Radioembolisation of hepatocellular carcinoma: a primer

A Recanalized Umbilical Vein Hypermetabolic Thrombosis Mimicked an Hepatocellular Carcinoma Recurrence: A New Pitfall?

ABSTRACT

A transarterial left hepatic artery radioembolization involving 90Y microspheres was performed on a cirrhotic man with hypermetabolic 18F-FDG segment III hepatocellular carcinoma. During the 18F-FDG PET/CT follow-up, the disappearance of the hypermetabolic lesion was initially observed. Then, a focal segment III hypermetabolism reappeared mimicking a recurrence before disappearing without any treatment. Finally, the hepatic MRI demonstrated that the transitory segment III hypermetabolism matched a thrombus of the dilated recanalized umbilical vein.

Contrast-enhanced ultrasound (CEUS) in HCC diagnosis and assessment of tumor response to locoregional therapies

Hepatocellular carcinoma (HCC) is a global problem constituting the second leading cause of cancer deaths worldwide, thereby necessitating an accurate and cost-effective solution for managing care. Ultrasound is well poised to address this need due to its low cost, portability, safety, and excellent temporal resolution. The role of ultrasound for HCC screening has been well established and supported by multiple international guidelines. Similarly, contrast-enhanced ultrasound (CEUS) can be used for the characterization of focal liver lesions in high-risk populations, and standardized criteria for CEUS have been established by the American College of Radiology Liver Imaging Reporting & Data System (LI-RADS). Following HCC identification, CEUS can also be highly beneficial in treatment planning, delivery, and monitoring HCC response to locoregional therapies. Specific advantages of CEUS include providing real-time treatment guidance and improved diagnostic performance for the detection of residual tumor viability or recurrence, thereby identifying patients in need of retreatment substantially earlier than contrast-enhanced CT and MRI. This review provides a primer on ultrasound and CEUS for the screening and characterization of HCC, with an emphasis on assessing tumor response to locoregional therapies.

18F-choline PET-computed tomography for the prediction of early treatment responses to transarterial radioembolization in patients with hepatocellular carcinoma

BACKGROUND

Transarterial radioembolization (TARE) is widely used for the treatment of hepatocellular carcinoma (HCC), but early treatment response can be very difficult to assess. The aim was to evaluate 18F-fluorocholine PET/computed tomography (CT) to assess the treatment response in patients with intermediate or locally advanced HCC.

METHODS

Between March 2019 and July 2020, nine HCC patients treated with TARE, who underwent PET/CT at baseline and 1 month after treatment, were enrolled. The maximum, mean (SUVmean), and peak (SUVpeak) standardized uptake value (SUV), SUV normalized by lean body mass (SUL), and total lesion glycolysis (TLG) were measured. Statistical analysis used the Mann-Whitney test to evaluate the differences in parameters between responders (partial and complete response) and nonresponders (stable or progressive disease) at the 6-month follow-up, according to the modified Response Evaluation Criteria in Solid Tumors.

RESULTS

Three patients were nonresponders (progressive disease and stable disease) and six were responders. Delta SUVmean, delta SUL, and delta TLG could predict an early response (P = 0.02, P = 0.04, and P = 0.02, respectively). None of the pre-therapeutic parameters were correlated with the response. Post-therapeutic SUL, SUVmean, TLG, and SUVpeak were also predictive of the response.

CONCLUSIONS

Our preliminary results showed that changes in certain metabolic parameters (from baseline PET to 1-month PET) are predictive of the response to TARE in HCC (Delta SUVmean, delta TLG, and delta SUL). The absence of post-treatment inflammation could lead to a better prediction than MRI evaluation. This study suggests that 1-month 18F-choline PET/CT could modify the clinical management predicting responders.Video Abstract: http://links.lww.com/NMC/A193.

Comparison of perfused volume segmentation between cone-beam CT and 99mTc-MAA SPECT/CT for treatment dosimetry before selective internal radiation therapy using 90Y-glass microspheres

PURPOSE

To compare the reliability and accuracy of the pre-treatment dosimetry predictions using cone-beam computed tomography (CBCT) versus ^99mTc-labeled macroaggregated albumin (MAA) SPECT/CT for perfused volume segmentation in patients with hepatocellular carcinoma treated by selective internal radiation therapy (SIRT) using ⁹⁰Y-glass microspheres.

MATERIALS AND METHODS

Fifteen patients (8 men, 7 women) with a mean age of 68.3±10.5 (SD) years (range: 47-82 years) who underwent a total of 17 SIRT procedures using ⁹⁰Y-glass microspheres for unresectable hepatocellular carcinoma were retrospectively included. Pre-treatment dosimetry data were calculated from ^99mTc-MAA SPECT/CT using either CBCT or ^99mTc-MAA SPECT/CT to segment the perfused volumes. Post-treatment dosimetry data were calculated using ⁹⁰Y imaging (SPECT/CT or PET/CT). The whole liver, non-tumoral liver, and tumor volumes were segmented on CT or MRI data. The mean absorbed doses of the tumor (D_T), non-tumoral liver, perfused liver (D_PL) and perfused non-tumoral liver were calculated. Intra- and interobserver reliabilities were investigated by calculating Lin's concordant correlation coefficients (ρ_c values). The differences (biases) between pre- and post-treatment dosimetry data were assessed using the modified Bland-Altman method (for non-normally distributed variables), and systematic bias was evaluated using Passing-Bablok regression.

RESULTS

The intra- and interobserver reliabilities were good-to-excellent (ρ_c: 0.80-0.99) for all measures using both methods. Compared with 90Y imaging, the median differences were 5.8Gy (IQR: -12.7; 16.1) and 5.6Gy (IQR: -13.6; 10.2) for D_PL-CBCT and D_PL-^99mTc-MAA SPECT/CT, respectively. The median differences were 1.6Gy (IQR: -29; 7.53) and 9.8Gy (IQR: -28.4; 19.9) for D_T-CBCT and D_T-^99mTc-MAA SPECT/CT respectively. Passing-Bablok regression analysis showed that both CBCT and ^99mTc-MAA SPECT/CT had proportional biases and thus tendencies to overestimate D_T and D_PL at higher post-treatment doses.

CONCLUSION

CBCT may be a reliable segmentation method, but it does not significantly increase the accuracy of dose prediction compared with that of ^99mTc-MAA SPECT/CT. At higher doses both methods tend to overestimate the doses to tumors and perfused livers.

Nanoparticulate formulations of radiopharmaceuticals: Strategy to improve targeting and biodistribution properties

Application of nanotechnology principles in drug delivery has created opportunities for treatment of several diseases. Nanotechnology offers the advantage of overcoming the adverse biopharmaceutics or pharmacokinetic properties of drug molecules, to be determined by the transport properties of the particles themselves. Through the manipulation of size, shape, charge, and type of nanoparticle delivery system, variety of distribution profiles may be obtained. However, there still exists greater need to derive and standardize definitive structure property relationships for the distribution profiles of the delivery system. When applied to radiopharmaceuticals, the delivery systems assume greater significance. For the safety and efficacy of both diagnostics and therapeutic radiopharmaceuticals, selective localization in target tissue is even more important. At the same time, the synthesis and fabrication reactions of radiolabelled nanoparticles need to be completed in much shorter time. Moreover, the extensive understanding of the several interesting optical and magnetic properties of materials in nanoscale provides for achieving multiple objectives in nuclear medicine. This review discusses the various nanoparticle systems, which are applied for radionuclides and analyses the important bottlenecks that are required to be overcome for their more widespread clinical adaptation.

BRAZILIAN SOCIETY OF HEPATOLOGY UPDATED RECOMMENDATIONS FOR DIAGNOSIS AND TREATMENT OF HEPATOCELLULAR CARCINOMA

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. The Brazilian Society of Hepatology (SBH) published in 2015 its first recommendations about the management of HCC. Since then, new data have emerged in the literature, prompting the governing board of SBH to sponsor a single-topic meeting in August 2018 in São Paulo. All the invited experts were asked to make a systematic review of the literature reviewing the management of HCC in subjects with cirrhosis. After the meeting, all panelists gathered together for the discussion of the topics and the elaboration of updated recommendations. The text was subsequently submitted for suggestions and approval of all members of the Brazilian Society of Hepatology through its homepage. The present manuscript is the final version of the reviewed manuscript containing the recommendations of SBH.

Yttrium-90 microsphere radioembolisation for unresectable hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the most common liver neoplasm and the sixth most common cancer worldwide. Its incidence has increased dramatically since the mid-2000s. Although surgical resection and liver transplantation are the main curative treatments, only about 20% of people with early hepatocellular carcinoma may benefit from these interventions. Treatment options for unresectable hepatocellular carcinoma include ablative and transarterial interventions - selective yttrium-90 microsphere transarterial radioembolisation - in addition to the drug sorafenib.

OBJECTIVES

To determine the benefits and harms of yttrium-90 (Y-90) microsphere transarterial radioembolisation given as monotherapy or in combination with other systemic or locoregional interventions versus placebo, no treatment, or other similar systemic or locoregional interventions for people with unresectable hepatocellular carcinoma.

SEARCH METHODS

We performed electronic searches in the Cochrane Hepato-Biliary Group (CHBG) Controlled Trials Register, CENTRAL, MEDLINE, Embase, Latin American Caribbean Health Sciences Literature (LILACS), Science Citation Index - Expanded, and Conference Proceedings Citation Index - Science until September 2019. We manually checked the reference lists of primary studies and review articles.

SELECTION CRITERIA

We searched for randomised clinical trials.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We extracted information on participants, interventions, outcomes, trial design, and trial methods. We assessed risk of bias of the included trials using pre-defined domains and the certainty of evidence using GRADE. Our primary review outcomes were all-cause mortality, quality of life, and serious adverse events; our secondary outcomes were cancer-related mortality, time to progression of the tumour, tumour response, non-serious adverse events, and liver transplantation. For dichotomous variables, we calculated risk ratio (RR), and for continuous variables, we planned to calculate mean difference (MD) or standardised mean difference (SMD), with 95% confidence intervals (CIs). We based time-to-event data analyses on hazard ratios (HRs).

MAIN RESULTS

Six randomised trials with 1340 participants in total fulfilled the review inclusion criteria and provided data for one or more of our analysed outcomes. All trials were at high risk of bias. We assessed the certainty of evidence as low to very low. One trial compared radioembolisation plus sorafenib versus sorafenib alone in people with advanced hepatocellular carcinoma. All-cause mortality, health-related quality of life, cancer-related mortality, time to progression, and tumour response rates were not reported. Serious adverse events were reported in 63 trial participants (39.6%) in the radioembolisation plus sorafenib group versus 70 trial participants (38.5%) in the sorafenib group (very low-certainty evidence). Hyperbilirubinaemia was approximately three times more common in the radioembolisation plus sorafenib group versus the sorafenib group (14.5% versus 4.4%; very low-certainty evidence). Fatigue was more common in the radioembolisation plus sorafenib group than in the sorafenib group, at 35.2% versus 24.2% of trial participants. Two trials compared radioembolisation versus sorafenib for unresectable hepatocellular carcinoma in people with locally advanced hepatocellular carcinoma. From the data we could extract, one-year all-cause mortality was 62.7% in the radioembolisation group versus 53.0% in the sorafenib group (1 trial; n = 360; very low-certainty evidence). There were no differences in the quality of life between radioembolisation and sorafenib groups (1 trial). Global health status subscore was better in the radioembolisation group than in the sorafenib group (P = 0.0048; 1 trial). Fewer participants had serious adverse events in the radioembolisation group than in the sorafenib group (27 (20.8%) in the radioembolisation group versus 57 (35.2%) in the sorafenib group; 1 trial). Median time to progression of the tumour in the radioembolisation group was 6.1 months versus 5.4 months in the sorafenib group (1 trial). The RR for disease control rate was 0.94 (95% CI 0.84 to 1.05; n = 748; 2 trials; very low-certainty evidence), favouring neither radioembolisation nor sorafenib. In two trials with 734 participants, radioembolisation seemed to be less likely to be associated with hand-foot skin reaction (RR 0.02, 95% CI 0.00 to 0.06; P < 0.001; low-certainty evidence), skin rash (RR 0.11, 95% CI 0.04 to 0.34; low-certainty evidence), diarrhoea (RR 0.11, 95% CI 0.04 to 0.34; low-certainty evidence), and hypertension (RR 0.10, 95% CI 0.01 to 0.88; low-certainty evidence). No trial reported cancer-related mortality. Three trials compared radioembolisation versus chemoembolisation in people with intermediate-stage hepatocellular carcinoma. From the data we could extract, none of these trials reported all-cause mortality and cancer-related mortality. The RR for serious adverse events was 1.41 (95% CI 0.63 to 3.14; n = 97; very low-certainty evidence), favouring neither radioembolisation nor chemoembolisation. One trial reported quality of life and noted no differences between intervention groups with regard to this outcome at week 12 (very low-certainty evidence). Median time to progression was not reached in the radioembolisation group and was 6.8 months in the chemoembolisation group (HR 0.122, 95% CI 0.027 to 0.557; 1 trial). Median time to progression of the tumour in the radioembolisation group was 371 days versus 336 days in the chemoembolisation group (P = 0.5764; 1 trial). Disease control rates (complete response + partial response + stable disease) were 73.3% with radioembolisation versus 76.9% with chemoembolisation (1 trial). According to World Health Organization (WHO) criteria, tumour response was reported in 52% of participants who received radioembolisation versus 63% of those who received chemoembolisation (1 trial). Patients in the chemoembolisation group experienced diarrhoea (P = 0.031; 1 trial) and hypoalbuminaemia (P < 0.001; 1 trial) more frequently. Four trials were sponsored by industry, and two by University. We found two ongoing trials.

AUTHORS' CONCLUSIONS

Evidence showing effects of radioembolisation with or without sorafenib compared with sorafenib alone in people with unresectable hepatocellular carcinoma is highly insufficient. We cannot determine if radioembolisation plus sorafenib compared with sorafenib alone affects all-cause mortality or the occurrence of adverse events. Radioembolisation compared with sorafenib seemed to achieve equivalent survival and to cause fewer adverse effects, but our certainty was very low. Evidence showing effects of radioembolisation versus chemoembolisation in people with unresectable hepatocellular carcinoma is also highly insufficient. Radioembolisation did not seem to differ from chemoembolisation in terms of serious adverse events and quality of life, but the certainty of evidence was very low. Further high-quality placebo-controlled randomised clinical trials are needed to assess patient-centred outcomes.

Locoregional treatments for hepatocellular carcinoma: Current evidence and future directions

Liver cancers are the second most frequent cause of global cancer-related mortality of which 90% are attributable to hepatocellular carcinoma (HCC). Despite the advent of screening programmes for patients with known risk factors, a substantial number of patients are ineligible for curative surgery at presentation with limited outcomes achievable with systemic chemotherapy/external radiotherapy. This has led to the advent of numerous minimally invasive options including but not limited to trans-arterial chemoembolization, radiofrequency/microwave ablation and more recently selective internal radiation therapy many of which are often the first-line treatment for select stages of HCC or serve as a conduit to liver transplant. The authors aim to provide a comprehensive overview of these various image guided minimally invasive therapies with a brief focus on the technical aspects accompanied by a critical analysis of the literature to assess the most up-to-date evidence from comparative systematic reviews and meta-analyses finishing with an assessment of novel combination regimens and future directions of travel.

Percutaneous image-guided therapies of primary liver tumors: Techniques and outcomes

Embolization and percutaneous ablations became well-established therapeutic options for hepatocellular carcinomas (HCC). All are performed under minimally invasive conditions using imaging guidance. Selection of a technique over another follows guidelines but also patient's status and availability of the techniques. The aim of this review is to present these techniques performed in routine to treat HCC and to report the outcomes.

RECOMMENDATIONS FOR INVASIVE PROCEDURES IN PATIENTS WITH DISEASES OF THE LIVER AND BILIARY TRACT: REPORT OF A JOINT MEETING OF THE BRAZILIAN SOCIETY OF HEPATOLOGY (SBH), BRAZILIAN SOCIETY OF DIGESTIVE ENDOSCOPY (SOBED) AND BRAZILIAN SOCIETY OF INTERVENTIONAL RADIOLOGY AND ENDOVASCULAR SURGERY (SOBRICE)

Liver and biliary tract diseases are common causes of morbidity and mortality worldwide. Invasive procedures are usually performed in those patients with hepatobiliary diseases for both diagnostic and therapeutic purposes. Defining proper indications and restraints of commonly used techniques is crucial for proper patient selection, maximizing positive results and limiting complications. In 2018, the Brazilian Society of Hepato-logy (SBH) in cooperation with the Brazilian Society of Interventional Radiology and Endovascular surgery (SOBRICE) and the Brazilian Society of Digestive Endoscopy (SOBED) sponsored a joint single-topic meeting on invasive procedures in patients with hepatobiliary diseases. This paper summarizes the proceedings of the aforementioned meeting. It is intended to guide clinicians, gastroenterologists, hepatologists, radiologists, and endoscopists for the proper use of invasive procedures for management of patients with hepatobiliary diseases.

Design and Challenges of Radiopharmaceuticals

This review describes general concepts with regard to radiopharmaceuticals for diagnostic or therapeutic applications that help to understand the specific challenges encountered during the design, (radio)synthesis, in vitro and in vivo evaluation and clinical translation of novel radiopharmaceuticals. The design of a radiopharmaceutical requires upfront decisions with regard to combining a suitable vector molecule with an appropriate radionuclide, considering the type and location of the molecular target, the desired application, and the time constraints imposed by the relatively short half-life of radionuclides. Well-designed in vitro and in vivo experiments allow nonclinical validation of radiotracers. Ultimately, in combination with a limited toxicology package, the radiotracer becomes a radiopharmaceutical for clinical evaluation, produced in compliance with regulatory requirements for medicines for intravenous (IV) injection.

Rethinking the Role of Radiation Therapy in the Treatment of Unresectable Hepatocellular Carcinoma: A Data Driven Treatment Algorithm for Optimizing Outcomes

Hepatocellular carcinoma (HCC) is the second most common cause of cancer death worldwide, with a majority of HCC patients not suitable for curative therapies. Approximately 70% of initially diagnosed patients cannot undergo surgical resection or transplantation due to locally advanced disease, poor liver function/underlying cirrhosis, or additional comorbidities. Local therapeutic options for patients with unresectable HCC, who are not suitable for thermal ablation, include transarterial embolization (bland, chemoembolization, radioembolization) and/or external beam radiation therapy (EBRT). Regarding EBRT specifically, technological advancements provide a means for safe and effective radiotherapy delivery in a wide spectrum of HCC patients. In multiple prospective studies, EBRT delivery in a variety of different fractionation schemes or in combination with transcatheter arterial chemoembolization (TACE) demonstrate improved outcomes, particularly with combination therapy. The Barcelona Clinic Liver Cancer classification provides a framework for treatment selection; however, given the growing complexity of treatment strategies, this classification system tends to simplify decision-making. In this review, we discuss the current literature regarding unresectable HCC and propose a modified treatment algorithm that emphasizes the role of radiation therapy for Child-Pugh score A or B patients with ≤3 nodules measuring >3 cm, multinodular disease or portal venous thrombosis.

Targeting the Tetraspanins with Monoclonal Antibodies in Oncology: Focus on Tspan8/Co-029

Tetraspanins are exposed at the surface of cellular membranes, which allows for the fixation of cognate antibodies. Developing specific antibodies in conjunction with genetic data would largely contribute to deciphering their biological behavior. In this short review, we summarize the main functions of Tspan8/Co-029 and its role in the biology of tumor cells. Based on data collected from recently reported studies, the possibilities of using antibodies to target Tspan8 in immunotherapy or radioimmunotherapy approaches are also discussed.

Quantitative Imaging Biomarkers for 90Y Distribution on Bremsstrahlung SPECT After Resin-Based Radioembolization

Our purpose was to identify baseline imaging features in patients with liver cancer that correlate with ⁹⁰Y distribution on postprocedural SPECT and predict tumor response to transarterial radioembolization (TARE). Methods: This retrospective study was approved by the institutional review board and included 38 patients with hepatocellular carcinoma (HCC) (n = 23; 18/23 men; mean age, 62.39 ± 8.62 y; 34 dominant tumors) and non-HCC hepatic malignancies (n = 15; 9/15 men; mean age, 61.13 ± 11.51 y; 24 dominant tumors) who underwent 40 resin-based TARE treatments (August 2012 to January 2018). Multiphasic contrast-enhanced MRI or CT was obtained before and Bremsstrahlung SPECT within 2 h after TARE. Total tumor volume (cm³) and enhancing tumor volume (ETV [cm³] and % of total tumor volume), and total and enhancing tumor burden (%), were volumetrically assessed on baseline imaging. Up to 2 dominant tumors per treated lobe were analyzed. After multimodal image registration of baseline imaging and SPECT/CT, ⁹⁰Y distribution was quantified on SPECT as tumor-to-normal-liver ratio (TNR). Response was assessed according to RECIST1.1 and quantitative European Association for the Study of the Liver criteria. Clinical parameters were also assessed. Statistical tests included Mann-Whitney U, Pearson correlation, and linear regression. Results: In HCC patients, high baseline ETV% significantly correlated with high TNR on SPECT, demonstrating greater ⁹⁰Y uptake in the tumor relative to the liver parenchyma (P < 0.001). In non-HCC patients, a correlation between ETV% and TNR was observed as well (P = 0.039). Follow-up imaging for response assessments within 1-4 mo after TARE was available for 23 patients with 25 treatments. The change of ETV% significantly correlated with TNR in HCC (P = 0.039) but not in non-HCC patients (P = 0.886). Additionally, Child-Pugh class B patients demonstrated significantly more ⁹⁰Y deposition in nontumorous liver than Child-Pugh A patients (P = 0.021). Conclusion: This study identified ETV% as a quantifiable imaging biomarker on preprocedural MRI and CT to predict ⁹⁰Y distribution on postprocedural SPECT in HCC and non-HCC. However, the relationship between the preferential uptake of ⁹⁰Y to the tumor and tumor response after radioembolization could be validated only for HCC.

The role of external beam radiotherapy in the treatment of hepatocellular cancer

Hepatocellular carcinoma (HCC) is increasing in incidence and mortality. Although the prognosis remains poor, long-term survival has improved from 3% in 1970 to an 18% 5-year survival rate today. This is likely because of the introduction of well tolerated, oral antiviral therapies for hepatitis C. Curative options for patients with HCC are often limited by underlying liver dysfunction/cirrhosis and medical comorbidities. Less than one-third of patients are candidates for surgery, which is the current gold standard for cure. Nonsurgical treatments include embolotherapies, percutaneous ablation, and ablative radiation. Technological advances in radiation delivery in the past several decades now allow for safe and effective ablative doses to the liver. Conformal techniques allow for both dose escalation to target volumes and normal tissue sparing. Multiple retrospective and prospective studies have demonstrated that hypofractionated image-guided radiation therapy, used as monotherapy or in combination with other liver-directed therapies, can provide excellent local control that is cost effective. Therefore, as the HCC treatment paradigm continues to evolve, ablative radiation treatment has moved from a palliative treatment to both a "bridge to transplant" and a definitive treatment.