Segmental Yttrium-90 Radioembolization versus Segmental Chemoembolization for Localized Hepatocellular Carcinoma: Results of a Single-Center, Retrospective, Propensity Score–Matched Study

Prognostic factors influencing outcomes in hepatocellular carcinoma patients undergoing selective internal radiation therapy

Selective internal radiation therapy (SIRT) has emerged as a viable endovascular treatment strategy for hepatocellular carcinoma (HCC). According to the Barcelona Clinic Liver Cancer (BCLC) classification, SIRT is currently recommended for early- and intermediate-stage HCC that is unsuitable for alternative locoregional therapies. Additionally, SIRT remains a recommended treatment for patients with advanced-stage HCC and portal vein thrombosis (PVT) without extrahepatic metastasis. Several studies have shown that SIRT is a versatile and promising treatment with a wide range of applications. Consequently, given its favourable characteristics in various scenarios, SIRT could be an encouraging treatment option for patients with HCC across different BCLC stages. Over the past decade, an increasing number of studies have focused on better understanding the prognostic factors associated with SIRT to identify patients who derive the most benefit from this treatment or to refine the optimal technical procedures of SIRT. Several variables can influence treatment decisions, with a growing emphasis on a personalised approach. This review, based on the literature, will focus on the prognostic factors associated with the effectiveness of radioembolization and related complications. By comprehensively analysing these factors, we aimed to provide a clearer understanding of how to optimise the use of SIRT in managing HCC patients, thereby enhancing outcomes across various clinical scenarios.

Selective internal radiation therapy segmentectomy: A new minimally invasive curative option for primary liver malignancies?

Transarterial radioembolization or selective internal radiation therapy (SIRT) has emerged as a minimally invasive approach for the treatment of tumors. This percutaneous technique involves the local, intra-arterial delivery of radioactive microspheres directly into the tumor. Historically employed as a palliative measure for liver malignancies, SIRT has gained traction over the past decade as a potential curative option, mirroring the increasing role of radiation segmentectomy. The latest update of the BCLC hepatocellular carcinoma guidelines recognizes SIRT as an effective treatment modality comparable to other local ablative methods, particularly well-suited for patients where surgical resection or ablation is not feasible. Radiation segmentectomy is a more selective approach, aiming to deliver high-dose radiation to one to three specific hepatic segments, while minimizing damage to surrounding healthy tissue. Future research efforts in radiation segmentectomy should prioritize optimizing radiation dosimetry and refining the technique for super-selective administration of radiospheres within the designated hepatic segments.

Local recurrence following a complete radiologic response in hepatocellular carcinoma patients: comparison of transarterial chemoembolisation and transarterial radioembolisation

AIM

To evaluate and compare the rates of local recurrence in hepatocellular carcinoma (HCC) patients who undergo selective transarterial radioembolisation (TARE) or transarterial chemoembolisation (TACE) and achieve a complete response (CR) radiologically.

MATERIALS AND METHODS

All patients undergoing treatment with TARE or TACE at a single academic institution were reviewed retrospectively. Those who had been treated previously, presented with multifocal disease, had non-selective TARE or TACE, or did not achieve a complete response (CR) radiologically were excluded.

RESULTS

In total 110 patients were included (TACE n=60 [54.5%]; TARE n=50 [45.5%]). TARE patients were older (66.4 ± 9.4 versus 61.2 ± 5.6 years, p<0.001) and had larger tumours (4.4 ± 2.2 versus 3 ± 1.4 cm, p=0.002). TACE patients were significantly more likely to suffer a local recurrence (31/60, 51.7% versus 9/50, 18%, p<0.001) and had a significantly shorter time to recurrence (median 8.3 {interquartile range [IQR]}: 12 versus median 17.9 [IQR: 23.5] months, p=0.001). A local time to progression (TTP) Kaplan-Meier curve demonstrated TACE patients had a significantly shorter local TTP (hazard ratio [HR]: 7.2; 95% confidence interval [CI]: 3.64-14.24; p<0.001) and treatment modality (TACE or TARE; HR: 0.05; 95% CI: 0.005-0.5; p=0.01) was found to be associated with local recurrences on multivariate Cox proportional HR analysis. When overall TTP was evaluated, again TACE patients were found to have a significantly shorter TTP (HR: 2.13 [1.28-3.53], p=0.004).

CONCLUSION

In HCC patients undergoing selective treatment who achieve a CR radiologically, those treated with TARE may be less likely to suffer recurrence, either local or general, than those treated with TACE.

Locoregional Therapies for Hepatocellular Carcinoma prior to Liver Transplant: Comparative Pathologic Necrosis, Radiologic Response, and Recurrence

PURPOSE

To compare pathologic tumor necrosis rates after locoregional therapies (LRTs) for hepatocellular carcinoma (HCC) prior to liver transplantation and evaluate radiologic-pathologic correlation along with posttransplant HCC recurrence.

MATERIALS AND METHODS

Consecutive patients with solitary HCC bridged or downstaged with LRT from 2010 to 2022 were included. LRTs were transarterial chemoembolization (TACE), radioembolization (yttrium-90 [90Y]), ablation, and stereotactic body radiotherapy (SBRT). Upfront combination therapy options were TACE/ablation and TACE/SBRT. Subsequent therapy crossover due to local recurrence was allowed. Posttreatment imaging closest to the time of transplant, explant histopathologic necrosis, and tumor recurrence after transplant were reviewed.

RESULTS

Seventy-three patients met inclusion criteria, of whom 5 (7%) required downstaging. 90Y alone (n = 36) and multimodal therapy (pooled upfront combination and crossover therapy, n = 23) resulted in significantly greater pathologic necrosis compared with TACE alone (n = 14; P = .01). High dose 90Y radiation segmentectomy (≥190 Gy; n = 27) and TACE/ablation (n = 7) showed highest rates of complete pathologic necrosis (CPN)-63% (n = 17) and 71% (n = 5), respectively. Patients with CPN had a mean lesion size of 2.5 cm, compared with 3.2 cm without CPN (P = .04), irrespective of LRT modality. HCC recurrence was more common in patients without CPN (16%, 6/37) than in those with CPN (3%, 1/36; P = .11). Using Liver Imaging Reporting and Data System (LI-RADS), a nonviable imaging response was 75% sensitive and 57% specific for CPN.

CONCLUSIONS

Radiation segmentectomy and multimodal therapy significantly improved CPN rates compared with TACE alone. A LI-RADS treatment response of nonviable did not confidently predict CPN.

Radiation Segmentectomy for the Treatment of Hepatocellular Carcinoma: A Practical Review of Evidence

Radiation segmentectomy is a versatile, safe, and effective ablative therapy for early-stage hepatocellular carcinoma. Advances in radiation segmentectomy patient selection, procedural technique, and dosimetry have positioned this modality as a curative-intent and guideline-supported treatment for patients with solitary HCC. This review describes key radiation segmentectomy concepts and summarizes the existing literary knowledgebase.

Downstaging Techniques for Hepatocellular Carcinoma in Candidates Awaiting Liver Transplantation

During the last decade, downstaging for hepatocellular carcinoma has expanded the pool of patients eligible for liver transplantation. The literature is rife with attempts to elucidate best treatment strategies with novel locoregional and systemic therapies continuing to emerge. Several trials have confirmed the large-scale success of downstaging protocols, with equitable long-term survival and recurrence rates after liver transplant. We review the currently available techniques used for downstaging, including their indications, complications, and efficacies. New frontiers have focused on the potential role of immunotherapy in the neoadjuvant setting, although more research is needed to delineate its role in current treatment paradigms.

Radiation Segmentectomy for Hepatocellular Carcinoma

The application of trans-arterial radioembolization (TARE) with Yttrium-90, historically a palliative treatment option for patients with advanced hepatocellular carcinoma (HCC), is evolving. Radiation segmentectomy (RADSEG), the segmental delivery of an ablative radiation dose, is a treatment option for patients with earlier-stage HCC. This review presents an in-depth exploration of RADSEG, emphasizing its technical considerations, dosimetry advancements, and patient selection. The integration of RADSEG into the Barcelona Clinic Liver Cancer (BCLC) paradigm will be highlighted. RADSEG outcomes concerning safety and efficacy will be explored and compared with traditional locoregional cancer treatments like trans-arterial chemoembolization (TACE), percutaneous thermal ablation, and surgical resection, with an eye on future directions and considerations.

Comparative study between Embosphere® and Marine gel® as embolic agents for chemoembolization of hepatocellular carcinoma

BACKGROUND

While gelatin sponge particles and calibrated microspheres are commonly used as embolic materials in conventional transarterial chemoembolization (cTACE), direct comparisons between these embolic agents are rare.

AIM

To compare the efficacy and safety of superselective cTACE using Embosphere® or Marine gel® in patients with early-stage hepatocellular carcinoma (HCC).

METHODS

This retrospective study included 70 patients with small (< 4 cm) HCC who underwent cTACE with Embosphere® (n = 33) or Marine gel® (n = 37) as the embolic agent at a single center between March 2021 and July 2022. The radiologic images and clinical data were retrospectively reviewed, with an emphasis on tumor response, procedure-related complications, and local tumor recurrence. The primary index tumor was assessed on a 1-mo follow-up image, and local progression-free survival was obtained using the Kaplan-Meier method and was compared by the log-rank test.

RESULTS

The median tumor size of both groups was 1.5 cm, and 69 patients achieved a complete response one month after cTACE. The cumulative local recurrence rate at 12 mo was 15.5% in the Embosphere® group and 14.4% in the Marine gel® group. The local progression-free survival was not significantly different between the two groups (P = 0.83). In the multivariate analysis, high serum alpha-fetoprotein was the only significant poor prognostic factor for local tumor progression (P = 0.01). Postembolization syndrome occurred in 36.4% of the Embosphere® group and 35.1% of the Marine gel® group, and there were no cases of biloma, biliary duct dilation, or liver abscess in either group.

CONCLUSION

Calibrated gelatin sponge particles (Marine gel®) and calibrated microspheres (Embosphere®) have similar outcomes in terms of tumor response for superselective cTACE of small HCC.

Optimal treatment for small HCC (<3 cm): Resection, liver transplantation, or locoregional therapy?

Hepatocellular carcinoma (HCC) remains the most common form of liver cancer, accounting for 90% of all primary liver cancers. Up to 30% of HCC cases could be small (2-3 cm in diameter) at the time of diagnosis with advances in imaging techniques and surveillance programmes. Treating patients with early-stage HCC can be complex and often requires interdisciplinary care, owing to the wide and increasing variety of treatment options, which include liver resection, liver transplantation, and various locoregional therapies offered by interventional radiology and radiation oncology. Decisions regarding the optimal management strategy for a patient involve many considerations, including patient- and tumour-specific characteristics, as well as socioeconomic factors. In this review, we aim to comprehensively summarise the commonly used therapies for single, small HCC (<3 cm), with a focus on the impact of tumour size (<2 cm vs. 2-3 cm), as well as a brief discussion on the cost-effectiveness of the different treatment options.

The Hong Kong consensus statements on unresectable hepatocellular carcinoma: narrative review and update for 2021

Background and Objective

Hong Kong, like many parts of Asia, faces a high burden of hepatocellular carcinoma (HCC) caused by high endemic rates of hepatitis B virus infection. Hong Kong clinicians have developed a high level of expertise in HCC treatment across surgical, transarterial, ablative, radiotherapeutic and systemic modalities. This publication summarizes the latest evidence-based recommendations on how these modalities should be used.

Methods

In two meetings held in 2020, a multidisciplinary panel of surgeons, oncologists and interventional radiologists performed a narrative review of evidence on the management of HCC, with an emphasis on treatment of HCC not amenable to surgical resection. Close attention was paid to new evidence published since the previous version of these statements in 2018.

Key Content and Findings

The expert panel has formulated 60 consensus statements to guide the staging and treatment of unresectable HCC. Since the previous version of these statements, considerable additions have been made to the recommendations on use of targeted therapies and immunotherapies because of the large volume of new evidence.

Conclusions

Our consensus statements offer guidance on how to select HCC patients for surgical or non-surgical treatment and for choosing among non-surgical modalities for patients who are not candidates for resection. In particular, there is a need for more evidence to aid physicians in the selection of second-line systemic therapies, as currently most data are limited to patients with disease progression on first-line sorafenib.

Advances in Radiation Therapy for Primary Liver Cancer

During the past 30 years, several advances have been made allowing for safer and more effective treatment of patients with liver cancer. This report reviews recent advances in radiation therapy for primary liver cancers including hepatocellular carcinoma and intrahepatic cholangiocarcinoma. First, studies focusing on liver stereotactic body radiation therapy (SBRT) are reviewed focusing on lessons learned and knowledge gained from early pioneering trials. Then, new technologies to enhance SBRT treatments are explored including adaptive therapy and MRI-guided and biology-guided radiation therapy. Finally, treatment with Y-90 transarterial radioembolization is reviewed with a focus on novel approaches focused on personalized therapy.

Clinical, dosimetric, and reporting considerations for Y-90 glass microspheres in hepatocellular carcinoma: updated 2022 recommendations from an international multidisciplinary working group

PURPOSE

In light of recently published clinical reports and trials, the TheraSphere Global Dosimetry Steering Committee (DSC) reconvened to review new data and to update previously published clinical and dosimetric recommendations for the treatment of hepatocellular carcinoma (HCC).

METHODS

The TheraSphere Global DSC is comprised of health care providers across multiple disciplines involved in the treatment of HCC with yttrium-90 (Y-90) glass microsphere-based transarterial radioembolization (TARE). Literature published between January 2019 and September 2021 was reviewed, discussed, and adjudicated by the Delphi method. Recommendations included in this updated document incorporate both the results of the literature review and the expert opinion and experience of members of the committee.

RESULTS

Committee discussion and consensus led to the expansion of recommendations to apply to five common clinical scenarios in patients with HCC to support more individualized efficacious treatment with Y-90 glass microspheres. Existing clinical scenarios were updated to reflect recent developments in dosimetry approaches and broader treatment paradigms evolving for patients presenting with HCC.

CONCLUSION

Updated consensus recommendations are provided to guide clinical and dosimetric approaches for the use of Y-90 glass microsphere TARE in HCC, accounting for disease presentation, tumor biology, and treatment intent.

Radiation segmentectomy for curative intent of unresectable very early to early stage hepatocellular carcinoma (RASER): a single-centre, single-arm study

BACKGROUND

Unresectable solitary very early to early stage hepatocellular carcinoma is managed with ablation for curative intent. Radiation segmentectomy is a treatment option that delivers radioactive ⁹⁰yttrium (⁹⁰Y)-bound microspheres transarterially to a segment of liver. The aim of this study was to assess the safety and efficacy of radiation segmentectomy in patients with unresectable hepatocellular carcinoma deemed unfavourable for ablation.

METHODS

RASER was a single-centre, single-arm study that included adults (>18 years) with solitary hepatocellular carcinoma with unfavourable location for ablation, without metastasis or macrovascular invasion. Eligibility criteria included measurable disease 3 cm or less in diameter, Child-Pugh score A-B7, an Eastern Cooperative Oncology Group score of 0, and adequate haematological and organ function. The primary endpoint was target tumour response measured by mRECIST. Patients were followed up with imaging and office visits for up to 24 months. The trial is registered with ClinicalTrials.gov (NCT03248375), and is completed.

FINDINGS

Individuals were enrolled between Aug 3, 2016, and April 4, 2019, and the last patient follow-up occurred on March 31, 2021. Of the 44 individuals assessed for eligibility, 29 patients were included in the study. Initial target lesion complete response was observed in 24 (83%) of 29 patients, and partial response was observed in five (17%) of patients. All patients had an initial objective response and 26 (90%) individuals had a sustained complete response. Four (14%) patients had grade 3 leukopenia and two (7%) had grade 3 thrombocytopenia. There were two (7%) non-laboratory-related grade 3 adverse events (one arterial injury and one ascites). The most frequent (>10% patients) grade 1 or 2 adverse events were fatigue (nine [31%]); nausea, vomiting, or anorexia (seven [24%]); abdominal discomfort (six [21%]), leukopenia (nine [31%]), thrombocytopenia (four [14%]), increased alkaline phosphatase (four [14%]), increased alanine or aspartate aminotransferase (four [14%]), increased bilirubin (four [14%]), and decreased albumin (six [21%]). There was one death that was not treatment related.

INTERPRETATION

Radiation segmentectomy was efficacious, with a low proportion of high-grade adverse events in patients with unresectable very early to early stage hepatocellular carcinoma with suboptimal location for ablation. These results suggest that radiation segmentectomy should be further investigated as a potential curative treatment option for well selected patients.

FUNDING

Boston Scientific.

TACE versus TARE for patients with hepatocellular carcinoma: Overall and individual patient level meta analysis

BACKGROUND

Transarterial radioembolization (TARE) is increasingly used as an alternative to transarterial chemoembolization (TACE) for the treatment of hepatocellular carcinoma (HCC). We aimed to perform an overall and individual patient data (IPD) meta-analysis of studies comparing TACE and TARE.

METHODS

We performed a systematic literature search using pre-specified keywords with the aid of an informationist for articles from inception to 3/2020. The primary endpoint was overall survival (OS), and the secondary endpoint was time to progression (TTP).

RESULTS

Seventeen studies met inclusion criteria with 2465 unique patients, with one randomized trial, 4 prospective studies and 12 retrospective studies. Barcelona Clinic Liver Cancer (BCLC) stage B (42.8%) was the most common stage followed by BCLC A (30.3%) and BCLC C (29.0%). There was no difference in OS between the two modalities (-0.55 months, 95% CI -1.95 to 3.05). In three studies with available TTP data, TARE resulted in a longer TTP than TACE (mean TTP 17.5 vs. 9.8 months; mean TTP difference 4.8 months, 95% CI 1.3-8.3 months). IPD-level meta-analysis of 311 patients from three studies showed no difference in overall OS between the two modalities including among subgroups stratified by tumor stage and liver function. Limitations of the current literature include inconsistent length of follow-up, inconsistency in response criteria, and safety reporting.

CONCLUSIONS

Current data suggest TARE provides significantly longer TTP than TACE, although the two treatments do not significantly differ in terms of OS. Given limitations of the current data, there is rationale for prospective studies comparing these modalities.

Radioembolization Dosimetry with Total-Body 90Y PET

Transarterial radioembolization (TARE) is a locoregional radiopharmaceutical therapy based on the delivery of radioactive ⁹⁰Y microspheres to liver tumors. The importance of personalized dosimetry to make TARE safer and more effective has been demonstrated in recent clinical studies, stressing the need for quantification of the dose-response relationship to ultimately optimize the administered activity before treatment and image it after treatment. ⁹⁰Y dosimetric studies are challenging because of the lack of accurate and precise methods but are best realized with PET combined with Monte Carlo simulations and other image modalities to calculate a segmental dose distribution. The aim of this study was to assess the suitability of imaging ⁹⁰Y PET patients with the total-body PET/CT uEXPLORER and to investigate possible improvements in TARE ⁹⁰Y PET-based dosimetry. The uEXPLORER is the first commercially available ultra-high-resolution (171 cps/kBq) total-body digital PET/CT device with a 194-cm axial PET field of view that enables the whole body to be scanned at a single bed position. Methods: Two PET/CT scanners were evaluated in this study: the Biograph mCT and the total-body uEXPLORER. Images of a National Electrical Manufacturers Association (NEMA) image-quality phantom and 2 patients were reconstructed using our standard clinical oncology protocol. A late portal phase contrast-enhanced CT scan was used to contour the liver segments and create corresponding volumes of interest. To calculate the absorbed dose, Monte Carlo simulations were performed using Geant4 Application for Tomographic Emission (GATE). The absorbed dose and dose-volume histograms were calculated for all 6 spheres (diameters ranging from 10 to 37 mm) of the NEMA phantom, the liver segments, and the entire liver. Differences between the phantom doses and an analytic ground truth were quantified through the root mean squared error. Results: The uEXPLORER showed a higher signal-to-noise ratio at 10- and 13-mm diameters, consistent with its high spatial resolution and system sensitivity. The total liver-absorbed dose showed excellent agreement between the uEXPLORER and the mCT for both patients, with differences lower than 0.2%. Larger differences of up to 60% were observed when comparing the liver segment doses. All dose-volume histograms were in good agreement, with narrower tails for the uEXPLORER in all segments, indicating lower image noise. Conclusion: This patient study is compelling for the use of total-body ⁹⁰Y PET for liver dosimetry. The uEXPLORER scanner showed a better signal-to-noise ratio than mCT, especially in lower-count regions of interest, which is expected to improve dose quantification and tumor dosimetry.

Bridging treatment prior to liver transplantation for hepatocellular carcinoma: radioembolization or transarterial chemoembolization?

BACKGROUND

In hepatocellular carcinoma (HCC) patients, intraarterial therapies are regularly employed as a bridge to liver transplantation to prevent tumor progression during waiting time. Objective of this study was to compare HCC recurrence after liver transplantation following TACE or radioembolization bridging treatment.

METHODS

We retrospectively analyzed prospectively collected data on 131 consecutive HCC patients who underwent liver transplantation between January 2007 and December 2017 at our liver transplant center (radioembolization n = 44, TACE n = 87). Multivariable logistic regression and cox proportional hazard regression models were used to evaluate factors associated with tumor recurrence and post-transplant survival.

RESULTS

Between groups, patients were comparable with regards to age and gender. In the radioembolization group, Milan criteria for HCC were met significantly less frequently (20.5% vs. 65.5%, p < 0.0001). Patients in the radioembolization group required significantly fewer intraarterial treatments (1 [1-2] vs. 1 [1-7], p = 0.0007). On explant specimen, tumor differentiation, microvascular invasion and tumor necrosis were comparable between the groups. HCC recurrence and overall survival were similar between the groups. Multivariable analysis detected increasing recipient age, male gender, complete tumor necrosis and absence of microvascular invasion being independently associated with decreased odds for HCC recurrence. Increasing model of end-stage liver disease (MELD) score and tumor recurrence were independently associated with increased odds of post-transplant death.

CONCLUSIONS

Intraarterial bridging treatment leading to tumor necrosis may not only prevent waitlist drop-out but also facilitate long-term successful liver transplantation in HCC patients. Both radioembolization and TACE represent potent treatment strategies.

TARE in Hepatocellular Carcinoma: From the Right to the Left of BCLC

The Barcelona Clinic Liver Cancer (BCLC) system is the most commonly used staging system for hepatocellular carcinoma (HCC) in Western countries. BCLC aims to categorize patients into five stages with different prognoses and to allocate treatment according to these stages based on the best possible contemporary evidence. Transarterial radioembolization (TARE) has recently entered at the left of the BCLC algorithm (i.e., BCLC 0-A), mainly because of negative phase III trials in BCLC C stage. TARE has shown a steady increase in nationwide studies over the past 20 years and has even been adopted in some tertiary centers as the primary HCC treatment across all BCLC stages. We aimed to review the history of TARE in HCC, starting from advanced HCC and gradually expanding to earlier stages at the left of the BCLC system.

Clinical application of advances and innovation in radiation treatment of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) management has evolved over the past two decades, with the development of newer treatment modalities. While various options are available, unmet needs are reflected through the mixed treatment outcome for intermediate-stage HCC. As HCC is radiosensitive, radiation therapies have a significant role in management. Radiation therapies offer local control for unresectable lesions and for patients who are not surgical candidates. Radiotherapy also provides palliation in metastatic disease, and acts as a bridge to resection and transplantation in selected patients. Advancements in radiotherapy modalities offer improved dose planning and targeted delivery, allowing for better tumor response and safer dose escalations while minimizing the risks of radiation-induced liver damage. Radiotherapy modalities are broadly classified into external beam radiation therapy and selective internal radiation therapy. With emerging modalities, radiotherapy plays a complementary role in the multidisciplinary care of HCC patients.

Aim

We aim to provide an overview of the role and clinical application of radiation therapies in HCC management.

Relevance for Patients

The continuous evolution of radiotherapy techniques allows for improved therapeutic outcomes while mitigating unwanted adverse effects, making it an attractive modality in HCC management. Rigorous clinical studies, quality research and comprehensive datasets will further its application in the present era of evidence-based practice in Medicine.

Unique situation of hepatocellular carcinoma in Egypt: A review of epidemiology and control measures

Hepatocellular carcinoma (HCC) is the sixth most common primary malignancy worldwide, and the third most common cause of death among cancers worldwide. HCC occurs in several pre-existing conditions, including hepatitis C, hepatitis B virus, and non-alcoholic cirrhosis. Egypt used to be the country with the heaviest hepatitis C virus (HCV) burden. The relationship between HCV and HCC is an important research area. In Egypt, HCC is a significant public health problem. A possible cause for the increasing rates of detection of HCC in Egypt is the mass screening program that was carried by the government for detecting and treating HCV. A multidisciplinary approach is now widely applied to HCC management in health centers all over Egypt. Different treatment modalities are available in Egypt, with success rates comparable to global rates. The Egyptian health authorities have made the elimination of HCV from Egypt a special priority, and this approach should lead to a decrease in number of HCC cases in the near future. In this article we review the current situation of HCC in Egypt, including epidemiological aspects, relevant risk factors for HCC development, strategies, and efforts established by health authorities for the screening and prevention of both HCV and HCC in Egypt. We highlight the different modalities for HCC treatment.

Yttrium-90 Radioembolization for the Treatment of Solitary, Unresectable HCC: The LEGACY Study

BACKGROUND AND AIMS

Locoregional therapies, including yttrium-90 radioembolization, play an important role in the treatment of unresectable HCC. The aim of the LEGACY (Local radioEmbolization using Glass Microspheres for the Assessment of Tumor Control with Y-90) study was to evaluate objective response rate (ORR) and duration of response (DoR) in patients with solitary unresectable HCC treated with yttrium-90 glass microspheres.

APPROACH AND RESULTS

LEGACY is a multicenter, single-arm, retrospective study conducted at three sites that included all eligible, consecutive patients with HCC treated with radioembolization between 2014 and 2017. Eligibility criteria included solitary HCC ≤ 8 cm, Child-Pugh A cirrhosis, and Eastern Cooperative Oncology Group performance status 0-1. Primary endpoints were ORR and DoR based on modified Response Evaluation Criteria in Solid Tumors in the treated area (localized), as evaluated by blinded, independent, central review. Radioembolization was performed with intent of ablative-level dosimetry in a selective fashion when possible. Overall survival was evaluated using Kaplan-Meier and multivariate Cox proportional hazards. Among the 162 patients included, 60.5% were Eastern Cooperative Oncology Group 0, and the median tumor size was 2.7 cm (range: 1-8) according to blinded, independent, central review. Radioembolization served as neoadjuvant therapy for transplantation or resection in 21.0% (34 of 162) and 6.8% (11 of 162) of patients, respectively, and as primary treatment for all others. Median follow-up time was 29.9 months by reverse Kaplan-Meier. ORR (best response) was 88.3% (CI: 82.4-92.4), with 62.2% (CI: 54.1-69.8) exhibiting a DoR ≥ 6 months. Three-year overall survival was 86.6% for all patients and 92.8% for those neoadjuvant patients with resected or transplanted liver.

CONCLUSIONS

In this multicenter study of radioembolization, clinical meaningful response rates and prolonged DoR were observed in the treatment of unresectable, solitary HCC ≤ 8 cm.

Radiation Segmentectomy

Radiation segmentectomy is an yttrium-90 transarterial radioembolization treatment where a high radiation dose is administered to a small volume of liver to achieve a high tumoricidal dose to a target with anatomic surgical precision while sparing surrounding parenchyma. This therapeutic modality is often used to treat hepatocellular carcinoma, and recent studies have demonstrated that radiation segmentectomy is an effective treatment as a neoadjuvant to transplant, resection, or as a standalone treatment. This article provides a review of radiation segmentectomy, indications for treatment, recent outcome data, and guidelines for postprocedural management.

Principles of Radioembolization

Radioembolization has become a mainstay therapy in the treatment of primary and secondary liver cancers. This article will specifically discuss a brief history of yttrium treatment as well as an overview of the physical properties of the currently available devices. A discussion of the mechanism of action will be followed by a discussion on patient selection for this treatment.

Review of Use of Y90 as a Bridge to Liver Resection and Transplantation in Hepatocellular Carcinoma

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) has been rising, and 80% of HCCs are unresectable at the time of presentation. In recent years, Yttrium-90 (Y90) radioembolization has arisen as a potential tool to treat the primary HCC tumor while also inducing contralateral liver hypertrophy to increase future liver remnant volumes. The goal of this multidisciplinary review is to summarize the contemporary evidence on the safety, efficacy, and utility of Y90 as a bridge to liver resection and transplant in patients with HCC.

METHODS

A narrative review was conducted of the recent literature regarding the utilization of Y90 as a therapy prior to liver resection or transplant in patients with HCC. A specific emphasis was placed on articles published in the last 10 years.

RESULTS

Y90 radioembolization has demonstrated a high safety profile and increasing utility in bridging and downstaging patients with HCC who subsequently undergo liver resection or transplant. The continuous advancements in treatment strategies and radiation dosimetry have paved the way for the incorporation of Y90 in all stages of HCC with different intents, including downstaging and bridging.

CONCLUSIONS

Y90 radioembolization can be safely used in the HCC population to bridge patients to resection or transplantation, induce future liver remnant growth, and select for less aggressive tumor biology prior to surgery.

Evolution of Radioembolization in Treatment of Hepatocellular Carcinoma: A Pictorial Review

Transarterial radioembolization (TARE) with yttrium 90 has increasingly been performed to treat hepatocellular carcinoma (HCC). TARE was historically used as a palliative lobar therapy for patients with advanced HCC beyond surgical options, ablation, or transarterial chemoembolization, but recent advancements have led to its application across the Barcelona Clinic Liver Cancer staging paradigm. Newer techniques, termed radiation lobectomy and radiation segmentectomy, are being performed before liver resection to facilitate hypertrophy of the future liver remnant, before liver transplant to bridge or downstage to transplant, or as a definite curative treatment. Imaging assessment of therapeutic response to TARE is challenging as the intent of TARE is to deliver local high-dose radiation to tumors through microembolic microspheres, preserving blood flow to promote radiation injury to the tumor. Because of the microembolic nature, early imaging assessment after TARE cannot rely solely on changes in size. Knowledge of the evolving methods of TARE along with the tools to assess posttreatment imaging and response is essential to optimize TARE as a therapeutic option for patients with HCC. ^©RSNA, 2021.

Management of Liver Tumors during the COVID-19 Pandemic: The Added Value of Selective Internal Radiation Therapy (SIRT)

Background: In the context of the coronavirus disease 2019 (COVID-19) pandemic, liver-directed therapies (LDTs) may offer minimally invasive integrative tools for tumor control. Among them, selective internal radiation therapy (SIRT) represents a safe, flexible and effective treatment. Purpose of this study is to present our experience with SIRT during the first wave of COVID-19 pandemic and provide an overview of the indications and challenges of SIRT in this scenario. Methods: We retrospectively analyzed the number of patients evaluated by Multidisciplinary Liver Tumor Board (MLTB) and who were undergoing LDTs between March and July 2020 and compared it with 2019. For patients treated with SIRT, clinical data, treatment details and the best radiological response were collected. Results: Compared to 2019, we observed a 27.5% reduction in the number of patients referred to MLTB and a 28.3% decrease in percutaneous ablations; transarterial chemoembolizations were stable, while SIRT increased by 64%. The majority of SIRT patients (75%) had primary tumors, mostly HCC. The best objective response and disease control rates were 56.7% and 72.2%, respectively. Conclusion: The first wave of the COVID-19 pandemic was characterized by an increased demand for SIRT, which represents a safe, flexible and effective treatment, whose manageability will further improve by simplifying the treatment workflow, developing user-friendly and reliable tools for personalized dosimetry and improving interdisciplinary communication.

Conventional Hepatic Volumetry May Lead to Inaccurate Segmental Yttrium-90 Radiation Dosimetry

OBJECTIVE

To compare radioembolization treatment zone volumes from mapping cone beam CT (CBCT) versus planning CT/MRI and to model their impact on dosimetry.

METHODS

Y90 cases were retrospectively identified in which intra-procedural CBCT angiograms were performed. Segmental and lobar treatment zone volumes were calculated with semi-automated contouring using Couinaud venous anatomy (planning CT/MRI) or tumor angiosome enhancement (CBCT). Differences were compared with a Wilcoxon signed-rank test. Treatment zone-specific differences in segmental volumes by volumetric method were also calculated and used to model differences in delivered dose using medical internal radiation dosimetry (MIRD) at 200 and 120 Gy targets. Anatomic, pathologic, and technical factors likely affecting segmental volumes by volumetric method were evaluated.

RESULTS

Forty segmental and 48 lobar CBCT angiograms and corresponding planning CT/MRI scans were included. Median Couinaud- and CBCT-derived segmental volumes were 281 and 243 mL, respectively (p = 0.005). Differences between Couinaud and CBCT lobar volumes (right, left) were not significant (p = 0.24, p = 0.07). Couinaud overestimated segmental volumes in 28 cases by a median of 98 mL (83%) and underestimated in 12 cases by median 69 mL (20%). At a 200 Gy dose target, Couinaud estimates produced median delivered doses of 367 and 160 Gy in these 28 and 12 cases. At a 120 Gy target, Couinaud produced doses of 220 and 96 Gy. Proximal vs. distal microcatheter positioning, variant arterial anatomy, and tumor location on or near segmental watersheds were leading factors linked to volumetric differences.

CONCLUSION

Use of CBCT-based volumetry may allow more accurate, personalized dosimetry for segmental Y90 radioembolization.

Bi-Centric Independent Validation of Outcome Prediction after Radioembolization of Primary and Secondary Liver Cancer

BACKGROUND

Yttrium-90 radioembolization (RE) plays an important role in the treatment of liver malignancies. Optimal patient selection is crucial for an effective and safe treatment. In this study, we aim to validate the prognostic performance of a previously established random survival forest (RSF) with an external validation cohort from a different national center. Furthermore, we compare outcome prediction models with different established metrics.

METHODS

A previously established RSF model, trained on a consecutive cohort of 366 patients who had received RE due to primary or secondary liver tumor at a national center (center 1), was used to predict the outcome of an independent consecutive cohort of 202 patients from a different national center (center 2) and vice versa. Prognostic performance was evaluated using the concordance index (C-index) and the integrated Brier score (IBS). The prognostic importance of designated baseline parameters was measured with the minimal depth concept, and the influence on the predicted outcome was analyzed with accumulated local effects plots. RSF values were compared to conventional cox proportional hazards models in terms of C-index and IBS.

RESULTS

The established RSF model achieved a C-index of 0.67 for center 2, comparable to the results obtained for center 1, which it was trained on (0.66). The RSF model trained on center 2 achieved a C-index of 0.68 on center 2 data and 0.66 on center 1 data. CPH models showed comparable results on both cohorts, with C-index ranging from 0.68 to 0.72. IBS validation showed more differentiated results depending on which cohort was trained on and which cohort was predicted (range: 0.08 to 0.20). Baseline cholinesterase was the most important variable for survival prediction.

CONCLUSION

The previously developed predictive RSF model was successfully validated with an independent external cohort. C-index and IBS are suitable metrics to compare outcome prediction models, with IBS showing more differentiated results. The findings corroborate that survival after RE is critically determined by functional hepatic reserve and thus baseline liver function should play a key role in patient selection.

Frontiers of therapy for hepatocellular carcinoma

The incidence of hepatocellular carcinoma continues to increase worldwide. Fortunately, there have been notable recent advances in locoregional and systemic therapy. In this current review, we will highlight these new developments and future directions of hepatocellular carcinoma treatment and address the importance of a multidisciplinary approach to treatment.

Radiation segmentectomy of hepatic metastases with Y-90 glass microspheres

PURPOSE

To evaluate safety and efficacy of radiation segmentectomy (RS) with ⁹⁰Y glass microspheres in patients with limited metastatic liver disease not amenable to resection or percutaneous ablation.

METHODS

Patients with ≤ 3 tumors treated with RS from 6/2015 to 12/2017 were included. Target tumor radiation dose was > 190 Gy based on medical internal radiation dose (MIRD) dosimetry. Tumor response, local tumor progression (LTP), LTP-free survival (LTPFS) and disease progression rate in the treated segment were defined using Choi and RECIST 1.1 criteria. Toxicities were evaluated using modified SIR criteria.

RESULTS

Ten patients with 14 tumors underwent 12 RS. Median tumor size was 3 cm (range 1.4-5.6). Median follow-up was 17.8 months (range 1.6-37.3). Response rates per Choi and RECIST 1.1 criteria were 8/8 (100%) and 4/9 (44%), respectively. Overall LTP rate was 3/14 (21%) during the study period. One-, two- and three-year LTPFS was 83%, 83% and 69%, respectively. Median LTPFS was not reached. Disease progression rate in the treated segment was 6/18 (33%). Median overall survival was 41.5 months (IQR 16.7-41.5). Median delivered tumor radiation dose was 293 Gy (range 163-1303). One major complication was recorded in a patient post-Whipple procedure who suffered anaphylactic reaction to prophylactic cefotetan and liver abscess in RS region 6.5 months post-RS. All patients were alive on last follow-up.

CONCLUSION

RS of ≤ 3 hepatic segments can safely provide a 2-year local tumor control rate of 83% in selected patients with limited metastatic liver disease and limited treatment options. Optimal dosimetry methodology requires further investigation.

Combination of 1st and 2nd Week Dosing of Glass Yttrium-90 Microspheres for Superselective Radioembolization

BACKGROUND/AIM

The aim of this study was to address the feasibility of combination of 1^st and 2^nd week dosing of glass microspheres in the setting of selective radioembolization for large hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Yttrium-90 radioembolization was performed in 53 patients with single nodular hepatocellular carcinomas larger than 5 cm. A total of 32 patients underwent radioembolization with glass microspheres from a single calibration date (single-dosing group), and 21 patients were treated with a combination of 1^st and 2^nd week dosing of glass microspheres (combined-dosing group). In the combined-dosing group, the lobar hepatic arteries and subsidiary tumor-feeding arteries were commonly treated with 1^st and 2^nd week dosing of glass microspheres, respectively.

RESULTS

The combined-dosing group tended to have a lower frequency of pain requiring analgesics without statistical significance (p=0.085). The objective response rate at 3 months in single-dosing group and combined-dosing group was 46.9% (15 out of 32) and 66.7% (14 out of 21), respectively.

CONCLUSION

The combined 1^st and 2^nd week dosing of glass microspheres demonstrated an acceptable toxicity and tumor response when both a lobar hepatic artery and a small tumor-feeding artery need to be treated in one session.

ACR-ABS-ACNM-ASTRO-SIR-SNMMI practice parameter for selective internal radiation therapy or radioembolization for treatment of liver malignancies

PURPOSE

The American College of Radiology (ACR), American Brachytherapy Society (ABS), American College of Nuclear Medicine (ACNM), American Society for Radiation Oncology (ASTRO), Society of Interventional Radiology (SIR), and Society of Nuclear Medicine and Molecular Imaging (SNMMI) have jointly developed a practice parameter on selective internal radiation therapy (SIRT) or radioembolization for treatment of liver malignancies. Radioembolization is the embolization of the hepatic arterial supply of hepatic primary tumors or metastases with a microsphere yttrium-90 brachytherapy device.

MATERIALS AND METHODS

The ACR -ABS -ACNM -ASTRO -SIR -SNMMI practice parameter for SIRT or radioembolization for treatment of liver malignancies was revised in accordance with the process described on the ACR website (https://www.acr.org/ClinicalResources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters-Interventional and Cardiovascular Radiology of the ACR Commission on Interventional and Cardiovascular, Committee on Practice Parameters and Technical Standards-Nuclear Medicine and Molecular Imaging of the ACR Commission on Nuclear Medicine and Molecular Imaging and the Committee on Practice Parameters-Radiation Oncology of the ACR Commission on Radiation Oncology in collaboration with ABS, ACNM, ASTRO, SIR, and SNMMI.

RESULTS

This practice parameter is developed to serve as a tool in the appropriate application of radioembolization in the care of patients with conditions where indicated. It addresses clinical implementation of radioembolization including personnel qualifications, quality assurance standards, indications, and suggested documentation.

CONCLUSIONS

This practice parameter is a tool to guide clinical use of radioembolization. It focuses on the best practices and principles to consider when using radioemboliozation effectively. The clinical benefit and medical necessity of the treatment should be tailored to each individual patient.

Pathologic Response of Hepatocellular Carcinoma Treated with Yttrium-90 Glass Microsphere Radiation Segmentectomy Prior to Liver Transplantation: A Validation Study

PURPOSE

To evaluate the pathologic outcomes of hepatocellular carcinoma (HCC) treated with Yttrium-90 radiation segmentectomy using glass microspheres prior to liver transplantation and explore parameters associated with pathologic necrosis.

MATERIALS AND METHODS

A single-institution retrospective analysis of HCC patients who received radiation segmentectomy prior to liver transplantation from November 2016 to May 2020 was performed. Patients were included if the treatment angiosome encompassed the entire tumor and could be correlated with available gross pathology. Archived histology slides were reviewed for percentage of pathologic necrosis. Thirty-three patients with 37 tumors were evaluated. The median tumor size was 2.3 cm (range, 1-6.7 cm).

RESULTS

All tumors received a single treatment. The median time from radiation segmentectomy to transplantation was 206 days (range, 58-550 days). Objective response per Modified Response Evaluation Criteria in Solid Tumors (mRECIST) was 92% (complete response, 76%; partial response, 16%). A total of 68% (n = 25) of tumors demonstrated ≥99% pathologic necrosis. Complete pathologic necrosis was present in 53% and 75% of tumors treated with >190 Gy (n = 18) and >500 Gy (n = 8) single-compartment Medical Internal Radiation Dose, respectively. Complete response per mRECIST, posttreatment angiosome T1 hypointensity, dose >190 Gy, microsphere specific activity >297 Bq, and a longer time between treatment and transplant were associated with ≥99% tumor necrosis (P < .05). No posttransplant tumor recurrences occurred within a median follow-up of 604 days (range, 138-1,223 days).

CONCLUSIONS

Radiation segmentectomy can serve as an ablative modality for the treatment of HCC prior to liver transplant.

Treatment Options for Early-Stage Hepatocellular Carcinoma

Patients with early stage hepatocellular carcinoma have good prognosis and are treated with curative intent. Although this cohort of patients is generally defined by limited tumor burden, good liver function, and preserved functional status, there remains utility in further stratification to optimize overall survival and limit post-operative morbidity and mortality. Transplant, resection, ablation, transarterial radioembolization, and transarterial chemoembolization, either as monotherapy or in combination, may play a crucial role in treating this cohort of patients depending on a multitude of factors. In this section, we review each treatment modality and provide general guidelines for patient selection.

Transarterial Yttrium-90 Radioembolization of Hepatocellular Carcinoma Perfused by the Cystic Artery: Multi-institutional Feasibility Study

PURPOSE

To assess the safety and efficacy of transarterial yttrium-90 radioembolization via the cystic artery for patients with hepatocellular carcinoma (HCC) adjacent to the gallbladder with cystic artery supply.

MATERIALS AND METHODS

This retrospective study included 17 patients treated at 4 institutions. Patients with HCC perfused by the cystic artery who received ablative-dose radioembolization were included. Median tumor size was 3.8 cm (range, 2.0-8.8 cm). Fourteen patients (82%) had Child-Pugh class A cirrhosis and 3 (18%) had class B cirrhosis. Adverse events, tumor response, and time to progression were analyzed.

RESULTS

Median dose to the tissue perfused by the cystic artery was 340 Gy (range, 200-720 Gy). There were no occurrences of acute cholecystitis warranting invasive intervention. Four patients (24%) experienced transient right upper quadrant pain, with symptom resolution within 3 mo. Six patients (35%) exhibited gallbladder wall edema on follow-up imaging. Two (12%) and 0 grade 3/4 increases in alkaline phosphatase and bilirubin were observed, respectively. Follow-up imaging demonstrated complete response in 13 target tumors (76%) and partial response in 4 (24%). There were no cases of target tumor progression during a median follow-up of 9 mo (range, 3-72 mo).

CONCLUSIONS

Direct infusion of 90Y microspheres via the cystic artery appears to have an acceptable safety profile, without resulting in acute cholecystitis warranting invasive intervention. In selected patients with HCC in whom other treatments may be contraindicated and the tumor is supplied via the cystic artery, treatment with selective ablative radioembolization can be considered.

Locoregional Therapies for Hepatocellular Carcinoma: What Has Changed in the Past Ten Years?

The evolution of locoregional therapies in the last decade has been refined with improved patient selection and a development of a more personalized approach. In doing so, there has been associated improved outcomes and less toxicity. With the rapidly changing landscape of systemic therapy, the role of locoregional therapies alone or in combination for downstaging and curative intent will continue to evolve.

Yttrium-90 radiation segmentectomy for hepatic metastases: A multi-institutional study of safety and efficacy

BACKGROUND AND OBJECTIVES

This study assessed the outcomes of Yttrium-90 (⁹⁰ Y) radiation segmentectomy for hepatic metastases unamenable to resection or ablation.

MATERIALS AND METHODS

Over 6 years, 36 patients with 53 tumors underwent segmental radioembolization. Patients were not candidates for surgical resection or thermal ablation. Malignancies included metastases from colorectal cancer (31%), neuroendocrine tumors (28%), sarcoma (19%), and others (22%). Eighty-one percent of patients had undergone prior treatment with systemic chemotherapy. Ongoing systemic chemotherapy was continued. Toxicity, tumor response, tumor progression, and survival were assessed.

RESULTS

The median tumor size was 3.6 cm (range 1.2-6.1 cm). Adverse event rates were low, with no hepatic-related Common Terminology Criteria for Adverse Events Grade 3 or 4 toxicity. Target tumor Response Evaluation Criteria in Solid Tumors disease control rate was 92% (28% partial response, 64% stable disease). For patients with enhancing tumors (n = 14), modified Response Evaluation Criteria in Solid Tumors target tumor objective response rate was 100%. During a median follow-up of 12 months, target tumor progression occurred in 28% of treated tumors. Overall survival was 96% and 83% at 6 and 12 months, respectively.

CONCLUSIONS

⁹⁰ Y radiation segmentectomy for hepatic metastases demonstrates high rates of tumor control and minimal toxicity. Radiation segmentectomy should be considered for patients with metastatic hepatic malignancy who are not candidates for surgical resection.

Selective internal radiation therapies for unresectable early-, intermediate- or advanced-stage hepatocellular carcinoma: systematic review, network meta-analysis and economic evaluation

BACKGROUND

Hepatocellular carcinoma is the most common type of primary liver cancer. Treatment choice is dependent on underlying liver dysfunction and cancer stage. Treatment options include conventional transarterial therapies for patients with intermediate-stage disease and systemic therapy [e.g. sorafenib (Nexavar®; Bayer plc, Leverkusen, Germany)] for patients with advanced-stage disease. Selective internal radiation therapies deliver radiation to liver tumours via microspheres that are injected into the hepatic artery. There are three selective internal radiation therapies: TheraSphere™ [BTG Ltd, London, UK (now Boston Scientific, Marlborough, MA, USA)], SIR-Spheres® (Sirtex Medical Ltd, Woburn, MA, USA) and QuiremSpheres® (Quirem Medical BV, Deventer, the Netherlands).

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of selective internal radiation therapies for treating patients with unresectable early-, intermediate- or advanced-stage hepatocellular carcinoma.

METHODS

A search was undertaken to identify clinical effectiveness literature relating to selective internal radiation therapies and relevant comparators for the treatment of hepatocellular carcinoma. Studies were critically appraised and summarised. The network of evidence was mapped to estimate the relative effectiveness of the different selective internal radiation therapies and comparator treatments. An economic analysis evaluated the cost-effectiveness.

RESULTS

Twenty studies were included in the clinical effectiveness review. Two large randomised controlled trials rated as having a low risk of bias [SARAH: Vilgrain V, Pereira H, Assenat E, Guiu B, Ilonca AD, Pageaux GP, et al. Efficacy and safety of selective internal radiotherapy with yttrium-90 resin microspheres compared with sorafenib in locally advanced and inoperable hepatocellular carcinoma (SARAH): an open-label randomised controlled Phase 3 trial. Lancet Oncol 2017;18:1624-36; and SIRveNIB: Chow PKH, Gandhi M, Tan SB, Khin MW, Khasbazar A, Ong J, et al. SIRveNIB: selective internal radiation therapy versus sorafenib in Asia-Pacific patients with hepatocellular carcinoma. J Clin Oncol 2018;36:1913-21] found no significant difference in overall survival or progression-free survival between SIR-Spheres and sorafenib (systemic therapy) in an advanced population, despite greater tumour response in the SIR-Spheres arm of both trials. There were some concerns regarding generalisability of the SARAH and SIRveNIB trials to UK practice. All other studies of SIR-Spheres, TheraSphere or QuiremSpheres were either rated as being at a high risk of bias or caused some concerns regarding bias. A network meta-analysis was conducted in adults with unresectable hepatocellular carcinoma who had Child-Pugh class A liver cirrhosis and were ineligible for conventional transarterial therapies. The analysis included the SARAH and SIRveNIB trials as well as a trial comparing lenvatinib (Kisplyx®; Eisai Ltd, Tokyo, Japan) (systemic therapy) with sorafenib. There were no meaningful differences in overall survival between any of the treatments. The base-case economic analysis suggested that TheraSphere may be cost-saving relative to both SIR-Spheres and QuiremSpheres. However, incremental cost differences between TheraSphere and SIR-Spheres were small. In a fully incremental analysis, which included confidential Patient Access Scheme discounts, lenvatinib was the most cost-effective treatment and dominated all selective internal radiation therapies. In pairwise comparisons of sorafenib with each selective internal radiation therapy, sorafenib also dominated all selective internal radiation therapies.

LIMITATIONS

The existing evidence cannot provide decision-makers with clear guidance on the comparative effectiveness of treatments in early- and intermediate-stage hepatocellular carcinoma or on the efficacy of TheraSphere or QuiremSpheres.

CONCLUSIONS

In the advanced-stage hepatocellular carcinoma population, two large randomised trials have shown that SIR-Spheres have similar clinical effectiveness to sorafenib. None of the selective internal radiation therapies was cost-effective, being more costly and less effective than lenvatinib, both at list price and with Patient Access Scheme discounts.

FUTURE WORK

Future studies may wish to include early- and intermediate-stage hepatocellular carcinoma patients and the low tumour burden/albumin-bilirubin 1 subgroup of advanced-stage patients. Future high-quality studies evaluating alternative selective internal radiation therapies would be beneficial.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019128383.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 48. See the NIHR Journals Library website for further project information.

Streamlining radioembolization in UNOS T1/T2 hepatocellular carcinoma by eliminating lung shunt estimation

BACKGROUND & AIMS

Pre-treatment Tc-99m macroaggregated albumin (MAA) scans are routinely performed prior to transarterial radioembolization (TARE) to estimate lung shunt fraction (LSF) and lung dose. In this study, we investigate LSF observed in early hepatocellular carcinoma (HCC) and provide the scientific rationale for eliminating this step from routine practice.

METHODS

Patients with HCC who underwent Y90 from 2004 to 2018 were reviewed. Inclusion criteria were early stage HCC (UNOS T1/T2/Milan criteria: solitary ≤5 cm, 3 nodules ≤3 cm). LSF was determined using MAA in all patients. Associations between LSF and baseline characteristics were investigated. A "no-MAA" paradigm was then proposed based on a homogenous group that expressed very low LSF.

RESULTS

Of 1,175 patients with HCC treated with TARE, 448 patients met inclusion criteria. Mean age was 65.6 years and 303 (68%) were males. A total of 352 (79%) had solitary lesions and 406 (91%) unilobar disease. Two-hundred and forty-three (54%), 178 (40%) and 27 (6%) patients were Child-Pugh class A, B and C, respectively. Median LSF was 3.9% (IQR 2.4-6%). Median administered activity was 0.9 GBq (IQR 0.6-1.4), for a median segmental volume of 170 cm³ (range: 60-530). Median lung dose was 1.9 Gy (IQR: 1.0-3.3). The presence of a transjugular intrahepatic portosystemic shunt (TIPS; n = 38) was associated with LSF >10% (odds ratio 12.2; 95% CI 5.2-28.6; p <0.001). Median LSF was 3.8% (IQR: 2.4-5.7%) and 6% (IQR: 3.8-15.3%) in no-TIPS vs. TIPS patients (p <0.001).

CONCLUSION

LSF is clinically negligible in patients with UNOS T1/T2 HCC without TIPS. When segmental injections are planned, this step can be eliminated, thereby reducing time-to-treatment, number of procedures, and improving convenience for patients traveling from faraway.

LAY SUMMARY

Transarterial radioembolization is a microembolic transarterial treatment for hepatocellular carcinoma. In our study, we found that early stage patients, where segmental injections are planned, exhibited low lung shunting, effectively eliminating the risk of radiation pneumonitis. We propose that the lung shunt study be eliminated in this subgroup, thus leading to fewer procedures, a cost reduction and improved convenience for patients.

Ablation plus Transarterial Embolic Therapy for Hepatocellular Carcinoma Larger than 3 cm: Science, Evidence, and Future Directions

Thermal ablation is widely regarded as definitive therapy for early-stage hepatocellular carcinoma, but its efficacy decreases in tumors greater than 3 cm. Extensive clinical studies have supported improved outcomes provided through combining transarterial embolic therapy with ablation in the treatment of larger tumors. This article will provide a survey of the science and data for combination therapy in both thermal and nonthermal ablation modalities, as well as describe emerging applications.

Clinical and dosimetric considerations for Y90: recommendations from an international multidisciplinary working group

The TheraSphere Global Dosimetry Steering Committee was formed in 2017 by BTG International to review existing data and address gaps in knowledge related to dosimetry. This committee is comprised of health care providers with diverse areas of expertise and perspectives on radiation dosimetry. The goal of these recommendations is to optimize glass microspheres radiation therapy for hepatocellular carcinoma while accounting for variables including disease presentation, tumour vascularity, liver function, and curative/palliative intent. The recommendations aim to unify glass microsphere users behind standardized dosimetry methodology that is simple, reproducible and supported by clinical data, with the overarching goal of improving clinical outcomes and advancing the knowledge of dosimetry.

Update on transarterial approaches to locoregional treatment in hepatocellular carcinoma

PURPOSE OF REVIEW

This review explores current knowledge and recent data about vascular-centered locoregional treatments and proposes alternate algorithms.

RECENT FINDINGS

Hepatocellular carcinoma represents the sixth most common neoplasm worldwide. Currently, the Barcelona Clinic Liver Cancer (BCLC) staging is the most commonly used in Europe for treatment allocation. According to this classification, European Society for Medical Oncology (ESMO) guidelines currently recommend transarterial chemoembolization for intermediate stage HCC and systemic treatments, such as, sorafenib in more advanced stages. However, strong evidences are still lacking to conclude to the superiority of one technique over another, as the optimal treatment choice remains challenging and should take into consideration more clinical, biological and imaging findings than reported in the BCLC staging system, such as patient age or clinical status, tumor characteristics (including distribution and heterogeneity), tumor vascularization and concomitant portal hypertension or biliary anomalies.

SUMMARY

Many controversies remain, in particular, the relative place of bland embolization versus chemoembolization, the clinical benefit of drug-eluting bead chemoembolization (DEB-TACE) over conventional chemoembolization (cTACE), as well as the real place of radioembolization in general setting as well as innovative applications, such as radiation segmentectomy and radiation lobectomy.

Radiation Segmentectomy and Radiation Lobectomy: A Practical Review of Techniques

The radiation segmentectomy technique may be defined as the administration of transarterial radioembolization delivered to 1 or 2 hepatic segments with the intention of segmental tissue ablation. Since first being described in 2011, radiation segmentectomy has quickly gained acceptance as a safe, effective, and potentially curative outpatient treatment for selected lower stage hepatocellular carcinomas. We describe our recommended techniques for radiation segmentectomy with glass or resin radiomicrospheres, including patient selection, dosimetry, microcatheter techniques, and clinical and imaging follow-up, accompanied by a brief review of the radiation segmentectomy literature. Radiation lobectomy, defined as the ablation of an entire hepatic lobe via transarterial radioembolization, is an area of growing interest in many centers. We also review the existing radiation lobectomy literature and suggest which patient and tumor factors may be associated with higher likelihood of successful treatment.

Y90 Radioembolization Dosimetry: Concepts for the Interventional Radiologist

Transarterial radioembolization (TARE) with beta particle emitting microspheres via Yttrium-90 decay has become a fundamental component of the contemporary Interventional Oncology practice. TARE continues to advance as a result of increased utilization, clinical study, technological improvements, and evolving applications. To maximize TARE safety and efficacy, a core understanding of dosimetry is essential. The intent of this overview is to provide the reader with a general survey of radiation physics and biology, device differentiation, patient selection, anatomic assessment, activity administration models, and procedural techniques involved with TARE dosimetry.