Selective internal radiation therapy using yttrium-90 resin microspheres in patients with unresectable hepatocellular carcinoma: a retrospective study

Transarterial Radioembolization (TARE) in Patients with Hepatocellular Carcinoma: A Comparison of Palliative with Bridging-to-Transplant Concepts

We investigated transarterial radioembolization (TARE) as a palliative measure and bridging-to-transplant therapy in hepatocellular carcinoma (HCC) patients. A total of 167 patients (50 bridging, 117 palliative) with 245 TARE procedures were assessed. Fourteen patients underwent subsequent liver transplantation (LT). Patients undergoing LT exhibited significantly prolonged progression-free survival (PFS) compared to those with bridging-without-transplant (p = 0.033). No significant differences were observed between patients with bridging-without-transplant and palliative cases (p = 0.116). Median overall survival (OS) post-TARE was 16.6 months, with estimated OS rates at 6/12 months of 82.0%/60.5%, respectively. Patients who underwent LT demonstrated statistically significantly longer OS compared to those with bridging-without-transplant (p = 0.001). No marked outcome distinctions were found between bridging-without-transplant and palliative groups. The findings underscored the superiority of LT over alternative treatments. TARE served as an important component in non-LT scenarios, allowing for subsequent therapeutic options. The study reflected the highly variable and complex situations of patients with HCC, emphasizing the need for further investigations to define an optimal multimodal approach.

Selecting the Appropriate Downstaging and Bridging Therapies for Hepatocellular Carcinoma: What Is the Role of Transarterial Radioembolization? A Pooled Analysis

Background: Transarterial radioembolization in HCC for LT as downstaging/bridging has been increasing in recent years but some indication criteria are still unclear. Methods: We conducted a systematic literature search of primary research publications conducted in PubMed, Scopus and ScienceDirect databases until November 2022. Relevant data about patient selection, HCC features and oncological outcomes after TARE for downstaging or bridging in LT were analyzed. Results: A total of 14 studies were included (7 downstaging, 3 bridging and 4 mixed downstaging and bridging). The proportion of whole liver TARE was between 0 and 1.6%. Multiple TARE interventions were necessary for 16.7% up to 28% of the patients. A total of 55 of 204 patients across all included studies undergoing TARE for downstaging were finally transplanted. The only RCT included presents a higher tumor response with the downstaging rate for LT of TARE than TACE (9/32 vs. 4/34, respectively). Grade 3 or 4 adverse effects rate were detected between 15 and 30% of patients. Conclusions: TARE is a safe therapeutic option with potential advantages in its capacity to necrotize and reduce the size of the HCC for downstaging or bridging in LT.

A descriptive analysis of the characteristics, treatment response and prognosis of hepatic dominant solid tumors undergoing selective internal radiation therapy (SIRT)

Background

Selective internal radiotherapy is widely used for liver dominant diseases of solid tumors. However, data about sequential treatment and prognostic factors are lacking.

Methods

We consecutively included all 209 patients who received a selective internal radiotherapy intervention between January 2015 and May 2019. A retrospective analysis of their electronic patient records was performed regarding diagnosis of cancer, previous therapies and applied radioactive activity. A multicenter follow-up at least 6 weeks after intervention to assess radiological response and irregular subsequent follow-ups to asses disease progression were conducted. In addition, subgroup analyses were carried out.

Results

The most frequently treated indications were hepatocellular carcinoma (37%), colorectal cancers (14%), neuroendocrine tumors (9%), and breast cancer (8%). In hepatocellular carcinoma, selective internal radiotherapy was most performed without prior systemic therapy (40%), and for the remaining indications, most often after surgery with systemic therapy in sequence. Local radiological response, defined as either regression or stable disease, was assessed at least 6 weeks after intervention and showed 52% across all indications. Hepatocellular carcinoma (59%) and breast cancer (67%) showed an excellent, colorectal cancers (29%) a particularly poor response rate. Neuroendocrine tumors showed the third longest median post-selective internal radiation therapy (SIRT) survival with 12.4 months and the second longest median progression-free time with 5.2 months. Hepatocellular carcinoma showed even better results with a post-SIRT survival of 15.7 months and a median progression-free time of 5.3 months. Pancreatic neuroendocrine tumors showed significantly worse outcomes than other neuroendocrine tumors, regarding median post-SIRT survival and median progression-free time. No relevant SIRT related differences among sexes were detected.

Conclusions

Patients with neuroendocrine tumors, breast cancer in late therapy lines and early-stage hepatocellular carcinoma seem to show better responses to SIRT than other entities. Colorectal cancers were mainly treated with SIRT in a second or third therapy line but with considerably weaker results than other entities.

Clinical consensus statement: Selective internal radiation therapy with yttrium 90 resin microspheres for hepatocellular carcinoma in Asia

BACKGROUND

Hepatocellular carcinoma (HCC) is subject to different management approaches and guidelines according to Eastern and Western therapeutic algorithms. Use of selective internal radiation therapy (SIRT) with resin yttrium 90 microspheres for HCC has increased in Asia in recent years, without clearly defined indications for its optimal application. The objective of this systematic review and expert consensus statement is to provide guidance and perspectives on the use of SIRT among patients with HCC in Asia.

MATERIALS AND METHODS

A systematic literature review identified current publications on HCC management and SIRT recommendations. A group of 10 experts, representing stakeholder specialties and countries, convened between August 2020 and March 2021 and implemented a modified Delphi consensus approach to develop guidelines and indications for use of SIRT for HCC in Asia. Final recommendations were organized and adjudicated based on the level of evidence and strength of recommendation, per approaches outlined by the American College of Cardiology/American Heart Association and Oxford Centre for Evidence-Based Medicine.

RESULTS

The experts acknowledged a general lack of evidence relating to use of SIRT in Asia and identified as an unmet need the lack of phase 3 randomized trials comparing clinical outcomes and survival following SIRT versus other therapies for HCC. Through an iterative process, the expert group explored areas of clinical relevance and generated 31 guidance statements and a patient management algorithm that achieved consensus.

CONCLUSION

These recommendations aim to support clinicians in their decision-making and to help them identify and treat patients with HCC using SIRT in Asia. The recommendations also highlight areas in which further clinical trials are needed to define the role of SIRT in management of HCC among Asian populations.

Transarterial Radioembolization for Unresectable Hepatocellular Carcinoma: Real-Life Efficacy and Safety Analysis of Korean Patients

Transarterial radioembolization (TARE) has become widely used in the treatment of HCC, one of the most common causes of cancer mortality worldwide. Here we investigated the long-term clinical outcomes of patients with hepatocellular carcinoma (HCC) treated with TARE in a multi-medical center in Korea. A total of 149 patients treated with TARE from 2008–2014 were recruited. The pre-treatment HCC stage was classified according to the BCLC stage, of which C and D were defined as advanced HCC. Advanced HCC stage and Child–Turcotte–Pugh (CTP) score A were identified in 62 (42%) and 134 (90%) patients, respectively. Portal vein thrombosis (PVT) was identified in 58 patients (38.9%). The median time to progression (TTP) was 14 months, and the median overall survival (OS) and progression-free survival (PFS) were 18.6 and 8.9 months, respectively. The overall tumor response was 47%, and the disease control rate was 78%. OS and PFS differed significantly according to the presence of liver cirrhosis, extrahepatic metastasis, tumor response and curative treatment after TARE (all, p < 0.05). Multiple tumors and major PVT were other independent factors related to OS, while the des-gamma carboxy protein level predicted PFS (all, p < 0.05). Tumor size was an independent predictor of tumor response. TTP, OS and PFS all differed among BCLC stages. The serious adverse effect after TARE was clinically not significant. Therefore, TARE is safe and effective in treating early to advanced HCCs.

Lobar Radioembolization for Intermediate and Advanced Hepatocellular Carcinoma: Retrospective and Prospective Data

Historically, outcomes reporting for radioembolization with yttrium-90 ( ⁹⁰ Y) of hepatocellular carcinoma has included patients across the range of Barcelona Clinic Liver Cancer (BCLC) stages. With the potential for curative radiation segmentectomy for BCLC 0/A patients and evolution of systemic therapy for BCLC C patients, focused review by group is of increasing interest. In this review, we report on efficacy of ⁹⁰ Y in patients with intermediate (BCLC B) and advanced (BCLC C) hepatocellular carcinoma as well as expected toxicities. Additionally, we review existing trials comparing ⁹⁰ Y to transarterial chemoembolization and systemic treatments in these patient groups and outline future studies.

Prognostic factors of unresectable hepatocellular carcinoma treated with yttrium-90 radioembolization: results from a large cohort over 13 years at a single center

Background

A previous study of patients with unresectable hepatocellular carcinoma (HCC) was extended to further examine factors associated with overall survival (OS) after selective internal radiation therapy with yttrium-90 resin microspheres (Y90 SIRT).

Methods

Data from patients of any age diagnosed with unresectable HCC and treated with Y90 SIRT at our institution from 2004 through 2017 were retrospectively analyzed. Among other criteria, patients had to have Eastern Cooperative Oncology Group performance status 0 to 2, not have received Y90 SIRT previously, and not have extrahepatic disease. Primary outcome was OS; secondary outcomes included tumor response and adverse events (AEs). Kaplan-Meier survival analyses and multivariable Cox proportional hazards models were used to evaluate prognostic factors for OS.

Results

Of the 226 patients, 59% were White, 77% were male, and the mean age at first SIRT procedure was 65.1±9.4 years. More than half had received previous treatment for HCC. The most common etiology was hepatitis C (n=138/224 available, 62%), followed by alcohol use (n=45, 20%), and nonalcoholic steatohepatitis (n=27, 12%). The mean model for end-stage liver disease score at baseline was 8.8±2.2. Patients were followed-up for a median of 12.2 months (95% CI, 0.0-62.6). Median OS was 16.6 months (95% CI, 13.1 to not reached). Bilobar disease, higher albumin-bilirubin score at baseline, prior treatment with sorafenib, alcohol use etiology, and higher administered dose were associated with shorter survival, whereas subsequent liver transplant [in 26 patients (11.5%)] was associated with longer survival. Of the 186 patients with AEs data, 75 (40.3%) patients reported an event and, of these, 13 (17.3%) patients had grade 4 bilirubin values.

Conclusions

In a large, diverse population treated at a single center over 13 years, Y90 SIRT produced a median OS of 16.6 months in patients with unresectable HCC and enabled subsequent transplantation in a subset of patients. Factors affecting the length of survival should be considered when making treatment decisions for unresectable HCC.

Efficacy and safety of selective internal radiation therapy with yttrium-90 for the treatment of unresectable hepatocellular carcinoma

Background

This retrospective analysis was undertaken to evaluate the efficiency of SIRT with Y-90 microspheres and determined prognostic factors affecting patients with unresectable HCC.

Methods

A total of 97 patients diagnosed with unresectable HCC who underwent SIRT with Y-90 microspheres. Patient survival was assessed using the Kaplan–Meier method, and prognostic factors affecting survival were assessed using log-rank tests and Cox proportional hazards regression.

Results

Among the 97 patients (90 males, mean age 60.4 ± 12.3 years) who underwent SIRT, the median clinical follow-up was 16.4 (1.8–62) months. The median overall survival (OS) was 23.9 ± 2.4 months. Tumor response according to the Modified RECIST in patients followed up beyond 6 months included a complete response (CR) to treatment in 12 patients (18.8%), partial response (PR) in 23 (35.8%), stable disease (SD) in 8 (12.5%), and progressive disease (PD) in 21 (32.8%). Factors associated with longer OS included age > 65 years, BCLC stage B, tumor size < 5 cm, tumor burden < 25%, and tumor response (CR/PR). In multivariate analysis, unilobar disease and objective tumor response (CR/PR) were predictors of longer OS.

Conclusion

SIRT was an effective treatment for unresectable HCC. Unilobar disease before SIRT and tumor response (CR/PR) were positive prognostic factors.

Liver-Directed Therapies for Neuroendocrine Neoplasms

PURPOSE OF REVIEW

To comprehensively synthesise and appraise the available evidence regarding therapies for metastatic neuroendocrine neoplasms that exploit the hepatic vasculature to deliver therapy to liver metastases.

RECENT FINDINGS

Various techniques including transarterial embolisation/chemoembolisation (TAE/TACE) and selective internal radiotherapy (SIRT, also termed radioembolisation [RE]) have been examined in patents with neuroendocrine liver metastases. Variations in the radioactive agents for selective internal radiotherapy (SIRT) have been explored, such as the use of Holmium-166, in addition to more established agents such as Yttrium-90. Recent trials have examined the safety and efficacy of combining liver-targeted therapy with systemic treatments, such as peptide receptor radionuclide therapy. More retrospective case series of liver-directed modalities will not provide additional knowledge. Randomised clinical trials have begun to compare the efficacy of different forms of liver-directed therapies, and also their combination with systemic treatment. Their results are expected to guide optimal treatment sequencing within multimodal concepts.

Selective Internal Radiation Therapy for Hepatocellular Carcinoma Across the Barcelona Clinic Liver Cancer Stages

BACKGROUND

Hepatocellular carcinoma (HCC) is the second most common lethal cancer, and there is a need for effective therapies. Selective internal radiation therapy (SIRT) has been increasingly used, but is not supported by guidelines due to a lack of solid evidence.

AIMS

Determine the efficacy and safety of SIRT in HCC across the Barcelona Clinic Liver Cancer (BCLC) stages A, B, and C.

METHODS

Consecutive patients that received SIRT between 2006 and 2016 at two centers in Canada were evaluated.

RESULTS

We analyzed 132 patients, 12 (9%), 62 (47%), and 58 (44%) belonged to BCLC stages A, B, and C; mean age was 61.2 (SD ± 9.2), and 89% were male. Median survival was 12.4 months (95% CI 9.6-16.6), and it was different across the stages: 59.7 (95% CI NA), 12.8 (95% CI 10.2-17.5), and 9.3 months (95% CI 5.9-11.8) in BCLC A, B, and C, respectively (p = 0.009). Independent factors associated with survival were previous HCC treatment (HR 2.01, 95% CI 1.23-3.27, p = 0.005), bi-lobar disease (HR 2.25, 95% CI 1.30-3.89, p = 0.003), ascites (HR 1.77, 95% CI 0.99-3.13, p = 0.05), neutrophil-to-lymphocyte ratio (HR 1.11, 95% CI 1.02-1.20, p = 0.01), Albumin-Bilirubin (ALBI) grade-3 (HR 2.69, 95% CI 1.22-5.92, p = 0.01), tumor thrombus (HR 2.95, 95% CI 1.65-5.24, p < 0.001), and disease control rate (HR 0.62, 95% CI 0.39-0.96, p = 0.03). Forty-four (33%) patients developed severe adverse events, and ALBI-3 was associated with higher risk of these events.

CONCLUSIONS

SIRT has the potential to be used across the BCLC stages in cases with preserved liver function. When using it as a rescue treatment, one should consider variables reflecting liver function, HCC extension, and systemic inflammation, which are associated with mortality.

Cost-Effectiveness Analysis of Selective Internal Radiotherapy With Yttrium-90 Versus Sorafenib in Locally Advanced Hepatocellular Carcinoma

PURPOSE

The recent sorafenib versus radioembolization in advanced hepatocellular carcinoma (SARAH) and selective internal radiation therapy versus sorafenib in locally advanced hepatocellular carcinoma (SIRveNIB) trials showed no statistically significant difference in overall survival for randomization to selective internal radiotherapy (SIRT) versus sorafenib for locally advanced hepatocellular carcinoma, although SIRT was better tolerated. Given the high cost of both treatments, we investigated their comparative cost-effectiveness from a US healthcare sector perspective.

PATIENTS AND METHODS

We constructed a state-transition microsimulation model to simulate patients allocated to SIRT versus sorafenib according to an intention-to-treat principle. Hazard rates of disease progression and death were based on pooled individual patient data generated from the SARAH and SIRveNIB trials' Kaplan-Meier curves. Inputs for adverse events, treatment adherence, and quality of life utility weights were derived from trial data as well. Costs were based on Medicare reimbursement rates and literature. We performed probabilistic sensitivity analysis and estimated costs and quality-adjusted life years (QALYs) over a 5-year time horizon. We evaluated sensitivity to uncertainty of key model parameters.

RESULTS

Costs were $78,859 v $58,397 (difference $20,462; 95% uncertainty interval $14,444 to 27,205) and QALYs were 0.88 v 0.87 (difference 0.02, -0.02 to 0.05) for sorafenib versus SIRT, respectively. The incremental cost-effectiveness ratio (ICER) of sorafenib was $1,280,224/QALY. The likelihood that sorafenib would be cost effective did not exceed 1%, assuming cost-effectiveness thresholds up to $200k/QALY. If the monthly price of sorafenib decreased from $16,390 to below $7,000, the ICER of sorafenib fell below $200k/QALY, and an ICER < $100k/QALY was reached if the monthly price fell below $6,600.

CONCLUSION

Sorafenib is unlikely to provide a gain in quality-adjusted survival compared with SIRT at an acceptable cost for the US healthcare sector. Only if the current price decreased by more than 50% would sorafenib be considered economically attractive.

A Step-by-Step Guide for the Novel Radiometal Production for Medical Applications: Case Studies with 68Ga, 44Sc, 177Lu and 161Tb

The production of novel radionuclides is the first step towards the development of new effective radiopharmaceuticals, and the quality thereof directly affects the preclinical and clinical phases. In this review, novel radiometal production for medical applications is briefly elucidated. The production status of the imaging nuclide 44Sc and the therapeutic β--emitter nuclide 161Tb are compared to their more established counterparts, 68Ga and 177Lu according to their targetry, irradiation process, radiochemistry, and quality control aspects. The detailed discussion of these significant issues will help towards the future introduction of these promising radionuclides into drug manufacture for clinical application under Good Manufacturing Practice (GMP).

Toxicity and Survival of Hepatocellular Carcinoma Patients with Hepatitis B Infection Treated with Yttrium-90 Radioembolization: An Updated 15-Year Study

PURPOSE

To evaluate the toxicity and survival of hepatocellular carcinoma (HCC) secondary to hepatitis B virus (HBV) infection treated with yttrium-90 transarterial radioembolization (TARE) over a 15-year period.

MATERIALS AND METHODS

This study retrospectively analyzed 93 consecutive patients with HBV HCC-all derived from an original cohort of 1,000 patients-who were treated with TARE via standard radiation segmentectomy/lobectomy between December 2003 and December 2018. This group comprised 80 males and 13 females, with 79 having only HBV and 14 having additional liver comorbidities. Toxicity grades were determined by Common Terminology Criteria for Adverse Events, version 5.0. Overall survival (OS) was reported using intention-to-treat (ITT), censored, or competing risk. Univariate/multivariate analyses were used to evaluate predictors of OS.

RESULTS

Posttreatment grade 3/4 toxicities included albumin (1.1%), bilirubin (4.3%), aspartate transaminase (6.5%), and alanine transaminase (3.2%). Median censored OS was 16.9 months (95% confidence interval [CI], 11.8-23.5): 17.5 months (95% CI, 11.5-86.9) for Child-Pugh (CP) A and 14.5 months (95% CI, 5.2-22.5) for CP B; not reached, 16.9 months (95% CI, 11.2-68.7), and 11.5 months (95% CI, 8.6-17.5) for Barcelona Clinic Liver Cancer (BCLC) A, B, and C, respectively. Multivariate analysis revealed albumin, alpha-fetoprotein, and portal vein thrombosis as independent predictors of ITT OS and albumin and tumor size as predictors when curative therapy was assigned as a competing risk.

CONCLUSIONS

This retrospective study showed that TARE therapy resulted in minimal toxicity in patients with HBV-derived HCC. Patients with CP A or BCLC A disease had superior survival outcomes compared to patients with CP B and BCLC B/C disease. These findings suggest that TARE is a viable treatment option for certain patient groups with HCC tumors secondary to HBV infection.

Tumor burden and liver function in HCC patient selection for selective internal radiation therapy: SARAH post-hoc study

Aim: To determine whether a liver tumor burden ≤25% and well-preserved liver function (albumin-bilirubin grade 1) are appropriate criteria for identifying patients with unresectable hepatocellular carcinoma who may benefit from selective internal radiation therapy (SIRT) using ⁹⁰yttrium resin microspheres versus sorafenib. Patients & methods: Post-hoc analysis of patients in the intention-to-treat population of the SARAH trial (SIRT vs sorafenib) with ≤25% tumor burden and albumin-bilirubin grade 1. Primary end point: overall survival. Results: Median overall survival was 21.9 months (95% CI: 15.2-32.5, n = 37) with SIRT and 17.0 months (11.6-20.8, n = 48) with sorafenib (hazard ratios: 0.73; 95% CI: 0.44-1.21; p = 0.22). Conclusion: A combination of good liver function and low tumor burden may be relevant for selection of hepatocellular carcinoma patients for SIRT.

Current State of Liver-Directed Therapies and Combinatory Approaches with Systemic Therapy in Hepatocellular Carcinoma (HCC)

The increasing set of liver-directed therapies (LDT) have become an integral part of hepatocellular carcinoma (HCC) treatment. These range from percutaneous ablative techniques to arterial embolization, and varied radiotherapy strategies. They are now used for local disease control, symptom palliation, and bold curative strategies. The big challenge in the face of these innovative and sometimes overlapping technologies is to identify the best opportunity of use. In real practice, many patients may take benefit from LDT used as a bridge to curative treatment such as resection and liver transplantation. Varying trans-arterial embolization strategies are used, and comparison between established and developing technologies is scarce. Also, radioembolization utilizing yttrium-90 (Y-90) for locally advanced or intermediate-stage HCC needs further evidence of clinical efficacy. There is increasing interest on LDT-led changes in tumor biology that could have implications in systemic therapy efficacy. Foremost, additional to its apoptotic and necrotic properties, LDT could warrant changes in vascular endothelial growth factor (VEGF) expression and release. However, trans-arterial chemoembolization (TACE) used alongside tyrosine-kinase inhibitor (TKI) sorafenib has had its efficacy contested. Most recently, interest in associating Y-90 and TKI has emerged. Furthermore, LDT-led differences in tumor immune microenvironment and immune cell infiltration could be an opportunity to enhance immunotherapy efficacy for HCC patients. Early attempts to coordinate LDT and immunotherapy are being made. We here review LDT techniques exposing current evidence to understand its extant reach and future applications alongside systemic therapy development for HCC.

Same-Day Yttrium-90 Radioembolization: Feasibility with Resin Microspheres

PURPOSE

To evaluate the feasibility of a same-day yttrium-90 (⁹⁰Y) radioembolization protocol with resin microspheres (including pretreatment angiography, lung shunt fraction [LSF] determination, and radioembolization) for the treatment of hepatocellular carcinoma (HCC) and liver metastases.

MATERIALS AND METHODS

All same-day radioembolization procedures performed over 1 y (February 2017 to January 2018) were included in this single-institutional retrospective analysis, in which 34 procedures were performed in 26 patients (median age, 63 y; 13 women), 19 with liver metastases and 7 with HCC. Yttrium-90 treatment activities were calculated by body surface area method. Tumor imaging response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 for liver metastases and modified RECIST for HCC. Clinical side effects and adverse events were graded per Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

All planned cases were technically successful, and no cases were canceled for elevated LSF or vascular anatomic reasons. Pretreatment angiography modified the planned ⁹⁰Y treatment activity in 1 case in which vascular anatomy required a lobar-dose split into 2 for segmental infusions. In 18% of cases, patients were briefly admitted after the procedure for observation or symptom management. Imaging evaluation of initial efficacy at 1 month demonstrated partial response in 25% and stable disease in 67% of patients with liver metastases and partial/complete response in 43% and stable disease in 14% of patients with HCC. Grade ≥ 3 adverse events occurred in 6% of cases, with no systemic therapy-limiting toxicities. The mean total procedure time was 4.2 hours.

CONCLUSIONS

A same-day ⁹⁰Y radioembolization protocol with resin microspheres is feasible in select patients, which can expedite cancer therapy.

HCC: Transarterial Therapies-What the Interventional Radiologist Can Offer

With the increasing incidence of hepatocellular carcinoma (HCC) and its high mortality rates, effective treatment options are of urgent need, preferably in a multidisciplinary setting. In the management of those patients, interventional radiologists play a key role. In this article, we reviewed the current literature for regional, intraarterial treatment strategies of advanced-stage HCC including conventional transarterial chemoembolization, transarterial embolization, transarterial embolization with drug-eluting beads, and selective internal radiation therapy.

Holmium-166 Radioembolization in Hepatocellular Carcinoma: Feasibility and Safety of a New Treatment Option in Clinical Practice

PURPOSE

To investigate clinical feasibility, technical success and toxicity of ¹⁶⁶Ho-radioembolization (¹⁶⁶Ho-RE) as new approach for treatment of hepatocellular carcinomas (HCC) and to assess postinterventional calculation of exact dosimetry through quantitative analysis of MR images.

MATERIALS AND METHODS

From March 2017 to April 2018, nine patients suffering from HCC were treated with ¹⁶⁶Ho-RE. To calculate mean doses on healthy liver/tumor tissue, MR was performed within the first day after treatment. For evaluation of hepatotoxicity and to rule out radioembolization-induced liver disease (REILD), the Model for End-Stage Liver Disease (MELD) Score, the Common Terminology Criteria for Adverse Events and specific laboratory parameters were used 1-day pre- and posttreatment and after 60 days. After 6 months, MR/CT follow-up was performed.

RESULTS

In five patients the right liver lobe, in one patient the left liver lobe and in three patients both liver lobes were treated. Median administered activity was 3.7 GBq (range 1.7-5.9 GBq). Median dose on healthy liver tissue was 41 Gy (21-55 Gy) and on tumor tissue 112 Gy (61-172 Gy). Four patients suffered from mild postradioembolization syndrome. No significant differences in median MELD-Score were observed pre-, posttherapeutic and 60 days after ¹⁶⁶Ho-RE. No deterioration of liver function and no indicators of REILD were observed. One patient showed a complete response, four a partial response, three a stable disease and one a progressive disease at the 6 months follow-up.

CONCLUSION

¹⁶⁶Ho-RE seems to be a feasible and safe treatment option with no significant hepatotoxicity for treatment of HCC.