Use of Yttrium-90 glass microspheres (TheraSphere) for the treatment of unresectable hepatocellular carcinoma in patients with portal vein thrombosis

Role of radiotherapy in the management of hepatocellular carcinoma: A systematic review

Many patients with hepatocellular carcinoma (HCC) present with advanced disease, not amenable to curative therapies such as surgery, transplantation or radiofrequency ablation. Treatment options for this group of patients include transarterial chemoembolization (TACE) and radiation therapy. Especially TACE, delivering a highly concentrated dose of chemotherapy to tumor cells while minimizing systemic toxicity of chemotherapy, has given favorable results on local control and survival. Radiotherapy, as a therapeutic modality of internal radiation therapy with radioisotopes, has also achieved efficacious tumor control in advanced disease. On the contrary, the role of external beam radiotherapy for HCC has been limited in the past, due to the low tolerance of surrounding normal liver parenchyma. However, technological innovations in the field of radiotherapy treatment planning and delivery, have provided the means of delivering radical doses to the tumor, while sparing normal tissues. Advanced and highly conformal radiotherapy approaches such as stereotactic body radiotherapy and proton therapy, evaluated for efficacy and safety for HCC, report encouraging results. In this review, we present the role of radiotherapy in hepatocellular carcinoma patients not suitable for radical treatment.

[Targeted radiological therapy of liver tumors]

BACKGROUND

Interventional radiology offers a variety of treatment options for liver tumors. Depending on the tumor entity and the extent of the disease, patients can be treated with a curative or palliative intent. In order to make a decision on the best course of treatment for the individual patient, knowledge about the possible therapies and their limitations is essential.

OBJECTIVES

The aim of this article is a structured listing of targeted radiological therapies for the treatment of liver tumors and an overview of the specific technical aspects and possible limitations.

MATERIALS AND METHODS

This study involved a selective literature search as well as personal experiences in interventional radiological treatment of liver tumors.

CONCLUSION

The wide range of available therapies requires an individual assessment of each patient taking the achievable results into account. The decision for an interventional radiological therapy should be made in an interdisciplinary tumor board.

Transarterial radioembolization using yttrium-90 microspheres in the treatment of hepatocellular carcinoma: a review on clinical utility and developments

A selective intra-arterial liver injection using yttrium-90-loaded microspheres as sources for internal radiation therapy is a form of transarterial radioembolization (TARE). Current data from the literature suggest that TARE is effective in hepatocellular carcinoma (HCC) and is associated with a low rate of adverse events; however, they are all based on retrospective series or non-controlled prospective studies, since randomized controlled trials comparing the other liver-directed therapies for intermediate and locally advanced stages HCC are still ongoing. The available data show that TARE provides similar or even better survival rates. TARE is very well tolerated and has a low rate of complications; these complications do not result from the embolic effects but mainly from the unintended irradiation to non-target tissue, including the liver parenchyma. The complications can be further reduced by accurate patient selection and a strict pre-treatment evaluation, including dosimetry and assessment of the vascular anatomy. First-line TARE is best indicated for intermediate-stage patients (according to the Barcelona Clinic Liver Cancer [BCLC] staging classification) who are poor candidates for transarterial chemoembolization or patients having locally advanced disease with segmental or lobar branch portal vein thrombosis. Moreover, data are emerging regarding the use of TARE in patients classified slightly above the criteria for liver transplantation with the purpose of downstaging them. TARE can also be applied as a second-line treatment in patients progressing to transarterial chemoembolization or sorafenib; a large number of Phase II/III trials are in progress in order to evaluate the best association with systemic therapies. Given the complexity of a correct treatment algorithm for potential TARE candidates and the need for clinical guidance, a comprehensive review was carried out analyzing both the best selection criteria of patients who really benefit from TARE and the new advances of this therapy which add significant value to the therapeutic weaponry against HCC.

Preparation and therapeutic evaluation of (188)Re-thermogelling emulsion in rat model of hepatocellular carcinoma

Radiolabeled Lipiodol^® (Guerbet, Villepinte, France) is routinely used in hepatoma therapy. The temperature-sensitive hydrogel polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol triblock copolymer is used as an embolic agent and sustained drug release system. This study attempted to combine the polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol hydrogel and radio-labeled Lipiodol to form a new radio-thermogelling emulsion, rhenium-188–N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride–Lipiodol/hydrogel (¹⁸⁸Re-ELH). The therapeutic potential of ¹⁸⁸Re-ELH was evaluated in a rodent hepatoma model. Rhenium-188 chelated with N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride was extracted with Lipiodol to obtain rhenium-188–N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride–Lipiodol (¹⁸⁸Re-EL), which was blended with the hydrogel in equal volumes to develop ¹⁸⁸Re-ELH. The ¹⁸⁸Re-ELH phase stability was evaluated at different temperatures. Biodistribution patterns and micro-single-photon emission computed tomography/computed tomography images in Sprague Dawley rats implanted with the rat hepatoma cell line N1-S1 were observed after in situ tumoral injection of ~3.7 MBq ¹⁸⁸Re-ELH. The therapeutic potential of ¹⁸⁸Re-EL (48.58±3.86 MBq/0.1 mL, n=12) was evaluated in a 2-month survival study using the same animal model. The therapeutic effects of ¹⁸⁸Re-ELH (25.52±4.64 MBq/0.1 mL, n=12) were evaluated and compared with those of ¹⁸⁸Re-EL. The responses were assessed by changes in tumor size and survival rates. The ¹⁸⁸Re-ELH emulsion was stable in the gel form at 25°C–35°C for >52 hours. Biodistribution data and micro-single-photon emission computed tomography/computed tomography images of the ¹⁸⁸Re-ELH group indicated that most activity was selectively observed in hepatomas. Long-term ¹⁸⁸Re-ELH studies have demonstrated protracted reductions in tumor volumes and positive effects on the survival rates (75%) of N1-S1 hepatoma-bearing rats. Conversely, the 2-month survival rate was 13% in the control sham group. Therapeutic responses differed significantly between the two groups (P<0.005). Thus, the hydrogel enhanced the injection stability of ¹⁸⁸Re-EL in an animal hepatoma model. Given the synergistic results, direct ¹⁸⁸Re-ELH intratumoral injection is a potential therapeutic alternative for hepatoma treatment.

Survival analysis of transarterial radioembolization with yttrium-90 for hepatocellular carcinoma patients with HBV infection

INTRODUCTION

For patients with resectable hepatocellular carcinoma (HCC), hepatectomy remains one of the best treatment options to provide long-term survival. However, more than 50% of the patients have unresectable disease upon diagnosis even though there are no distant metastases. Transarterial chemoembolization (TACE) is a well-established treatment option that offers a palliative survival benefit for this group of patients. A better treatment for unresectable HCC has been sought after. There is some evidence that transarterial radioembolization (TARE) with the agent yttrium-90 produces encouraging outcomes, especially in patients with portal vein tumor thrombus. This study aims to analyze the outcomes of TARE at our center.

METHODS

From August 2009 to April 2013, 16 patients underwent TARE at our center. Sixteen patients with similar tumor characteristics were selected to undergo TACE alone for comparison. A retrospective analysis of the prospectively collected data of the patients was conducted. Only patients with newly diagnosed primary tumors were included in this study.

RESULTS

The median survival for patients having TARE was 19.9 versus 14.0 months in the TACE group (P=0.615). There was no difference in terms of tumor response according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST) (P=0.632). The 1-, 2- and 3-year survival rates in the TARE group were 80.0%, 30.5% and 20.3% respectively. The 1-year survival in the TACE group was 58.3% (P=0.615). For patients who had major vascular invasion (eight in each group), the 1- and 2-year survival rates in the TARE group were 62.5% and 15.6% respectively, while the 1-year survival in the TACE group was 35.0% (P=0.664).

CONCLUSIONS

The two groups showed similar results in terms of tumor response and overall survival benefit. TARE might provide a survival benefit for patients with major vessel invasion.

Regional hepatic therapies: an important component in the management of colorectal cancer liver metastases

The treatment of colorectal cancer liver metastases (CRLM) has evolved significantly in the last 15 years. Currently, complete surgical resection remains the only potentially curative option; unfortunately, approximately 80% of patients with CRLM are not candidates for complete tumor resection. For patients with unresectable CRLM the available treatment options were historically limited; however, the development of regional hepatic therapies (RHT) and improvement of systemic chemotherapeutic regimens have emerged as viable options to improve overall survival and quality of life for this group of patients. The selection, sequence and integration of interventions into a multi-modal approach is a complex and evolving discipline. In this article, the currently available RHT modalities for CRLM are presented as a guide to the options for clinical treatment decisions.

Usefulness of conventional MRI sequences and diffusion-weighted imaging in differentiating malignant from benign portal vein thrombus in cirrhotic patients

OBJECTIVE

The objective of our study was to determine the value of diffusion-weighted imaging (DWI) and conventional MRI (non-DWI sequences) in differentiating benign portal vein thrombus (PVT) from malignant PVT in cirrhotic patients.

MATERIALS AND METHODS

A retrospective search of the department of radiology's MRI database of examinations performed from October 2006 through December 2010 for "portal vein thrombosis" and "cirrhosis" and "hepatocellular cancer" was performed. Patients who underwent diagnostic DWI and had thrombus shown to be rapidly (< 3 months) increasing in size despite anticoagulation therapy were considered to have malignant PVT (n = 16 cases) and patients with MRI findings showing stability or reduction in the extent of thrombus over a 12-month follow-up were considered to have benign PVT (n = 20 cases). Two blinded and independent reviewers analyzed the DW images and conventional MR images.

RESULTS

There was no difference in the distribution of patients by age (p = 0.25) or sex (p = 0.68) between the benign and malignant PVT groups. On multivariate analysis, the only parameter to predict the type of PVT was the size of HCC (p = 0.05); other parameters were excluded from the model. There was substantial overlap in apparent diffusion coefficient (ADC) values and PVT/liver ADC ratios of benign PVT and malignant PVT. The presence of at least two of the three following MRI findings had a sensitivity of 100% and specificity of 90% for the diagnosis of malignant PVT: distance from tumor to PVT of less than 2 cm, HCC size of greater than 5 cm, and arterial enhancement of PVT.

CONCLUSION

Signal-intensity characteristics on DWI and measured ADC values do not reliably differentiate benign PVT from malignant PVT. On the other hand, careful assessment of conventional MRI findings may allow this distinction, thus obviating biopsy.

Transarterial chemoembolisation (TACE) combined with endovascular implantation of an iodine-125 seed strand for the treatment of hepatocellular carcinoma with portal vein tumour thrombosis versus TACE alone: a two-arm, randomised clinical trial

PURPOSE

There was no standard treatment for hepatocellular carcinoma with portal vein tumour thrombosis (PVTT). This prospective, randomised, two-arm clinical trial aims to investigate the feasibility, safety and effectiveness of transarterial chemoembolisation (TACE) combined with the endovascular implantation of an iodine-125 seed strand for the treatment of hepatocellular carcinoma with portal vein tumour thrombosis versus conventional TACE.

PATIENTS AND METHODS

Eighty-five patients who met the eligibility requirements were randomly assigned to receive the treatment of TACE combined with the endovascular implantation of an iodine-125 seed strand (43 cases) or conventional TACE (42 cases). The end points were survival time, complications related to the procedure and adverse events.

RESULTS

No significant differences in baseline characteristics were observed between groups. The mean and median survival times were 221.7 ± 16.3 days [95 % confidence interval (CI) 189.8-253.6 days] and 210.0 ± 17.5 days (95 % CI 175.8-244.2 days) in group A and 155.1 ± 7.9 days (95 % CI 139.6-170.5 days) and 154.0 ± 11.2 days (95 % CI 133.2-176.0 days) in group B (P = 0.000). The 90-, 180- and 360-day cumulative survival rates were 97.6, 58.9 and 12.3 % in group A and 92.5, 30.7 and 0 % in group B (P = 0.000).

CONCLUSION

Transarterial chemoembolisation combined with the endovascular implantation of an iodine-125 seed strand is feasible, safe and effective in the treatment for hepatocellular carcinoma with PVTT.

Diffusion-weighted MRI of hepatocellular carcinoma in cirrhosis

The internationally accepted diagnostic criteria for hepatocellular carcinoma (HCC) in cirrhosis are highly accurate for large tumours, but offer relatively low sensitivity for small (<2 cm) tumours. Diffusion-weighted imaging (DWI) is a functional magnetic resonance imaging (MRI) technique that has been studied extensively as an aid to visualize various abdominal malignancies, including HCC in cirrhosis. DWI maps water diffusivity, which in HCC may be restricted as a result of changes ensuing from hepatocarcinogenesis. The present review is based on up-to-date evidence and describes the strengths and weaknesses of DWI, both as a standalone technique and as an adjunct sequence to conventional protocols, in the diagnosis, staging, prognostication, and assessment of treatment response of HCC in cirrhosis.

ACR Appropriateness Criteria radiologic management of hepatic malignancy

Management of hepatic malignancy is a challenging clinical problem involving several different medical and surgical disciplines. Because of the wide variety of potential therapies, treatment protocols for various malignancies continue to evolve. Consequently, development of appropriate therapeutic algorithms necessitates consideration of medical options, such as systemic chemotherapy; surgical options, such as resection or transplantation; and locoregional therapies, such as thermal ablation and transarterial embolization. The authors discuss treatment strategies for the 3 most common subtypes of hepatic malignancy treated with locoregional therapies: hepatocellular carcinoma, neuroendocrine metastases, and colorectal metastases. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Lobar hepatocellular carcinoma with ipsilateral portal vein tumor thrombosis treated with yttrium-90 glass microsphere radioembolization: preliminary results

Portal vein tumor thrombosis (PVTT) is a common complication of hepatocellular carcinoma (HCC) and has a negative impact on prognosis. This characteristic feature led to the rationale of the present trial designed to assess the efficacy and the safety of yttrium-90 glass-microsphere treatment for advanced-stage lobar HCC with ipsilateral PVTT. 18 patients with unresectable lobar HCC and ipsilateral PVTT were treated in our institution with (90)Y-microS radioembolization. Patients were evaluated every 3 to 6 months for response, survival, and toxicity. Mean follow-up was 13.0 months (2.2-50.6). Outcomes were: complete response (n = 2), partial response (n = 13), stable disease (n = 1), and progressive disease (n = 2) giving a disease control rate of 88.9%. Four patients were downstaged. Treating lobar hepatocellular carcinoma with ipsilateral portal vein thrombosis with yttrium-90 glass-microsphere radioembolization is safe and efficacious. Further clinical trials are warranted to confirm these results and to compare (90)Y-microS with sorafenib, taking into account not only survival but also the possibility of secondary surgery for putative curative intention after downstaging.

Radioembolization and chemoembolization for unresectable neuroendocrine liver metastases - a systematic review

This review examines the clinical efficacy and safety of the use of hepatic arterial chemoembolization, bland embolization and radioembolization in the treatment of unresectable neuroendocrine tumor liver metastases (NETLM). Response to treatment, survival outcome and toxicity were examined in this review of 37 studies comprising 1575 patients. These therapies are safe and effective in the treatment of NETLM. Prospective clinical trials to compare the relative efficacy and toxicity are warranted.

Update on yttrium-90-based radio-embolization for treatment of hepatocellular carcinoma

BACKGROUND

  Catheter-based intra-arterial therapies provided effective tumour control for unresectable hepatocellular carcinoma without distant metastasis. There was a renewed interest in the advancement of yttrium-90 radio-embolization.

METHOD

  An extensive search on the MEDLINE databases identified seven case series and two comparative studies regarding yttrium-90 radio-embolization.

RESULTS

  Case series on yttrium-90 radio-embolization indicated a tumour response rate that ranged from 20% to 70%, and median survival that ranged from 7.7 to 26.6 months. Two comparative studies did not demonstrate significant difference in terms of tumour response rate and survival. One of these comparative studies demonstrated a statistically significant reduction in treatment-related neutropaenia.

CONCLUSION

  The current use of yttrium-90 radio-embolization was mainly based on small case series. Yttrium-90 radio-embolization seemed equivalent to conventional chemo-embolization in terms of tumour response rate and survival benefit. Emerging evidence suggested that yttrium-90 radio-embolization may have a more favourable side effects profile, in particular in reducing the chance of neutropaenia. Cost and logistics arrangement were two important considerations in generalizing the application of yttrium-90 radio-embolization.

Interventional therapies for hepatocellular carcinoma

Hepatocellular carcinoma is the third most common cause of cancer-related death. In the past few years, staging systems have been developed that enable patients to be stratified into treatment algorithms in a multidisciplinary setting. Several of these treatments involve minimally invasive image-guided therapy that can be performed by radiologists.

The optimal selection of radiotherapy treatment for hepatocellular carcinoma

The majority of patients who present with hepatocellular carcinoma (HCC) are already at an advanced stage, and the tumors are unresectable. Radiotherapy (RT) technology can safely provide focused high-dose irradiation to these patients. A wide spectrum of RT technologiesis currently available, including internal RT consisting of Yttrium-90 ((90)Y), Iodine-131 ((131)I) anti-ferritin antibody and Homium-199 ((199)Ho) and external RT, such as three-dimensional conformal RT, intensity-modulated RT, helical tomotherapy, stereotactic body RT, and image-guided RT. However, it may be difficult for physicians to understand all of the available options and to select the optimal RT treatment. Physicians frequently query radiation oncologists on the practical indications of RT for managing patients with HCC. According to the Korean Liver Cancer Study Group practice guidelines, RT is considered appropriate for unresectable, locally advanced HCC without extrahepatic metastasis, a Child-Pugh class A or B, and tumors that occupy less than two-thirds of the liver with level II evidence. In this review, we discuss the application of various RT modalities based on disease status and the detailed indications for RT according to the Barcelona Clinic Liver Cancer staging system.

Interventional radiological treatment of hepatocellular carcinoma: an update

Hepatocellular carcinoma is the commonest primary liver tumor and its incidence is on an increase.Transplantation and surgical resection are the gold standard curative treatment options but less than 20%patients are surgical candidates because of advanced liver disease and/or co-morbidities.Various interventional radiological procedures have been developed and intensively investigated for treatment of inoperable HCC.This review summarizes the various interventional radiological treatments in HCC including patient selection, procedural considerations and response evaluation. Transarterial chemoembolization, radioembolization and radiofrequency ablation are mainly discussed.

Radiotherapeutic strategies in the management of hepatocellular carcinoma

Although potentially curative therapies for hepatocellular carcinoma (HCC) are well established, they are offered only to a limited number of patients. For advanced HCC, sorafenib is now the treatment of choice. Radiotherapy technology has evolved remarkably during the past decade and can be precisely delivered, thereby permitting higher doses to the tumor and reduced doses to surrounding normal tissues. According to the Korean Liver Cancer Study Group (KLCSG) practice guidelines, radiation therapy is considered appropriate for unresectable, locally advanced HCC without extrahepatic metastasis, Child-Pugh class A or B, and tumors occupying less than two thirds of the liver with level II evidence. In this review, we discuss the radiotherapeutic strategies for each clinical setting in patients with HCC.

Radioembolization for hepatocellular carcinoma: a review of the evidence and treatment recommendations

Treatment decisions for hepatocellular carcinoma involve the evaluation of multiple factors including tumor size, location, and morphology; comorbidity and/or extrahepatic disease; health status; patient preferences; and the treating physician's expertise and skill. For patients who are not candidates for transplant or resection, and for whom other therapies (radiofrequency ablation, systemic chemotherapies, transarterial embolization or chemoembolization), may have limited efficacy, an urgent need for bridging procedures, to enable surgery or ablation, or meet transplantation criteria, has led to investigations with radioembolization. A number of recent reports have supported the effectiveness of Yttrium-90 ((90)Y) labeled microspheres to treat intermediate and advanced disease in patients with good overall functional status and liver reserve; patients with portal vein involvement and in a limited role to treat unresectable early-stage disease. This review addresses response rates and survival benefit following radioembolization in different patient populations, in centers throughout Europe, North America, and Asia, and across the spectrum of patients presenting with various prognostic factors. By using stringent selection criteria and conservative models for calculating radiation dosage, radioembolization can be performed safely even in cirrhotic patients, without postembolization syndrome or radiation-induced liver disease, and even with multiple treatments to whole or part of the liver.

General selection criteria of patients for radioembolization of liver tumors: an international working group report

A combined treatment approach that incorporates surgical resection, ablation, chemotherapy, targeted agents, and radiotherapy has augmented the management of liver tumors (both primary and metastatic). The challenge that remains is how to reduce the burden of liver disease and thus enable greater patient eligibility for resection as well as lengthened survival for those who remain unsuitable for surgery. Radioembolization can deliver high doses of radiation preferentially to liver tumors and is a valuable treatment option that should be considered as part of a multimodal treatment approach for the management of patients in whom the liver is the sole or dominant site of disease. Essential in this consideration is a careful assessment by a multidisciplinary team of the individuals most likely to benefit from this treatment modality. Along with the clinical benefits, integration of radioembolization into the treatment paradigm can provide added options of using systemic chemotherapy synergistically as a radiosensitizer and to control extrahepatic metastases, permitting a reduction in hepatic disease and conserving remaining liver function. If successful, the possibility of improved patient survival and quality of life is increased.

Hepatic angiosarcoma presenting as an acute intraabdominal hemorrhage treated with transarterial chemoembolization

Primary malignant neoplasms of the liver are some of the most uncommon malignancies in many parts of the world. They include hepatocellular carcinoma and stromal tumors such as hepatic angiosarcoma. It is a lethal tumor with life expectancy of less than six months. Once discovered, it is often too late for surgical intervention. Like other vascular tumors of the liver and spleen, intraperitoneal hemorrhage is a well-documented finding of angiosarcoma which can be lethal if not diagnosed and treated immediately. As in our case, intraperitoneal hemorrhage from primary tumor rupture was the only clinical presentation of this neoplasm. Approximately 15% of patients present with acute hemoperitoneum from either tumor rupture or peritoneal metastasis. Although several therapeutic options are available, we describe apalliative therapy for hepatic angiosarcoma utilizing transcatheter arterial chemoembolization (TACE) techniques incorporating the newer embolization agent Embospheres to locally target and treat this aggressive tumor.

Yttrium-90 radioembolization of hepatocellular carcinoma and metastatic disease to the liver

Yttrium-90 ((90)Y) radioembolization is a catheter-based therapy that delivers internal radiation to hepatic tumors in the form of microspheres. (90)Y can be delivered to the hepatic tumor as either a constituent of a glass microsphere, TheraSphere(®), or as a biocompatible resin-based microsphere, SIR-Spheres(®). Once embedded within the tumor microcirculation, these microspheres emit β-radiation at therapeutic levels. While the technical aspects of radioembolization are quite complex, the collective clinical experience presented in the literature supports the use of (90)Y radioembolization for unresectable hepatic malignancies.

Iodine-131-lipiodol therapy in hepatic tumours

The incidence of hepatocellular carcinoma (HCC) is worldwide sharply on the rise and patients with advanced disease carry a poor prognosis. HCC is the sixth most common cancer and the third leading cause of cancer associated deaths in the world. Intra-arterially administered (131)I-Lipiodol is selectively retained by hepatocellular carcinomas, and has been used as a vehicle for delivery of therapeutic agents to these tumours. In this review we focus on the therapeutic indications, usefulness and methods of treatment with 131-Iodine Lipiodol. The effectiveness of (131)I-Lipiodol treatment is proven both in the treatment of HCC with portal thrombosis and also as an adjuvant to surgery after the resection of HCCs. It is at least as effective as chemoembolization and is tolerated much better. Severe liver dysfunction represents theoretic contraindication for radioembolization as well as for TACE. In such cases (131)I-Lipiodol is an alternative therapy option especially in tumours smaller than 6cm.

Locoregional therapy for hepatocellular carcinoma

Locoregional therapies for hepatocellular carcinoma have progressed greatly in the last 30 years, beginning with the introduction of chemoembolization. Embolization techniques have evolved with the use of drug-eluting beads and radioembolization with yttrium-90. In the last 10 years, several new ablation techniques were developed including radiofrequency ablation, microwave ablation, cryoablation, laser ablation, and irreversible electroporation. Isolated or in combination, these techniques have already shown that they can improve patient survival and/or provide acceptable palliation.

MR imaging of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignancy typically associated with chronic liver disease and is a leading cause of mortality among these patients. Prognosis is improved when detected early. MRI is the best imaging examination for accurate diagnosis. Although arterial enhancement with delayed washout, increased T2-weighted signal intensity, delayed capsular enhancement, restricted diffusion, and tumor thrombus are typical features, not all lesions demonstrate these findings. The radiologist must be familiar with these typical imaging characteristics, and less common appearances and associated findings of HCC, and must be able to differentiate them from those of lesions that mimic HCC. Knowledge of therapeutic options and how those are related to imaging findings is imperative to assist clinicians in managing these patients.

Current role of selective internal irradiation with yttrium-90 microspheres in the management of hepatocellular carcinoma: a systematic review

PURPOSE

This article reviews the role of selective internal irradiation (SIR) with yttrium-90 ((90)Y) microspheres for hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Studies were identified by searching Medline and PubMed databases for articles from 1990 to 2009 using the keywords "selective internal irradiation," "hepatocellular carcinoma," "therapeutic embolization," and "yttrium-90."

RESULTS

(90)Y microspheres are a safe and well-tolerated therapy for unresectable HCC (median survival range, 7 -21.6 months). The evidence was limited to cohort studies and comparative studies with historical control. (90)Y microspheres have been reported to downstage unresectable HCC to allow for salvage treatments with curative intent, act as a bridging therapy before liver transplantation, and treat HCC with curative intent for patients who are not surgical candidates because of comorbidities.

CONCLUSIONS

(90)Y microsphere is recommended as an option of palliative therapy for large or multifocal HCC without major portal vein invasion or extrahepatic spread. It can also be used for recurrent unresectable HCC, as a bridging therapy before liver transplantation, as a tumor downstaging treatment, and as a curative treatment for patients with associated comorbidities who are not candidates for surgery.

[Nonsurgical management of hepatocellular carcinoma]

Most of patients with hepatocellular carcinoma (HCC) cannot benefit from surgical therapies. Among nonsurgical options, only radiofrequency can challenge surgery for small size tumours. Conformal radiotherapy is likely highly efficient on solitary tumours, but controlled studies are warranted to conclude. Other options are purely palliative. Transarterial hepatic chemoembolization is the goal-standard for multifocal hepatocellular carcinoma and sorafenib for hepatocellular carcinoma with portal vein invasion, leading to modest but significant benefit on survival rates. Yttrium-90 radioembolization is under evaluation through controlled studies, and could be of major interest for multifocal hepatocellular carcinoma with or without portal venous invasion.

Radiation safety issues in y-90 microsphere selective hepatic radioembolization therapy: possible radiation exposure from the patients

PURPOSE

The purpose of this study was to estimate the possible external radiation dose to other individuals from patients treated with Y-90 resin microspheres for unresectable hepatocellular carcinoma.

METHODS

We designed the study prospectively to estimate the possible radiation dose to other individuals from patients who had been treated with Y-90 microspheres for unresectable hepatocellular carcinoma. We estimated the total effective dose equivalent (TEDE) using two methods: 'theoretical' TEDEs according to the administered activity and 'measured' TEDE based on the 'measured' ambient radiation exposure rate. We compared the results from each method to determine when we can release patients from confinement at the earliest time complying with the patient release criteria.

RESULTS

A total of 20 administrations of Y-90 resin microspheres were done in 18 patients. The average administered activity was 1.2 ± 0.77 (0.28-2.97) GBq. The 'theoretical' TEDEs were in the range of 0.8-10 μSv. The 'measured' TEDEs were in the range of 2.31-185 μSv. The measured TEDEs tend to be higher than the theoretical TEDEs. The values of theoretical and measured TEDE were both far less than 1 mSv, the upper limit at which the licensee can release a patient without any written documents.

CONCLUSION

The effective dose equivalent caused by the Y-90 microsphere administered patient is very low. It is safe in terms of radiation safety to the other individuals when Y-90 microsphere radioembolization therapy is done with dose less than 3 GBq. Because the measured TEDE tends to be higher than the theoretical TEDE, it is recommended to use 'measured' TEDE for determining patient release.

Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography predicts extrahepatic metastatic potential of colorectal metastasis: a practical guide for yttrium-90 microsphere liver-directed therapy

The objective of this retrospective study was to assess the likelihood of extrahepatic metastases based on tumor metabolic load index (TMLI) for patients with colorectal liver metastases to determine the potential intermediate endpoint of yttrium-90 (Y-90) microsphere liver-directed therapy. Forty-eight (48) patients with colorectal metastatic cancer of the liver who were referred for Y-90 microsphere therapy and F-18 fluoro-2-deoxy-D-glucose positron emission tomography (PET) imaging were included. All patients had baseline computed tomography, hepatic angiography, and planning intra-arterial technetium-99m macro-aggregated albumin scans. Pretreatment PET images were analyzed by visual inspection of extrahepatic metastases and by computer quantification of total liver tumor metabolism. For each patient, regions of interest were drawn along the liver edge to measure total liver standard uptake value on axial images, covering the entire span of the liver. The total liver standard uptake value was then converted by logarithm in equivalent volumes of liver mass to obtain TMLI for comparison. A Levene test for equality of variances and t-tests were used for comparing pretreatment TMLIs of patients with or without extrahepatic metastasis. Discriminant and receiver operating characteristic (ROC) analyses were used to obtain a cutoff value with highest specificity in predicting negative extrahepatic metastasis. There were 21 and 27 patients identified as negative and positive for extrahepatic metastasis, respectively. The TMLI of the group with negative extrahepatic metastasis was significantly lower than that with positive extrahepatic metastasis (10.22 + 0.32 versus 10.74 + 0.57, p < 0.0005). The cutoff TMLI with 100% specificity was found to be 10.65. There was a significant difference in liver tumor load with respect to the presence or absence of an extrahepatic metastatic tumor as evaluated objectively with PET. This leads to the identification of TMLI threshold, below which extrahepatic metastases are unlikely and thus may provide guidance for Y-90 therapy.

Use of yttrium-90 microspheres in patients with advanced hepatocellular carcinoma and portal vein thrombosis

PURPOSE

Patients with portal vein thrombosis (PVT) and hepatocellular carcinoma (HCC) have limited treatment options because of increased disease burden and diminished hepatic perfusion. Yttrium-90 ((90)Y) microspheres may be better tolerated than chemoembolization in these patients. The present study reviews the safety and efficacy of (90)Y microspheres in HCC with major PVT.

MATERIALS AND METHODS

A retrospective review of HCC with main (n = 10) or first-branch (n = 12) PVT treated with (90)Y microspheres (N = 22) was conducted. Cancer of the Liver Italian Program (CLIP) scores ranged from 2 to 5, with 18% of patients having a score of 4 or greater. Imaging response at 8-12 was based on Response Evaluation Criteria In Solid Tumors. Overall survival (OS) was estimated by the Kaplan-Meier method.

RESULTS

A total of 32 microsphere treatments (26 glass, six resin) were administered to 22 patients. Common grade 1/2 toxicities included abdominal pain (38%), nausea (28%), and fatigue (22%). Four posttreatment hospitalizations occurred, all less than 48 hours in duration. One death occurred 10 days after therapy. The partial response rate was 8% and progressive disease was seen in 42% of patients. Stable disease was achieved in 50% of treatments. Median OS was 7 months from initial treatment. Patients with Child-Pugh class A disease had a median OS of 7.7 months; those with class B/C disease had an OS of 2.7 months (P = .01). Median OS for patients with CLIP scores of 2/3 was 7 months, versus 1.3 months for those with scores of 4/5 (P = .04).

CONCLUSIONS

Yttrium-90 microspheres are tolerated in patients with HCC and major PVT. Compared with chemoembolization, rates of severe adverse events appear low. Radiographic response rates are low. The median OS of 7 months is promising and warrants further study versus systemic therapy.

Radioembolization (yttrium-90 microspheres) for primary and metastatic hepatic malignancies

Radioembolization using radioactive yttrium-90-labeled microspheres is gaining a stronger foothold in the management of primary and metastatic hepatic cancers. The expanding literature reveals good and encouraging results in both retrospective and prospective reports as demonstrated by low acute or late toxicity and high response rates. This treatment modality, which is most beneficial in patients with good liver reserve and low Eastern Cooperative Oncology Group performance status, has led to improved time to liver progression and extended overall patient survival. Although the phase III trials of radioembolization are ongoing as a first-line treatment of patients with metastatic colorectal cancer, there are sufficient phase II and retrospective clinical data supporting its use in salvage therapy for most patients. Patients with hepatocellular cancer, neuroendocrine tumors, and other primary sites, including breast and lung, have also shown promising response and survival increases in multi-institutional experiences.

Interventional radiological treatment of hepatocellular carcinoma

BACKGROUND

Locoregional treatments of hepatocellular carcinoma (HCC) have evolved over the past 20 years. Interventional radiologists have developed an important role in the palliative and curative treatment of the disease. This review summarizes commonly used interventional radiological treatment protocols to assist practitioners in understanding the techniques used to treat HCC.

METHODS

Various searches were performed to evaluate recent publications regarding systemic treatments of HCC as well as transplant/surgery, chemoembolization, yttrium-90 radioembolization, percutaneous radiofrequency ablation (RFA), cryoablation, and percutaneous ethanol injection (PEI).

RESULTS

No standard for chemoembolization was found. Two studies evaluating survival with chemoembolization vs medical therapy found benefits with the former. PEI offers favorable outcomes in small HCC but has increased recurrence and decreased long-term survival compared with RFA. Local recurrence, response rates, and mortality from RFA rival surgical resection in HCC less than 3 cm. Cryoablation appears to be effective, and yttrium-90 radioembolization is an additional tool.

CONCLUSIONS

Chemoembolization improves survival and offers improved tumor response compared to systemic treatment. More studies are needed to standardize chemoembolization preparations and techniques. RFA provides better results than PEI but has not been compared with cryoablation. Radioembolization appears to be as effective as chemoembolization, but the preprocedure evaluation and costs may limit its use.

Radioembolization of liver tumors with yttrium-90 microspheres

Radioembolization (RE), also termed selective internal radiation therapy (SIRT), has been gradually introduced to the clinical arsenal of cytoreductive modalities in recent years. There is growing evidence for efficiency in liver tumors of various entities, with the most prominent ones being hepatocellular carcinoma, colorectal cancer, and neuroendocrine tumors. Hepatic metastases of numerous other tumor entities including breast cancer, cholangiocarcinoma, and pancreatic cancer are treatment-sensitive, even when being refractory to other treatment modalities such as bland-embolization, regional, or systemic chemotherapy. The antitumor effect of SIRT is related to radiation rather than embolization, with extraordinary high local radiation doses obtained selectively at the site of viable tumor and little affection of the surrounding normal liver tissue. Morphologic changes after RE may pose difficulties for interpretation in conventional restaging with regard to tumor viability and true response to treatment. Therefore, functional imaging, that is, metabolic imaging with (18)F fluorodeoxyglucose positron emission tomography (computed tomography) in the majority of treated tumors, is regarded the gold standard in this respect and should be included for pre- and post-SIRT assessment. To prevent serious toxicity to be associated with the potent antitumor efficacy, meticulous pretreatment evaluation is of particular importance. Improvements in predicting dosimetry will help optimize treatment and patient selection. Nuclear medicine procedures are essential for planning, performing, and monitoring of RE. However, the interdisciplinary aspect of patient management has to be emphasized for this particular treatment form. As SIRT is moving forward from the salvage setting indication to the use in earlier stages of hepatic tumor disease and with the advent of new treatment protocols and targeted therapies, embedding SIRT into a multidisciplinary approach will become even more important. This article focuses on procedural and technical aspects for selection, preparation, and performance of treatment as well as post-therapeutic monitoring and response assessment.

Preparation of porous yttrium oxide microparticles by gelation of ammonium alginate in aqueous solution containing yttrium ions

Porous Y2O3 microparticles 500 microm in size were obtained, when 1 wt%-ammonium alginate aqueous solution was dropped into 0.5 M-YCl3 aqueous solution by a Pasteur pipette and the resultant gel microparticles were heat-treated at 1100 degrees C. Small pores less than 1 microm were formed in the microparticles by the heat treatment. The bulk density of the heat-treated microparticle was as low as 0.66 g cm(-3). The chemical durability of the heat-treated microparticles in simulated body fluid at pH = 6 and 7 was high enough for clinical application of in situ radiotherapy. Although the size of the microparticles should be decreased to around 25 microm using atomizing device such as spray gun for clinical application, we found that the porous Y2O3 microparticles with high chemical durability and low density can be obtained by utilizing gelation of ammonium alginate in YCl3 aqueous solution in this study.

Review article: the management of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the leading cause of death in cirrhosis. A majority of patients present at an advanced stage with poor prognosis.

AIM

To review the current screening, diagnosis and management strategies involved in hepatocellular carcinoma.

METHODS

A literature search was performed using PubMed for publications with a predetermined search string to identify relevant studies.

RESULTS

Hepatocellular carcinoma is dramatically increasing in incidence that is mostly attributed to chronic hepatitis C and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis and its clinical phenotype diabetes and obesity. Cirrhosis is the major predisposing risk factor and its presence necessitates close surveillance for hepatocellular carcinoma with serial imaging studies. Hepatocellular carcinoma can be diagnosed by its unique radiological behaviour of arterial enhancement and washout on delayed images. The Barcelona Clinic Liver Cancer staging classification system is a clinically useful algorithm for the management of patients with hepatocellular carcinoma. The simultaneous presence of cirrhosis in the patients complicates their management and monitoring for cirrhosis-related complications is important.

CONCLUSIONS

Early diagnosis and definitive treatment remains the key to long-term outcome. A multidisciplinary approach is critical to the successful management of hepatocellular carcinoma. Studies combining sorafenib with locoregional or other targeted molecular therapies are likely to improve responses and outcome.

Evaluating the potential of (188)Re-ECD/lipiodol as a therapeutic radiopharmaceutical by intratumoral injection for hepatoma treatment

BACKGROUND/OBJECTIVES

Intratumoral injection of a radiopharmaceutical is a potential modality to treat liver tumors. Rhenium-188 ((188)Re) was used to chelate with ethyl cysteinate dimer (ECD) in lipiodol solution to form (188)Re-ECD/lipiodol, which was then evaluated for its therapeutic potential in a rodent hepatoma model.

MATERIALS AND METHODS

Male Sprague-Dawley rats were implanted with N1-S1 hepatoma cells orthotopically and randomly divided into two groups. Group 1 (n = 29) and group 2 (n = 10) received (188)Re-ECD/lipiodol (30.4 +/- 21.8 MBq/0.1 mL) and 0.1 mL of normal saline by intratumoral injection, respectively. Three rats in group 1 were imaged by micro-single-photon emission computed tomography/computed tomography scan to evaluate the biodistribution pattern. All rats were monitored for change of tumor size and survival rate after 2 months.

RESULTS

The in vitro stability test showed that (188)Re-ECD was well-retained in the lipiodol phase for 48 hours. The biodistribution image revealed that radioactivity was retained well in hepatomas 24 hours postinjection. Long-term studies demonstrated that rats treated with (188)Re-ECD/Lipiodol had smaller tumor volumes and a better survival rate, compared to the control group. At the end of observation, the survival rates in groups 1 and 2 were 62% and 20%, respectively (p < 0.05).

CONCLUSIONS

(188)Re-ECD/lipiodol via direct intratumoral injection shows potential for treating hepatoma and warrants further clinical trials.