Value of fusing PET plus CT images in hepatocellular carcinoma and combined hepatocellular and cholangiocarcinoma patients with extrahepatic metastases: preliminary findings

Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer

ABSTRACT

PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology.

Achievement of Complete Response and Drug-Free Status by Atezolizumab plus Bevacizumab Combined with or without Curative Conversion in Patients with Transarterial Chemoembolization-Unsuitable, Intermediate-Stage Hepatocellular Carcinoma: A Multicenter Proof-Of-Concept Study

Introduction

Atezolizumab plus bevacizumab therapy is extremely effective in the treatment of intermediate-stage hepatocellular carcinoma (HCC), with a response rate of 44%, as reported in the IMbrave150 trial. When tumor shrinkage is obtained, achieving complete response (CR) is possible in many cases using curative conversion with resection, ablation, or superselective transarterial chemoembolization (TACE) with curative intent. This concept, i.e., curative conversion by combining systemic therapy and locoregional therapy, has not been reported before. This multicenter proof-of-concept study was conducted to show the value of curative conversion in immunotherapy-treated intermediate-stage HCC meeting TACE-unsuitable criteria.

Methods

This study included 110 consecutive Child-Pugh A patients who received atezolizumab plus bevacizumab as first-line treatment for unresectable and TACE-unsuitable intermediate-stage HCC at seven centers in Japan. CR rate, drug-free rate, time to CR, change in liver function, efficacy in positron emission tomography (PET)-positive HCC, progression-free survival (PFS), and overall survival (OS) were assessed in patients who achieved CR using resection, ablation, superselective TACE with curative intent following atezolizumab plus bevacizumab or atezolizumab plus bevacizumab alone.

Results

Clinical or pathological CR was achieved in 38 patients (35%) (median observation period: 21.2 months). The modalities of curative conversion in 35 patients were as follows: resection, 7; ablation, 13; and superselective TACE, 15. Three patients achieved clinical CR with atezolizumab plus bevacizumab therapy alone. Among the 38 CR patients, 25 achieved drug-free status. PFS was not reached, and 3 patients experienced recurrence after reaching CR. Regarding OS, there were no deaths in any of the CR patients. The albumin-bilirubin score did not deteriorate after locoregional therapy or resection. Of seven PET-positive patients who achieved CR with atezolizumab plus bevacizumab followed by curative conversion, five achieved drug-free status.

Conclusion

The achievement of CR rate by curative conversion in patients treated with atezolizumab plus bevacizumab as the preceding therapy for unresectable and TACE-unsuitable intermediate-stage HCC was 35%. Overall, 23% of patients achieved drug-free status and no recurrence was observed from this patient subgroup with CR and drug-free status. Thus, achieving CR and/or drug-free status should be a therapeutic goal for patients with intermediate-stage HCC without vascular invasion or extrahepatic spread.

Differences in diagnostic impact of dual-tracer PET/computed tomography according to the extrahepatic metastatic site in patients with hepatocellular carcinoma

OBJECTIVES

We compared the diagnostic performance of C-11 acetate and F-18 fluorodeoxyglucose (FDG) PET/computed tomography (CT) for the detection of extrahepatic metastasis in patients with hepatocellular carcinoma (HCC) and evaluated whether the improvement in the diagnostic performance of dual tracer PET/CT differs by the metastatic site.

METHODS

Fifty-eight patients who had extrahepatic metastasis on either C-11 acetate or F-18 FDG PET/CT were enrolled, and 193 metastatic lesions were analyzed in this retrospective study. The metastatic lesions were categorized based on six sites of involvement. According to each involved site, the tracer avidity of the metastatic lesions was compared using the maximum standardized uptake value (SUVmax).

RESULTS

Bone was the most frequent categorized metastatic site (44.8%), followed by lymph node (39.7%), lung (34.5%), soft tissue (27.6%), adrenal gland (6.9%), and vascular category (3.4%). C-11 acetate PET/CT showed a higher SUVmax than F-18 FDG PET/CT in metastatic bone lesions (P = 0.003). F-18 FDG uptake was significantly higher than C-11 acetate uptake in metastatic lymph node lesions (P < 0.001). The detection rate of dual tracer PET/CT was significantly higher in the metastatic lung (93.6%) and soft tissue (100%) lesions. However, the diagnostic performance of dual tracer PET/CT was limited in the metastatic bone and lymph node lesions because each tracer's detection rate was very high (bone: 94.6% in C-11 acetate, lymph node: 94.1% in F-18 FDG).

CONCLUSIONS

The tracer avidity of metastatic lesions differed according to the involved site. This difference affected the complementary role of dual tracer PET/CT in the diagnosis of extrahepatic metastases in patients with 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.

Contrast enhanced ultrasound in mixed hepatocellular cholangiocarcinoma: Case series and review of the literature

BACKGROUND

Mixed hepatocellular cholangiocarcinoma is a rare form of primary liver cancer.

AIMS

The aim of this study is to report the results of the use of contrast enhanced ultrasound in a series of patients with confirmed mixed hepatocellular cholangiocarcinoma and to provide an updated literature review.

METHODS

Between January 2012 and October 2016, 25 Asian patients with confirmed mixed hepatocellular cholangiocarcinoma were included in this bicentric retrospective analysis. Clinical data as well recorded images of a standardized conventional B-mode ultrasound and contrast-enhanced ultrasound examination were interpreted by two blinded, independent, experienced radiologists in consensus.

RESULTS

All mixed hepatocellular cholangiocarcinoma lesions were heteroechoic on B-mode ultrasound, with ill-defined margins and irregular shapes. Arterial phase hyperenhancement was present in all 25 patients. Late-phase washout and hypoenhancement was present in 24/25 (96%) patients. However, rim-enhancement and early wash-out (which are common in cholangiocellular carcinoma) were found in over 60% of the cases.

CONCLUSION

Contrast-enhanced ultrasound demonstrated findings not typical for HCC in a large proportion of patients with confirmed mixed hepatocellular cholangiocarcinoma. Therefore, histological confirmation is crucial, especially in lesions with atypical findings.

Biphenotypic hepatic tumors: imaging findings and review of literature

PURPOSE

To describe imaging findings in biphenotypic hepatic tumors (BPT) and a proposal for new imaging classification based on contrast-enhanced imaging.

METHODS

Retrospective review of CT, MRI, PET/CT, and ultrasound findings in 39 patients with histologically confirmed BPT was performed. Tumor markers including AFP, L3 fraction, CA 19.9, CA 125, and CEA were recorded. Based on the dynamic enhancement features, BPT were categorized into 4 enhancement patterns (Types 1-4). Enhancement patterns were correlated with other imaging findings and tumor markers. Imaging features and tumor markers that were not consistent with diagnosis of hepatocellular carcinoma or intrahepatic cholangiocarcinoma based on enhancement pattern were considered discordant findings.

RESULTS

Enhancement patterns in 29 patients (CT/MR) included 23 Type 2 (continuous peripheral rim of late arterial hyperenhancement with washout or fade in portal venous and/or delayed phases, ±delayed central enhancement) and 2 of each Types 1, 2, and 3. Discordant imaging findings were present in two patients with Type 2 pattern and in one patient with Type 1 pattern. Both AFP and CA 19.9 were elevated in 15 of 33 of patients. Tumor markers AFP and CA 19.9 were discordant in 17 of 21 patients with Type 2 pattern, two of two patients with Type 3 pattern. Most BPTs were markedly PET avid with average SUV max of 8.2. Most frequent ultrasound appearance is peripheral hypoechogenicity and central hyperechogenicity.

CONCLUSIONS

BPT most commonly present with imaging features similar to cholangiocarcinoma or metastases. BPT can be suggested when imaging findings or tumor markers are discordant with the most likely diagnosis based on enhancement pattern.

Imaging Techniques for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Several imaging modalities are available for diagnosis of hepatocellular carcinoma (HCC).

PURPOSE

To evaluate the test performance of imaging modalities for HCC.

DATA SOURCES

MEDLINE (1998 to December 2014), the Cochrane Library Database, Scopus, and reference lists.

STUDY SELECTION

Studies on test performance of ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI).

DATA EXTRACTION

One investigator abstracted data, and a second investigator confirmed them; 2 investigators independently assessed study quality and strength of evidence.

DATA SYNTHESIS

Few studies have evaluated imaging for HCC in surveillance settings. In nonsurveillance settings, sensitivity for detection of HCC lesions was lower for ultrasonography without contrast than for CT or MRI (pooled difference based on direct comparisons, 0.11 to 0.22), and MRI was associated with higher sensitivity than CT (pooled difference, 0.09 [95% CI, 0.07 to 12]). For evaluation of focal liver lesions, there were no clear differences in sensitivity among ultrasonography with contrast, CT, and MRI. Specificity was generally 0.85 or higher across imaging modalities, but this item was not reported in many studies. Factors associated with lower sensitivity included use of an explanted liver reference standard, and smaller or more well-differentiated HCC lesions. For MRI, sensitivity was slightly higher for hepatic-specific than nonspecific contrast agents.

LIMITATIONS

Only English-language articles were included, there was statistical heterogeneity in pooled analyses, and costs were not assessed. Most studies were conducted in Asia and had methodological limitations.

CONCLUSION

CT and MRI are associated with higher sensitivity than ultrasonography without contrast for detection of HCC; sensitivity was higher for MRI than CT. For evaluation of focal liver lesions, the sensitivities of ultrasonography with contrast, CT, and MRI for HCC are similar.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (

PROSPERO

CRD42014007016).

Appropriateness criteria of FDG PET/CT in oncology

(18)Fluorine-2-fluoro-2-Deoxy-d-glucose ((18)F-FDG) positron emission tomography/computerized tomography (PET/CT) is a well-established functional imaging method widely used in oncology. In this article, we have incorporated the various indications for (18)FDG PET/CT in oncology based on available evidence and current guidelines. Growing body of evidence for use of (18)FDG PET/CT in select tumors is also discussed. This article attempts to give the reader an overview of the appropriateness of using (18)F-FDG PET/CT in various malignancies.

Cancer stem cells in primary liver cancers: pathological concepts and imaging findings

There is accumulating evidence that cancer stem cells (CSCs) play an integral role in the initiation of hepatocarcinogenesis and the maintaining of tumor growth. Liver CSCs derived from hepatic stem/progenitor cells have the potential to differentiate into either hepatocytes or cholangiocytes. Primary liver cancers originating from CSCs constitute a heterogeneous histopathologic spectrum, including hepatocellular carcinoma, combined hepatocellular-cholangiocarcinoma, and intrahepatic cholangiocarcinoma with various radiologic manifestations. In this article, we reviewed the recent concepts of CSCs in the development of primary liver cancers, focusing on their pathological and radiological findings. Awareness of the pathological concepts and imaging findings of primary liver cancers with features of CSCs is critical for accurate diagnosis, prediction of outcome, and appropriate treatment options for patients.

Recurrence in regional pulmonary lymph nodes after surgery for isolated pulmonary metastasis from hepatocellular carcinoma

Hepatocellular carcinoma occasionally metastasizes to extrahepatic organs, rarely to the mediastinal lymph nodes. We present the case of a 64-year-old man who presented with nodules in the upper and right lower lobes of the lung 4 years after undergoing resection of a hepatocellular carcinoma. We performed wedge resection of both lesions. Pathological examination showed that the lesion in the right upper lobe was non-small cell lung cancer and that in the right lower lobe hepatocellular carcinoma. We accordingly performed right upper lobectomy with lymph node dissection. Nine months later, enlarged subcarinal and segmental lymph nodes were detected and mediastinal lymph node metastases from the hepatocellular carcinoma diagnosed by transbronchial needle aspiration.

(18)F-Fluorodeoxyglucose positron-emission tomography could have a prognostic role in patients with advanced hepatocellular carcinoma

INTRODUCTION

We set out to evaluate the prognostic value of (18)F-fluorodeoxyglucose positron-emission tomography (pet) in patients with advanced (non-transplant-eligible) hepatocellular carcinoma (hcc) and to evaluate the correlation between standardized uptake values (suvs) and survival outcomes.

METHODS

We identified patients with hcc who, from 2005 to 2013, underwent pet imaging before any treatment. This retrospective study from our hcc database obtained complete follow-up data for the 63 identified patients.

RESULTS

Of the 63 patients, 10 underwent surgical resection, and 59 underwent locoregional therapy. In this cohort, 28 patients were pet-positive (defined as any lesion with a suv ≥ 4.0) before any therapy was given, and 35 patients were pet negative (all lesions with a suv < 4.0). On survival analysis, median survival was greater for the pet-negative than for the pet-positive patients: 29 months (range: 16.3-41.1 months) versus 12 months (range: 4.0-22.1 months) respectively, p = 0.0241. The pet-positive patients more often had large tumours (≥5 cm), poor differentiation, and extrahepatic disease, reflecting more aggressive tumours. On multivariate analysis, only pet positivity was associated with poor survival (p = 0.049).

CONCLUSIONS

Compared with pet-positive patients, pet-negative patients with hcc experienced longer survival. Imaging by pet can be of value in early prognostication for patients with hcc, especially patients receiving locoregional therapy for whom pathologic tumour differentiation is rarely available. This potential role for pet requires further validation in a prospective study.

Nodule in Liver: Investigations, Differential Diagnosis and Follow-up

Conventional ultrasonogram of the abdomen being noninvasive, inexpensive and ubiquitously available is the first imaging modality that raises suspicion of HCC in a patient with chronic liver disease with or without cirrhosis. The lesions in liver particularly nodule are being recognized with increased frequency with the wide spread use of ultrasonogram as the initial investigation and computerized tomography and magnetic resonance imaging subsequently. Any nodule in a cirrhotic liver should be considered as hepatocellular carcinoma until otherwise proved. This approach certainly is helpful in diagnosing HCC at its earliest possible stage to offer meaningful curative measures be it transplant, resection or ablative therapy. After a nodule is detected on ultrasonogram the next imaging modality can be a contrast enhanced study (dynamic CT scan or an MRI) to see if are present or not. Two vital clues for diagnosis of HCC by contrast enhanced imaging are presence of arterial hypervascularity and washout which are considered as "classical imaging features". This sequence of events of arterial uptake followed by washout is highly specific for diagnosis of HCC by imaging. If the features are typical showing classical imaging features (i.e hypervascular in the arterial phase with washout in portal venous or delayed phase) the lesion should be treated as HCC biopsy is not necessary. Nodular lesions showing an atypical imaging pattern, such as iso- or hypovascular in the arterial phase or arterial hypervascularity alone without portal venous washout, should undergo further examinations with another contrast enhanced imaging. Biopsy is advisable for those lesions which do not show classical features on the imaging.

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.

Molecular mechanisms of [18F]fluorodeoxyglucose accumulation in liver cancer

To elucidate the molecular mechanisms underlying the insufficient sensitivity in the detection of hepatocellular carcinoma (HCC) by [18F] 2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), the characteristics of glucose metabolism-related protein expression in HCC were examined in liver metastasis from colorectal cancer (Meta). Thirty-four patients (14 Meta and 20 HCC) who underwent FDG-PET and hepatectomy were studied. The relationships between the maximum standardized uptake value (SUV) in tumors and the mRNA expression of glucose metabolism-related proteins [hexokinase (HK), glucose transporter 1 (GLUT1), and glucose-6-phosphatase (G6Pase)] and proliferating cell nuclear antigen (PCNA) were examined in snap-frozen specimens with quantitative PCR. Tumor detection rates were lower in HCC (15/20) compared to Meta (13/14) patients. HK and GLUT1 expression was lower and G6Pase expression was higher in HCC compared to Meta. In particular, GLUT1 overexpression was 92-fold in Meta and 11-fold in HCC compared to the surrounding liver. The SUV correlated with GLUT1 and PCNA expression in HCC, but not Meta patients. Of note, four cases of poorly differentiated (P/D) HCC compared to moderately differentiated (M/D) HCC produced completely different results for FDG uptake (SUV, 14.4 vs. 4.0) and mRNA expression (G6Pase expression, 0.007 vs. 1.5). Variations in the expression of glucose metabolism-related enzymes between HCC and Meta patients are attributed to origin or degree of differentiation. Low FDG uptake in M/D HCC reflected low GLUT1 and high G6Pase expression, while high FDG accumulation in P/D HCC could reflect increased GLUT1 and decreased G6Pase expression. These results may explain why M/D HCC is not detected as sensitively by FDG-PET.

Clinicopathological analysis of 14 patients with combined hepatocellular carcinoma and cholangiocarcinoma

BACKGROUND

Combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) is an uncommon subtype of primary hepatic carcinoma, and its prognosis is poor. This study was undertaken to investigate the prognosis and the clinicopathological characteristics of cHCC-CC, including their possible cellular origin.

METHODS

Among 852 patients with a primary hepatic carcinoma who underwent hepatectomy from January 1998 to April 2008 at our hospital, cHCC-CC was identified in 14 patients. The clinicopathological characteristics of the 14 patients were analyzed retrospectively. The expression of the liver stem cell markers (c-kit, CD90, CD133 and CK19) in the tumor tissue was detected by immunohistochemistry, and the Kaplan-Meier method was used to evaluate survival.

RESULTS

Among the 14 patients, 9 presented with abdominal pain, 3 with anorexia and debilitation, and the remaining two patients were asymptomatic. The mean age was 53.6+/-3.0 (range 38-74) years. Among the included patients, 11 had an elevated serum alpha-fetoprotein level, 13 were infected with hepatitis B virus, 9 had vascular invasion and 1 had lymph node metastasis. The average diameter of the tumors was 9.9+/-1.1 (range 5.0-16.0) cm. The median overall survival time was 7.9+/-1.0 months. In addition, the presence of the liver stem cell markers, c-kit, CD90, CD133 and CK19 was 71.4%, 85.7%, 92.9% and 78.6%, respectively. All four markers were simultaneously expressed in eight cases.

CONCLUSIONS

cHCC-CC has aggressive characteristics and the prognosis is extremely dismal. The high expression of liver stem cell markers in the tumor tissue suggests that these tumors may derive from liver stem cells.

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.

A case of primary biliary cirrhosis that complicated with combined hepatocellular and cholangiocellular carcinoma

Primary biliary cirrhosis (PBC) is frequently complicated with hepatocellular carcinoma (HCC), but complication with combined hepatocellular and cholangiocellular carcinoma (cHCC-CC) or cholangiocellular carcinoma (CCC) has not been reported. Here, we describe a case of PBC in which cHCC-CC occurred. The patient was a 70-year-old man who had developed jaundice at 62 years old. He was diagnosed with PBC based on a liver biopsy and blood tests. In August 2006, blood tests showed elevated alpha-fetoprotein, and a liver tumor in the right lobe and a metastatic lymphadenopathy in the back near to the head of the pancreas were detected by abdominal contrast-enhanced CT. A (18)F-fluorodeoxyglucose-PET scan showed accumulation of the tracer in the tumor and in a lymph node at the back of the pancreas. The tumor and lymph node were removed, and the tumor was diagnosed pathologically as cHCC-CC based on the presence of features of HCC and CCC. This case is the first to show that a patient with PBC can develop cHCC-CC. This is of interest, since cHCC-CC may originate in hepatic stem cells or hepatic precursor cells. This case also suggests that cHCC-CC should be included as a differential diagnosis for a liver tumor complicated with PBC.

FDG PET for the Detection of Bone Metastases: Sensitivity, Specificity and Comparison with Other Imaging Modalities

A literature review was performed of studies reporting sensitivity and specificity of [18F]fluorodeoxyglucose (FDG) PET from January 1, 2000 to January 1, 2010. PET was found to have higher sensitivity for the detection of osseous metastases when compared to CT, skeletal scintigraphy, whole body MRI and combined conventional imaging modalities. A potential exception is when comparing PET with bone scan in the setting of blastic metastases. PET may be a better indicator of active bony metastases. The efficacy of PET can be increased with fused anatomic imaging.

Usefulness 18F-FDG positron emission tomography/computed tomography for detecting recurrence of hepatocellular carcinoma in posttransplant patients

(18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) has recently been shown to be able to predict a poor outcome after liver transplantation (LT) for patients with hepatocellular carcinoma (HCC). However, there are few reports on the usefulness of PET during follow-up after LT. In this study, we assessed the efficacy of (18)F-FDG PET/CT for the detection of HCC recurrence after LT. From February 2005 to December 2008, out of 93 adult LT cases (91 living donors and 2 deceased donors), 10 patients who showed HCC recurrence and received (18)F-FDG PET/CT during follow-up were included. The accuracy of (18)F-FDG PET/CT was assessed with imaging and histological studies. The most common sites of recurrence were extrahepatic (60%). The most common extrahepatic sites were the lungs and bone (31.3% each). Among 4 patients with intrahepatic recurrence, 1 patient (25%) was positive according to (18)F-FDG PET/CT. The detection rate of (18)F-FDG PET/CT was 92.9% for extrahepatic metastases >or= 1 cm and 0% for lesions < 1 cm. The detection rate of (18)F-FDG PET/CT was 100% in bone and the lymph nodes, 60% in the lungs, and 0% in the brain. (18)F-FDG PET/CT identified 2 lesions in bone that were not found in a bone scan. In conclusion, because of its limitations for small lesions, intrahepatic lesions, and brain lesions, (18)F-FDG PET/CT is not suitable as a screening tool after LT. However, (18)F-FDG PET/CT could provide additional information beyond that provided by conventional modalities, and it could contribute to the clinical management of HCC recurrence after LT, especially in patients with extrahepatic recurrence.

Approach to Solid Liver Masses in the Cirrhotic Patient

Liver masses in cirrhosis are increasingly being recognized with the use of new imaging modalities. The majority of these lesions are detected by ultrasound, enhanced CT and MRI. The most likely diagnosis of a solid liver lesion in a cirrhotic liver is hepatocellular carcinoma, followed by high grade or low grade dysplastic nodule, and cholangiocarcinoma. Lymphoma and liver metastasis are extremely rare. Diagnosis is made by contrast enhanced ultrasound, multi detector (MDCT) and MRI. Fine needle core biopsy (FNCB) or aspiration (FNAB) or both may be required in doubtful cases. If uncertainty persists on the nature of the lesion, surgical liver resection is recommended. This review discusses the main characteristics of the most common solid liver masses in cirrhotic patient.

Characteristics of common solid liver lesions and recommendations for diagnostic workup

Due to the widespread clinical use of imaging modalities such as ultrasonography, computed tomography and magnetic resonance imaging (MRI), previously unsuspected liver masses are increasingly being found in asymptomatic patients. This review discusses the various characteristics of the most common solid liver lesions and recommends a practical approach for diagnostic workup. Likely diagnoses include hepatocellular carcinoma (the most likely; a solid liver lesion in a cirrhotic liver) and hemangioma (generally presenting as a mass in a non-cirrhotic liver). Focal nodular hyperplasia and hepatic adenoma should be ruled out in young women. In 70% of cases, MRI with gadolinium differentiates between these lesions. Fine needle core biopsy or aspiration, or both, might be required in doubtful cases. If uncertainty persists as to the nature of the lesion, surgical resection is recommended. If the patient is known to have a primary malignancy and the lesion was found at tumor staging or follow up, histology is required only when the nature of the liver lesion is doubtful.

FDG positron emission tomography/computed tomography for the detection of extrahepatic metastases from hepatocellular carcinoma

AIMS

To compare the efficacy of positron emission tomography (PET) computed tomography (CT), multi-detector helical computed tomography (MDCT) and bone scintigraphy for the detection of extrahepatic metastases in patients with hepatocellular carcinoma (HCC).

METHODS

Thirty-four patients diagnosed with metastatic HCC were enrolled in this study. The lesions included lung (n = 18), bone (n = 12) and lymph node (n = 16) metastases. For receiver operating characteristic (ROC) analysis, lesions were diagnosed as metastatic HCC by two experienced abdominal radiologists. Another three physicians independently reviewed both positive and negative images. Each physician read three sets of images of MDCT, PET-CT and bone scintigraphy for bone metastasis.

RESULTS

The mean sensitivity and specificity for diagnosis of lung metastasis were 85.2 and 88.9% for MDCT, and 59.2 and 92.6% for PET-CT, respectively. For lymph node metastasis, these values were 62.5 and 79.2% for MDCT, and 66.7 and 91.7% for PET-CT, respectively; and for bone metastasis 41.6 and 94.5% for MDCT, 83.3 and 86.1% for PET-CT, and 52.7 and 83.3% for bone scintigraphy, respectively. The mean Az values were 0.95 and 0.77 for MDCT and PET-CT in lung metastasis, respectively, 0.75 and 0.80 for MDCT and PET-CT for lymph node metastasis, respectively, and 0.59, 0.88 and 0.62 for MDCT, PET-CT and bone scintigraphy for bone metastasis, respectively.

CONCLUSION

PET-CT has high sensitivity and is more suitable for the detection of bone metastases from primary HCC, relative to MDCT and bone scintigraphy.

A prospective evaluation of 18F-FDG and 11C-acetate PET/CT for detection of primary and metastatic hepatocellular carcinoma

Because (18)F-FDG PET has insufficient sensitivity for the detection of hepatocellular carcinoma (HCC), (11)C-acetate PET has been proposed as another technique for this use. We prospectively evaluated the value of PET/CT using these 2 tracers for the detection of primary and metastatic HCC.

METHODS

One hundred twelve patients (99 with HCC, 13 with cholangiocellular carcinoma) underwent biopsy and (18)F-FDG and (11)C-acetate PET/CT.

RESULTS

The overall sensitivities of (18)F-FDG, (11)C-acetate, and dual-tracer PET/CT in the detection of 110 lesions in 90 patients with primary HCC were 60.9%, 75.4%, and 82.7%, respectively. Elevated serum alpha-fetoprotein levels, an advanced tumor stage, portal vein tumor thrombosis, large tumors, and multiple tumors were significantly associated with positive (18)F-FDG PET/CT results. Uptake of (11)C-acetate was associated with large and multiple tumors. For (18)F-FDG, the sensitivities according to tumor size (1-2, 2-5, and >/=5 cm) were 27.2%, 47.8%, and 92.8%, respectively; for (11)C-acetate, these respective values were 31.8%, 78.2%, and 95.2%. (18)F-FDG was more sensitive in the detection of poorly differentiated HCC. Overall survival was lower in patients with (18)F-FDG PET/CT positive for all indexed lesions than in those with FDG negative or partially positive through the entire follow-up period. In analysis based on biopsied lesions, the sensitivity of (18)F-FDG PET/CT was 64.4% for primary HCC and 84.4% for (11)C-acetate PET/CT. The overall sensitivities of (18)F-FDG, (11)C-acetate, and dual-tracer PET/CT for 35 metastatic HCCs were 85.7%, 77.0%, and 85.7%, respectively. There was no significant difference in the sensitivity of tracers according to metastatic tumor size, location, or differentiation.

CONCLUSION

The addition of (11)C-acetate to (18)F-FDG PET/CT increases the overall sensitivity for the detection of primary HCC but not for the detection of extrahepatic metastases. (18)F-FDG, (11)C-acetate, and dual-tracer PET/CT have a low sensitivity for the detection of small primary HCC, but (18)F-FDG PET/CT has a relatively high sensitivity for the detection of extrahepatic metastases of HCC.

Management of combined hepatocellular and cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare primary liver malignancy composed of cells with histopathological features of both cholangiocarcinoma (CC) and hepatocellular carcinoma (HCC). It reportedly accounts for 0.4-14.2% of all primary liver carcinomas, with incidence varying in different regions. The clinical features are similar to those of either HCC or CC. Preoperative noninvasive diagnosis of cHCC-CC with conventional radiography is difficult. Because the origin of cHCC-CC is from two different tumour entities, despite intensive preoperative imaging studies, most studied patients were misdiagnosed either as HCC or CC. Accurate preoperative diagnosis is important because the most appropriate treatment depends on the major component of the tumour (HCC or CC). A high index of suspicion, imaging studies (ultrasound, computed tomography, positron emission tomography), levels of serum tumour markers (alpha-fetoprotein, carbohydrate antigen 19-9), and histology assist case detection and treatment choice. Patients who qualify for surgery should have a partial hepatectomy with hilar lymph node dissection, which can result in 5-year survival rates exceeding 50%. The role of liver transplantation is not yet known.

Pulmonary resection of metastatic hepatocellular carcinoma after liver transplantation

BACKGROUND

The primary limitation to long-term survival after liver transplantation for hepatocellular carcinoma (HCC) is tumor recurrence. Pulmonary resection for metastatic HCC prolongs survival in patients after liver resection; this success may be extrapolated to the transplant population in the treatment of pulmonary recurrence of HCC after liver transplantation.

METHODS

Between January 2000 and January 2006, five patients who underwent orthotopic liver transplantation for HCC were identified on routine follow-up with pulmonary metastases. They all underwent resection of the pulmonary recurrence of HCC and were studied retrospectively.

RESULTS

The time from transplant to diagnosis of pulmonary recurrence ranged from 150 days to 880 days, with a mean of 500 days. All of the recurrences were amenable to complete resection. Two patients developed a second tumor. One patient had a new primary of squamous cell carcinoma. Another patient had a bony recurrence of HCC in the ninth rib. Four of the patients are still alive, and the fifth died from hepatic failure. The stage of the tumor in the explanted liver ranged from II to IVb. The average time for survival from transplant was 44 months, and the average time from pulmonary resection was 27.5 months.

CONCLUSIONS

The patients in this study demonstrate survival times similar to patients with HCC treated with liver resection. Although the size of the study population is small, the long survival times in the patients is encouraging. The advanced stage and histologically invasive nature of the primary tumors may predispose to subsequent pulmonary recurrence.

The use of imaging in the diagnosis and staging of hepatobiliary malignancies

This review addresses the optimal use of imaging in the diagnosis, staging, and treatment planning of patients with hepatobiliary neoplasms. We focus on primary liver cancers, including hepatocellular carcinoma and intrahepatic cholangiocarcinoma as well as extrahepatic biliary tract malignancies, including hilar cholangiocarcinoma and gallbladder cancer. In each section, we provide an overview of the staging requirements for each disease followed by a discussion of various imaging modalities that can be used to optimally stage the disease and plan therapy.