Toxicities after radioembolization with yttrium-90 SIR-spheres: incidence and contributing risk factors at a single center

Safety and Efficacy of Selective Internal Radionuclide Therapy with 90Y Glass Microspheres in Patients with Progressive Hepatocellular Carcinoma after the Failure of Repeated Transarterial Chemoembolization

Transarterial chemoembolization (TACE) is currently the standard of care in patients with unresectable hepatocellular carcinoma (HCC), and selective internal radionuclide therapy (SIRT) with 90Y microspheres is mainly used as an alternative modality in patients considered poor candidates for TACE. Treatment with sorafenib is the recommended option for patients with progressive disease after TACE. This study aims to evaluate the safety and efficacy of SIRT with glass microspheres in patients with progressive HCC after repeated TACE who are not eligible for treatment with sorafenib. Forty-seven patients with progressive HCC after a median of three TACE sessions (range 2-14) underwent SIRT (3.5 ± 1.5 GBq; liver target dose 110-120 Gy). Toxicity was recorded 4 and 12 weeks after treatment and reported according to the Common Terminology Criteria for Adverse Events Version 5.0. Treatment response was assessed three months after SIRT using multiphase computed tomography and modified criteria in solid tumors (mRECIST). Survival analyses were performed using Kaplan-Meier curves and a Cox proportional hazards model for uni- and multivariate analyses. Significant but reversible hepatotoxicity (≥grade 3) occurred in five patients (11%). No radioembolization-induced liver disease (REILD) was observed. The number of previous TACE sessions and cumulative administered activity did not predict the incidence of post-SIRT significant hepatotoxicity. Treatment responses consisted of partial responses in 26 (55%), stable disease in 12 (26%), and progressive disease in 9 (19%) patients. The median overall survival (OS) was 11 months (95% confidence interval (CI), 9-13), and objective responses to SIRT were associated with a longer OS (p = 0.008). Significant hepatotoxicity (≥grade 3) after SIRT was a contributor to impaired survival (median OS 6 months (95% CI, 4-8) vs. 12 months (95% CI, 10-14), p < 0.001). SIRT with glass microspheres is a safe and effective salvage treatment for patients with progressive HCC refractory to TACE who are considered poor candidates for sorafenib treatment.

Prophylactic Medication during Radioembolization in Metastatic Liver Disease: Is It Really Necessary? A Retrospective Cohort Study and Systematic Review of the Literature

PURPOSE

Trans-arterial radioembolization is a well-studied tumoricidal treatment for liver malignancies; however, consensus and evidence regarding periprocedural prophylactic medication (PPM) are lacking.

METHODS

A single-center retrospective analysis from 2014 to 2020 was performed in patients treated with 90Y-glass microspheres for neuroendocrine or colorectal liver metastases. Inclusion criteria were the availability of at least 3 months of clinical, biochemical, and imaging follow-up and post-treatment 90Y-PET/CT imaging for the determination of the whole non-tumorous liver absorbed dose (Dh). Logistic regression models were used to investigate if variables (among which are P/UDCA and Dh) were associated with either clinical toxicity, biochemical toxicity, or hepatotoxicity. Additionally, a structured literature search was performed in November 2022 to identify all publications related to PPM use in radioembolization treatments.

RESULTS

Fifty-one patients received P/UDCA as post-treatment medication, while 19 did not. No correlation was found between toxicity and P/UDCA use. Dh was associated with biochemical toxicity (p = 0.05). A literature review resulted in eight relevant articles, including a total of 534 patients, in which no consistent advice regarding PPM was provided.

CONCLUSION

In this single-center, retrospective review, P/UDCA use did not reduce liver toxicity in patients with metastatic liver disease. The whole non-tumorous liver-absorbed dose was the only significant factor for hepatotoxicity. No standardized international guidelines or supporting evidence exist for PPM in radioembolization.

Intrahepatic flow diversion prior to segmental Yttrium-90 radioembolization for challenging tumor vasculature

Background

Hepatic tumors with complex vascular supply or poor relative perfusion are prone to decreased rates of objective response. This is compounded in the setting of Yttrium-90 (Y90) transarterial radioembolization (TARE), which is minimally embolic and flow-dependent, relying on high threshold dose for complete response.

Objective

We describe our experience with intrahepatic flow diversion (FD) prior to TARE of hepatocellular carcinoma (HCC) with challenging vascular supply.

Materials and methods

Between April 2014 and January 2020, 886 cases of coinciding MAA or TARE and bland embolization or temporary occlusion were identified. Intraprocedural embolizations performed for more routine purposes were excluded. FD was performed by bland embolization or temporary occlusion of vessels supplying non-malignant parenchyma in cases where flow was not preferential to target tumor. Lesion characteristics, vascular supply, treatment approach, angiography, and adverse events (AEs) were reviewed. Radiographic response was assessed using mRECIST criteria.

Results

22 cases of FD of focal HCC were identified. Embolics included calibrated microspheres (n ​= ​11), microcoils (n ​= ​4), gelfoam (n ​= ​3), temporary balloon occlusion (n ​= ​2) and temporary deployment of a microvascular plug (n ​= ​1). Post-treatment SPECT-CT dosimetry coverage was concordant with target lesions in all cases. Mean follow-up was 16.7 months (1.4-45 ​mos). Tumor-specific response per mRECIST was 41% complete response, 50% objective response, and 59% disease control rate. No major adverse events or grade 3/4 hepatotoxicity were reported.

Conclusion

Our findings suggest that FD prior to TARE is safe and potentially effective in treating HCC with complex vascular supply or poor tumor perfusion.

Repeated Transarterial Radioembolization Adverse Event and Hepatotoxicity Profile in Cirrhotic Patients With Hepatocellular Carcinoma: A Single-Center Experience

Purpose

The study aimed to evaluate the adverse event (AE) and hepatotoxicity profile, including radioembolization induced liver disease (REILD), following repeat radioembolization (RE) to the same or overlapping vascular territories in patients with hepatocellular carcinoma (HCC) and limited functional hepatic reserve/cirrhosis.

Methods

Nine patients (seven male and two female; median age, 66 years) with cirrhosis and HCC who underwent repeat RE (cycle 1 and cycle 2) between January 2012 and August 2019 were included. Patient demographics, clinical and treatment history, and pertinent laboratory values were recorded at baseline and post-treatment time points over a period of four months. Post-RE AE/hepatotoxicity was assessed, organized by type and frequency, and graded by severity according to the National Cancer Institute common terminology criteria for adverse events, version 5.0 (CTCAE v5.0). To assess rudimentary comparisons for post-RE hepatotoxicity vs. factors of interest, Spearman's rank correlation/rho was calculated, and all relevant plots were constructed. Kaplan-Meier analysis was performed along with associated median survival time. All statistical analyses were performed with Stata v16.1.

Results

Following cycle 1, 22 objective AE were identified according to CTCAE v.5 (17 grade I, four grade II, and one grade III), with grade I, II, and III AE experienced by 78%, 33%, and 11% of patients, respectively. Following cycle 2, 19 objective AE were identified according to CTCAE v.5 (11 grade I, seven grade II, and one grade III), with grade I, II, and III AE experienced by 89%, 56%, and 11% of patients, respectively. A single patient developed REILD after cycle 1, which progressed to fatal REILD following cycle 2. Following cycle 2, an additional patient advanced from less severe hepatotoxicity to REILD. Following cycle 2, positive correlations between the higher model for end-stage liver disease (MELD; rho=0.70) and Child-Pugh (rho=0.74) scores and degree of post-RE hepatotoxicity/REILD appear to emerge. Post-repeat RE median overall survival was 12.5 months.

Conclusion

Post-RE hepatotoxicity following repeat RE to the same or overlapping vascular territories in patients with limited functional hepatic reserve/cirrhosis is a common occurrence with variable severity ranging from transient laboratory derangement to fatal REILD. Lack of a consensus REILD definition and grading scale results in non-uniform reporting of incidence as well as clinical and laboratory features of the disease process. Strides aimed at improving clinical characterization, forming a more complete diagnostic definition, and establishing a uniform grading system with respect to REILD are of particular importance and would ultimately improve repeat RE patient selection and risk management. 

Impact of Pharmaceutical Prophylaxis on Radiation-Induced Liver Disease Following Radioembolization

Simple Summary

Radioembolization has failed to prove survival benefit in randomized trials, and, depending on various factors including tumor biology, response rates may vary considerably. Studies showed positive correlations between survival and absorbed tumor dose. Therefore, increasing currently prescribed tumor doses may be favorable for improving patient outcomes. The dominant limiting factor for increasing RE dose prescriptions is the relatively low tolerance of liver parenchyma to radiation with the possible consequence of a radiation-induced liver disease. Advances in RILD prevention may help increasing tolerable radiation doses to improve patient outcomes. Our study aimed to evaluate the impact of post-therapeutic RILD-prophylaxis in a cohort of intensely pretreated liver metastatic breast cancer patients. The results of this study as well as pathophysiological considerations warrant further investigations of RILD prophylaxis to increase dose prescriptions in radioembolization.

Abstract

Background: Radioembolization (RE) with yttrium-90 (⁹⁰Y) resin microspheres yields heterogeneous response rates in with primary or secondary liver cancer. Radiation-induced liver disease (RILD) is a potentially life-threatening complication with higher prevalence in cirrhotics or patients exposed to previous chemotherapies. Advances in RILD prevention may help increasing tolerable radiation doses to improve patient outcomes. This study aimed to evaluate the impact of post-therapeutic RILD-prophylaxis in a cohort of intensely pretreated liver metastatic breast cancer patients; Methods: Ninety-three patients with liver metastases of breast cancer received RE between 2007 and 2016. All Patients received RILD prophylaxis for 8 weeks post-RE. From January 2014, RILD prophylaxis was changed from ursodeoxycholic acid (UDCA) and prednisolone (standard prophylaxis [SP]; n = 59) to pentoxifylline (PTX), UDCA and low-dose low molecular weight heparin (LMWH) (modified prophylaxis (MP); n = 34). The primary endpoint was toxicity including symptoms of RILD; Results: Dose exposure of normal liver parenchyma was higher in the modified vs. standard prophylaxis group (47.2 Gy (17.8–86.8) vs. 40.2 Gy (12.5–83.5), p = 0.017). All grade RILD events (mild: bilirubin ≥ 21 µmol/L (but <30 μmol/L); severe: (bilirubin ≥ 30 µmol/L and ascites)) were observed more frequently in the SP group than in the MP group, albeit without significance (7/59 vs. 1/34; p = 0.140). Severe RILD occurred in the SP group only (n = 2; p > 0.1). ALBI grade increased in 16.7% patients in the MP and in 27.1% patients in the SP group, respectively (group difference not significant); Conclusions: At established dose levels, mild or severe RILD events proved rare in our cohort. RILD prophylaxis with PTX, UDCA and LMWH appears to have an independent positive impact on OS in patients with metastatic breast cancer and may reduce the frequency and severity of RILD. Results of this study as well as pathophysiological considerations warrant further investigations of RILD prophylaxis presumably targeting combinations of anticoagulation (MP) and antiinflammation (SP) to increase dose prescriptions in radioembolization.

Does significantly elevated lung shunt fraction (LSF >20%) promote extrahepatic progression in patients with hepatocellular carcinoma treated with radioembolization?

PURPOSE

Radioembolization with yttrium-90 (Y-90) is an effective locoregional therapy for primary and metastatic liver tumors, but its use is restricted or contraindicated for patients with elevated lung shunt fraction (LSF) because of an increased risk of developing pulmonary adverse events, including but not limited to radiation pneumonitis. Elevated LSF is also thought to be correlated with liver tumor progression and metastases.

METHODS

In this retrospective cohort study, we examine rates of metastasis development, rates of adverse events and overall survival (OS) in 23 patients with hepatocellular carcinoma (HCC) and elevated LSF >20% on Tc-99 m macroaggregated albumin scan treated with Y-90 radioembolization at our institution from 2005 to 2016. To minimize confounding variables, patients with baseline extrahepatic metastases or portal vein tumor thrombosis were excluded. Kaplan-Meier estimates were performed for OS and time to development of metastases.

RESULTS

No patient developed clinical and imaging signs of radiation pneumonitis. Median intention to treat OS from day of radioembolization was 21.3 months; median censored OS was 14.7 months. Five out of 23 patients (22%) developed at least one metastasis during follow-up, for an incidence of 20 per 1000 patient-years (compared to the historical rate of 6 per 1000 patient-years for HCC patients in general).

CONCLUSION

HCC patients with LSF >20% treated with Y-90 radioembolization have acceptable toxicities and appear to have a rate of extrahepatic tumor development (22%) higher than expected for patients with HCC.

Factors affecting the response to Y-90 microsphere therapy in the cholangiocarcinoma patients

OBJECTIVE

The aim of this study was to assess the early therapy response in patients with unresectable CCA who received Y-90 microsphere therapy for CCA and define the factors related to therapy response.

MATERIALS AND METHODS

Data of 19 patients [extrahepatic (n: 6) and intrahepatic (n: 13)] who received 24 sessions of Y-90 microsphere therapy [glass (n: 13) and resin (n: 11)] were retrospectively evaluated. Tumor load, tumor size, therapy response evaluation by RECIST1.1 criteria (n: 13), tumor lesion glycolysis (TLG), metabolic tumor volume (MTV), and metabolic therapy responses were evaluated (n: 8) using PERCIST1.0 criteria.

RESULTS

No significant relation was found between therapy response and tumor localization, treated liver lobe, type of Y90 microspheres, the presence of previous therapies, perfusion pattern on hepatic artery perfusion scintigraphy, or patient demographics. The mean overall survival (OS) was 11.9 ± 2.3 months and was similar after both resin and glass Y90 microspheres; however, it was longer RECIST responders (p: 0.005). MTV and TLG values significantly decreased after therapy, and ΔMTV (- 45.4% ± 12.1) was found to be positively correlated with OS. No statistical difference was found between iCCA and eCCA, in terms of OS and response to therapy. Although not quantitatively displayed, better-perfused areas on HAPS images had a better metabolic response and less perfused areas were prone to local recurrences.

CONCLUSIONS

Both resin and glass microsphere therapy can be applied safely to iCCA and eCCA patients. Early therapy response can be evaluated with both RECIST and PERCIST criteria. Both anatomical and metabolic therapy response evaluations give complementary information.

Incidence of Radioembolization-Induced Liver Disease and Liver Toxicity Following Repeat 90Y-Radioembolization: Outcomes at a Large Tertiary Care Center

PURPOSE

The complication profile following repeat Y-radioembolization (RE) is not well understood, and repeat RE is sometimes avoided because of concerns for RE-induced liver disease (REILD) and liver toxicity. The purpose of this study was to examine the incidence of REILD and liver toxicity following repeat Y-RE and to identify potential risk factors.

METHODS

A retrospective analysis of patients undergoing repeat RE to the same hepatic lobe between 2013 and 2018 was performed. Baseline factors were evaluated as predictors of liver toxicity, mortality, and REILD, which was defined as the presence symptomatic ascites or jaundice in the absence of biliary obstruction within 8 weeks following RE. Post-RE complications were graded according to the Common Terminology Criteria for Adverse Events version 5.

RESULTS

A total of 39 patients underwent repeat RE with 14 (35.9%) experiencing Common Terminology Criteria for Adverse Events toxicity of grade 2 or greater, 3 (10.3%) grade 3, and no grade 4 or greater. A Model for End Stage Liver Disease score of 8 or greater was associated with grade 2 toxicity or greater (26.7% vs 75%; P = 0.013). Only 3 patients (7.7%) experienced REILD due to symptomatic ascites without jaundice. Greater than 2 REs were associated with a greater rate of 6-month mortality (12% vs 58.3%, P = 0.003), 12-month mortality (28% vs 75%, P = 0.007), and REILD (0% vs 21.4%, P = 0.016). Age, sex, microsphere type, cirrhosis, Child-Pugh, and Eastern Cooperative Oncology Group status were not significantly associated with complications, REILD, or survival.

CONCLUSIONS

Repeat Y-RE appears to be well tolerated with a low rate of high-grade adverse events and REILD.

Yttrium-90 Radioembolization After Local Hepatic Therapy: How Prior Treatments Impact Patient Selection, Dosing, and Toxicity

Numerous local treatment strategies now exist for patients with primary and metastatic liver tumors. Increasingly, patients who cannot be adequately treated with a single form of focal therapy, go on to receive a variety of sequential treatments. However, the impact of each prior therapy on subsequent treatments and the cumulative toxicity of these therapies remains uncertain. Yttrium-90 radioembolization is becoming an increasingly common treatment for patients with hepatic malignancies. Though the baseline toxicity of radioembolization is low, greater care must be taken when treating patients who have undergone prior hepatic treatments. While this population can be treated safely, additional measures should be taken to ensure that patients are carefully screened and all effort is made to minimize liver toxicity.

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

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

Hepatotoxic Dose Thresholds by Positron-Emission Tomography After Yttrium-90 Radioembolization of Liver Tumors: A Prospective Single-Arm Observational Study

PURPOSE

To define a threshold radiation dose to non-tumoral liver from ⁹⁰Y radioembolization that results in hepatic toxicity using pair-production PET.

MATERIALS AND METHODS

This prospective single-arm study enrolled 35 patients undergoing radioembolization. A total of 34 patients (27 with HCC and 7 with liver metastases) were included in the final analysis. Of 27 patients with underlying cirrhosis, 22 and 5 patients were Child-Pugh A and B, respectively. Glass and resin microspheres were used in 32 (94%) and 2 (6%) patients, respectively. Lobar and segmental treatment was done in 26 (76%) and 8 (24%) patients, respectively. Volumetric analysis was performed on post-radioembolization time-of-flight PET imaging to determine non-tumoral parenchymal dose. Hepatic toxicity was evaluated up to 120 days post-treatment, with CTCAE grade ≤ 1 compared to grade ≥ 2.

RESULTS

The median dose delivered to the non-tumoral liver in the treated lobe was 49 Gy (range 0-133). A total of 15 patients had grade ≤ 1 hepatic toxicity, and 19 patients had grade ≥ 2 toxicity. Patients with a grade ≥ 2 change in composite toxicity (70.7 vs. 43.8 Gy), bilirubin (74.1 vs. 43.3 Gy), albumin (84.2 vs. 43.8 Gy), and AST (94.5 vs. 47.1 Gy) have significantly higher non-tumoral parenchymal doses than those with grade ≤ 1. Liver parenchymal dose and Child-Pugh status predicted grade ≥ 2 toxicity, observed above a dose threshold of 54 Gy.

CONCLUSION

Increasing delivered ⁹⁰Y dose to non-tumoral liver measured by internal pair-production PET correlates with post-treatment hepatic toxicity. The likelihood of toxicity exceeds 50% at a dose threshold of 54 Gy. ClinicalTrials.gov identifier: NCT02848638.

Nonthrombotic Pulmonary Embolism From Inorganic Particulate Matter and Foreign Bodies

Nonthrombotic pulmonary embolism (NTPE) is a complete or partial occlusion of the pulmonary vasculature by various organic and inorganic materials. These materials include organic particulate matter (PM) such as adipocytes, tumor cells, bacteria, fungi, or gas and inorganic PM. Although NTPE due to organic PM has been extensively reported in the medical literature, there are no comprehensive reviews of inorganic material embolizing to the lungs. The purpose of this article is to examine the current literature describing NTPE resulting from inorganic PM and foreign bodies. Cases of NTPE are uncommon and often difficult to diagnose. The diagnosis is challenging due to its varied presentation, clinical features, and unusual radiologic features. In contrast to the "classic" pulmonary thromboembolism, the pathophysiologic effects of embolism by PM are not only mechanical but also a consequence of the nature of the offending material. NTPE caused by these substances can be relatively innocuous, life-threatening, or lead to chronic pulmonary disease, if left undetected. We hope that the heightened sense of awareness of this entity may allow earlier diagnosis and recognition of its complications.

Safety and Efficacy of Transarterial Radioembolization Combined with Chemoembolization for Bilobar Hepatocellular Carcinoma: A Single-Center Retrospective Study. Cardiovasc Intervent Radiol. 2018;41:459-465. [PMID: 29067511 DOI: 10.1007/s00270-017-1826-7]

BACKGROUND

Radioembolization induced liver disease (REILD) is a possible sequela of transarterial radioembolization (TARE), particularly in cases of whole-liver treatment. To mitigate this problem, the safety and efficacy of combined transarterial chemoembolization (TACE) and TARE were evaluated for patients with bilobar hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Nineteen patients (mean age 60 years; range 27-82 years) treated for HCC between June 2012 and September 2014 were included in the analysis. Each patient was treated with combined TARE and TACE for bilobar HCC, with or without portal vein thrombosis. The hepatic lobe with large HCC was treated with TARE, and the other lobe with small HCC(s) was treated with TACE. Laboratory and clinical data were investigated to determine REILD occurrence. Survival data were analyzed to compare the treatment efficacy of alternative treatment modalities, including TACE and sequential TARE.

RESULTS

All patients underwent TARE for a dominant tumor in one lobe and TACE for small nodule(s) in the other lobe of the liver. The mean yttrium-90 microspheres used in TARE were 2.8 GBq (range; 1.0-3.5 GBq), and the mean doses of doxorubicin and iodized oil were 24.5 mg and 5.2 mL, respectively, for TACE. No statistical differences were noted between laboratory data measured before and after treatment, and no procedure-related major clinical complications occurred. The median time-to-progression of patients was 10.0 months, and the median overall survival was 27.3 months.

CONCLUSION

Combined radioembolization and chemoembolization appears to be a safe and effective treatment modality for bilobar HCC.

Prevention and treatment of complications of selective internal radiation therapy: Expert guidance and systematic review

Selective internal radiation therapy (or radioembolization) by intra-arterial injection of radioactive yttrium-90-loaded microspheres is increasingly used for the treatment of patients with liver metastases or primary liver cancer. The high-dose beta-radiation penetrates an average of only 2.5 mm from the source, thus limiting its effects to the site of delivery. However, the off-target diversion of yttrium-90 microspheres to tissues other than the tumor may lead to complications. The most prominent of these complications include radiation gastritis and gastrointestinal ulcers, cholecystitis, radiation pneumonitis, and radioembolization-induced liver disease, which may occur despite careful pretreatment planning. Thus, selective internal radiation therapy demands an expert multidisciplinary team approach in order to provide comprehensive care for patients. This review provides recommendations to multidisciplinary teams on the optimal medical processes in order to ensure the safe delivery of selective internal radiation therapy. Based on the best available published evidence and expert opinion, we recommend the most appropriate strategies for the prevention, early diagnosis, and management of potential radiation injury to the liver and to other organs. (Hepatology 2017;66:969-982).

Selective internal radiation therapy with SIR-Spheres in hepatocellular carcinoma and cholangiocarcinoma

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) often present at stages where patients have limited treatment options. Use of selective internal radiation therapy (SIRT) with yttrium-90 (Y-90) resin microspheres has progressed as data increasingly speak to its utility in patients with both intermediate and late stage disease in these cancers. In anticipation of the pending completion of several prospective randomized controlled multicenter studies exploring the use of Y-90 resin microspheres in primary liver cancers, this article outlines mechanisms involved in SIRT administration and reviews key efficacy and safety data that are currently available in the literature involving use of this therapy in both HCC and ICC.

Radioembolization-induced liver disease: a systematic review

Radioembolization (RE) is a relatively novel treatment modality for primary and secondary hepatic malignancies. Microspheres embedded with a β-emitting radioisotope are injected into the hepatic artery, resulting in microsphere deposition in the tumor arterioles and normal portal triads. Microsphere deposition in nontumorous parenchyma can result in radiation-induced liver injury, with lethal RE-induced liver disease (REILD) at the outer end of the spectrum. The primary aim of this study was to evaluate RE-related hepatotoxicity and present an overview of the currently applied definitions and clinically relevant characteristics of REILD. A systematic literature search on REILD was performed. Studies after the introduction of the term REILD (2008) were screened for definitions of REILD. Hepatotoxicity and applied definitions of REILD were compared. Liver biochemistry test abnormalities occur in up to 100% of patients after RE, mostly self-limiting. The incidence of symptomatic REILD varied between 0 and 31%, although in most reports, the incidence was 0-8%, with a lethal outcome in 0-5%. With the exception of bilirubin, the presentation of hepatotoxicity and REILD was similar for cirrhotic and noncirrhotic patients. No uniform definition of REILD was established in the current literature. Here, we propose a unifying definition and grading system for REILD. RE-related hepatotoxicity is a common phenomenon; symptomatic REILD, however, is rare. Currently, reporting of REILD is highly variable, precluding reliable comparison between studies, identification of risk factors, and treatment developments.

Yttrium-90 Microsphere Brachytherapy for Liver Metastases From Uveal Melanoma: Clinical Outcomes and the Predictive Value of Fluorodeoxyglucose Positron Emission Tomography

OBJECTIVES

To report outcomes after yttrium-90 microsphere brachytherapy for unresectable liver metastases from uveal melanoma and to evaluate factors predictive for overall survival (OS) and hepatic progression-free survival (PFS).

METHODS

A total of 71 patients were consecutively treated with microsphere brachytherapy for unresectable liver metastases from uveal melanoma between 2007 and 2012. Clinical, radiographic, and positron emission tomography-derived, functional tumor parameters were evaluated by log-rank test in univariate analysis and backwards stepwise multivariate Cox proportional hazards regression. OS and hepatic PFS were estimated by Kaplan-Meier analysis.

RESULTS

A total of 134 procedures were performed in 71 patients with a median age of 63 years (range, 23 to 91 y). Fifty-eight patients (82%) received microsphere brachytherapy as a salvage therapy. Median hepatic PFS and OS after microsphere brachytherapy were 5.9 months (range, 1.3 to 19.1 mo) and 12.3 months (range, 1.9 to 49.3 mo), respectively. Median OS times after diagnosis of liver metastases was 23.9 months (range, 6.2 to 69.0 mo). In univariate analysis, female sex, pretreatment metabolic tumor volume, and total glycolic activity (TGA) were significantly correlated with hepatic PFS and OS. In multivariate analysis, female sex and TGA retained significance as independent predictors of hepatic PFS and OS. A low pretreatment TGA (<225 g) was associated with a significantly longer median OS than was a TGA≥225 g (17.2 vs. 9.7 mo, P=0.01).

CONCLUSIONS

Yttrium-90 microsphere brachytherapy provided favorable survival times in patients with unresectable liver metastases from uveal melanoma. Metabolic tumor volume and TGA are predictive functional tumor parameters, which may aid patient selection and risk stratification.

Factors associated with increased incidence of severe toxicities following yttrium-90 resin microspheres in the treatment of hepatic malignancies

AIM: To further define variables associated with increased incidences of severe toxicities following administration of yttrium-90 (⁹⁰Y) microspheres.

METHODS: Fifty-eight patients undergoing 79 treatments were retrospectively assessed for development of clinical and laboratory toxicity incidence following ⁹⁰Y administration. Severe toxicity events were defined using Common Terminology Criteria for Adverse Events version 4.03 and defined as grade ≥ 3. Univariate logistic regression analyses were used to evaluate the effect of different factors on the incidence of severe toxicity events. Multicollinearity was assessed for all factors with P < 0.1 using Pearson correlation matrices. All factors not excluded due to multicollinearity were included in a multivariate logistic regression model for each measurement of severe toxicity.

RESULTS: Severe (grade ≥ 3) toxicities occurred following 21.5% of the 79 treatments included in our analysis. The most common severe laboratory toxicities were severe alkaline phosphatase (17.7%), albumin (12.7%), and total bilirubin (10.1%) toxicities. Decreased pre-treatment albumin (OR = 26.2, P = 0.010) and increased pre-treatment international normalized ratio (INR) (OR = 17.7, P = 0.048) were associated with development of severe hepatic toxicity. Increased pre-treatment aspartate aminotransferase (AST; OR = 7.4, P = 0.025) and decreased pre-treatment hemoglobin (OR = 12.5, P = 0.025) were associated with severe albumin toxicity. Increasing pre-treatment model for end-stage liver disease (MELD) score (OR = 1.8, P = 0.033) was associated with severe total bilirubin toxicity. Colorectal adenocarcinoma histology was associated with severe alkaline phosphatase toxicity (OR = 5.4, P = 0.043).

CONCLUSION: Clinicians should carefully consider pre-treatment albumin, INR, AST, hemoglobin, MELD, and colorectal histology when choosing appropriate candidates for ⁹⁰Y microsphere therapy.

Outcomes and Predictors of Toxicity after Selective Internal Radiation Therapy Using Yttrium-90 Resin Microspheres for Unresectable Hepatocellular Carcinoma

Purpose

We sought to report outcomes and toxicity in patients with hepatocellular carcinoma (HCC) who received resin yttrium-90 selective internal radiation therapy (⁹⁰Y-SIRT) and to identify factors associated with declining liver function.

Methods

Patients treated with ⁹⁰Y-SIRT were retrospectively evaluated. Radiographic response was assessed using RECIST 1.1. Median liver progression-free survival (LPFS) and overall survival (OS) were calculated using the Kaplan–Meier method. Bivariate analysis was used to examine associations between change in Child-Pugh (CP) score/class and patient characteristics and treatment parameters.

Results

Twenty-seven patients with unresectable HCC underwent SIRT, 52% were CP Class A, 48% were Class B, 11% were BCLC stage B, and 89% were stage C. Forty-four percent of patients had portal vein thrombus at baseline. One-third of patients received bilobar treatment. Median activity was 32.1 mCi (range 9.18–43.25) and median-­absorbed dose to the liver was 39.6 Gy (range 13.54–67.70). Median LPFS and OS were 2.5 and 11.7 months, respectively. Three-month disease control rate was 63 and 52% in the target lesions and whole liver, respectively. New onset or worsened from baseline clinical toxicities were confined to Grade 1–2 events. However, new or worsened Grade 3–4 laboratory toxicities occurred in 38% of patients at 3 months and 43% of patients at 6 months following SIRT (six had lymphocytopenia, three had hypoalbuminemia, and two had transaminasemia). After 3 months, six patients had worsened in CP score and five had worsened in class from baseline. After 6 months, four patients had worsened in CP score and one had worsened in class from baseline. Pretreatment bilirubinemia was associated with a 2+ increase in CP score within 3 months (P = 0.001) and 6 months (P = 0.039) of ⁹⁰Y-SIRT. Pretreatment transaminasemia and bilirubinemia were associated with increased CP class within 3 months of SIRT (P = 0.021 and 0.009, respectively).

Conclusion

⁹⁰Y-SIRT was well-tolerated in patients with unresectable HCC, with no Grade 3–4 clinical toxicities. However, Grade 3–4 laboratory toxicities and worsened CP scores were more frequent. HCC patients with pretreatment bilirubinemia or transaminasemia may be at higher risk of experiencing a decline in liver function following ⁹⁰Y-SIRT.

Side effects of yttrium-90 radioembolization

Limited therapeutic options are available for hepatic malignancies. Image guided targeted therapies have established their role in management of primary and secondary hepatic malignancies. Radioembolization with yttrium-90 ((90)Y) microspheres is safe and efficacious for treatment of hepatic malignancies. The tumoricidal effect of radioembolization is predominantly due to radioactivity and not ischemia. This article will present a comprehensive review of the side effects that have been associated with radioembolization using (90)Y microspheres. Some of the described side effects are associated with all transarterial procedures. Side effects specific to radioembolization will also be discussed in detail. Methods to decrease the incidence of these potential side effects will also be discussed.

Cost effectiveness of radioembolization compared with conventional transarterial chemoembolization for treatment of hepatocellular carcinoma

PURPOSE

To assess cost effectiveness of radioembolization versus conventional transarterial chemoembolization.

MATERIALS AND METHODS

The cost of radioembolization versus conventional transarterial chemoembolization was determined based on Medicare reimbursements. Three patient subgroups were defined based on the Barcelona Clinic Liver Cancer (BCLC) classification system (A, B, or C). Efficacy and safety outcomes after each procedure were obtained from the literature. A Monte Carlo case-based simulation was designed for 60 months in 250 patients in each subgroup. Survival was calculated based on average survival from the literature and the Monte Carlo model. The primary outcome was the cost effectiveness of radioembolization over transarterial chemoembolization by considering calculated survival.

RESULTS

The costs approached $17,000 for transarterial chemoembolization versus $31,000 or $48,000 for unilobar or bilobar radioembolization, respectively. Based on the simulation, median estimated survival was greater with transarterial chemoembolization than radioembolization in BCLC-A and BCLC-B subgroups (40 months vs 30 months and 23 months vs 16 months, respectively, P = .001). However, in the BCLC-C subgroup, survival was greater with radioembolization than transarterial chemoembolization (13 months vs 17 months, P = .001). The incremental cost-effectiveness ratio of radioembolization over transarterial chemoembolization in the BCLC-C subgroup was $360 per month. The results were dependent on bilobar versus unilobar radioembolization and the total number of radioembolization procedures.

CONCLUSIONS

The model suggests radioembolization costs may be justified for patients with BCLC-C disease, whereas radioembolization may not be cost effective in patients with BCLC-A disease; however, many patients with BCLC-C disease have extensive disease precluding locoregional therapies. Secondary considerations may determine treatment choice in more borderline patients (BCLC-B disease) because there is no persistent survival benefit with radioembolization.

Early arterial stasis during resin-based yttrium-90 radioembolization: incidence and preliminary outcomes

OBJECTIVES

This study was conducted to determine the incidence of early stasis in radioembolization using resin yttrium-90 (Y-90) microspheres, to evaluate potential contributing factors, and to review initial imaging outcomes.

METHODS

Patients in whom early stasis occurred were compared with those in whom complete delivery was achieved for tumour type and vascularity, tumour : normal liver ratio (T : N ratio) at technetium-99m-macroaggregated albumin (Tc-99m-MAA) angiography, previous intra-arterial therapy, and infusion site (left, right or whole liver). Tumour response was evaluated at 3 months and defined according to whether a partial response and stable disease versus progressive disease were demonstrated.

RESULTS

A total of 71 patients underwent 128 Y-90 infusions in which 26 (20.3%) stasis events occurred. Hypervascular and hypovascular tumours had similar rates of stasis (17.4% versus 27.8%; P = NS). The mean ± standard deviation T : N ratio was 3.03 ± 1.54 and 3.66 ± 2.79 in patients with and without stasis, respectively (P = NS). Stasis occurred in 14 of 81 (17.3%) and 12 of 47 (25.5%) infusions following previous intra-arterial therapy and in therapy-naïve territories, respectively (P = NS). Early stasis occurred in 15 of 41 (36.6%) left, 10 of 65 (15.4%) right and one of 22 (4.5%) whole liver infusions (P < 0.001). Rates of partial response and stable disease were similar in the stasis (88.3%) and non-stasis (76.0%) groups (P = NS).

CONCLUSIONS

Early stasis occurred in approximately 20% of infusions with similar incidences in hyper- and hypovascular tumours. Whole-liver therapy reduced the incidence of stasis. Stasis did not appear to affect initial imaging outcomes.

Early treatment response evaluation after yttrium-90 radioembolization of liver malignancy with CT perfusion. J Vasc Interv Radiol. 2014;25:747-759. [PMID: 24630751 DOI: 10.1016/j.jvir.2014.01.025]

PURPOSE

To evaluate computed tomography (CT) perfusion for assessment of early treatment response after transarterial radioembolization of patients with liver malignancy.

MATERIALS AND METHODS

Dynamic contrast-enhanced CT liver perfusion was performed before and 4 weeks after transarterial radioembolization in 40 patients (25 men and 15 women; mean age, 64 y ± 11; range, 35-80 y) with liver metastases (n = 27) or hepatocellular carcinoma (HCC) (n = 13). Arterial perfusion (AP) of tumors derived from CT perfusion and tumor diameters were measured on CT perfusion before and after transarterial radioembolization. Success of transarterial radioembolization was evaluated on morphologic follow-up imaging (median follow-up time, 4 mo) based on Response Evaluation Criteria in Solid Tumors (Version 1.1). CT perfusion parameters before and after transarterial radioembolization for different response groups were compared. Kaplan-Meier curves were plotted to illustrate overall 1-year survival rates.

RESULTS

Liver metastases showed significant differences in AP before and after transarterial radioembolization in responders (P < .05) but not in nonresponders (P = .164). In HCC, AP values before and after transarterial radioembolization were not significantly different in responders and nonresponders (P = .180 and P = .052). Tumor diameters were not significantly different on CT perfusion before and after transarterial radioembolization in responders and nonresponders with liver metastases and HCC (P = .654, P = .968, P = .148, P = .164). In patients with significant decrease of AP in liver metastases after transarterial radioembolization, 1-year overall survival was significantly higher than in patients showing no reduction of AP.

CONCLUSIONS

CT perfusion showed early reduction of AP in liver metastases responding to transarterial radioembolization; tumor diameter remained unchanged early after treatment. No significant early treatment response to transarterial radioembolization was found in patients with HCC. In patients with liver metastases, a decrease of AP after transarterial radioembolization was associated with a higher 1-year overall survival rate.

Feasibility of temporary protective embolization of normal liver tissue using degradable starch microspheres during radioembolization of liver tumours

PURPOSE

To describe a new approach to protect nontarget healthy liver tissue using degradable starch microspheres (DSM) as a short-term embolizate during radioembolization of liver tumours with (90)Y microspheres.

METHODS

Between December 2011 and July 2012 radioembolization was performed in 54 patients. Five of these patients (three women, two men; mean age 67 years) underwent protective temporary embolization using DSM (EmboCept® S) of normal liver tissue that could not be excluded from the area treated by radioembolization through catheter repositioning. Clinical symptoms, laboratory findings, preinterventional imaging, and (99m)Tc-MAA and bremsstrahlung SPECT/CT, as well as baseline and follow-up imaging with (18)F-FDG PET/CT and MRI, were evaluated in relation to the technical and clinical success of the protective embolization.

RESULTS

Temporary embolization of arteries supplying normal liver tissue using DSM was technically successful in all five patients. (99m)Tc-MAA SPECT/CT performed in the first two patients after DSM injection showed no increased pulmonary shunting compared to the MAA test injection without DSM. Bremsstrahlung SPECT/CT after radioembolization demonstrated satisfactory irradiation of the tumour and successful protection of normal liver tissue. There were only mild hepatotoxic effects (grade 1) on laboratory follow-up examinations, and no adverse events associated with DSM embolization or radioembolization were recorded.

CONCLUSION

Temporary embolization with DSM before radioembolization is feasible and can effectively protect areas of normal liver tissue from irradiation and avoid permanent embolization if other methods such as catheter repositioning are not possible due to the location of the metastases.

Clinical and laboratory toxicity after intra-arterial radioembolization with (90)y-microspheres for unresectable liver metastases

OBJECTIVE

To investigate clinical and laboratory toxicity in patients with unresectable liver metastases, treated with yttrium-90 radioembolization ((90)Y-RE).

METHODS

Patients with liver metastases treated with (90)Y-RE, between February 1(st) 2009 and March 31(st) 2012, were included in this study. Clinical toxicity assessment was based on the reporting in patient's charts. Laboratory investigations at baseline and during a four-month follow-up were used to assess laboratory toxicity according to the Common Terminology Criteria for Adverse Events version 4.02. The occurrence of grade 3-4 laboratory toxicity was stratified according to treatment strategy (whole liver treatment in one session versus sequential sessions). Response assessment was performed at the level of target lesions, whole liver and overall response in accordance with RECIST 1.1 at 3- and 6 months post-treatment. Median time to progression (TTP) and overall survival were calculated by Kaplan-Meier analysis.

RESULTS

A total of 59 patients, with liver metastases from colorectal cancer (n = 30), neuroendocrine tumors (NET) (n = 6) and other primary tumors (n = 23) were included. Clinical toxicity after (90)Y-RE treatment was confined to grade 1-2 events, predominantly post-embolization symptoms. No grade 3-4 clinical toxicity was observed, whereas laboratory toxicity grade 3-4 was observed in 38% of patients. Whole liver treatment in one session was not associated with increased laboratory toxicity. Three-months disease control rates for target lesions, whole liver and overall response were 35%, 21% and 19% respectively. Median TTP was 6.2 months for target lesions, 3.3 months for the whole liver and 3.0 months for overall response. Median overall survival was 8.9 months.

CONCLUSION

The risk of severe complications or grade 3-4 clinical toxicity in patients with liver metastases of various primary tumors undergoing (90)Y-RE is low. In contrast, laboratory toxicity grade 3-4 can be expected to occur in more than one-third of patients without any clinical signs of radiation induced liver disease.