Diagnostic imaging of hepatocellular carcinoma in patients with cirrhosis before liver transplantation

Prospective evaluation of Gadoxetate-enhanced magnetic resonance imaging and computed tomography for hepatocellular carcinoma detection and transplant eligibility assessment with explant histopathology correlation

BACKGROUND

We aimed to prospectively compare the diagnostic performance of gadoxetic acid-enhanced MRI (EOB-MRI) and contrast-enhanced Computed Tomography (CECT) for hepatocellular carcinoma (HCC) detection and liver transplant (LT) eligibility assessment in cirrhotic patients with explant histopathology correlation.

METHODS

In this prospective, single-institution ethics-approved study, 101 cirrhotic patients were enrolled consecutively from the pre-LT clinic with written informed consent. Patients underwent CECT and EOB-MRI alternately every 3 months until LT or study exclusion. Two blinded radiologists independently scored hepatic lesions on CECT and EOB-MRI utilizing the liver imaging reporting and data system (LI-RADS) version 2018. Liver explant histopathology was the reference standard. Pre-LT eligibility accuracies with EOB-MRI and CECT as per Milan criteria (MC) were assessed in reference to post-LT explant histopathology. Lesion-level and patient-level statistical analyses were performed.

RESULTS

Sixty patients (49 men; age 33-72 years) underwent LT successfully. One hundred four non-treated HCC and 42 viable HCC in previously treated HCC were identified at explant histopathology. For LR-4/5 category lesions, EOB-MRI had a higher pooled sensitivity (86.7% versus 75.3%, p <  0.001) but lower specificity (84.6% versus 100%, p <  0.001) compared to CECT. EOB-MRI had a sensitivity twice that of CECT (65.9% versus 32.2%, p <  0.001) when all HCC identified at explant histopathology were included in the analysis instead of imaging visible lesions only. Disregarding the hepatobiliary phase resulted in a significant drop in EOB-MRI performance (86.7 to 72.8%, p <  0.001). EOB-MRI had significantly lower pooled sensitivity and specificity versus CECT in the LR5 category with lesion size < 2 cm (50% versus 79%, p = 0.002 and 88.9% versus 100%, p = 0.002). EOB-MRI had higher sensitivity (84.8% versus 75%, p <  0.037) compared to CECT for detecting < 2 cm viable HCC in treated lesions. Accuracies of LT eligibility assessment were comparable between EOB-MRI (90-91.7%, p = 0.156) and CECT (90-95%, p = 0.158).

CONCLUSION

EOB-MRI had superior sensitivity for HCC detection; however, with lower specificity compared to CECT in LR4/5 category lesions while it was inferior to CECT in the LR5 category under 2 cm. The accuracy for LT eligibility assessment based on MC was not significantly different between EOB-MRI and CECT.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03342677 , Registered: November 17, 2017.

[Radiologic Diagnosis of Hepatocellular Carcinoma]

There are various causes of hepatocellular carcinoma, including viral hepatitis, and treatment strategies are often established based on the radiology diagnosis, unlike other carcinomas. The liver imaging reporting and data system (LI-RADS) is a diagnostic system developed by the American College of Radiologists for clear communication and standardized reports of the liver imaging findings. It was recently included in the clinical guidance of the American Association for the Study of Liver Diseases. In addition, the radiologic findings of hepatocellular carcinoma (HCC) enable a prediction of the prognosis after treatment and a diagnosis of diseases because the use of gadoxetic acid MRI has become more common. Thus, the role of radiology for the diagnosis and treatment of HCC is expected to be developed further.

Living Donor Liver Transplantation for Hepatocellular Carcinoma: Appraisal of the United Network for Organ Sharing Modified TNM Staging

Background: In deceased donor liver transplantation (DDLT), transplant eligibility for T3–T4 HCC requires successful downstaging (DS). Living donor liver transplantation (LDLT) can be considered selectively in these patients without DS, but its role is not defined. The objective of the current study was to assess outcomes of LDLT for HCC based on UNOS staging with no prior DS.

Materials and Methods: Patients who underwent LDLT for HCC (n = 262) were staged based on modified UNOS TNM staging. High-risk factors were identified and 5-year recurrence free survival was compared in patients with T2–T4 HCC.

Results: Median follow-up was 30.2 (16.4–46.3) months. Recurrence rate in T1, T2, T3, T4a, and T4b HCC was 0, 10.1, 16.1, 5.9, and 37.5% (P = 0.02), respectively. On multivariate analysis, AFP > 600 ng/mL [HR:11.7, P < 0.001] and T4b HCC (macrovascular invasion) [HR = 5.6, P = 0.03] were predictors of recurrence. After exclusion of AFP > 600 ng/mL, 5-year RFS for T2, T3, and T4a HCC was 94, 86, and 92% (P = 0.3). Rate of microvascular invasion between T2 and T3 HCC was 24.3 vs. 53.6% (P = 0.005), and between T2 and T4a HCC was 24.3 vs. 36.7% (P = 0.2). Overall, 26 (19.4%) patients were overstaged and 23 (17.1%) were understaged on preoperative imaging. The 5-year RFS in patients with identical preoperative and histopathological staging was 94, 87, and 94% (P = 0.6).

Conclusion: LDLT without prior DS leads to comparable survival for UNOS T2, T3, and T4a HCC as long as AFP is < 600 ng/mL.

Comparison of LI-RADS with other non-invasive liver MRI criteria and radiological opinion for diagnosing hepatocellular carcinoma in cirrhotic livers using gadoxetic acid with histopathological explant correlation

AIM

To establish the diagnostic accuracy of the Liver Imaging Reporting and Data System (LI-RADS) for hepatocellular carcinoma (HCC) and compare its performance to that of international criteria from European Assofor the Study of the Liver (EASL), Japan Society of Hepatology (JSH), Asian Pacific Association for the Study of the Liver (APASL), and Organ Procurement and Transplantation Network (OPTN), and to the reporting radiologist's overall opinion regarding the probability of a nodule being a HCC by correlating with a histological diagnosis from whole liver explants.

MATERIALS AND METHODS

The present single-centre, retrospective review selected participants based on the following criteria: adults (≥18 years) listed for liver transplantation in 2014/2015, with liver cirrhosis at the time of magnetic resonance imaging (MRI) with hepatocyte specific contrast agent, and at least one liver lesion ≥10 mm on MRI with histology from subsequent liver explant for comparison. Each lesion was assessed against international criteria and given a "radiologist opinion" score of 1-5 (1 = definitely benign, 5 = definitely HCC).

RESULTS

Total 268 patient records were reviewed, with 105 eligible lesions identified from 47 patients. Median lesion size was 15.5 mm (range 10-68 mm). Sensitivity (%), specificity (%), and positive predictive value (PPV; %) for LI-RADS LR5 was 45, 89, and 89, for LI-RADS LR4+5 + TIV was 61, 80, and 86, for EASL was 44, 86 and 86, for JSH/APASL was 64, 81, and 87, for OPTN was 36, 90, and 88, and for "radiologist impression" of probably or definitely HCC was 79, 79, and 88 respectively.

CONCLUSIONS

MRI has moderate sensitivity and good specificity for the diagnosis of HCC with considerable variation depending on criteria used. OPTN criteria have the best specificity, but low sensitivity. "Radiologist opinion" gives highest overall accuracy with increases in sensitivity and reduction in specificity when compared to the imaging criteria.

Recurrence of Hepatocellular Carcinoma After Liver Transplantation: A Single-Center Experience

Background

There is a worldwide increase in use of liver transplantation (LT) for treatment of hepatocellular carcinoma (HCC). We analyzed our experience with LT for HCC to determine long-term and recurrence-free survival, accuracy of imaging diagnosis of HCC compared to the explant pathology, recurrence rate of HCC, and predictors of recurrence.

Material/Methods

The whole explant was examined by the same pathologist and compared with the baseline diagnosis established according to clinical, laboratory, and radiological data. A group of patients with pathologically confirmed HCC was characterized, with special attention to etiology, survival, recurrence, and diagnostic accuracy of imaging techniques.

Results

Among 718 patients transplanted from 2000 to 2018 in our center, HCC was found in 166 explanted livers. In 42 cases the clinical diagnosis of HCC was not accurate, being either false positive or negative; however, the specificity and sensitivity of CT/MRI in HCC recognition was 97.87% and 88.24%, respectively. Five- and 10-year survival was 81.27% and 66.57%, respectively, and it was inferior to the overall survival. The recurrence rate was 9.6% with a median time to recurrence of 14 months and a median survival time of 9 months. Poor differentiation of HCC and HCV etiology of the baseline disease, but not previous DAA treatment, were the risk factors of HCC recurrence.

Conclusions

Adherence to strictly defined selection criteria for LT in HCC patients guarantees the success of LT in HCC treatment.

Joint Consensus Statement of the Indian National Association for Study of the Liver and Indian Radiological and Imaging Association for the Diagnosis and Imaging of Hepatocellular Carcinoma Incorporating Liver Imaging Reporting and Data System

Hepatocellular carcinoma (HCC) is the 6th most common cancer and the second most common cause of cancer-related mortality worldwide. There are currently no universally accepted practice guidelines for the diagnosis of HCC on imaging owing to the regional differences in epidemiology, target population, diagnostic imaging modalities, and staging and transplant eligibility. Currently available regional and national guidelines include those from the American Association for the Study of Liver Disease (AASLD), the European Association for the Study of the Liver (EASL), the Asian Pacific Association for the Study of the Liver, the Japan Society of Hepatology, the Korean Liver Cancer Study Group, Hong Kong, and the National Comprehensive Cancer Network in the United States. India with its large population and a diverse health infrastructure faces challenges unique to its population in diagnosing HCC. Recently, American Association have introduced a Liver Imaging Reporting and Data System (LIRADS, version 2017, 2018) as an attempt to standardize the acquisition, interpretation, and reporting of liver lesions on imaging and hence improve the coherence between radiologists and clinicians and provide guidance for the management of HCC. The aim of the present consensus was to find a common ground in reporting and interpreting liver lesions pertaining to HCC on imaging keeping LIRADSv2018 in mind.

Role of [18F] fludeoxyglucose positron emission tomography in the selection of liver transplantation candidates in patients with hepatocellular carcinoma

BACKGROUND

The Milan criteria are widely accepted among many centers. However, patients with hepatocellular carcinoma beyond the Milan criteria might still benefit from liver transplantation (LT) when tumor itself is not aggressive. [¹⁸F] fluorodeoxyglucose positron emission tomography/computed tomography imaging could provide useful information of tumor behaviors, which is helpful to predict the prognosis for many tumors.

METHOD

In order to determine its role in candidate selection for LT, we therefore retrospectively analyzed 103 recipients with preoperative positron emission tomography (PET) findings.

RESULTS

Positive PET findings (PET⁺) were significantly associated with tumor nodule numbers (P=0.013), tumor grade (P=0.025), macro- (P=0.002) and micro-vascular invasion (P=0.002), as well as the Milan criteria (P=0.018). PET⁺ patients had significantly increased risk of tumor recurrence post-LT compared to PET negative (PET^-) patients (P=0.007). The 1-, 3-, and 5-year overall survival rate of PET^- patients were 96.0%, 87.2% and 76.2%, compared to 74.7%, 55.4% and 49.9% in PET⁺ patients, respectively (P<0.05). The 1-, 3-, and 5-year recurrence-free survival rate of PET^- patients were 91.8%, 81.9% and 76.0%, compared to 70.1%, 39.3% and 21.9% in PET⁺ patients, respectively (P<0.05). Recipients within the Milan criteria showed comparable 1-, 3-, and 5-year survival rates in comparison with those beyond the Milan criteria with a PET^- findings (1-, 3-, and 5-year overall survival rates, 97.5%, 83.3%, and 83.3% vs 90.0%, 80.0%, and 66.7%, P= 0.123; 1-, 3-, and 5-year recurrence-free survival rates, 95.1%, 73.1%, and 73.1% vs 90.0%, 78.8%, and 65.6%, P=0.148).

CONCLUSIONS

Certain patients with hepatocellular carcinoma and negative PET findings, who have exceeded the Milan criteria, are also eligible candidates for LT. Preoperative PET/CT imaging is an important marker, which should be incorporated in extended candidate selection criteria for LT.

The extended Toronto criteria for liver transplantation in patients with hepatocellular carcinoma: A prospective validation study

The selection of liver transplant candidates with hepatocellular carcinoma (HCC) relies mostly on tumor size and number. Instead of relying on these factors, we used poor tumor differentiation and cancer-related symptoms to exclude patients likely to have advanced HCC with aggressive biology. We initially reported similar 5-year survival for patients whose tumors exceeded (M+ group) and were within (M group) the Milan criteria. Herein, we validate our original data with a new prospective cohort and report the long-term follow-up (10-years) using an intention-to-treat analysis. The previously published study (cohort 1) included 362 listed (294 transplanted) patients from January 1996 to August 2008. The validation cohort (cohort 2) includes 243 listed (105 M+ group, 76 beyond University of California San Francisco criteria; 210 transplanted) patients from September 2008 to December 2012. Median follow-up from listing was 59.7 (26.8-103) months. For the validation cohort 2, the actuarial survival from transplant for the M+ group was similar to that of the M group at 1 year, 3 years, and 5 years: 94%, 76%, and 69% versus 95%, 82%, and 78% (P = 0.3). For the combined cohorts 1 and 2, there were no significant differences in the 10-year actuarial survival from transplant between groups. On an intention-to-treat basis, the dropout rate was higher in the M+ group and the 5-year and 10-year survival rates from listing were decreased in the M+ group. An alpha-fetoprotein level >500 ng/mL predicted poorer outcomes for both the M and M+ groups.

CONCLUSION

Tumor differentiation and cancer-related symptoms of HCC can be used to select patients with advanced HCC who are appropriate candidates for liver transplantation; alpha-fetoprotein level limitations should be incorporated in the listing criteria for patients within or beyond the Milan criteria. (Hepatology 2016;64:2077-2088).

Incidence, Characteristics, and Prognosis of Incidentally Discovered Hepatocellular Carcinoma after Liver Transplantation

Background. We aimed to assess incidentally discovered hepatocellular carcinoma (iHCC) over time and to compare outcome to preoperatively diagnosed hepatocellular carcinoma (pdHCC) and nontumor liver transplants. Methods. We studied adults transplanted with a follow-up of at least one year. Patients were divided into 3 groups according to diagnosis of hepatocellular carcinoma. Results. Between 1990 and 2010, 887 adults were transplanted. Among them, 121 patients (13.6%) had pdHCC and 32 patients (3.6%) had iHCC; frequency of iHCC decreased markedly over years, in parallel with significant increase in pdHCC. Between 1990 and 1995, 120 patients had liver transplants, 4 (3.3%) of them had iHCC, and only 3 (2.5%) had pdHCC, while in the last 5 years, 263 patients were transplanted, 7 (0.03%) of them had iHCC, and 66 (25.1%) had pdHCC (P < 0.001). There was no significant difference between groups regarding patient survival; 5-year survival was 74%, 75.5%, and 77.3% in iHCC, pdHCC, and non-HCC groups, respectively (P = 0.702). Patients with iHCC had no recurrences after transplant, while pdHCC patients experienced 17 recurrences (15.3%) (P = 0.016). Conclusions. iHCC has significantly decreased despite steady increase in number of transplants for hepatocellular carcinoma. Patients with iHCC had excellent outcomes with no tumor recurrence and survival comparable to pdHCC.

Review of imaging techniques in the diagnosis of hepatocellular carcinoma in patients who require a liver transplant

OBJECTIVES

The aim of the study was to retrospectively compare the diagnostic performance of ultrasound (US), contrast-enhanced multidetector computed tomography (MDCT) and contrast-enhanced MRI in cirrhotic patients who were candidates for liver transplantation.

MATERIALS AND METHODS

A total of 273 consecutive patients with 218 hepatocellular carcinoma (HCC) nodules, who underwent imaging and subsequent transplantation, were examined. Diagnosis of HCC was based on explant correlation of the whole liver. Three different imaging data sets were evaluated: US, MDCT and MRI unenhanced and dynamic phases. Diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value, with corresponding 95% confidence intervals, were determined. Statistical analysis was performed for all lesions and for two lesion subgroups (≤2 and >2 cm). Preoperative tumour staging was analysed.

RESULTS

Patient sensitivity to US, MDCT and MRI was 80.4, 81.1 and 90.5%, respectively. Specificity was 96.3, 96.2 and 82.1%. Combined US and MDCT improved sensitivity (88%) without significant loss in specificity (95.7%). Imaging tests resulted in accurate tumour staging in 83.4% of the patients. In per-nodule analysis, technique sensitivity was 55.6, 52.4 and 65.9%, respectively. Sensitivity figures improved when the nodule was larger than 2 cm.

CONCLUSION

Combining imaging techniques is a good strategy for pretransplant HCC diagnosis and provides more accurate cancer staging in patients, which is necessary to decide the correct therapeutic approach.

Update on the Liver Imaging Reporting and Data System: What the Pathologist Needs to Know

Hepatocellular carcinoma (HCC) is frequently diagnosed noninvasively with imaging techniques. Computed tomography and magnetic resonance imaging play critical roles in the detection, diagnosis, and staging of HCC. Standardization in the interpretation and reporting of imaging modalities has not existed until recently. In 2008, the American College of Radiology supported the development of the Liver Imaging Reporting and Data System (LI-RADS) for standardized terminology, interpretation, and reporting of imaging examinations for the diagnosis of HCC inpatients at risk for HCC. This article reviews the basic concepts of LI-RADS, emphasizing aspects that are most relevant to pathologists, including the categories, diagnostic algorithm, major features, and ancillary features for the diagnosis of HCC. The similarities and differences between LI-RADS and other major radiology-based diagnostic systems in terms of target population, intended users, categorization of observations, and imaging methods are addressed. Importantly, LI-RADS and other systems are designed to diagnose progressed HCC with high specificity and modest sensitivity. LI-RADS and other systems are not designed to detect early HCC and so have limited sensitivity for such lesions. Moreover, despite continuous advances in imaging technology, imaging detection and characterization of small (<1 cm) nodules remains limited; in addition, colocalization of small nodules and pathology is difficult. For these reasons LI-RADS and most other systems require lesions to be 1 cm or greater for the noninvasive diagnosis of HCC. As LI-RADS evolves, it is critical that stakeholders, including pathologists, provide expert input to help standardize and enhance reporting of radiologic findings.

[18F]fludeoxyglucose positron emission tomography and computed tomography as a prognostic tool before liver transplantation, resection, and loco-ablative therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most common cause of cancer-related death worldwide. Orthotopic liver transplantation (OLT) and resection are curative treatment options for well-selected patients with HCC, whereas loco-ablative therapy has been shown to prolong survival. Organ and treatment allocations for these patients are currently based on the number and size of tumors, as defined by the Milan criteria, and on functional capacity, and they are incorporated into the Barcelona Clinic Liver Cancer staging system and treatment strategy. Even though these staging criteria have markedly improved the outcomes of patients with HCC, they still lack accuracy in predicting the risk of tumor recurrence because they do not incorporate markers of tumor biology and behavior. Positron emission tomography (PET) and computed tomography (CT) with [(18) F]fludeoxyglucose ([(18) F]FDG) constitute an imaging modality for detecting tumor tissue that is metabolically active. Uptake of [(18) F]FDG is highly associated with tumor aggressiveness. In this review, we present the accumulating data on the use of [(18) F]FDG PET-CT as an in vivo biomarker and its predictive value in identifying patients at risk for HCC recurrence after liver transplantation, resection, or ablation. These data suggest that the introduction of [(18) F]FDG PET-CT into the imaging algorithm of patients planned for liver transplantation, resection, or ablation may improve outcomes.

The effectiveness of ultrasound surveillance for hepatocellular carcinoma in a Canadian centre and determinants of its success

BACKGROUND

The effectiveness of surveillance for hepatocellular carcinoma (HCC) using ultrasound (US) in North America has been questioned due to the predominance of patients of Caucasian ethnicity and larger body habitus.

OBJECTIVE

To determine the effectiveness of US surveillance for HCC in a Canadian hepatobiliary centre and to identify independent variables associated with early detection of tumour(s).

METHODS

A retrospective review of patients with first HCC in a US surveillance population at the authors' hospital yielded 201 patients (over a 10.5-year period). Patients were categorized into three groups: regular surveillance (frequency of surveillance ≤12 months [n=109]); irregular surveillance (frequency of surveillance >12 months [n=38]); or first surveillance (tumour detected on first scan [n=54]). The Milan criteria for transplantation and Barcelona Clinic Liver Cancer (BCLC) staging system were used as outcome measures. Effective surveillance was defined as tumour detection within Milan criteria or curative BCLC stages 0 and A; its association with multiple patient- and disease-related variables was tested.

RESULTS

When using the Milan criteria as outcome, 84 of 109 (77%) regular surveillance patients, 23 of 38 (61%) irregular surveillance patients and 40 of 54 (74%) first surveillance patients had tumours meeting the transplantation criteria. The difference between regular and irregular surveillance was statistically significant (P=0.03). When using the BCLC staging system, 87 of 109 (80%) regular surveillance patients, 26 of 38 (68%) irregular surveillance patients and 41 of 54 (76%) first surveillance patients had their tumours detected in BCLC curative stages (0 and A; P=0.11). Regular surveillance was the only variable significantly associated with detection of tumour(s) within the Milan criteria (OR 2.76 [95% CI 1.10 to 6.88]). Tumours detected more recently were more likely to be <2 cm in size (BCLC stage 0; OR 2.38 [95% CI 1.07 to 5.31]).

CONCLUSION

A high rate of HCC surveillance success was achieved using US alone when performed regularly in a specialized hepatobiliary centre.

Imaging-based diagnostic systems for hepatocellular carcinoma

OBJECTIVE

Noninvasive imaging plays critical roles in the treatment of patients with cirrhosis or other risk factors for the development of hepatocellular carcinoma. In recognition of the critical roles played by imaging, numerous international scientific organizations and societies have, in the past 12 years, proposed diagnostic systems for the interpretation of liver imaging examinations performed of at-risk patients.

CONCLUSION

Although these imaging-based diagnostic systems represent important advances, they have limitations and they are not perfectly consistent with each other. The limitations and inconsistencies potentially cause confusion and may impair the integration of the systems into clinical practice as well as their utilization in research studies. The purpose of this article is to synthesize and critically appraise the current published imaging-based diagnostic systems endorsed by major societies for the noninvasive diagnosis and staging of hepatocellular carcinoma and to propose future directions that we hope may be helpful in further advancing the field.

Validation of organ procurement and transplant network (OPTN)/united network for organ sharing (UNOS) criteria for imaging diagnosis of hepatocellular carcinoma

BACKGROUND

Imaging diagnosis of hepatocellular carcinoma (HCC) presents an important pathway for transplant exception points and priority for cirrhotic patients. The purpose of this retrospective study is to evaluate the validity of the new Organ Procurement and Transplant Network (OPTN) classification system on patients undergoing transplantation for HCC.

METHODS

One hundred twenty-nine patients underwent transplantation for HCC from April 14, 2006 to April 18, 2011; a total of 263 lesions were reported as suspicious for HCC on pretransplantation magnetic resonance imaging. Magnetic resonance imaging examinations were reviewed independently by two experienced radiologists, blinded to final pathology. Reviewers identified major imaging features and an OPTN classification was assigned to each lesion. Final proof of diagnosis was pathology on explant or necrosis along with imaging findings of ablation after transarterial chemoembolization.

RESULTS

Application of OPTN imaging criteria in our population resulted in high specificity for the diagnosis of HCC. Sensitivity in diagnosis of small lesions (≥1 and <2 cm) was low (range, 26%-34%). Use of the OPTN system would have resulted in different management in 17% of our population who had received automatic exception points for HCC based on preoperative imaging but would not have met criteria under the new system. Eleven percent of the patients not meeting OPTN criteria were found to have T2 stage tumor burden on pathology.

CONCLUSIONS

The OPTN imaging policy introduces a high level of specificity for HCC but may decrease sensitivity for small lesions. Management may be impacted in a number of patients, potentially requiring longer surveillance periods or biopsy to confirm diagnosis.

A survival benefit of major hepatectomy for hepatocellular carcinoma identified by preoperative [18F] fluorodeoxyglucose positron emission tomography in patients with well-preserved hepatic function

AIMS

Hepatic resection can cure hepatocellular carcinoma (HCC). However, the optimal extent of resection remains controversial. Major hepatectomy could minimize a tumor recurrence, but it is harmful due to decreased hepatic functional reserve. [18F] fluorodeoxyglucose positron emission tomography (FDG-PET) scans are known as their reflection tumor differentiation and biological activity in HCC. To evaluate a benefit of major hepatectomy for HCC, we performed this retrospective analysis in patients with well-preserved hepatic function, and further analyzed in the subset identified by preoperative FDG-PET.

METHODS

We reviewed the medical records of 189 patients with HCC who underwent curative resection between August 2004 and December 2010 at two institutes. All patients underwent anatomical resection, either by major or minor hepatectomy.

RESULTS

Median overall survival did not differ significantly between the major and minor hepatectomy groups (29.4 versus 26.3 months, p = 0.269). However, the major hepatectomy group had a better recurrence-free survival (24.5 versus 19.9 months, p = 0.004). On multivariate analysis, the presence of intrahepatic metastasis independently predicted overall survival (p = 0.009), but other examined variables did not. Overall survival and recurrence-free survival were significantly better following major hepatectomy rather than minor hepatectomy in patients whose preoperative FDG-PET indicated that the maximum standardized uptake value of the tumor (SUVtumor) was ≥4 and the tumor-to-nontumor SUV ratio (TNR) was ≥1.5.

CONCLUSIONS

Our findings suggest that preoperative FDG-PET may be useful in identifying patients with favorable hepatic reserve who are most likely to benefit from major rather than minor hepatectomy.

Toward a standardized system for hepatocellular carcinoma diagnosis using computed tomography and MRI

Contrast-enhanced computed tomography and MRI are frequently used for the noninvasive diagnosis of hepatocellular carcinoma (HCC). Despite their important role in diagnosis and management of HCC, until recently, there has been no standardized system for their interpretation, reporting and data collection. In 2008, the American College of Radiology convened a committee to develop such a standardized system. This article reviews the role of computed tomography and MRI in the diagnosis and management of HCC; the need for a standardized imaging interpretation system; current HCC imaging criteria included in management guidelines endorsed by the European Association for the Study of Liver, American Association for Study of Liver Diseases, United Network for Organ Sharing and Asian Pacific Association for the Study of the Liver; and the limitations of these criteria. The article then provides an overview of the Liver Imaging Reporting and Data System and discusses future directions.

[Radiological diagnosis of primary hepatic malignancy]

Modern radiology offers countless opportunities both in the detection but also in the characterization of primary liver malignancies. Ultrasound remains usually the first exploratory overview study whereat using ultrasound contrast agent for a further characterization of liver lesions improves this technique considerably. Advanced cross-sectional imaging methods can, in most cases, already provide an exact diagnosis. Thus, the CT is already considered a standard technique for liver imaging and magnetic resonance imaging has gained in recent years due to liver-specific contrast agents and faster sequences a central role in liver imaging. The following article provides an overview of these various radiological procedures and describes the different primary liver malignancies and their imaging characteristics.

Imaging of hepatocellular carcinoma: diagnosis, staging and treatment monitoring

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Imaging is important for establishing a diagnosis of HCC. Several imaging modalities including ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and angiography are used in evaluating patients with chronic liver disease and suspected HCC. CT, MRI and contrast-enhanced US have replaced biopsy for diagnosis of HCC. Dynamic multiphase contrast-enhanced CT or MRI is the current standard for imaging diagnosis of HCC. Functional imaging techniques such as perfusion CT and diffusion-weighted MRI provide additional information about tumor angiogenesis that may be useful for treatment. Techniques evaluating tissue mechanical properties such as magnetic resonance elastography, and acoustic radiation force impulse imaging are being explored for characterizing liver lesions. The role of PET in the evaluation of HCC is evolving with promise seen especially with the use of a hepatocyte-specific PET tracer. Imaging is also critical for assessment of treatment response and detection of recurrence following locoregional treatment. Knowledge of the post-treatment appearance of HCC is essential for correct interpretation. This review article provides an overview of the role of imaging in the diagnosis, staging and post-treatment follow-up of HCC.

11C-acetate and 18F-FDG PET/CT for clinical staging and selection of patients with hepatocellular carcinoma for liver transplantation on the basis of Milan criteria: surgeon's perspective

The success of liver transplantation (LT) for hepatocellular carcinoma (HCC) is enhanced by careful patient selection on the basis of the Milan criteria. The criteria are traditionally assessed by contrast CT, which is known to be affected by structural or architectural changes in cirrhotic livers. We aimed to compare dual-tracer ((11)C-acetate and (18)F-FDG) PET/CT with contrast CT for patient selection on the basis of the Milan criteria.

METHODS

Patients who had HCC and had undergone both preoperative dual-tracer PET/CT and contrast CT within a 1-mo interval were retrospectively studied. They then underwent either LT (n = 22) or partial hepatectomy (PH) (n = 21; HCC of ≤ 8 cm). Imaging data were compared with data from postoperative pathologic analysis for accuracy in assessment of parameters specified by the Milan criteria (tumor size and extent, vascular invasion, and metastasis), TNM staging, and patient selection for LT.

RESULTS

Dual-tracer PET/CT performed equally well in both LT and PH groups for HCC detection (94.1% vs. 95.8%) and TNM staging (90.9% vs. 90.5%). Contrast CT performed reasonably well in the LT group but not in the PH group for HCC detection (67.6% vs. 37.5%) and TNM staging (54.5% vs. 28.6%). In the LT group, the sensitivity and specificity of contrast CT for patient selection on the basis of the Milan criteria were 43.8% and 66.7%, respectively (comparable to values in the literature); the sensitivity and specificity of dual-tracer PET/CT were 93.8% and 100%, respectively (both Ps < 0.05). From the surgeon's perspective, we tended to perform transplantation for patients with higher diagnostic certainty (stricter CT criteria) because of a shortage of donor grafts. Patients who were not transplant candidates usually underwent up-front hepatectomy without the benefit of reassessment contrast CT, resulting in lower accuracies for the PH group. The overall sensitivity (96.8%) and specificity (91.7%) of dual-tracer PET/CT for patient selection for LT were significantly higher than those of contrast CT (41.9% and 33.0%, respectively) (both Ps < 0.05). Sources of error for contrast CT were related to cirrhosis or previous treatment and included difficulty in differentiating cirrhotic nodules from HCC (39%) and estimation of tumor size (14%). Overstaging of vascular invasion (4.6%) and extrahepatic metastases (4.6%) was infrequent. The rate of false-negative results of dual-tracer PET/CT was 4.7%.

CONCLUSION

Dual-tracer PET/CT was significantly less affected by cirrhotic changes than contrast CT for HCC staging and patient selection for LT on the basis of the Milan criteria. The inclusion of dual-tracer PET/CT in pretransplant workup may warrant serious consideration.

(18)F-FDG-PET/CT predicts early tumor recurrence in living donor liver transplantation for hepatocellular carcinoma

The prognosis including (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) for the early recurrence for hepatocellular carcinoma (HCC) after living donor liver transplantation (LDLT) was not well established. Consecutive patients who underwent (18)F-FDG-PET/CT and subsequent LDLT for HCC from March 2005 to June 2011 were enrolled. The 191 patients with a median follow-up of 26.1 months were evaluated. There were 20 patients (10.5%) with early recurrence (≤6 months), 18 patients (9.4%) with late recurrence (>6 months), and 153 patients (80.1%) with no recurrence. Fifty-five patients (28.8%) displayed increased PET/CT tumor uptake. Three-year overall and disease-free survival for PET/CT-positive patients were 65.5% and 57.1%, respectively, while PET/CT-negative patients showed respective values of 89.8% and 86.8% (P = 0.001 vs. P < 0.001). Tumor variables associated with PET/CT-positive finding were preoperative AFP level, Milan, UCSF criteria, maximum tumor size, total tumor size, differentiation, vascular invasion, and serosal invasion. PET/CT-positive status was identified as an independent prognostic factor for disease-free survival influencing early recurrence in multivariable analysis (HR 3.945, 95% CI 1.196-13.016, P = 0.024). (18)F-FDG-PET/CT is an independent and significant predictor of early tumor recurrence in LDLT for HCC.

Single HCC in cirrhotic patients: liver resection or liver transplantation? Long-term outcome according to an intention-to-treat basis

BACKGROUND

Compensated cirrhotic patients with single hepatocellular carcinoma (HCC) ≤5 cm may benefit from both liver resection (LR) and liver transplantation (LT); however, the better 10-year actuarial survival of the two treatments remains unclear. We aimed to assess the long-term outcome of cirrhotic patients with single HCC ≤5 cm treated either with LR or LT on an intention-to-treat basis.

METHODS

A total of 217 cirrhotic patients with single HCC ≤5 cm were evaluated at our department: 95 were treated with LR (LR group), and 122 were included on the waiting list for LT (LT group). Patients in the LR group were divided into very early HCC (tumor size ≤2 cm) and early HCC (tumor size >2 cm). Median follow-up was 5.3 (range 0.1-18) years.

RESULTS

Tumor recurrence was 72 % in the LR group versus 16 % in the LT group (p < 0.001). 1-, 5-, and 10-year cumulative risk of recurrence was 18, 69, and 83 % in the LR group versus 4, 18, and 20 % in the LT group (p < 0.001). Ten-year actuarial survival was 33 % in the LR group versus 49 % in the LT group (p = 0.002). At HCC recurrence, 27.3 % were included on the waiting list for salvage transplantation (very early HCC group) versus 15.1 % (early HCC group) (p = 0.2). After salvage transplantation, HCC recurrence was 0 % (very early HCC group) versus 40 % (early HCC group) (p = 0.2). No significant differences were observed in 1-, 5-, and 10-year actuarial survival between the very early HCC group and the LT group (95, 55, and 50 % vs. 82, 62, and 50 %).

CONCLUSIONS

LR should be the treatment of choice for cirrhotic patients with very early HCC.

Hepatocellular carcinoma: management of an increasingly common problem

Hepatocellular carcinoma (HCC) is a common cancer that typically occurs in the setting of cirrhosis and chronic hepatitis virus infections. Hepatitis B and C account for approximately 80% of cases worldwide. HCC is currently the fifth most common malignancy in men and the eighth in women worldwide; its incidence is increasing dramatically in many parts of the world. Recognition of those at risk and early diagnosis by surveillance with imaging, with or without serologic testing, are extremely important. Many highly effective and even curative therapies are now available and include resection, liver transplantation, and local ablation. Appropriate application of these interventions offers hope of prolonged survival to many patients with this otherwise lethal complication of liver disease.

Characterization of hepatocellular carcinoma recurrence after liver transplantation: perioperative prognostic factors, patterns, and outcome

OBJECTIVE

Liver transplantation (LT) is known to be a promising treatment for patients with liver cirrhosis associated with hepatocellular carcinoma (HCC). This study, however, found that HCC recurrence remains to be a concern.

METHODS

A total of 126 HCC patients who had undergone LT between January 2000 and December 2009 were retrospectively reviewed. The clinicopathological features of the patients were analyzed by univariate and multivariate analyses to determine prognostic factors. Patients who had HCC recurrence were further analyzed in terms of recurrent pattern, management, and outcome.

RESULTS

Seventeen patients (13.5%) exhibited HCC recurrence following LT. Univariate and multivariate analyses identified two prognostic factors: tumor number > three [hazard ratio (HR) = 3.249] and presence of microvascular invasion (HR = 4.336). Among patients with HCC recurrence, 15 out of 17 (88%) patients developed extrahepatic metastasis shortly after recurrence. The survival of patients after HCC recurrence was dismal with 18.3 months of median survival.

CONCLUSIONS

Multiple tumors (>three) are an important prognostic factor for HCC recurrence following LT, but an accurate assessment of tumor status by pretransplantation radiological examination is required. The outcome of patients with HCC recurrence after LT remains very poor because of a tendency of HCC to recur as extrahepatic metastasis.

Assessment of the diagnostic accuracy of T2*-weighted MR imaging for identifying hepatocellular carcinoma with liver explant correlation

BACKGROUND

T2*-weighted MRI may represent a novel method for identifying hepatocellular carcinoma (HCC). The goal of this study was to assess the diagnostic accuracy of T2*-weighted MRI for HCC with liver explant correlation.

MATERIALS AND METHODS

A retrospective review identified 25 patients who had undergone liver transplantation with pre-operative T2*-weighted MRI. All patients had Child's-Pugh A (9), B (9), or C (7) liver disease with 13 transplanted for liver dysfunction and 12 for HCC. The T2*-weighted images were interpreted by 2 blinded, independent observers and the results compared with the explanted specimens. Sensitivity and specificity of T2*-weighted MRI for the identification of HCC was assessed.

RESULTS

By pathology, 16 HCC (mean largest diameter 2.1 cm; range 0.9-3.6 cm) were identified in 14 patients. Reader 1 had a sensitivity of 69% (95% confidence interval 41-88%) and a specificity of 100% (68-100%). Reader 2 had a sensitivity of 56% (31-79%) and a specificity of 100% (68-100%). There was a very good inter-observer agreement (kappa=0.84).

CONCLUSION

T2*-weighted MRI had a moderate sensitivity for identifying HCC but had an excellent specificity. A T2*-weighted MR sequence may be a useful component of a liver MRI protocol due to its high specificity for HCC, and may be particularly useful in patients unable to undergo gadolinium enhanced MRI.

Model for end-stage liver disease exceptions committee activity in Argentina: does it provide justice and equity among adult patients waiting for a liver transplant?

BACKGROUND

In 2005, the model of end-stage liver disease (MELD)-based allocation system was adopted to assess potential liver transplant (LT) recipients in Argentina. The aim of the present study was to revise the activity of the MELD Exception Experts Committee.

METHODS

Between 2005 and 2009, 1623 patients were listed for LT. Regulation provides extra-MELD points for amyloidosis, hepatopulmonary syndrome (HPS) and T(2) hepatocellular carcinoma (T(2) HCC). Centres could also request priority for other situations. Using a prospective database, we identified patients in whom priority points were requested. Pathology reports of explanted livers were analysed for patients with T(2) HCC.

RESULTS

From 234 out of 1623 (14.4%) requests, the overall approval rate was 60.2% including: 2 amyloidosis, 6 HPS, 111 T(2) HCC and 22 non-regulated situations. Of the 111 patients with T(2) HCC, 6 died (5.4%), 8 had tumour progression (7.2%), 94 were transplanted (84.2%) and 3 are still waiting. An explants correlation showed that presumed diagnosis of T(2) HCC was incorrect in 20/94 (22%) and was correct in only 41/94 (43%) cases being T(1) HCC in 9 and T(3) HCC in 23.

CONCLUSIONS

MELD exceptions are frequently requested in Argentina. Unfortunately, most receiving priority points for T(2) HCC benefited by medical error or imaging limitations. An intense review process is urgently needed to maintain equity and justice in the allocation system.

Added value of 80 kVp images to averaged 120 kVp images in the detection of hepatocellular carcinomas in liver transplantation candidates using dual-source dual-energy MDCT: results of JAFROC analysis

BACKGROUND

To assess the added value of 80 kVp images to weighted average 120 kVp images for detecting hepatocellular carcinomas (HCCs) using dual-source, dual-energy MDCT.

MATERIALS AND METHODS

Forty-one HCCs in 42 patients who underwent liver transplantation (LT) were included. All patients underwent quadruple-phase CT using a 64-row dual-source, dual-energy MDCT with 80 kVp and 140 kVp. For 120 kVp, a linear blending ratio of 0.3 was chosen. Interval reviews for both simulated 120 kVp images without and with pure 80 kVp data were performed independently by two radiologists. They detected HCCs using a 4-point confidence scale. Tumor-to-liver contrast-to-noise ratio (CNR) was calculated and compared between the 80 kVp and simulated 120 kVp images. The additional diagnostic value of 80 kVp images was evaluated by jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis.

RESULTS

There were 41 HCCs on pathology and 37 of the 41 HCCs were depicted on CT scan. The mean CNR of the 37 HCCs in late arterial and portal-phase images was significantly better in the 80 kVp images than in 120 kVp images. The average JAFROC figure of merit, however, was not significantly improved when 80 kVp was added. Furthermore, the number of false-positives was significantly increased in reader 1 when adding 80kVp data.

CONCLUSION

The addition of 80 kVp CT images to simulated 120 kVp images did not significantly improve the detection of HCCs despite of the significantly better CNR of 80 kVp images.

Multiphasic MDCT enhancement pattern of hepatocellular carcinoma smaller than 3 cm in diameter: tumor size and cellular differentiation

OBJECTIVE

The purpose of this study was to evaluate according to size and degree of cellular differentiation the multiphasic MDCT enhancement pattern of hepatocellular carcinoma (HCC) smaller than 3 cm in diameter in patients with cirrhosis.

MATERIALS AND METHODS

In 155 consecutively registered patients (126 men, 29 women; mean age, 58.4 years), 204 pathologically proven HCCs smaller than 3 cm were detected at multiphasic MDCT. Three radiologists in consensus classified the relative attenuation of the tumors compared with the surrounding liver parenchyma as hyperattenuation, isoattenuation, or hypoattenuation on biphasic (n = 86) and triphasic (n = 69) CT scans.

RESULTS

The prevalent enhancement patterns of HCC differed depending on tumor size. The prevalent pattern of HCC measuring 20-29 mm was arterial hyperattenuation with venous washout (47%, 47/101). The prevalent enhancement patterns of HCC smaller than 10 mm and HCC measuring 10-19 mm were isoattenuation during the arterial and portal venous phases (29%, 6/21) and hyperattenuation and isoattenuation during the arterial and portal venous phases (33%, 27/82). The typical HCC enhancement pattern (arterial hyperattenuation with venous washout) was identified in 48% (67/141) of the moderately and poorly differentiated HCCs and in 13% (8/63) of well-differentiated HCCs.

CONCLUSION

The prevalent enhancement patterns of HCC smaller than 3 cm on multiphasic MDCT scans differed depending on tumor size and cellular differentiation. HCCs smaller than 2 cm and well-differentiated HCCs frequently had atypical enhancement patterns.

Diagnostic performance of multidetector row computed tomography, superparamagnetic iron oxide-enhanced magnetic resonance imaging, and dual-contrast magnetic resonance imaging in predicting the appropriateness of a transplant recipient based on milan criteria: correlation with histopathological findings

PURPOSE

To retrospectively evaluate the diagnostic performance of multidetector row CT (MDCT), superparamagnetic iron oxide (SPIO)-enhanced MRI (S-MRI), and dual-contrast MRI (DC-MRI) in predicting the appropriateness of recipients with hepatocellular carcinoma (HCC) for liver transplantation (LT), based on Milan criteria.

MATERIALS AND METHODS

This retrospective study received Institutional Review Board approval. Requirement for patient informed consent was waived. During a 3-year period, 80 patients who underwent LT were enrolled in this study. However, 2 patients in whom >10 HCCs were present were excluded from the analysis of detection performance of imaging modalities for HCC. MDCT and DC-MRI examinations with the sequential use of SPIO and gadolinium were performed in all patients. Interval readings for MDCT, S-MRI, and DC-MRI were performed. Two radiologists independently recorded confidence levels using a 4- and 5-point scale for the presence of HCC and for the appropriateness regarding LT, respectively. Image interpretation was compared with histopathological results on a lesion-by-lesion basis. Diagnostic performance of the 3 imaging techniques was compared using jackknife alternative free-response receiver operating characteristic and ROC analyses.

RESULTS

Eighty-two HCCs were detected in 38 of 78 patients. Twenty-seven HCCs were larger than 2 cm in diameter and 55 HCCs were smaller than 2 cm in diameter. Among 80 patients included for the assessment of eligibility for LT, 69 recipients were categorized as appropriate and the remaining 11 patients were found to be inappropriate for LT based on Milan criteria. In terms of detecting HCCs, the reader-averaged figure of merit was highest for DC-MRI (0.764), followed by S-MRI (0.702) and MDCT (0.672). The use of DC-MRI was significantly better than the use of the other 2 modalities specifically for HCCs smaller than 2 cm in diameter (P < 0.001) although not for those larger than or equal to 2 cm (P = 0.125-1). The AZ value for predicting the appropriateness for LT was highest with the use of S-MRI (0.841), followed by the use of DC-MRI (0.830) and the use of MDCT (0.790). However, significant differences were not seen for the predictions determined by both radiologists (P = 0.384-1). This result might be because of the small number of patients who had a critical number of HCCs (ie, 2 approximately 4 HCCs).

CONCLUSION

DC-MRI showed significantly better diagnostic performance in transplantation candidates for the detection of HCCs, particularly small HCCs, than both MDCT and S-MRI. However, for assessing the appropriateness of a transplantation recipient based on Milan criteria, MDCT, S-MRI, and DC-MRI showed comparable diagnostic accuracy without a statistical difference.

Imaging in liver transplantation

The aim of this study was to illustrate the role of non-invasive imaging tools such as ultrasonography, multi-detector row computed tomography, and magnetic resonance imaging in the evaluation of pediatric and adult liver recipients and potential liver donors, and in the detection of potential complications arising from liver transplantation.

Liver transplantation for hepatocellular carcinoma: results of down-staging in patients initially outside the Milan selection criteria

Conventional criteria for liver transplantation for patients with hepatocellular carcinoma are single HCC <or= 5 cm or less than or equal to three HCCs <or= 3 cm. We prospectively evaluated the possibility of slightly extending these criteria in a down-staging protocol, which included patients initially outside conventional criteria: single HCC 5-6 cm or two HCCs <or= 5 cm or less than six HCCs <or= 4 cm and sum diameter <or= 12 cm, but within Milan criteria in the active tumors after the down-staging procedures. The outcome of patients down-staged was compared to that of Milan criteria after liver transplantation and since the first evaluation according to an intention-to-treat principle. From 2003 to 2006, 177 patients with HCC were considered for transplantation: the transplantation rate was comparable between the Milan and down-staging groups: 88/129 cases (68%) versus 32/48 cases (67%), respectively. At a median follow-up of 2.5 years after transplantation, the 1 and 3 years' disease-free survival rates were comparable: 80% and 71% in the Milan group versus 78% and 71% in the down-staging. The actuarial intention-to-treat survival was 27/48 patients (56.3%) in the down-staging and 81/129 cases (62.8%) in the Milan group, p = n.s. The proposed down-staging criteria provide a comparable outcome to the conventional criteria.

Liver transplantation for hepatocellular carcinoma without preoperative tumor biopsy

BACKGROUND

Progress in liver imaging has made pretransplantation tumor biopsy no longer systematic in patients with hepatocellular carcinoma (HCC).

OBJECTIVES

Our aim was to evaluate the accuracy of a preoperative diagnosis of HCC based on clinical and radiological findings in 102 cirrhotics qualified for liver transplantation (LT) between January 1995 and August 2003 at our institution.

METHODS

The diagnostic accuracy of our policy was assessed by comparing pretransplant diagnosis with the pathologic report of explanted livers.

RESULTS

Sensitivity, specificity, positive, and negative predictive values for the preoperative clinical and radiological diagnosis of HCC were 89%, 94.3%, 77%, and 93.3%, respectively. A false-positive preoperative diagnosis was made in 20 of 102 patients (19.6%) (dysplastic nodules [n=9], regenerative nodules [n=5] cholangiocellular carcinoma [n=1], hemangioma [n=1], and no lesion [n=4]). All tumors larger than 3 cm were correctly diagnosed, irrespective of serum alpha-fetoprotein (sAFP) levels. The risk of overestimating the diagnosis of HCC in the subgroup of patients with tumors less than 3 cm was conversely correlated with preliver transplantation sAFP (sAFP<or=100 ng/L: 28%; sAFP>100: 11%; sAFP>200: 0%).

CONCLUSION

In cirrhotics with nodules larger than 3 cm irrespective of sAFP or nodules less than 3 cm with sAFP greater than 200 ng/L, the pretransplant diagnosis of HCC can be made without performing biopsy. In other cases (i.e., nodules less than 3 cm and sAFP lower than 200 ng/L), histologic confirmation of HCC or a close follow-up imaging should be considered.

Liver tumors: pediatric population

Liver tumors in childhood are rare and are typically not detected clinically until they reach a large size and often spread within the organ or metastasize. This can make surgical resection problematic, and almost all of them require extirpation for cure. With very effective chemotherapy for hepatoblastoma and to some extent for sarcomas, many cancers can be shrunk to permit partial hepatectomy, but for most hepatocarcinomas, some of the other malignancies, and even some benign proliferations, their location at the hilum and multiplicity of masses in multiple lobes make transplantation the treatment of choice. Major advances in diagnostic imaging, especially enhanced computed tomography and magnetic resonance imaging, permit a preoperative choice of resection versus transplantation to be achieved in almost all instances, and for the remainder, intraoperative ultrasonography can further help to determine the most desirable approach. The outcome is very much better in the case of hepatoblastoma when transplantation is a primary modality rather than following unsuccessful attempts at resection. In this review, transplantation for liver tumors in children is considered from all aspects, including the importance of screening for tumors whenever possible to avoid the need for transplantation.

Diagnostic accuracy of multi-/single-detector row CT and contrast-enhanced MRI in the detection of hepatocellular carcinomas meeting the milan criteria before liver transplantation

Liver transplantation has been considered to be the only causal treatment for liver cirrhosis patients with hepatocellular carcinoma (HCC) due to its theoretical advantage of eliminating both the tumor and liver disease. However, because of the shortage of donor organs, it is strongly recommended that liver transplantations should be performed on cirrhotic patients with HCCs only when the patients meet the predetermined criteria in terms of number and extent of HCCs. Imaging is thus decisive in the patient inclusion or exclusion from transplantation lists. The imaging techniques used are CT, MRI and ultrasonography. The latter has been proven to be ineffective for HCC surveillance in transplant recipients because of its heavy operator dependence and unreliable detection of small and intermediately sized HCCs. The purpose of this article, then, is to systematically review the diagnostic performances of single-/multidetector row CT, dynamic gadolinium-enhanced MRI, superparamagnetic iron oxide (SPIO)-enhanced MRI and double-contrast MRI using both gadolinium and SPIO for the detection of HCCs with special emphasis on liver transplantation.

Liver transplantation in patients with hepatocellular carcinoma across Milan criteria

Milan criteria are the most frequently used limits for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC), but our previous experience with expanded criteria showed encouraging results. The aim of this study was to investigate whether our expanded Clinica Universitaria de Navarra (CUN) criteria (1 nodule up to 6 cm or 2-3 nodules up to 5 cm each) could be used to select patients with HCC for LT. Eighty-five patients with HCC fulfilling CUN criteria were included as candidates for LT. Survival of transplanted HCC patients was compared with survival of patients without HCC (n = 180). After the exclusion of 2 patients with tumor seeding of the chest wall due to pre-LT tumor biopsy, survival and recurrence rates were compared according to tumor staging. Twenty-six out of 85 (30%) patients exceeded Milan criteria. Twelve patients had tumor progression on the waiting list. Patients exceeding Milan criteria had a higher dropout rate due to tumoral progression. One-, 3-, 5-, 7-, and 10-year survival rates of the 73 transplanted HCC patients were 86%, 74%, 70%, 61%, and 50%, respectively. Survival of patients with HCC was significantly lower than that of patients without HCC, but by multivariate analysis, HCC was not associated with lower survival. Tumor recurrence and survival rates were similar for patients fulfilling Milan and CUN criteria. Pathological staging showed 55 patients within Milan criteria, 7 patients exceeding them but within CUN criteria, and 9 patients exceeding CUN criteria. Tumor recurrence rates were 2/55 (4%), 0/7 (0%), and 4/9 (44%) in each of these groups, respectively. In conclusion, following CUN criteria could increase the number of HCC patients who could benefit from LT, without worsening the results. Because of the short number of patients in this series, these data need external validation.

Early detection of liver cancer: diagnosis and management

Hepatocellular carcinoma (HCC) is the fifth most common cause of cancer deaths worldwide, and the incidence is rising. Despite a wide array of treatment options, fewer than half of candidates for potentially curative treatments receive them. The diagnosis and management of HCC require a multidisciplinary approach involving various clinical specialties. The foundation of diagnosis is high-quality imaging, with MRI being the test of choice. Some patients also require guided biopsy when MRI is equivocal. Treatment options depend upon the tumor stage and the degree of underlying synthetic dysfunction. Potentially curative treatments include surgical resection and transplantation. Other treatments that prolong survival include percutaneous ablation and transarterial chemoembolization. A new oral agent, sorafenib, was recently shown to prolong survival in patients with advanced HCC. By increasing surveillance and treatment of HCC, outcomes for these patients may be improved.

Liver transplantation for hepatocellular carcinoma: role of biopsy

Patients with compensated cirrhosis (and low Model for End-Stage Liver Disease score) should not undergo transplantation unless they have small hepatocellular carcinoma (HCC). Therefore, presence of HCC should be definitely ascertained before deciding on transplantation in this group of patients. Current imaging techniques allow detection of small liver nodules (<1 cm). Not all liver nodules between 1 and 2 cm are HCC. In addition, benign regenerative nodules have a relatively low potential for degeneration. It is generally agreed that in patients with evidence of cirrhosis, a definitive diagnosis of HCC can be made without tissue analysis in case of nodules >2 cm with a characteristic pattern on either computed tomography (CT) or magnetic resonance imaging (MRI) (hypervascularity in the arterial phase and washout in the early or delayed venous phase). Two concordant imaging techniques (triphasic CT and MRI) are needed to ascertain HCC in case of nodules between 1 and 2 cm. Biopsy is needed for making a diagnosis of HCC in patients with cirrhosis with nodules that do not fulfill the above criteria. Whatever the characteristics of the nodules, biopsy should also be performed in patients without documented cirrhosis. In case of HCC, percutaneous biopsy carries a risk of needle tract seeding of 1-2%. Percutaneous biopsy carries a potential risk of hematogenous dissemination that has not been clearly assessed. There is no clear evidence that the risk of posttransplantation recurrence is higher in patients who undergo biopsy before transplantation. Therefore, in case of HCC, previous biopsy should not be considered a contraindication for transplantation. Even though the specificity of biopsy is close to 100%, its negative predictive value is low. Negative biopsy findings do not exclude the presence of HCC. Patients with negative biopsy findings should either undergo a second biopsy or an enhanced surveillance protocol.