Bland embolization in the treatment of hepatic adenomas: preliminary experience

Stereotactic radiofrequency ablation as a valid first-line treatment option for hepatocellular adenomas

OBJECTIVES

This study aimed to assess the safety and efficacy of stereotactic radiofrequency ablation (SRFA) in patients with hepatocellular adenomas (HCA).

METHODS

Retrospective analyses of all patients referred for SRFA treatment at our institution between January 2010 and October 2020 revealed 14 patients (10 women; mean age 34.4 [range, 17-73 years]) with 38 HCAs treated through 18 ablation sessions. Ablations were considered successful if a safety margin >5 mm was achieved. Demographic, interventional, and outcome data were collected and analyzed. Primary and secondary technical efficacy rates were assessed based on follow-up images consisting of contrast-enhanced CT or MR scans.

RESULTS

The mean tumor size was 22 mm (range, 7-75 mm). Overall, 37/38 (97.4%) tumors were successfully ablated at the initial SRFA (primary efficacy rate of 97.4%). The median follow-up duration was 49.6 months. No deaths or adenoma-related complications (hemorrhage or malignant transformation) were observed. Disease-free survival rates at 1, 3, and 5 years from the date of the first SRFA were 100%, 85.8%, and 85.8%, respectively. Two patients developed new distant tumors retreated with consecutive re-ablation. No major complications occurred during any of the 18 ablation sessions.

CONCLUSIONS

Percutaneous thermal ablation is efficient in the treatment of HCAs and may thus be considered a valid first-line treatment option. In addition, SRFA allows for an effective, minimally invasive treatment of large and multiple hepatic tumors within one session.

Bland Embolization of Benign Liver Tumors: Review of the Literature and a Single Center Experience

Transarterial embolization has shown promise as a safe, effective, and less invasive treatment modality for benign liver lesions (hemangioma, focal nodular hyperplasia (FNH), and hepatic adenoma (HA)) with fewer complications compared to surgical intervention. There is no consensus regarding the most appropriate embolization material(s) for the treatment of benign liver tumors. The purpose of this study was to review the current literature regarding the transarterial embolization of benign liver tumors and to share our single center experience. This was a non-blinded, retrospective, single-institution review of the bland embolization of benign liver tumors. Clinical data and imaging before and after embolization were used to evaluate lesion response to transarterial embolization. Twelve patients were included in the study. Five patients with six hemangiomas were treated. Pain was a presenting complaint in all five of these patients. The median change in tumor volume was −12.4% and ranged from −30.1% to +42.3%. One patient with two FNH lesions was treated, and both lesion volumes decreased by more than 50%. Six patients with 10 adenomas were treated. Pain was a presenting complaint in three patients, and five patients had a lesion >5 cm. The median change in tumor volume was −67.0% and ranged from −92.9% to +65.8%. Bland transarterial embolization of liver hemangiomas, FNH, and HA can be an effective and minimally invasive treatment modality to control the size and/or symptoms of these lesions. There is a variable response depending on tumor type and the embolization materials used.

Progress of gelatin-based microspheres (GMSs) as delivery vehicles of drug and cell

Gelatin has various attractive features as biomedical materials, for instance, biocompatibility, low immunogenicity, biodegradability, and ease of manipulation. In recent years, various gelatin-based microspheres (GMSs) have been fabricated with innovative technologies to serve as sustained delivery vehicles of drugs and genetic materials as well as beneficial bacteria. Moreover, GMSs have exhibited promising potentials to act as both cell carriers and 3D scaffold components in tissue engineering and regenerative medicine, which not only exhibit excellent injectability but also could be integrated into a macroscale construct with the laden cells. Herein, we aim to thoroughly summarize the recent progress in the preparations and biomedical applications of GMSs and then to point out the research direction in future. First, various methods for the fabrication of GMSs will be described. Second, the recent use of GMSs in tumor embolization and in the delivery of cells, drugs, and genetic material as well as bacteria will be presented. Finally, several key factors that may enhance the improvement of GMSs were suggested as delivery vehicles.

Endovascular approaches in pediatric interventional oncology

The demand for interventional oncological (IO) treatment of pediatric cancers is becoming increasingly common, at least at several tertiary care institutions. The data and techniques used in pediatric IO are largely extrapolated from experience in adult patients. The management of pediatric tumors differs from that in adults in several categories, such as, the curative intent of treatment, wide use of general anesthesia, aggressive pain management, potentially longer hospital stay, variation in chemotherapy dosing etc. Additionally, pediatric cancers are managed by protocols directed by national and international oncology groups such as the Children’s Oncology Group (COG). Consequently, the translation and adoption of these techniques is gradual, but there is a noticeable uptrend due to the growing need. This review will update the current endovascular IO treatments for common pediatric liver, renal, bone and soft tissue tumors.

New insights in the management of Hepatocellular Adenoma

Hepatocellular adenoma (HCA) are benign liver tumours that may be complicated by haemorrhage or malignant transformation to hepatocellular carcinoma. Epidemiological data are fairly outdated, but it is likely to assume that the incidence has increased over the past decades as HCA are more often incidentally found due to the more widespread use of imaging techniques and the increased incidence of obesity. Various molecular subgroups have been described. Each of these molecular subgroups are defined by specific gene mutations and pathway activations. Additionally, they are all related to specific risk factors and show a various biological behaviour. These molecular subgroups may be identified using immunohistochemistry and molecular characterization. Contrast-enhanced MRI is the recommended imaging modality to analyse patients with suspected hepatocellular adenoma allowing to determine the subtype in up to 80%. Surgical resection remains to be the golden standard in treating HCA, although resection is deemed unnecessary in a large number of cases, as studies have shown that the majority of HCA will regress over time without complications such as haemorrhage or malignant transformation occurring. It is preferable to treat patients with suspected HCA in high volume centres with combined expertise of liver surgeons, hepatologists, radiologists and (molecular) pathologists.

Safety and efficacy of transarterial embolization of hepatocellular adenomas

BACKGROUND

Hepatocellular adenoma (HCA) larger than 5 cm in diameter has an increased risk of haemorrhage and malignant transformation, and is considered an indication for resection. As an alternative to resection, transarterial embolization (TAE) may play a role in prevention of complications of HCA, but its safety and efficacy are largely unknown. The aim of this study was to assess outcomes and postembolization effects of selective TAE in the management of HCA.

METHODS

This retrospective, multicentre cohort study included patients aged at least 18 years, diagnosed with HCA and treated with TAE. Patient characteristics, 30-day complications, tumour size before and after TAE, symptoms before and after TAE, and need for secondary interventions were analysed.

RESULTS

Overall, 59 patients with a median age of 33.5 years were included from six centres; 57 of the 59 patients were women. Median tumour size at time of TAE was 76 mm. Six of 59 patients (10 per cent) had a major complication (cyst formation or sepsis), which could be resolved with minimal therapy, but prolonged hospital stay. Thirty-four patients (58 per cent) were symptomatic at presentation. There were no significant differences in symptoms before TAE and symptoms evaluated in the short term (within 3 months) after TAE (P = 0·134). First follow-up imaging was performed a median of 5·5 months after TAE and showed a reduction in size to a median of 48 mm (P < 0·001).

CONCLUSION

TAE is safe, can lead to adequate size reduction of HCA and, offers an alternative to resection in selected patients.

Massive hepatic adenoma response to bland embolization: A case study

Hepatic adenomas are rare, benign liver masses of rising incidence in the United States. We present a report of a 22-year-old asymptomatic female with a massive (14.2 × 11.4 cm), centrally located hepatic adenoma. The unique presentation of the adenoma in close proximity to the hepatic vasculature meant the patient was not a candidate for surgical resection. An arterial embolization was used as an alternative approach to initial treatment. Arterial branches supplying the adenoma were identified via computed tomography and embolized with embospheres and coils. The treatment resulted in a large reduction in size and density of the adenoma identified at a 1-month follow-up. The case supports further use of arterial embolization as an initial treatment for large adenomas to improve the outcome of subsequent surgical approaches.

Systematic review: benefits and harms of transarterial embolisation for treating hepatocellular adenoma

BACKGROUND

Transarterial embolisation (TAE) is a standard treatment for bleeding hepatocellular adenoma (HCA) and, occasionally, symptomatic HCA involving large tumours. Whether TAE is similarly safe and effective as an elective treatment for bleeding and nonbleeding HCA remains unclear.

AIM

To investigate the benefits and harms of TAE for bleeding and nonbleeding HCA.

METHODS

PubMed, Scopus, Embase and Cochrane Library databases were systematically searched for studies that examined post-TAE tumour reduction in patients with bleeding or nonbleeding HCA and that were published between January 2000 and January 2017.

RESULTS

Systematic review of 21 case series involving 1468 patients with HCA in the systematic review identified 140 (9.5%) patients with 189 lesions who received TAE. Of these 140 patients, 66.4% had bleeding HCA and 33.6% had nonbleeding HCA. Intended elective TAE was performed in 27.1% of patients (38.6% of HCA lesions). Adenomatosis was observed in 6.1% of patients, and the rate of β-catenin expression was 4.5%. No malignant transformation was observed among the 189 tumours during a median follow-up time of 40 months. The complete response rate among 70 patients was 10.6%, and the partial response rate was 71.7%. No mortality or severe adverse side effects were reported during the hospitalisation period.

CONCLUSIONS

The available evidence suggests that TAE can be considered safe for elective managment of HCA as well as for management of bleeding HCA. Elective TAE can be regarded as a reasonable alternative to surgery. High-quality prospective studies with long-term follow-up are needed to corroborate and strengthen available evidence.

Hepatocellular adenoma: when and how to treat? Update of current evidence

Hepatocellular adenoma (HCA) is a rare, benign liver tumor. Discovery of this tumor is usually as an incidental finding, correlated with the use of oral contraceptives, or pregnancy. Treatment options have focused on conservative management for the straightforward, smaller lesions (<5 cm), with resection preferred for larger lesions (>5 cm) that pose a greater risk of hemorrhage or malignant progression. In recent years, a new molecular subclassification of HCA has been proposed, associated with characteristic morphological features and loss or increased expression of immunohistochemical markers. This subclassification could possibly provide considerable benefits in terms of patient stratification, and the selection of treatment options. In this review we discuss the decision-making processes and associated risk analyses that should be made based on lesion size, and subtype. The usefulness of this subclassification system in terms of the procedures instigated as part of the diagnostic work-up of a suspected HCA will be outlined, and suitable treatment schemes proposed.

Management of Hepatocellular Adenoma: Recent Advances

Hepatocellular adenoma (HCA) is a rare benign liver cell neoplasm that occurs more frequently in young women with a history of prolonged use of oral contraceptives. Surgical resection is considered because of the risk of hemorrhage in 25% and of malignant transformation in 5% of patients with HCA. HCA is a heterogeneous disease comprising 3 subtypes with distinct molecular and complication profiles. The inflammatory or telangiectatic subtype is at increased risk for hemorrhage, the β-catenin-activated subtype is at increased risk for malignant transformation, and the hepatocyte nuclear factor-1α-inactivated or steatotic subtype is at the least risk for complications. One-third of the patients with HCA have multiple tumors on imaging with no increased risk of complications. Magnetic resonance imaging is the modality of choice for the diagnosis and subtype characterization of HCA. Systematic resection of HCA is recommended in male patients owing to the higher incidence of malignant transformation, and surgical excision in women should be reserved for tumors 5 cm or larger associated with an increased risk of complications. Cessation of hormonal therapy and radiologic surveillance in women with HCA tumors smaller than 5 cm shows that the vast majority of HCA remain stable or undergo spontaneous regression. Percutaneous core needle biopsy is of limited value because the therapeutic strategy is based primarily on patient sex and tumor size. Transarterial embolization is the initial treatment for HCA complicated by hemorrhage. Pregnancy should not be discouraged in the presence of HCA, however, frequent sonographic surveillance is recommended.

Interreader and inter-test agreement in assessing treatment response following transarterial embolization for hepatocellular carcinoma

PURPOSE

To evaluate interreader and inter-test agreement in applying size- and necrosis-based response assessment criteria after transarterial embolization (TAE) for hepatocellular carcinoma (HCC), applying two different methods of European Association for the Study of the Liver (EASL) criteria.

METHODS

Seventy-four patients (median age, 67 years) from a prospectively accrued study population were included in this retrospective study. Four radiologists independently evaluated CT data at 2-3 (1st follow-up, FU) and 10-12 (2nd FU) weeks after TAE and assessed treatment response using size-based (WHO, RECIST) and necrosis-based (mRECIST, EASL) criteria. Enhancing tissue was bidimensionally measured (EASLmeas) and also visually estimated (EASLest). Interreader and inter-test agreements were assessed using intraclass correlation coefficient (ICC) and κ statistics.

RESULTS

Interreader agreement for all response assessment methods ranged from moderate to substantial (κ = 0.578-0.700) at 1st FU and was substantial (κ = 0.716-0.780) at 2nd FU. Inter-test agreement was substantial between WHO and RECIST (κ = 0.610-0.799, 1st FU; κ = 0.655-0.782, 2nd FU) and excellent between EASLmeas and EASLest (κ = 0.899-0.918, 1st FU; κ = 0.843-0.877, 2nd FU).

CONCLUSION

Size- and necrosis-based criteria both show moderate to excellent interreader agreement in evaluating treatment response after TAE for HCC. Inter-test agreement regarding EASLmeas and EASLest was excellent, suggesting that either may be used.

KEY POINTS

• Applying EASL criteria, visual estimation and bidimensional measurements show comparable interreader agreement. • EASL meas and EASL est show substantial interreader agreement for treatment response in HCC. • Agreement was excellent for EASL meas and EASL est after TAE of HCC. • Visual estimation of enhancement is adequate to assess treatment response of HCC.

Diagnosis and management of solid benign liver lesions

More and more asymptomatic benign liver tumours are discovered incidentally and can be divided into regenerative lesions and true neoplastic lesions. The most common regenerative lesions include hemangioma, focal nodular hyperplasia and inflammatory pseudotumours of the liver. Neoplastic lesions include hepatocellular adenomas and angiomyolipomas. Regenerative lesions rarely increase in volume, do not yield a higher risk of complications and usually do not require treatment. By contrast, hepatocellular adenomas and angiomyolipomas can increase in volume and are associated with a risk of complications. Large hepatocellular adenomas (>5 cm in diameter) are undoubtedly associated with a risk of bleeding and malignant transformation, particularly the inflammatory (also known as telangiectatic) and β-catenin mutated subtypes. Accurate diagnosis needs to be obtained to select patients eligible for surgical resection. MRI has markedly improved diagnosis and can identify the major hepatocellular adenomas subtypes. The use of biopsy results to inform the indication for resection remains questionable. However, when diagnosis remains uncertain after imaging, percutaneous biopsy could help improve diagnostic accuracy.

Regression of hepatocellular adenomas with strict dietary therapy in patients with glycogen storage disease type I

Hepatocellular adenomas (HCAs) are a common complication in patients with glycogen storage disease type I (GSD I). In this series, we report regression of HCAs in a cohort of patients who achieved metabolic control with strict dietary therapy. A retrospective review of the clinical records for all patients with GSD I was performed at our institution. All available imaging studies were reviewed in patients with reported regression of HCAs in the medical record. The charts of 163 patients with GSD Ia and 42 patients with GSD Ib were reviewed, and HCAs were documented in 47 subjects (43 Ia/4 Ib). After review of all available imaging studies, eight patients met criteria of being followed with both magnetic resonance imaging and ultrasound and were found to show evidence of regression of HCAs. In these individuals, regression of the HCAs occurred once metabolic control was obtained, as determined by decreasing levels of serum triglyceride levels. The average triglyceride level in all patients prior to regression of HCAs was 753 mg/dL (SD ± 293). The average serum triglyceride level in all patients at the time of regression of HCAs was 340 mg/dL (SD ± 164). These findings suggest that strict dietary therapy may cause regression of HCAs. If HCAs are documented in a patient with suboptimal metabolic control, intensive medical therapy may be an alternative to surgical intervention in some individuals.

Resection, transplantation and local regional therapies for liver adenomas

Hepatocellular adenoma (HCA) is a rare benign liver-cell neoplasm, occurring predominantly in young obese women using oral contraceptives. HCA is a heterogeneous disease, which includes four subtypes (including unclassified) associated with various risks of haemorrhagic complications and malignant transformation. Magnetic resonance imaging is the modality of choice for both diagnosis and subtype characterization of HCA whereas percutaneous biopsy has only limited impact on the therapeutic strategy. In men HCA should be always resected while in women surgery should only be considered for lesions ≥5 cm and after cessation of hormonal therapy. Women with single or multiple HCAs <5 cm may be followed with regular MRI imaging since the vast majority of HCA remains stable or decreases in size. Pregnancy should not be discouraged provided close sonographic surveillance is undertaken.

Management of hepatocellular adenoma: comparison of resection, embolization and observation

INTRODUCTION

Hepatocellular adenoma (HA) is an uncommon benign hepatic tumour with the potential for malignant change or spontaneous haemorrhage. Resection has been the recommended treatment, but outcomes with other approaches are ill defined.

METHODS

Demographic and outcomes data were retrospectively collected on patients diagnosed with HA at a tertiary hepatobiliary centre from 1992-2011 whom underwent resection, bland embolization or observation.

RESULTS

In total, 52 patients with 100 adenomas were divided into single HA (n = 27), multiple HA (n = 18), and adenomatosis (n = 7) groups. Eighty-seven per cent were female and 37% had a history of hormone use. Median sizes of resected, embolized and observed adenomas were 3.6 cm, 2.6 cm and 1.2 cm, respectively. Forty-eight adenomas were resected as a result of suspicion of malignancy (39%) or large size (39%); 61% of these were solitary. Thirty-seven were embolized for suspicion of malignancy (56%) or hsemorrhage (20%); 92% of these were multifocal. Two out of three resected adenomas with malignancy were ≥10 cm and recurred locally [4%, confidence interval (CI) 1-14%]. Ninety-two per cent of the embolized adenomas were effectively treated; three persisted (8.1%, CI 2-22%). Most observed lesions did not change over time.

CONCLUSIONS

While solitary adenomas are often resected, multifocal HAs are frequently embolized. Small adenomas can safely be observed. Given low recurrence rates, select HAs can be considered for embolization.

Changes in the management of benign liver tumours: an analysis of 285 patients

OBJECTIVES

Benign liver tumours (BLTs) are common and their management remains controversial. This study assesses the safety of a selective management approach.

METHODS

Patients with BLT were identified from an institutional database. Patients with simple cysts or an incidental BLT in the setting of metastasis or concomitant malignancy were excluded.

RESULTS

A total of 285 patients presenting during the period from January 1992 to December 2009 with haemangioma (53.0%), focal nodular hyperplasia (23.9%), adenoma (10.2%) or indeterminate/other lesions (13.0%) were evaluated. Of these, 117 patients (41.1%) underwent immediate resection and 168 patients (58.9%) were followed with serial imaging (median follow-up: 30 months). During observation, eight patients (4.8%) underwent resection for tumour growth, inability to exclude malignancy or symptoms; no patients demonstrated malignant transformation or tumour-related complications. During the study period, the number of BLTs evaluated and the proportion of patients observed increased from 129 BLTs of which 36.4% were observed in 1992-2002 to 156 BLTs of which 71.2% were observed in 2003-2009 (P < 0.001). Diagnostic uncertainty led to resection in 29.5% of patients during the earlier period, but in only 13.4% during the more recent 7 years (P < 0.05).

CONCLUSIONS

Asymptomatic BLTs without concern for malignancy or adenoma can be safely observed with minimal risk for misdiagnosis. Patients selected for observation rarely require resection or develop tumour-related complications.

Changing epidemiology of hepatocellular adenoma in the United States: review of the literature

Hepatocellular adenoma (HCA) is a benign neoplasm arising from hepatocytes. There is evidence that the inflammatory subtype may be associated with obesity and alcohol use and that men with metabolic syndrome may be at risk for malignant transformation of HCA. We sought to explore the combined experience of US centers as reported in the literature to document the epidemiologic shift in risk factors for HCA formation in the United States, namely, a shift from oral contraceptive pills (OCPs) to an emerging role of obesity as a contributing factor. Methods. Publications reporting HCA in the United States were identified through a PubMed search and a review of the literature. We excluded publications prior to 1970, single case reports, and publications for which there was no data available regarding patient characteristics including OCP use and the number of adenomas. Conclusion. Whereas earlier reports of HCA in the United States described cases exclusively in women exposed to OCPs, there is a trend towards an increase in HCAs reported in men, HCAs in the absence of OCP use, and increased reporting of multiple HCAs. This may be a result of newer OCP formulations and increasing prevalence of obesity.