A Prospective Phase II Trial of Radioembolization for Treatment of Uveal Melanoma Hepatic Metastasis

The Current State of Systemic Therapy of Metastatic Uveal Melanoma

Uveal melanoma (UM) is genetically a distinct tumor compared to cutaneous melanoma (CM), and due to its low mutational burden, it is far less perceptible to the immune system. Thus, treatments that have revolutionized the treatment of CM remain widely inefficient in metastatic UM or only demonstrate effectiveness in a small subpopulation of patients. To this end, the therapeutic benefit of immune checkpoint blockade is very limited and may come at the expense of severe immune-related adverse events that could potentially affect all organ systems. Notably, tebentafusp, an entirely novel class of anti-cancer drugs, has received official authorization for the treatment of metastatic UM. It is the first agent that demonstrated a survival advantage in a randomized controlled trial of metastatic UM patients. Despite the survival benefit and approval, the restriction of tebentafusp to HLA-A*02:01-positive patients and the low objective response rate indicate the persistent need for additional therapies. Thus, liver-directed therapies are commonly used for tumor control of hepatic metastases and represent a central pillar of the daily management of liver-dominant disease. Further, promising data from targeted therapies independent of MEK-inhibitors, such as the combination of darovasertib and crizotinib, raise hope for additional options in metastatic UM in the future. This narrative review provides a timely and comprehensive overview of the current treatment landscape for metastatic UM.

Immunoembolization for the Treatment of Uveal Melanoma Hepatic Metastases

Uveal melanoma is the most common primary intraocular tumor in adults. Approximately 50% of patients develop metastatic disease despite successful treatment of the primary eye tumor. The liver is the most common site of metastatic disease occurring in more than 90% of patients. Clinical prognosis is dependent on the ability to control the growth of liver tumors. Locoregional therapies play an important role in stabilizing liver metastases, prolonging survival for patients with metastatic uveal melanoma. As overall survival is prolonged, the development of extrahepatic disease becomes more common. Immunoembolization, a form of liver-directed therapy, not only focuses on treating hepatic metastases by stimulating the local immune system to suppress the growth of liver tumors, but it potentially generates a systemic immune response delaying the growth of extrahepatic metastases as well. The following article discusses immunoembolization for the treatment of metastatic uveal melanoma including the rationale, mechanism of action, indications, contraindications, outcomes, and associated toxicities.

Chemoembolization Beyond Hepatocellular Carcinoma: What Tumors Can We Treat and When?

Liver metastases are the most common malignancy found in the liver and are 20 to 40 times more common than primary hepatic tumors, including hepatocellular carcinoma. Patients with liver metastases often present with advanced disease and are not eligible for curative-intent surgery or ablative techniques. The unique hepatic arterial blood supply of liver metastases allows interventional radiologists to target these tumors with transarterial therapies. Transarterial chemoembolization (TACE) has been studied in the treatment of liver metastases originating from a variety of primary malignancies and has demonstrated benefits in terms of hepatic progression-free survival, overall survival, and symptomatic relief, among other benefits. Depending on the primary tumor from which they originate, liver metastases may have different indications for TACE, may utilize different TACE regimens and techniques, and may result in different post-procedural outcomes. This review offers an overview of TACE techniques and specific considerations in the treatment of liver metastases, provides an in-depth review of TACE in the treatment of liver metastases originating from colorectal cancer, neuroendocrine tumor, and uveal melanoma, which represent some of the many tumors beyond hepatocellular carcinoma that can be treated by TACE, and summarizes data regarding when one should consider TACE in their treatment algorithms.

Management of Uveal Melanoma: Updated Cancer Care Alberta Clinical Practice Guideline

OBJECTIVE

The purpose of this guideline update is to reassess and update recommendations in the prior guideline from 2016 on the appropriate management of patients with uveal melanoma.

METHODS

In 2021, a multidisciplinary working group from the Provincial Cutaneous Tumour Team, Cancer Care Alberta, Alberta Health Services was convened to update the guideline. A comprehensive review of new research evidence in PubMed as well as new clinical practice guidelines from prominent oncology groups informed the update. An enhancement in methodology included adding levels of evidence and strength of recommendations. The updated guideline was circulated to all members of the Provincial Cutaneous Tumour Team for review and endorsement.

RESULTS

New and modified recommendations address provider training requirements, diagnostic imaging for the detection of metastases, neo-adjuvant pre-enucleation radiotherapy, intravitreal anti-vascular endothelial growth factor agents for radiation retinopathy, genetic prognostic testing, surveillance following definitive local therapy, and systemic therapy for patients with metastatic uveal melanoma.

DISCUSSION

The recommendations represent evidence-based standards of care agreed to by a large multidisciplinary group of healthcare professionals.

Liver-directed treatment is associated with improved survival and increased response to immune checkpoint blockade in metastatic uveal melanoma: results from a retrospective multicenter trial

Metastases of uveal melanoma (UM) spread predominantly to the liver. Due to low response rates to systemic therapies, liver-directed therapies (LDT) are commonly used for tumor control. The impact of LDT on the response to systemic treatment is unknown. A total of 182 patients with metastatic UM treated with immune checkpoint blockade (ICB) were included in this analysis. Patients were recruited from prospective skin cancer centers and the German national skin cancer registry (ADOReg) of the German Dermatologic Cooperative Oncology Group (DeCOG). Two cohorts were compared: patients with LDT (cohort A, n = 78) versus those without LDT (cohort B, n = 104). Data were analyzed for response to treatment, progression-free survival (PFS), and overall survival (OS). The median OS was significantly longer in cohort A than in cohort B (20.1 vs. 13.8 months; P = 0.0016) and a trend towards improved PFS was observed for cohort A (3.0 vs. 2.5 months; P = 0.054). The objective response rate to any ICB (16.7% vs. 3.8%, P = 0.0073) and combined ICB (14.1% vs. 4.5%, P = 0.017) was more favorable in cohort A. Our data suggest that the combination of LDT with ICB may be associated with a survival benefit and higher treatment response to ICB in patients with metastatic UM.

Minimally Invasive Treatment Options for Hepatic Uveal Melanoma Metastases

Uveal melanoma is one of the most common primary intraocular malignancies that accounts for about 85% of all ocular melanomas. The pathophysiology of uveal melanoma is distinct from cutaneous melanoma and has separate tumor profiles. The management of uveal melanoma is largely dependent on the presence of metastases, which confers a poor prognosis with a one-year survival reaching only 15%. Although a better understanding of tumor biology has led to the development of novel pharmacologic agents, there is increasing demand for minimally invasive management of hepatic uveal melanoma metastases. Multiple studies have already summarized the systemic therapeutic options available for metastatic uveal melanoma. This review covers the current research for the most prevalent locoregional treatment options for metastatic uveal melanoma including percutaneous hepatic perfusion, immunoembolization, chemoembolization, thermal ablation, and radioembolization.

Dosimetric impact of 3D motion-compensated SPECT reconstruction for SIRT planning

BACKGROUND

In selective internal radiation therapy, ^99mTc SPECT images are used to optimize patient treatment planning, but they are affected by respiratory motion. In this study, we evaluated on patient data the dosimetric impact of motion-compensated SPECT reconstruction on several volumes of interest (VOI), on the tumor-to-normal liver (TN) ratio and on the activity to be injected.

METHODS

Twenty-nine patients with liver cancer or hepatic metastases treated by radioembolization were included in this study. The biodistribution of ⁹⁰Y is assumed to be the same as that of ^99mTc when predictive dosimetry is implemented. A total of 31 ^99mTc SPECT images were acquired and reconstructed with two methods: conventional OSEM (3D) and motion-compensated OSEM (3Dcomp). Seven VOI (liver, lungs, tumors, perfused liver, hepatic reserve, healthy perfused liver and healthy liver) were delineated on the CT or obtained by thresholding SPECT images followed by Boolean operations. Absorbed doses were calculated for each reconstruction using Monte Carlo simulations. Percentages of dose difference (PDD) between 3Dcomp and 3D reconstructions were estimated as well as the relative differences for TN ratio and activities to be injected. The amplitude of movement was determined with local rigid registration of the liver between the 3Dcomp reconstructions of the extreme phases of breathing.

RESULTS

The mean amplitude of the liver was 9.5 ± 2.7 mm. Medians of PDD were closed to zero for all VOI except for lungs (6.4%) which means that the motion compensation overestimates the absorbed dose to the lungs compared to the 3D reconstruction. The smallest lesions had higher PDD than the largest ones. Between 3D and 3Dcomp reconstructions, means of differences in lung dose and TN ratio were not statistically significant, but in some cases these differences exceed 1 Gy (4/31) and 8% (2/31). The absolute differences in activity were on average 3.1% ± 5.1% and can reach 22.8%.

CONCLUSION

The correction of respiratory motion mainly impacts the lung and tumor doses but only for some patients. The largest dose differences are observed for the smallest lesions.

Advances in the clinical management of uveal melanoma

Melanomas arising in the uveal tract of the eye are a rare form of the disease with a biology and clinical phenotype distinct from their more common cutaneous counterparts. Treatment of primary uveal melanoma with radiotherapy, enucleation or other modalities achieves local control in more than 90% of patients, although 40% or more ultimately develop distant metastases, most commonly in the liver. Until January 2022, no systemic therapy had received regulatory approval for patients with metastatic uveal melanoma, and these patients have historically had a dismal prognosis owing to the limited efficacy of the available treatments. A series of seminal studies over the past two decades have identified highly prevalent early, tumour-initiating oncogenic genomic aberrations, later recurring prognostic alterations and immunological features that characterize uveal melanoma. These advances have driven the development of a number of novel emerging treatments, including tebentafusp, the first systemic therapy to achieve regulatory approval for this disease. In this Review, our multidisciplinary and international group of authors summarize the biology of uveal melanoma, management of primary disease and surveillance strategies to detect recurrent disease, and then focus on the current standard and emerging regional and systemic treatment approaches for metastatic uveal melanoma.

Chemosaturation of the Liver - an Update

BACKGROUND

Percutaneous hepatic perfusion (CS-PHP) is a treatment option for primary and secondary liver neoplasms and subject of intensive research. This present article provides an overview of CS-PHP regarding patient safety, feasibility and effectiveness based on recent studies.

METHOD

We performed a PubMed search including the search terms chemosaturation, hepatic chemosaturation, percutaneous perfusion and melphalan.

RESULTS AND CONCLUSION

CS-PHP is a promising procedure for the treatment of uveal melanoma and cholangiocellular carcinoma. There are insufficient data regarding the effectiveness of CS-PHP with respect to other tumor entities. Since CS-PHP can be accompanied by multiple transient side effects and complications, close interdisciplinary cooperation is necessary.

KEY POINTS

· Chemosaturation of the liver is a safe procedure.. · CS-PHP is a potent therapy for hepatic metastatic ocular melanoma and cholangiocellular carcinoma.. · The procedure requires close interdisciplinary coordination.. · CS-PHP is a repeatable and thus long-term therapeutic option for some patients..

CITATION FORMAT

· Ebel S, Struck MF, van Boemmel F et al. Chemosaturation of the Liver - an Update. Fortschr Röntgenstr 2023; 195: 30 - 37.

Tebentafusp for the treatment of HLA-A*02:01-positive adult patients with unresectable or metastatic uveal melanoma

INTRODUCTION

Metastatic uveal melanoma is associated with poor prognosis and few treatment options. Tebentafusp recently became the first FDA-approved agent for metastatic uveal melanoma.

AREAS COVERED

In this review, we describe the mechanism of action of tebentafusp as well as preclinical data showing high tumor specificity of the drug. We also review promising early-phase trials in which tebentafusp demonstrated activity in metastatic uveal melanoma patients with an acceptable toxicity profile that included cytokine-mediated, dermatologic-related, and liver-related adverse events. Finally, we summarize findings from a pivotal phase III randomized trial in which tebentafusp demonstrated significant improvement in overall survival in comparison with investigator choice therapy.

EXPERT OPINION

Tebentafusp has transformed the treatment paradigm for metastatic uveal melanoma and should be the preferred frontline agent for most HLA-A*0201 positive patients. However, patients with rapidly progressing disease or high tumor benefit may not derive the same benefit. Areas of future study should focus on its role in the adjuvant setting as well as strategies to improve the efficacy of tebentafusp in the metastatic setting.

Tumor Growth Rate as a Predictive Marker for Recurrence and Survival After Liver Resection in Patients with Liver Metastases of Uveal Melanoma

BACKGROUND

Surgical management of liver metastases of uveal melanoma (LMUM) is associated with the best survival rates, especially for patients with a low tumor burden in the liver. The aim was to determine whether the tumor growth rate (TGR₀) before liver resection helps predict survival in patients with resectable LMUM.

METHODS

This retrospective study included 99 patients with LMUM treated with liver resection between November 2007 and November 2020. TGR₀ was expressed as the percentage change in tumor volume over 1 month according to two pretreatment imaging scans. Multivariate Cox analyses identified independent predictors of disease-free survival (DFS) and overall survival (OS).

RESULTS

DFS and OS had a statistically significant positive linear relationship (Spearman correlation r = 0.68, p < 0.001). A disease-free interval (DFI) > 24 months and a TGR₀ ≤ 50%/month were independent factors associated with better DFS and OS. The 2-component model including TGR₀ and DFI had a mean time-dependent area under the curve (AUC) of 0.81 (95% CI, 0.75-0.86) and 0.77 (95% CI, 0.67-0.87), respectively, for predicting DFS and OS. DFI with TGR₀ defined three kinetic risk groups that had distinct DFS and OS outcomes (p < 0.001). Cytogenetic alterations at baseline were partially predictive factors of the kinetic risk score based on TGR₀ and DFI.

DISCUSSION

The assessment of TGR₀ improves prognostic stratification by identifying patients at high risk of recurrence and poor survival after liver resection. TGR₀ and DFI, reflecting tumor aggressivity, have the potential to be important markers for systemic adjuvant decisions.

Improved Uveal Melanoma Copy Number Subtypes Including an Ultra–High-Risk Group

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Efficacy and tolerability of chemosaturation in patients with hepatic metastases from uveal melanoma

BACKGROUND

Patients with hepatic metastatic uveal melanoma still have a poor outcome.

PURPOSE

To evaluate overall survival (OS), progression-free survival (PFS), and response predictors in these patients treated with chemosaturation by percutaneous hepatic perfusion with melphalan (CS-PHP).

MATERIAL AND METHODS

Between June 2015 and March 2020, a total of 29 patients (median age 69.7 years; age range 30-81 years; 60% women; median BMI 25.7 kg/m²; range 18.7-35.3kg/m²; 1-6 procedures per patient) were treated with 53 CS-PHPs. All patients received cross-sectional imaging for initial and follow-up examinations. Baseline tumor load, extrahepatic tumor load, tumor response, PFS, and OS were assessed. Non-parametric statistics were used.

RESULTS

After the initial CS-PHP, a partial response was observed in 11 patients (41%), stable disease in 12 patients (44%) and progressive disease in 4 patients (15%); two patients died before the response was evaluated. After initial CS-PHP, median OS was 12.9 ± 7.4 months and median PFS was 7.1 ± 7.4 months. OS after one year was 50%. After the second CS-PHP, median PFS was 7.9 ± 5.7 months. Seven patients had a liver tumor burden >25%, associated with a significantly shorter OS (6.0 ± 2.4 vs. 14.1 ± 12.7 months; P = 0.008). At the time of first CS-PHP, 41% (12/29) of the patients had extrahepatic metastases that did not affect OS (11.1 ± 8.4 months vs. 12.9 ± 13.6 months; P = 0.66).

CONCLUSION

CS-PHP is a safe and effective treatment for the hepatic metastatic uveal melanoma, especially for patients with a hepatic tumor burden <25%.

Safety and Efficacy of Ipilimumab plus Nivolumab and Sequential Selective Internal Radiation Therapy in Hepatic and Extrahepatic Metastatic Uveal Melanoma

Simple Summary

Despite recent progress on the treatment of metastatic uveal melanoma (mUM), prognosis remains dismal for the majority of patients. Directed liver therapies including selective internal radiation therapy (SIRT) have been the pillar of hepatic metastases management. Independently, immune checkpoint blockade by combination of ipilimumab plus nivolumab has demonstrated a median survival slightly superior to 1 year. However, the benefit of sequential ipilimumab plus nivolumab immunotherapy and SIRT has not been elucidated.

Abstract

To assess the safety and efficacy of ipilimumab plus nivolumab around selective internal radiation therapy (SIRT) in patients with metastatic uveal melanoma (mUM). We present a retrospective, single center study of 32 patients with mUM divided into two groups based on the treatment received between April 2013 and April 2021. The SIRT_IpiNivo cohort was treated with Yttrium-90 microspheres and ipilimumab plus nivolumab before or after the SIRT (n = 18). The SIRT cohort underwent SIRT but did not receive combined immunotherapy with ipilimumab plus nivolumab (n = 14). Twelve patients (66.7%) of the SIRT_IpiNivo arm received SIRT as first-line treatment and six patients (33.3%) received ipilimumab plus nivolumab prior to SIRT. In the SIRT group, seven patients (50.0%) received single-agent immunotherapy. One patient treated with combined immunotherapy 68 months after the SIRT was included in this group. At the start of ipilimumab plus nivolumab, 94.4% (n = 17) presented hepatic metastases and 72.2% (n = 13) had extra liver disease. Eight patients (44.4%) of the SIRT_IpiNivo group experienced grade 3 or 4 immune related adverse events, mainly colitis and hepatitis. Median overall survival from the diagnosis of metastases was 49.6 months (95% confidence interval (CI); 24.1-not available (NA)) in the SIRT_IpiNivo group compared with 13.6 months (95% CI; 11.5-NA) in the SIRT group (log-rank p-value 0.027). The presence of extra liver metastases at the time of SIRT, largest liver lesion more than 8 cm (M1c) and liver tumor volume negatively impacted the survival. This real-world cohort suggests that a sequential treatment of ipilimumab plus nivolumab and SIRT is a well-tolerated therapeutic approach with promising survival rates.

A Pilot Study of Hepatic Irradiation with Yttrium90 Microspheres Followed by Immunotherapy with Ipilimumab and Nivolumab for Metastatic Uveal Melanoma

Background: Liver metastases from uveal melanoma carry a very poor prognosis. Hepatic artery infusions with Yttrium-90 (⁹⁰Y) resin microspheres have some activity in this disease, and radiation and immunotherapy may be synergistic. The primary objective of this study was to determine the safety and tolerability of sequential ⁹⁰Y resin microspheres and immunotherapy with ipilimumab and nivolumab in metastatic uveal melanoma.

Materials and Methods: Twenty-six patients with uveal melanoma with hepatic metastases were entered into a pilot study. Treatment consisted of two infusions of ⁹⁰Y resin microspheres, one to each lobe of the liver, followed in 2–4 weeks by immunotherapy with ipilimumab and nivolumab every 3 weeks for four doses, then maintenance immunotherapy with nivolumab alone.

Results: Initial dosing of both ⁹⁰Y and immunotherapy resulted in excessive toxicity. With decreasing the dosage of ⁹⁰Y to limit the normal liver dose to 35Gy and lowering the ipilimumab dose to 1 mg/kg, the toxicity was tolerable, with no apparent change in efficacy. There was one complete and four confirmed partial responses, for an objective response rate of 20% and a disease control rate of 68%. The median progression-free survival was 5.5 months (95% confidence interval [CI]: 1.3–9.7 months), with a median overall survival of 15 months (95% CI: 9.7–20.1 months).

Conclusions: With dose reductions, sequential therapy with ⁹⁰Y and immunotherapy with ipilimumab and nivolumab is safe and tolerable, and has activity in metastatic uveal melanoma. These results justify a controlled trial to demonstrate whether ⁹⁰Y resin microspheres add to the utility of combination immunotherapy in this disease.

Clinical Trial Registration number: NCT02913417.

Metastatic uveal melanoma: The final frontier

Treatment of primary intraocular uveal melanoma has developed considerably, its driver genes are largely unraveled, and the ways to assess its risk for metastases are very precise, being based on an international staging system and genetic data. Unfortunately, the risk of distant metastases, which emerge in approximately one half of all patients, is unaltered. Metastases are the leading single cause of death after uveal melanoma is diagnosed, yet no consensus exists regarding surveillance, staging, and treatment of disseminated disease, and survival has not improved until recently. The final frontier in conquering uveal melanoma lies in solving these issues to cure metastatic disease. Most studies on metastatic uveal melanoma are small, uncontrolled, retrospective, and do not report staging. Meta-analyses confirm a median overall survival of 10-13 months, and a cure rate that approaches nil, although survival exceeding 5 years is possible, estimated 2% either with first-line treatment or with best supportive care. Hepatic ultrasonography and magnetic resonance imaging as surveillance methods have a sensitivity of 95-100% and 83-100%, respectively, to detect metastases without radiation hazard according to prevailing evidence, but computed tomography is necessary for staging. No blood-based tests additional to liver function tests are generally accepted. Three validated staging systems predict, each in defined situations, overall survival after metastasis. Their essential components include measures of tumor burden, liver function, and performance status or metastasis free interval. Age and gender may additionally influence survival. Exceptional mutational events in metastases may make them susceptible to checkpoint inhibitors. In a large meta-analysis, surgical treatment was associated with 6 months longer median overall survival as compared to conventional chemotherapy and, recently, tebentafusp as first-line treatment at the first interim analysis of a randomized phase III trial likewise provided a 6 months longer median overall survival compared to investigator's choice, mostly pembrolizumab; these treatments currently apply to selected patients. Promoting dormancy of micrometastases, harmonizing surveillance protocols, promoting staging, identifying predictive factors, initiating controlled clinical trials, and standardizing reporting will be critical steppingstones in reaching the final frontier of curing metastatic uveal melanoma.

Selective internal radiation therapy for hepatic metastases of uveal melanoma: a systematic review

OBJECTIVE

Uveal melanoma (UM) commonly metastasizes to the liver. Treatment usually consists of liver-directed therapies, such as selective internal radiation therapy (SIRT). This review aimed to assess the effectiveness and safety of SIRT for hepatic metastases from UM.

METHODS

The study protocol is available at OSF (https://osf.io/vhyct/). EMBASE and MEDLINE were searched until July 2020, using terms related to SIRT and hepatic metastases from UM. Studies reporting outcomes of SIRT in patients with UM and at least one hepatic metastasis were included. Data on overall survival (OS), hepatic progression free survival (hPFS) or tumor response were collected. The Newcastle-Ottawa Scale (NOS) was used to assess risk of bias.

RESULTS

11 studies were included, reporting outcomes for 268 patients with hepatic metastases from UM. Most studies (n = 9, 81.8%) were retrospective. Disease control was achieved in 170 patients (67.5%) and the median OS from time of SIRT was 12.3 months. Median hPFS was 5.4 months. Low-grade side-effects were common but serious complications were infrequent. There were two treatment-related deaths. The median NOS score was 6 (moderate risk of bias).

CONCLUSION

SIRT appears to be a safe and effective treatment for patients with unresectable hepatic metastases from UM. The certainty of our results is unclear due to predominantly retrospective data with moderate risk of bias. Further prospective studies are required to explore the role of SIRT in UM.

ADVANCES IN KNOWLEDGE

SIRT appears to be a safe treatment for patients with unresectable hepatic metastases from UM. Further prospective work is required.

Prognostic Values of G-Protein Mutations in Metastatic Uveal Melanoma

Simple Summary

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. More than 90% of UMs harbor mutually exclusive activating mutations in G-proteins. The mutations are early events in UM development and considered to be driver mutations in carcinogenesis. Even after treatment of primary uveal melanoma, up to 50% of patients subsequently develop recurrence, predominantly in the liver. GNAQ mutations are not reported to be correlated to survival, while the mutations in GNA11 are reported more frequently in metastatic UM. We investigated the correlation of survival after development of metastasis (Met-to-Death) of metastatic uveal melanoma (MUM) patients with GNA11 and GNAQ mutations. We identified that MUM with mutation patterns of Q209P vs. Q209L in GNA11 and GNAQ might predict survival of MUM patients.

Abstract

Uveal melanoma is the most common primary ocular malignancy in adults, characterized by gene mutations in G protein subunit alpha q (GNAQ) and G protein subunit alpha 11 (GNA11). Although they are considered to be driver mutations, their role in MUM remains elusive. We investigated key somatic mutations of MUM and their impact on patients’ survival after development of systemic metastasis (Met-to-Death). Metastatic lesions from 87 MUM patients were analyzed by next generation sequencing (NGS). GNA11 (41/87) and GNAQ (39/87) mutations were most predominantly seen in MUM. Most GNA11 mutations were Q209L (36/41), whereas GNAQ mutations comprised Q209L (14/39) and Q209P (21/39). Epigenetic pathway mutations BAP1 (42/66), SF3B1 (11/66), FBXW7 (2/87), PBRM1 (1/66), and SETD2 (1/66) were found. No specimen had the EIF1AX mutation. Interestingly, Met-to-Death was longer in patients with GNAQ Q209P compared to GNAQ/GNA11 Q209L mutations, suggesting the difference in mutation type in GNAQ/GNA11 might determine the prognosis of MUM. Structural alterations of the GNAQ/GNA11 protein and their impact on survival of MUM patients should be further investigated.

The Role of HGF/MET Signaling in Metastatic Uveal Melanoma

Simple Summary

Hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) signaling plays an important role in the metastatic formation and therapeutic resistance to uveal melanoma. Here, we review the various functions of MET signaling contributing to metastatic formation, as well as review resistance to treatments in metastatic uveal melanoma.

Abstract

Hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) signaling promotes tumorigenesis and tumor progression in various types of cancer, including uveal melanoma (UM). The roles of HGF/MET signaling have been studied in cell survival, proliferation, cell motility, and migration. Furthermore, HGF/MET signaling has emerged as a critical player not only in the tumor itself but also in the tumor microenvironment. Expression of MET is frequently observed in metastatic uveal melanoma and is associated with poor prognosis. It has been reported that HGF/MET signaling pathway activation is the major mechanism of treatment resistance in metastatic UM (MUM). To achieve maximal therapeutic benefit in MUM patients, it is important to understand how MET signaling drives cellular functions in uveal melanoma cells. Here, we review the HGF/MET signaling biology and the role of HGF/MET blockades in uveal melanoma.

Uveal melanoma diagnosis and current treatment options (Review)

Uveal melanoma is a rare condition accounting for only 5% of all primary melanoma cases. Still, it is the most frequently diagnosed primary intraocular malignant tumor in adults. Almost 90% of the tumors involve the choroid and only a small percentage affects the ciliary body or the iris. There is a consistent difference in incidence between different regions with individuals of northern European descent having a significantly higher risk as compared to Hispanics, Asians, and Blacks. Among the many risk factors, mutations in the G protein subunit alpha Q (GNAQ) or G protein subunit alpha 11 (GNA11) genes and different receptors are highly suggestive. While iris melanoma can easily be noticed by the patient itself or diagnosed at a routine slit-lamp evaluation, a consistent percentage of posterior uveal tumors are incidentally diagnosed at funduscopic evaluation as they can evolve silently for years, especially if located in the periphery. Uveal melanoma classifications rely on the tumor size (thickness and basal diameter) and also on intraocular and extraocular extension. The differential diagnosis with pseudomelanomas is carried out according to the tumor aspect and position. Iris melanoma has a better prognosis and a lower mortality rate as compared to choroidal melanoma that has a much higher rate of metastasis (50% of the patients) and a subsequent limited life expectancy from 6 to 12 months. While conservative therapeutic options for the primary tumor, relying on different surgical excision techniques and/or irradiation therapies, offer good local tumor control, the treatment options for metastatic disease, although numerous, are still inadequate in preventing a fatal outcome.

Systemic and liver-directed therapies in metastatic uveal melanoma: state-of-the-art and novel perspectives

Metastatic uveal melanoma (MUM) is the most common form of noncutaneous melanoma. It is different from its cutaneous counterpart and is characterized by a very poor prognosis. Despite groundbreaking improvements in the treatment of cutaneous melanoma, there have been few advances in the treatment of MUM, and standard treatments for MUM have not been defined. We performed a systematic review focusing our attention on all interventional studies, ongoing or already published, concerning the treatment of MUM. We present results from studies of chemotherapy, targeted therapy, immunotherapy and liver-directed therapies. Although the results in this setting have been disappointing until now, trials investigating novel immunotherapeutic strategies alone and in combination with targeted agents and liver-directed therapies are ongoing.

Development of a Metastatic Uveal Melanoma Prognostic Score (MUMPS) for Use in Patients Receiving Immune Checkpoint Inhibitors

Simple Summary

This is a retrospective cohort study of metastatic uveal melanoma patients. This study undertook to identify clinical characteristics that were predictive and prognostics of benefit to immune checkpoint inhibitors in patients with metastatic uveal melanoma. We developed a Metastatic Uveal Melanoma Prognostic risk Score based on retrospective data that is comprised of 3 readily available clinical variables (time to metastatic diagnosis, presence of bone metastases, and LDH). Our findings demonstrated that the Metastatic Uveal Melanoma Prognostic risk Score was associated with a statistically significant association with overall survival outcomes in patients with metastatic uveal melanoma treated with ICI. There was a significant predictive association with disease control to ICI for patients with a ‘good risk’ Metastatic Uveal Melanoma Prognostic risk score. This is one of the larger analysis of clinical outcomes in metastatic uveal melanoma patients to date and could inform clinical decision-making.

Abstract

Metastatic uveal melanoma (mUM) is a rare disease. There are limited data on prognostic clinical factors for overall survival (OS) in patients with mUM treated with immune checkpoint inhibitors (ICI). Retrospective and non-randomized prospective studies have reported response rates of 0–17% for anti-PD1/L1 ± anti-CTLA4 ICI in mUM, indicating a potential benefit only in a subset of patients. This study evaluates the characteristics associated with ICI benefit in patients with mUM. We performed a single-center retrospective cohort study of patients with mUM who received anti-PD1/L1 ± anti-CTLA4 ICI between 2014–2019. Clinical and genomic characteristics were collected from a chart review. Treatment response and clinical progression were determined by physician assessment. Multivariable Cox regression models and Kaplan–Meier log-rank tests were used to assess differences in clinical progression-free survival (cPFS) and OS between groups and identify clinical variables associated with ICI outcomes. We identified 71 mUM patients who received 75 lines of ICI therapy. Of these, 54 received anti-PD1/L1 alone, and 21 received anti-PD1/L1 + anti-CTLA4. Patient characteristics were: 53% female, 48% were 65 or older, 72% received one or fewer lines of prior therapy. Within our cohort, 53% of patients had developed metastatic disease <2 years after their initial diagnosis. Bone metastases were present in 12% of patients. The median cPFS was 2.7 months, and the median OS was 10.0 months. In multivariable analyses for both cPFS and OS, the following variables were associated with a good prognosis: ≥2 years from the initial diagnosis to metastatic disease (n = 25), LDH < 1.5 × ULN (n = 45), and absence of bone metastases (n = 66). We developed a Metastatic Uveal Melanoma Prognostic Score (MUMPS). Patients were divided into 3 MUMPS groups based on the number of the above-mentioned prognostic variables: Poor prognosis (0–1), Intermediate prognosis (2) and Good prognosis (3). Good prognosis patients experienced longer cPFS (6.0 months) and OS (34.5 months) than patients with intermediate (2.3 months cPFS, 9.4 months OS) and poor prognosis disease (1.8 months cPFS, 3.9 months OS); p < 0.0001. We developed MUMPS—a prognostic score based on retrospective data that is comprised of 3 readily available clinical variables (time to metastatic diagnosis, presence of bone metastases, and LDH). This MUMPS score has a potential prognostic value. Further validation in independent datasets is warranted to determine the role of this MUMPS score in selecting ICI treatment management for mUM.

Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging-Part II: treatment indications and complications

Therapy of uveal melanoma aims to preserve the eye and its function and to avoid metastatic dissemination. The treatment choice is difficult and must keep into account several factors; the therapeutic strategy of uveal melanoma should therefore be personalized, sometimes requiring to combine different treatment techniques. Nowadays globe-sparing radiotherapy techniques are often preferred to enucleation. Plaque brachytherapy, the most commonly used eye-preserving therapy, is suitable for small- and medium-sized uveal melanomas. Proton beam radiotherapy is indicated for tumours with noticeable size, challenging shape and location, but is more expensive and less available than brachytherapy. Enucleation is currently restricted to advanced tumours, uveal melanomas with orbital or optic nerve involvement, blind and painful eyes because of treatment-related complications (neovascular glaucoma, chronic inflammatory processes). The effect of proton beam therapy on neoplastic tissue is related to direct cytotoxic action of the radiations, impairment of neoplastic vascular supply and immunologic response. Complications after radiotherapy are frequent and numerous and mainly related to tumour thickness, radiation dose and distance between the tumour and optic nerve. The purpose of this pictorial review is to provide the radiologists with awareness about diagnostic methods and therapeutic options of uveal melanoma. In the present second section, we discuss the therapeutic management of uveal melanoma, describing the main ocular-conserving radiotherapic techniques. We subsequently present an overview of the effects of radiations on neoplastic tissue. Lastly, we review ocular complications following radiotherapy that should be evaluated by radiologists during follow-up MRI examinations.

Immunotherapy in uveal melanoma: novel strategies and opportunities for personalized treatment

INTRODUCTION

Uveal melanoma (UM) is the most common intraocular cancer and represents a discrete subtype of melanoma. Metastatic disease, which occurs in half of patients, has a dismal prognosis. Immunotherapy with immune checkpoint inhibitors has produced promising results in cutaneous melanoma but has failed to show analogous efficacy in metastatic UM. This is attributable to UM's distinct genetics and its complex interaction with the immune system. Hence, more efficacious immunotherapeutic approaches are under investigation.

AREAS COVERED

We discuss those novel immunotherapeutic strategies in clinical and preclinical studies for advanced disease and which are thought to overcome the hurdles set by UM in terms of immune recognition. We also highlight the need to determine predictive markers in relation to these strategies to improve clinical outcomes. We used a simple narrative analysis to summarize the data. The search methodology is located in the Introduction.

EXPERT OPINION

Novel immunotherapeutic strategies focus on transforming immune excluded tumor microenvironment in metastatic UM to T cell inflamed. Preliminary results of approaches such as vaccines, adoptive cell transfer and other novel molecules are encouraging. Factors such as HLA compatibility and expression level of targeted antigens should be considered to optimize personalized management.

Current molecular and clinical insights into uveal melanoma (Review)

Uveal melanoma (UM) represents the most prominent primary eye cancer in adults. With an incidence of approximately 5 cases per million individuals annually in the United States, UM could be considered a relatively rare cancer. The 90-95% of UM cases arise from the choroid. Diagnosis is based mainly on a clinical examination and ancillary tests, with ocular ultrasonography being of greatest value. Differential diagnosis can prove challenging in the case of indeterminate choroidal lesions and, sometimes, monitoring for documented growth may be the proper approach. Fine needle aspiration biopsy tends to be performed with a prognostic purpose, often in combination with radiotherapy. Gene expression profiling has allowed for the grading of UMs into two classes, which feature different metastatic risks. Patients with UM require a specialized multidisciplinary management. Primary tumor treatment can be either enucleation or globe preserving. Usually, enucleation is reserved for larger tumors, while radiotherapy is preferred for small/medium melanomas. The prognosis is unfavorable due to the high mortality rate and high tendency to metastasize. Following the development of metastatic disease, the mortality rate increases to 80% within one year, due to both the absence of an effective treatment and the aggressiveness of the condition. Novel molecular studies have allowed for a better understanding of the genetic and epigenetic mechanisms involved in UM biological activity, which differs compared to skin melanomas. The most commonly mutated genes are GNAQ, GNA11 and BAP1. Research in this field could help to identify effective diagnostic and prognostic biomarkers, as well as novel therapeutic targets.

Targeting primary and metastatic uveal melanoma with a G protein inhibitor

Uveal melanoma (UM) is the most common intraocular tumor in adults. Nearly half of UM patients develop metastatic disease and often succumb within months because effective therapy is lacking. A novel therapeutic approach has been suggested by the discovery that UM cell lines driven by mutant constitutively active Gq or G11 can be targeted by FR900359 (FR) or YM-254890, which are bioavailable, selective inhibitors of the Gq/11/14 subfamily of heterotrimeric G proteins. Here, we have addressed the therapeutic potential of FR for UM. We found that FR inhibited all oncogenic Gq/11 mutants reported in UM. FR arrested growth of all Gq/11-driven UM cell lines tested, but induced apoptosis only in a few. Similarly, FR inhibited growth of, but did not efficiently kill, UM tumor cells from biopsies of primary or metastatic tumors. FR evoked melanocytic redifferentiation of UM tumor cells with low (class 1), but not high (class 2), metastatic potential. FR administered systemically below its LD₅₀ strongly inhibited growth of PDX-derived class 1 and class 2 UM tumors in mouse xenograft models and reduced blood pressure transiently. FR did not regress xenografted UM tumors or significantly affect heart rate, liver function, hematopoiesis, or behavior. These results indicated the existence of a therapeutic window in which FR can be explored for treating UM and potentially other diseases caused by constitutively active Gq/11.

A Comprehensive Prognostic and Immunological Analysis of a Six-Gene Signature Associated With Glycolysis and Immune Response in Uveal Melanoma

Uveal melanoma (UM) is a subtype of melanoma with poor prognosis. This study aimed to construct a new prognostic gene signature that can be used for survival prediction and risk stratification of UM patients. In this work, transcriptome data from the Molecular Signatures Database were used to identify the cancer hallmarks most relevant to the prognosis of UM patients. Weighted gene co-expression network, univariate least absolute contraction and selection operator (LASSO), and multivariate Cox regression analyses were used to construct the prognostic gene characteristics. Kaplan-Meier and receiver operating characteristic (ROC) curves were used to evaluate the survival predictive ability of the gene signature. The results showed that glycolysis and immune response were the main risk factors for overall survival (OS) in UM patients. Using univariate Cox regression analysis, 238 candidates related to the prognosis of UM patients were identified (p < 0.05). Using LASSO and multivariate Cox regression analyses, a six-gene signature including ARPC1B, BTBD6, GUSB, KRTCAP2, RHBDD3, and SLC39A4 was constructed. Kaplan-Meier analysis of the UM cohort in the training set showed that patients with higher risk scores had worse OS (HR = 2.61, p < 0.001). The time-dependent ROC (t-ROC) curve showed that the risk score had good predictive efficiency for UM patients in the training set (AUC > 0.9). Besides, t-ROC analysis showed that the predictive ability of risk scores was significantly higher than that of other clinicopathological characteristics. Univariate and multivariate Cox regression analyses showed that risk score was an independent risk factor for OS in UM patients. The prognostic value of risk scores was further verified in two external UM cohorts (GSE22138 and GSE84976). Two-factor survival analysis showed that UM patients with high hypoxia or immune response scores and high risk scores had the worst prognosis. Moreover, a nomogram based on the six-gene signature was established for clinical practice. In addition, risk scores were related to the immune infiltration profiles. Taken together, this study identified a new prognostic six-gene signature related to glycolysis and immune response. This six-gene signature can not only be used for survival prediction and risk stratification but also may be a potential therapeutic target for UM patients.

An Overview of Liver Directed Locoregional Therapies

An overview of all liver-directed locoregional therapies, including surgical resection for melanoma liver metastases (MLMs), is provided. MLM patients are divided by their primary melanoma location; cutaneous, uvea (eye), and mucosal melanoma. If patients with isolated cutaneous MLMs are considered for surgical resection, treatment with systemic therapy should be part of the treatment course. For uveal MLMs, complete surgical or ablative treatment of all MLMs suggests superior results compared with other liver-directed or systemic therapies, based on current evidence, no recommendations for any liver-directed regional therapy in the treatment of mucosal MLMs can be made.

Locoregional Therapies for the Treatment of Uveal Melanoma Hepatic Metastases

Uveal melanoma is the most common primary intraocular malignant tumor in adults. Approximately 50% of patients develop metastatic disease of which greater than 90% of patients develop hepatic metastases. Following the development of liver tumors, overall survival is dismal with hepatic failure being the cause of death in nearly all cases. To prolong survival for patients with metastatic uveal melanoma, controlling the growth of hepatic tumors is essential. This article will discuss imaging surveillance following the diagnosis of primary uveal melanoma; locoregional therapies used to control the growth of hepatic metastases including chemoembolization, immunoembolization, radioembolization, percutaneous hepatic perfusion, and thermal ablation; as well as currently available systemic treatment options for metastatic uveal melanoma.

The Latest on Uveal Melanoma Research and Clinical Trials: Updates from the Cure Ocular Melanoma (CURE OM) Science Meeting (2019)

Uveal melanoma is a rare cancer in adults, but its treatment is one of the clinical unmet needs in the melanoma field. Metastatic disease develops in approximately 50% of patients and is associated with poor survival due to the lack of effective treatment options. It provides a paradigm for cancers that show evidence of aberrant G protein-coupled receptor signaling, tumor dormancy, and liver-selective metastatic tropism and are associated with the loss of the BAP1 tumor suppressor. At the Melanoma Research Foundation CURE OM Science Meeting at the Society for Melanoma Research Meeting held in Utah on November 20, 2019, clinicians and researchers presented findings from their studies according to three themes within uveal melanoma: (i) ongoing clinical trials, (ii) molecular determinants, and (iii) novel targets that could be translated into clinical trials. This meeting underscored the high interest in the uveal melanoma research field and the unmet need for effective treatment strategies for late-stage disease. Findings from ongoing clinical trials are promising, and multiple studies show how novel combinatorial strategies increase response rates. Novel targets and tumor vulnerabilities identified bioinformatically or through high-throughput screens also reveal new opportunities to target uveal melanoma. The future directions pursued by the uveal melanoma research field will likely have an impact on other cancer types that harbor similar genetic alterations and/or show similar biological properties.

Molecular Insights and Emerging Strategies for Treatment of Metastatic Uveal Melanoma

Uveal melanoma (UM) is the most common intraocular cancer. In recent decades, major advances have been achieved in the diagnosis and prognosis of UM allowing for tailored treatments. However, nearly 50% of patients still develop metastatic disease with survival rates of less than 1 year. There is currently no standard of adjuvant and metastatic treatment in UM, and available therapies are ineffective resulting from cutaneous melanoma protocols. Advances and novel treatment options including liver-directed therapies, immunotherapy, and targeted-therapy have been investigated in UM-dedicated clinical trials on single compounds or combinational therapies, with promising results. Therapies aimed at prolonging or targeting metastatic tumor dormancy provided encouraging results in other cancers, and need to be explored in UM. In this review, the latest progress in the diagnosis, prognosis, and treatment of UM in adjuvant and metastatic settings are discussed. In addition, novel insights into tumor genetics, biology and immunology, and the mechanisms underlying metastatic dormancy are discussed. As evident from the numerous studies discussed in this review, the increasing knowledge of this disease and the promising results from testing of novel individualized therapies could offer future perspectives for translating in clinical use.

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.

Treatment of Metastatic Uveal Melanoma: Systematic Review

INTRODUCTION

More than 50% of patients with uveal melanoma end up developing metastases. Currently, there is no standard first-line treatment that facilitates proper management of the metastatic disease.

METHODS

A systematic review of the last 40 years in PubMed with an exhaustive and strict selection of studies was conducted, in which the unit of measurement was overall survival (OS) expressed in Kaplan-Meier curves or numerically.

RESULTS

After the selection process, 110 articles were included. Regional therapies, such as intra-arterial liver chemotherapy (OS: 2, 9-22 months), isolated liver perfusion (OS: 9, 6-27, 4 months), or selective internal radiation therapy (OS: 18 months in monotherapy and 26 months in combination with other therapies) showed some superiority when compared to systemic therapies, such as chemotherapy (OS: 4, 6-17 months), immunotherapy (OS: 5-19, 1 month), immunosuppression (OS: 11 months), or targeted therapy (OS: 6-12 months), without being significant.

CONCLUSIONS

The results of this review suggest that there are no important differences in OS when comparing the different current treatment modalities. Most of the differences found seem to be explained by the heterogenicity of the different studies and the presence of biases in their design, rather than actual extensions of patient survival.

Percutaneous Hepatic Perfusion with Melphalan in Patients with Unresectable Ocular Melanoma Metastases Confined to the Liver: A Prospective Phase II Study

Background

Ocular melanoma is the most common primary intraocular malignancy and has a very poor prognosis once liver metastases occur. The aim of this study was to prospectively assess the efficacy and safety of percutaneous hepatic perfusion with melphalan (M-PHP) using the new second-generation (GEN 2) hemofiltration system in patients with ocular melanoma metastases confined to the liver.

Methods

Prospective, single-center, single-arm, phase II study including patients with unresectable ocular melanoma metastases confined to the liver. Treatment consisted of two M-PHP procedures at 6–8 weeks interval. Procedures were performed using the CHEMOSAT (GEN 2) system with 3 mg/kg melphalan. Primary endpoints were overall response rate (ORR) and best overall response (BOR). Secondary endpoints included overall survival (OS), progression-free survival (PFS), hepatic PFS (hPFS), and safety.

Results

Sixty-four M-PHP procedures were performed in 35 patients between February 2014 and June 2017. The ORR was 72%. BOR was as follows: complete response in 3%, partial response in 69%, stable disease in 13%, and progressive disease in 16%. There was no treatment-related mortality. Fourteen serious adverse events occurred. At a median follow-up of 19.1 months (range 5.6–69.5), median OS was 19.1 months and was significantly longer in responders than in nonresponders (27.5 vs. 11.9 months, p < 0.001). The 1- and 2-year OS was 77% and 43%, respectively. PFS and hPFS were 7.6 and 11.2 months, respectively.

Conclusions

M-PHP using the GEN 2 filter can achieve a high ORR and prolonged survival in patients with liver-only ocular melanoma metastases.

Safety and Effectiveness of Yttrium-90 Radioembolization around the Time of Immune Checkpoint Inhibitors for Unresectable Hepatic Metastases

PURPOSE

To assess the safety and effectiveness of yttrium-90 radioembolization and checkpoint inhibitor immunotherapy within a short interval for the treatment of unresectable hepatic metastases.

MATERIALS AND METHODS

This single-institution retrospective study included 22 patients (12 men; median age, 65 y ± 11) with unresectable hepatic metastases and preserved functional status (Eastern Cooperative Oncology Group performance status 0/1) who received immunotherapy and radioembolization within a 15-month period (median, 63.5 d; interquartile range, 19.7-178.2 d) from February 2013 to March 2018. Primary malignancies were uveal melanoma (12 of 22; 54.5%), soft tissue sarcoma (3; 13.6%), cutaneous melanoma (3; 14%), and others (4; 18.2%). Studies were reviewed to March 2019 to assess Common Terminology Criteria for Adverse Events grade 3/4 toxicities, disease progression, and death.

RESULTS

There were no grade 4 toxicities within 6 mo of radioembolization. Grade 3 hepatobiliary toxicities occurred in 3 patients (13.6%) within 6 months, 2 from rapid disease progression and 1 from a biliary stricture. Two patients (9.1%) experienced clinical toxicities, including grade 4 colitis at 6 months and hepatic abscess at 3 months. Median overall survival (OS) from first radioembolization was 20 mo (95% confidence interval [CI], 12.5-27.5 mo), and median OS from first immunotherapy was 23 months (95% CI, 15.9-30.1 mo). Within the uveal melanoma subgroup, the median OS from first radioembolization was 17.0 months (95% CI, 14.2-19.8 mo). Median time to progression was 7.8 months (95% CI, 3.3-12.2 mo), and median progression-free survival was 7.8 mo (95% CI, 3.1-12.4 mo).

CONCLUSIONS

Checkpoint immunotherapy around the time of radioembolization is safe, with a low incidence of toxicity independent of primary malignancy.