with portal vein involvement. F-FDG PET/CT has a role in differentiating malignant from benign portal vein thrombosis.

Privileged portal metastasis of hepatocellular carcinoma in light of the coevolution of a visceral portal system and liver in the chordate lineage: a search for therapeutic targets

Hepatocellular carcinoma (HCC) disseminates systemically, but metastases occur in distant organs only in minority of patients, whereas HCC routinely metastasizes to liver and its vessels. HCC cells disseminate via hepatic veins, but portal veins are affected by metastasis more frequently than are hepatic veins, and correlates with poor prognosis. In this review, I suggest that privileged HCC portal metastasis occurs because of high levels of pancreatic family hormones and growth factors (PHGFs) in the portal blood. The analysis suggests that the appearance of the portal system carrying PHGFs in the evolution of invertebrate chordate (Amphioxus) led to the evolution of the liver in vertebrate; given that the portal pattern of HCC metastasis and selection of more-aggressive clones are PHGF dependent, PHGFs and their ligands constitute therapeutic targets.

Hepatocellular Carcinoma with Macrovascular Invasion: Defining the Optimal Treatment Strategy

BACKGROUND

Tumoral macrovascular invasion (MVI) of hepatic and/or portal vein branches is a common phenomenon in hepatocellular carcinoma (HCC) and is associated with poorer prognosis when compared to HCC without MVI.

SUMMARY

Current international guidelines for the management of HCC recommend sorafenib as the only treatment option in case of MVI. Despite guideline recommendations, several alternative options have been tested to manage HCC with MVI: surgery, transarterial chemoembolization, external or internal radiation, hepatic arterial infusion chemotherapy, percutaneous treatment, cryotherapy, or the combination of two or more of these strategies, with or without sorafenib. Here we will provide a comprehensive state-of-the-art review for the management of this challenging clinical entity based on the most recent available data.

KEY MESSAGES

There is a growing body of evidence suggesting that alternative strategies to standard-of-care sorafenib might improve survival in patients with advanced HCC with MVI but the level of evidence remains weak. Randomized phase III trials are ongoing and will hopefully provide information leading towards a more personalized treatment algorithm.

Advances in medical imaging for the diagnosis and management of common genitourinary cancers

Medical imaging of the 3 most common genitourinary (GU) cancers-prostate adenocarcinoma, renal cell carcinoma, and urothelial carcinoma of the bladder-has evolved significantly during the last decades. The most commonly used imaging modalities for the diagnosis, staging, and follow-up of GU cancers are computed tomography, magnetic resonance imaging (MRI), and positron emission tomography (PET). Multiplanar multidetector computed tomography and multiparametric MRI with diffusion-weighted imaging are the main imaging modalities for renal cell carcinoma and urothelial carcinoma, and although multiparametric MRI is rapidly becoming the main imaging tool in the evaluation of prostate adenocarcinoma, biopsy is still required for diagnosis. Functional and molecular imaging using 18-fluorodeoxyglucose-PET and sodium fluoride-PET are essential for the diagnosis, and especially follow-up, of metastatic GU tumors. This review provides an overview of the latest advances in the imaging of these 3 major GU cancers.

Budd-Chiari Syndrome Demonstrated on PET/CT

Budd-Chiari syndrome is a rare clinical condition that involves diminution or interruption of hepatic venous blood flow from the liver. We describe a case of Budd-Chiari syndrome visualized via F-FDG PET/CT in a 60-year-old woman with medical history of B-cell non-Hodgkin lymphoma who presented with abdominal pain. FDG PET/CT fusion images demonstrate increased FDG uptake with SUVmax of 2.2 along the course of the middle hepatic vein with decreased attenuation within both the middle and right hepatic veins, consistent with thrombus.

Portal vein thrombosis: The role of imaging in the clinical setting

Portal vein thrombosis is an infrequent condition occurring in several different clinical scenarios. In the last years it has been increasingly recognised due to the broad use of radiological methods. In this review we underline the central role of imaging in diagnosing portal vein thrombosis, in clarifying its etiology, choosing the best therapeutic approach and screening possible complications. Special attention is given to the role of imaging to differentiate portal vein thrombosis from neoplastic invasion of the portal vein, and to new diagnostic methods available for clinical practice in this field.

Prognostic Value of FDG Uptake of Portal Vein Tumor Thrombosis in Patients With Locally Advanced Hepatocellular Carcinoma

PURPOSE

This study aimed to evaluate the prognostic value of F-FDG uptake of portal vein tumor thrombosis (PVTT) for predicting progression-free survival (PFS) and overall survival (OS) in patients with locally advanced hepatocellular carcinoma (HCC).

METHODS

The study retrospectively included 166 HCC patients with PVTT and no extrahepatic metastases who underwent staging FDG PET/CT. Tumor-to-liver uptake ratio (TLR) and PVTT-to-liver uptake ratio (PLR) were measured for each patient, and the prognostic values of clinical factors, TLR, and PLR were assessed. Furthermore, patients were classified into 2 subgroups according to TLR, and the prognostic value of PLR was evaluated in each subgroup.

RESULTS

Median PFS and OS were 6.2 and 10.1 months, respectively. On multivariate analysis, tumor size (P = 0.006) and PLR (P = 0.03) were independent prognostic factors for PFS, whereas Child-Pugh class (P = 0.02) and PLR (P = 0.02) were independent prognostic factors for OS. Tumor-to-liver uptake ratio was a significant prognostic factor for PFS and OS on univariate analysis but failed to show significance on multivariate analysis. In both patient subgroups with low and high TLR, PLR remained a significant prognostic factor for predicting OS (P = 0.04 for all).

CONCLUSIONS

FDG uptake of PVTT, but not FDG uptake of HCC, is an independent prognostic factor for PFS and OS in HCC patients with PVTT and no extrahepatic metastasis. Given the prognostic significance, it is strongly encouraged to use FDG uptake of PVTT in further risk stratification for HCC patients with PVTT.

Multifocal Intrahepatic Artery Aneurysm with FDG-avid Thrombosis Simulating Metastasis: Report of a Rare Case

Hepatic artery aneurysm (HAA), although rare, represents a serious diagnostic and therapeutic challenge due to high rupture rate and associated mortality. Early detection and accurate diagnosis are essential for successful management. Here, we present an extremely rare case of multi-focal intrahepatic HAA with confined intrahepatic rupture and hypermetabolic activity at PET imaging, simulating metastasis of melanoma. A retrospective review found only two other HAA at our institution between 2000 and 2015, both of which involved the extrahepatic artery. This report highlights the importance of clinical, radiological, and pathological correlation in the management of this rare condition.

Cardiac Magnetic Resonance for Evaluating Catheter Related FDG Avidity

A 53-year-old female with a history of metastatic left arm melanoma presented for F(18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) which showed a moderately FDG avid focus at her port catheter tip near the cavoatrial junction. Although catheter tip related FDG avidity has previously been suggested to be bland thrombus or infection, melanoma can metastasize to unusual locations including the superior vena cava. In addition, the patient had an elevated risk of anticoagulation due to a history of hemorrhagic brain metastases. Therefore, confirmatory cardiac magnetic resonance (CMR) was obtained and findings were consistent with bland catheter-related thrombus.

Contrast-enhanced ultrasound in differentiating malignant from benign portal vein thrombosis in hepatocellular carcinoma

Portal vein thrombosis (PVT) may occur in liver cirrhosis patients. Malignant PVT is a common complication in cirrhotic patients with concomitant hepatocellular carcinoma (HCC) and, in some cases, it may be even the initial sign of an undetected HCC. Detection of malignant PVT in a patient with liver cirrhosis heavily affects the therapeutic strategy. Gray-scale ultrasound (US) is widely unreliable for differentiating benign and malignant thrombi. Although effective for this differential diagnosis, fine-needle biopsy remains an invasive technique. Sensitivity of color-doppler US in detection of malignant thrombi is highly dependent on the size of the thrombus. Contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance (MRI) can be useful to assess the nature of portal thrombus, while limited data are currently available about the role of positron emission tomography (PET) and PET-CT. In contrast with CT, MRI, PET, and PET-CT, contrast-enhanced ultrasound (CEUS) is a fast, effective, well tolerated and cheap technique, that can be performed even in the same session in which the thrombus has been detected. CEUS can be performed bedside and can be available also in transplanted patients. Moreover, CT and MRI only yield a snapshot analysis during contrast diffusion, while CEUS allows for a continuous real-time imaging of the microcirculation that lasts several minutes, so that the whole arterial phase and the late parenchymal phase of the contrast diffusion can be analyzed continuously by real-time US scanning. Continuous real-time monitoring of contrast diffusion entails an easy detection of thrombus maximum enhancement. Moreover, continuous quantitative analyses of enhancement (wash in - wash out studies) by CEUS during contrast diffusion is nowadays available in most CEUS machines, thus giving a more sophisticated and accurate evaluation of the contrast distribution and an increased confidence in diagnosis in difficult cases. In conclusion, CEUS is a very reliable technique with a high intrinsic sensitivity for portal vein patency assessment. More expensive and sophisticated techniques (i.e., CT, MRI, PET, and PET-CT) should only be indicated in undetermined cases at CEUS.

Differentiation of bland from neoplastic thrombus of the portal vein in patients with hepatocellular carcinoma: application of susceptibility-weighted MR imaging

Background

Neoplastic and bland portal vein thrombi (PVT) are both common in patients with hepatocellular carcinoma (HCC). The correct discrimination of them is essential for therapeutic strategies planning and survival predicting. The current study aims to investigate the value of susceptibility-weighted imaging (SWI) in differentiating bland from neoplastic PVT in HCC patients.

Methods

20 HCC patients with bland PVT and 22 HCC patients with neoplastic PVT were imaged with non-contrast SWI at 3.0 Tesla MRI. The signal intensity (SI) of the PVT and HCC lesions in the same patients was compared on SW images. The phase values of the PVT were compared between neoplastic and bland thrombi cohorts. Receiver operator characteristics (ROC) analysis was conducted to evaluate the diagnostic ability of the phase values for neoplastic and bland thrombi discrimination.

Results

20 of 22 neoplastic PVT were judged similar SI and 2 were judged lower SI than their HCC. For 20 bland PVT, 19 were judged lower SI and 1 was judged similar SI as their HCC (P<0.001). The average phase values (0.361 ± 0.224) of the bland PVT were significantly higher than those of the neoplastic PVT (−0.328 ± 0.127, P<0.001). The AUC for phase values in differentiating bland from neoplastic PVT was 0.989. The best cut-off value was −0.195, which gave a sensitivity of 95% and a specificity of 95.5%.

Conclusions

SW imaging appears to be a promising new method for distinguishing neoplastic from bland PVT. The high sensitivity and specificity suggest its high value in clinical practice.